S9 OR Tools basic scheduling

AGENTS.md

@@ -1,6 +1,8 @@
 # Project skills and specifications
 
 - Project skills are stored in `skills/`; specifications belong in `specs/`.
+- For code reviews, read and follow `skills/code-review/SKILL.md`. If no
+  dedicated Skill tool is available, load the file directly.
 - Use `grill-me` only when the user explicitly requests it, for example
   `Use grill-me to review this plan` or `Gebruik grill-me voor dit ontwerp`.
 - Before using it, read `skills/grill-me/SKILL.md` and its dependency

README.md

@@ -117,7 +117,7 @@ Request bodies (dates use ISO `yyyy-MM-dd`):
 ```
 
 ```json
-{"name": "Annual show", "date": "2027-06-12"}
+{"name": "Annual show", "dayParts": [{"date": "2027-06-12", "type": "AFTERNOON"}]}
 ```
 
 Names and categories must be nonblank. Birth dates cannot be in the future.
@@ -138,9 +138,25 @@ Both operations return `204` and are idempotent for existing groups and dancers.
 Deleting a dancer removes all their memberships; deleting a group retains the
 dancers; deleting a school also deletes its dancers, groups and shows.
 
-Shows have a name, a date and three automatically created day parts: `MORNING`,
+Shows have a name, zero to six dated dayparts (`MORNING`, `AFTERNOON`, `EVENING`),
-`AFTERNOON`, `EVENING`. Each day part has an empty `danceGroupIds` list; assigning
+with unique date/type combinations. The displayed date range comes from these
-groups is not exposed yet. Multiple shows per year are allowed.
+dayparts. Each show stores `appearances` for every group type. Omitting counts
+initializes defaults on creation or the initial daypart configuration; later
+edits preserve saved counts and reject counts outside 1..N. With no dayparts,
+shows remain unscheduled and saved counts are retained.
+
+`POST /api/dance-schools/{schoolId}/shows/{showId}/schedule` uses OR-Tools to
+assign every current school group to its required number of distinct dayparts,
+minimizing the busiest/quietest appearance gap. It replaces assignments only on
+a valid, current result. The response distinguishes optimal balance from a valid
+result whose optimality is unproven. Concurrent runs return `409`; changed inputs
+also reject the result with `409`. Failed runs preserve existing assignments.
+Scheduling runs synchronously with a 30-minute solver limit; development and
+production proxies allow 31 minutes. The UI warns before edits that may invalidate
+existing schedules and offers explicit scheduling again afterward.
+
+School JSON exports use format version **2**, including dated dayparts, assignments,
+and all appearance counts. Version 1 files are intentionally unsupported.
 
 Run the HTTP integration tests with:
 

agiledancers-be/src/main/java/nl/agilecc/agiledancers/model/DayPart.java

@@ -4,6 +4,7 @@ import lombok.*;
 import nl.agilecc.agiledancers.model.specifications.DayPartType;
 
 import java.util.List;
+import java.time.LocalDate;
 
 @Getter
 @AllArgsConstructor(access = AccessLevel.PRIVATE)
@@ -12,7 +13,9 @@ import java.util.List;
 public class DayPart extends AbstractEntity {
     @ToString.Include
     private final DayPartType type;
+    private final LocalDate date;
     @ToString.Include
+    @Setter
     private List<DanceGroup> danceGroups;
 
     public void removeDanceGroup(DanceGroup group) {

agiledancers-be/src/main/java/nl/agilecc/agiledancers/model/Show.java

@@ -3,7 +3,8 @@ package nl.agilecc.agiledancers.model;
 import lombok.*;
 
 import java.util.List;
-import java.time.LocalDate;
+import java.util.Map;
+import nl.agilecc.agiledancers.model.specifications.DanceGroupType;
 
 @Getter
 @AllArgsConstructor(access = AccessLevel.PRIVATE)
@@ -13,7 +14,8 @@ public class Show extends AbstractEntity {
     @Setter
     private String name;
     @Setter
-    private LocalDate date;
+    private Map<DanceGroupType, Integer> appearances;
     @ToString.Include
-    private final List<DayPart> dayParts;
+    @Setter
+    private List<DayPart> dayParts;
 }

agiledancers-be/src/main/java/nl/agilecc/agiledancers/model/specifications/DanceGroupType.java

@@ -1,18 +1,5 @@
 package nl.agilecc.agiledancers.model.specifications;
 
-import lombok.Getter;
-
 public enum DanceGroupType {
-    SHOW_CASE(3),
+    SHOW_CASE, PRE_EDUCATION, SELECTION, REGULAR, PRE_SCHOOLER
-    PRE_EDUCATION(1), // TODO check if this is one group mentioned with different docent each time, or three different groups - and thus if they are required 1 day or 3
-    SELECTION(2),
-    REGULAR(2),
-    PRE_SCHOOLER(1);
-
-    @Getter
-    private int dayPartsRequired;
-
-    DanceGroupType(int dayPartsRequired) {
-        this.dayPartsRequired = dayPartsRequired;
-    }
 }

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/JacksonConfiguration.java

@@ -0,0 +1,14 @@
+package nl.agilecc.agiledancers.rest;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.quarkus.jackson.ObjectMapperCustomizer;
+import jakarta.inject.Singleton;
+
+@Singleton
+public class JacksonConfiguration implements ObjectMapperCustomizer {
+    @Override
+    public void customize(ObjectMapper mapper) {
+        mapper.disable(DeserializationFeature.ACCEPT_FLOAT_AS_INT);
+    }
+}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/ManagementExceptionMapper.java

@@ -14,6 +14,7 @@ public class ManagementExceptionMapper implements ExceptionMapper<ManagementExce
         int status = switch (exception.getKind()) {
             case NOT_FOUND -> 404;
             case INVALID_INPUT -> 400;
+            case CONFLICT -> 409;
         };
         return Response.status(status).type(MediaType.APPLICATION_JSON_TYPE)
                 .entity(new ErrorView(exception.getMessage())).build();

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/ShowResource.java

@@ -6,6 +6,9 @@ import jakarta.validation.constraints.NotNull;
 import jakarta.ws.rs.*;
 import jakarta.ws.rs.core.*;
 import nl.agilecc.agiledancers.service.SchoolManagementService;
+import nl.agilecc.agiledancers.service.SchedulingService;
+import nl.agilecc.agiledancers.model.DayPart;
+import nl.agilecc.agiledancers.rest.apimodel.SchedulingView;
 
 import java.util.List;
 
@@ -19,6 +22,9 @@ public class ShowResource {
     @Inject
     SchoolManagementService service;
 
+    @Inject
+    SchedulingService scheduling;
+
     @PathParam("schoolId")
     long schoolId;
 
@@ -35,7 +41,7 @@ public class ShowResource {
 
     @POST
     public Response create(@NotNull @Valid ShowRequest request, @Context UriInfo uriInfo) {
-        var entity = service.createShow(schoolId, request.name(), request.date());
+        var entity = service.createShow(schoolId, request.name(), parts(request), request.appearances());
         return Response.created(uriInfo.getAbsolutePathBuilder().path(entity.getId().toString()).build())
                 .entity(ShowView.of(entity)).build();
     }
@@ -43,7 +49,21 @@ public class ShowResource {
     @PUT
     @Path("/{id}")
     public ShowView update(@PathParam("id") long id, @NotNull @Valid ShowRequest request) {
-        return ShowView.of(service.updateShow(schoolId, id, request.name(), request.date()));
+        return ShowView.of(service.updateShow(schoolId, id, request.name(), parts(request), request.appearances()));
+    }
+
+    private static List<DayPart> parts(ShowRequest request) {
+        return request.dayParts().stream().map(p -> DayPart.builder()
+                .date(p.date()).type(p.type()).danceGroups(List.of()).build()).toList();
+    }
+
+    @POST
+    @Path("/{id}/schedule")
+    @Consumes(MediaType.WILDCARD)
+    public SchedulingView schedule(@PathParam("id") long id) {
+        var result = scheduling.schedule(schoolId, id);
+        return new SchedulingView(result.optimal(), result.optimal()
+                ? "Optimal balance" : "Valid result; optimal balance not proven");
     }
 
     @DELETE

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/apimodel/DayPartRequest.java

@@ -0,0 +1,5 @@
+package nl.agilecc.agiledancers.rest.apimodel;
+import java.time.LocalDate;
+import jakarta.validation.constraints.NotNull;
+import nl.agilecc.agiledancers.model.specifications.DayPartType;
+public record DayPartRequest(@NotNull LocalDate date, @NotNull DayPartType type) {}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/apimodel/DayPartView.java

@@ -1,6 +1,5 @@
 package nl.agilecc.agiledancers.rest.apimodel;
-
 import nl.agilecc.agiledancers.model.specifications.DayPartType;
 import java.util.List;
-
+import java.time.LocalDate;
-public record DayPartView(DayPartType type, List<Long> danceGroupIds) {}
+public record DayPartView(LocalDate date, DayPartType type, List<Long> danceGroupIds) {}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/apimodel/SchedulingView.java

@@ -0,0 +1,2 @@
+package nl.agilecc.agiledancers.rest.apimodel;
+public record SchedulingView(boolean optimal, String message) {}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/apimodel/ShowRequest.java

@@ -1,7 +1,7 @@
 package nl.agilecc.agiledancers.rest.apimodel;
-
+import jakarta.validation.Valid;
-import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.*;
-import jakarta.validation.constraints.NotNull;
+import java.util.*;
-import java.time.LocalDate;
+import nl.agilecc.agiledancers.model.specifications.DanceGroupType;
-
+public record ShowRequest(@NotBlank String name, @NotNull List<@NotNull @Valid DayPartRequest> dayParts,
-public record ShowRequest(@NotBlank String name, @NotNull LocalDate date) {}
+                          Map<DanceGroupType, Integer> appearances) {}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/rest/apimodel/ShowView.java

@@ -1,14 +1,10 @@
 package nl.agilecc.agiledancers.rest.apimodel;
-
+import nl.agilecc.agiledancers.model.*;
-import nl.agilecc.agiledancers.model.Show;
+import nl.agilecc.agiledancers.model.specifications.DanceGroupType;
-import nl.agilecc.agiledancers.model.DanceGroup;
+import java.util.*;
-import java.time.LocalDate;
+public record ShowView(long id, String name, List<DayPartView> dayParts, Map<DanceGroupType, Integer> appearances) {
-import java.util.List;
-
-public record ShowView(long id, String name, LocalDate date, List<DayPartView> dayParts) {
     public static ShowView of(Show show) {
-        return new ShowView(show.getId(), show.getName(), show.getDate(), show.getDayParts().stream()
+        return new ShowView(show.getId(), show.getName(), show.getDayParts().stream()
-                .map(dayPart -> new DayPartView(dayPart.getType(), dayPart.getDanceGroups().stream()
+                .map(p -> new DayPartView(p.getDate(), p.getType(), p.getDanceGroups().stream().map(DanceGroup::getId).toList())).toList(), show.getAppearances());
-                        .map(DanceGroup::getId).toList())).toList());
     }
 }

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/ManagementException.java

@@ -1,7 +1,7 @@
 package nl.agilecc.agiledancers.service;
 
 public class ManagementException extends RuntimeException {
-    public enum Kind { NOT_FOUND, INVALID_INPUT }
+    public enum Kind { NOT_FOUND, INVALID_INPUT, CONFLICT }
 
     private final Kind kind;
 

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/SchedulingEngine.java

@@ -0,0 +1,4 @@
+package nl.agilecc.agiledancers.service;
+public interface SchedulingEngine {
+    SchoolManagementService.SchedulingResult solve(SchoolManagementService.SchedulingInput input);
+}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/SchedulingService.java

@@ -0,0 +1,19 @@
+package nl.agilecc.agiledancers.service;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+@Singleton
+public class SchedulingService {
+    @Inject SchoolManagementService schools;
+    @Inject SchedulingEngine engine;
+    public SchoolManagementService.SchedulingResult schedule(long schoolId, long showId) {
+        var input = schools.beginScheduling(schoolId, showId);
+        try {
+            var result = engine.solve(input);
+            schools.finishScheduling(schoolId, input, result);
+            return result;
+        } catch (ManagementException e) { throw e; }
+        catch (RuntimeException | LinkageError e) {
+            throw new ManagementException(ManagementException.Kind.INVALID_INPUT, "Solver failed. Existing assignments were preserved. Please run scheduling again.");
+        } finally { schools.endScheduling(showId); }
+    }
+}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/SchoolManagementService.java

@@ -18,6 +18,52 @@ public class SchoolManagementService {
     private final DanceGroupRepository groups = new DanceGroupRepository();
     private final ShowRepository shows = new ShowRepository();
 
+    private final Map<Long, Long> revisions = new HashMap<>();
+    private final Set<Long> running = new HashSet<>();
+    private void touch(Show show) { revisions.merge(show.getId(), 1L, Long::sum); }
+
+    public record SchedulingInput(long showId, long revision, int dayParts, List<Long> groupIds, List<Integer> required) {}
+    public record SchedulingResult(boolean optimal, List<List<Long>> assignments) {}
+    public synchronized SchedulingInput beginScheduling(long schoolId, long showId) {
+        Show show = show(schoolId, showId);
+        if (running.contains(showId)) throw new ManagementException(CONFLICT, "Scheduling is already running for this show.");
+        List<DanceGroup> current = groups(schoolId);
+        if (current.isEmpty() || show.getDayParts().isEmpty()) throw new ManagementException(INVALID_INPUT, "Scheduling requires at least one school group and one daypart.");
+        ShowConfiguration.validate(show.getDayParts(), show.getAppearances());
+        running.add(showId);
+        return new SchedulingInput(showId, revisions.getOrDefault(showId, 0L), show.getDayParts().size(),
+                current.stream().map(DanceGroup::getId).toList(), current.stream().map(g -> show.getAppearances().get(g.getType())).toList());
+    }
+    public synchronized void finishScheduling(long schoolId, SchedulingInput input, SchedulingResult result) {
+        Show show;
+        try { show = show(schoolId, input.showId()); }
+        catch (ManagementException e) { throw new ManagementException(CONFLICT, "Scheduling inputs changed. Run scheduling again."); }
+        if (revisions.getOrDefault(input.showId(), 0L) != input.revision())
+            throw new ManagementException(CONFLICT, "Scheduling inputs changed. Run scheduling again.");
+        // Validate the complete solver output before mutating any assignments.
+        if (result == null || result.assignments() == null || result.assignments().size() != input.dayParts())
+            throw new ManagementException(INVALID_INPUT, "Solver returned an invalid result. Existing assignments were preserved.");
+        Map<Long, DanceGroup> current = new HashMap<>();
+        groups(schoolId).forEach(g -> current.put(g.getId(), g));
+        for (var part : result.assignments()) {
+            if (part == null || new HashSet<>(part).size() != part.size() || !input.groupIds().containsAll(part))
+                throw new ManagementException(INVALID_INPUT, "Solver returned invalid group assignments.");
+        }
+        for (int g = 0; g < input.groupIds().size(); g++) {
+            long id = input.groupIds().get(g);
+            if (result.assignments().stream().filter(p -> p.contains(id)).count() != input.required().get(g))
+                throw new ManagementException(INVALID_INPUT, "Solver did not satisfy every required appearance.");
+        }
+        List<DayPart> replacement = new ArrayList<>();
+        for (int p = 0; p < input.dayParts(); p++) {
+            DayPart old = show.getDayParts().get(p);
+            replacement.add(DayPart.builder().date(old.getDate()).type(old.getType())
+                    .danceGroups(result.assignments().get(p).stream().map(current::get).toList()).build());
+        }
+        show.setDayParts(List.copyOf(replacement));
+    }
+    public synchronized void endScheduling(long showId) { running.remove(showId); }
+
     public synchronized List<DanceSchool> schools() {
         return schools.findAll();
     }
@@ -89,6 +135,7 @@ public class SchoolManagementService {
         DanceGroup group = groups.add(DanceGroup.builder().category(category).type(type)
                 .startAge(startAge).endAge(endAge).styles(new LinkedHashSet<>(styles)).build());
         school.addDanceGroup(group);
+        school.getShows().forEach(this::touch);
         return group;
     }
 
@@ -97,6 +144,7 @@ public class SchoolManagementService {
         DanceGroup group = group(schoolId, groupId);
         validateAgeRange(startAge, endAge);
         group.setCategory(category);
+        if (group.getType() != type) school(schoolId).getShows().forEach(this::touch);
         group.setType(type);
         group.setStartAge(startAge);
         group.setEndAge(endAge);
@@ -107,6 +155,7 @@ public class SchoolManagementService {
     public synchronized void deleteGroup(long schoolId, long groupId) {
         DanceGroup group = group(schoolId, groupId);
         school(schoolId).getShows().forEach(show -> show.getDayParts().forEach(part -> part.removeDanceGroup(group)));
+        school(schoolId).getShows().forEach(this::touch);
         school(schoolId).removeDanceGroup(group);
         groups.delete(groupId);
     }
@@ -129,22 +178,34 @@ public class SchoolManagementService {
         return member(school(schoolId).getShows(), showId, "Show");
     }
 
-    public synchronized Show createShow(long schoolId, String name, LocalDate date) {
+    public synchronized Show createShow(long schoolId, String name, List<DayPart> parts, Map<DanceGroupType, Integer> counts) {
         DanceSchool school = school(schoolId);
-        List<DayPart> dayParts = Arrays.stream(DayPartType.values())
+        if (counts == null) counts = ShowConfiguration.defaults(parts.size());
-                .map(type -> DayPart.builder().type(type).danceGroups(List.of()).build()).toList();
+        ShowConfiguration.validate(parts, counts);
-        Show show = shows.add(Show.builder().name(name).date(date).dayParts(dayParts).build());
+        Show show = shows.add(Show.builder().name(name).dayParts(List.copyOf(parts)).appearances(Map.copyOf(counts)).build());
         school.addShow(show);
         return show;
     }
 
-    public synchronized Show updateShow(long schoolId, long showId, String name, LocalDate date) {
+    public synchronized Show updateShow(long schoolId, long showId, String name, List<DayPart> parts, Map<DanceGroupType, Integer> counts) {
         Show show = show(schoolId, showId);
+        if (counts == null) counts = show.getAppearances().isEmpty() ? ShowConfiguration.defaults(parts.size()) : show.getAppearances();
+        ShowConfiguration.validate(parts, counts);
+        boolean changed = !counts.equals(show.getAppearances()) || !partKeys(parts).equals(partKeys(show.getDayParts()));
+        List<DayPart> retained = parts.stream().map(p -> DayPart.builder().date(p.getDate()).type(p.getType())
+                .danceGroups(show.getDayParts().stream().filter(old -> old.getDate().equals(p.getDate()) && old.getType() == p.getType())
+                        .findFirst().map(DayPart::getDanceGroups).orElse(List.of())).build()).toList();
         show.setName(name);
-        show.setDate(date);
+        show.setDayParts(retained);
+        show.setAppearances(Map.copyOf(counts));
+        if (changed) touch(show);
         return show;
     }
 
+    private static List<String> partKeys(List<DayPart> parts) {
+        return parts.stream().map(p -> p.getDate() + ":" + p.getType()).toList();
+    }
+
     public synchronized void deleteShow(long schoolId, long showId) {
         Show show = show(schoolId, showId);
         school(schoolId).removeShow(show);
@@ -191,8 +252,8 @@ public class SchoolManagementService {
         }
         List<Show> rebuiltShows = new ArrayList<>();
         for (Show show : importedShows) {
-            Show rebuilt = Show.builder().name(show.getName()).date(show.getDate()).dayParts(show.getDayParts().stream()
+            Show rebuilt = Show.builder().name(show.getName()).appearances(show.getAppearances()).dayParts(show.getDayParts().stream()
-                    .map(p -> DayPart.builder().type(p.getType()).danceGroups(p.getDanceGroups().stream().map(replacements::get).toList()).build()).toList()).build();
+                    .map(p -> DayPart.builder().date(p.getDate()).type(p.getType()).danceGroups(p.getDanceGroups().stream().map(replacements::get).toList()).build()).toList()).build();
             rebuilt.setId(shows.nextId()); rebuiltShows.add(rebuilt);
         }
         DanceSchool imported = DanceSchool.builder().key(staged.getKey()).name(staged.getName())

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/SchoolSnapshot.java

@@ -5,31 +5,31 @@ import nl.agilecc.agiledancers.model.specifications.*;
 import java.time.LocalDate;
 import java.util.*;
 
-/** Version 1 file format. IDs are local to the file, never server identifiers. */
+/** Version 2 file format. IDs are local to the file, never server identifiers. */
 public record SchoolSnapshot(Integer formatVersion, UUID key, String name, List<Person> dancers,
                              List<Trainer> coaches, List<Group> groups, List<Performance> shows) {
     public record Person(String id, String name, LocalDate birthDate) {}
     public record Trainer(String id, String name) {}
     public record Group(String id, String category, DanceGroupType type, Integer startAge, Integer endAge,
                         List<DanceGroupStyle> styles, List<String> dancerIds, String coachId) {}
-    public record Part(DayPartType type, List<String> groupIds) {}
+    public record Part(LocalDate date, DayPartType type, List<String> groupIds) {}
-    public record Performance(String id, String name, LocalDate date, List<Part> dayParts) {}
+    public record Performance(String id, String name, List<Part> dayParts, Map<DanceGroupType, Integer> appearances) {}
 
     public static SchoolSnapshot of(DanceSchool s) {
         Map<Dancer, String> dancers = ids(s.getDancers());
         Map<Coach, String> coaches = ids(s.getCoaches());
         Map<DanceGroup, String> groups = ids(s.getDanceGroups());
         Map<Show, String> shows = ids(s.getShows());
-        return new SchoolSnapshot(1, s.getKey(), s.getName(),
+        return new SchoolSnapshot(2, s.getKey(), s.getName(),
                 s.getDancers().stream().map(d -> new Person(dancers.get(d), d.getName(), d.getBirthDate())).toList(),
                 s.getCoaches().stream().map(c -> new Trainer(coaches.get(c), c.getName())).toList(),
                 s.getDanceGroups().stream().map(g -> new Group(groups.get(g), g.getCategory(), g.getType(),
                         g.getStartAge(), g.getEndAge(), List.copyOf(g.getStyles()),
                         g.getDancers().stream().map(dancers::get).toList(),
                         g.getCoach() == null ? null : coaches.get(g.getCoach()))).toList(),
-                s.getShows().stream().map(show -> new Performance(shows.get(show), show.getName(), show.getDate(),
+                s.getShows().stream().map(show -> new Performance(shows.get(show), show.getName(),
-                        show.getDayParts().stream().map(p -> new Part(p.getType(),
+                        show.getDayParts().stream().map(p -> new Part(p.getDate(), p.getType(),
-                                p.getDanceGroups().stream().map(groups::get).toList())).toList())).toList());
+                                p.getDanceGroups().stream().map(groups::get).toList())).toList(), show.getAppearances())).toList());
     }
 
     private static <T> Map<T, String> ids(Collection<T> values) {
@@ -39,7 +39,7 @@ public record SchoolSnapshot(Integer formatVersion, UUID key, String name, List<
     }
 
     public DanceSchool restore() {
-        check(Objects.equals(formatVersion, 1), "Niet-ondersteunde formatVersion: " + formatVersion);
+        check(Objects.equals(formatVersion, 2), "Niet-ondersteunde formatVersion: " + formatVersion);
         check(key != null, "key ontbreekt"); text(name, "schoolnaam");
         DanceSchool school = DanceSchool.builder().key(key).name(name).build();
         Map<String, Dancer> dancerMap = new LinkedHashMap<>();
@@ -73,14 +73,14 @@ public record SchoolSnapshot(Integer formatVersion, UUID key, String name, List<
         for (Performance show : list(shows, "shows")) {
             check(show != null, "Lege show"); text(show.id, "show-id");
             check(showIds.add(show.id), "Dubbele show-id " + show.id); text(show.name, "shownaam");
-            check(show.date != null, "Showdatum ontbreekt voor " + show.name);
+            List<DayPart> parts = new ArrayList<>(); Set<String> types = new HashSet<>();
-            List<DayPart> parts = new ArrayList<>(); Set<DayPartType> types = new HashSet<>();
             for (Part part : list(show.dayParts, "dayParts")) {
-                check(part != null && part.type != null && types.add(part.type), "Ongeldig of dubbel dagdeel voor " + show.name);
+                check(part != null && part.type != null && part.date != null && types.add(part.date + ":" + part.type), "Ongeldig of dubbel dagdeel voor " + show.name);
-                parts.add(DayPart.builder().type(part.type).danceGroups(unique(part.groupIds, "groupIds").stream()
+                parts.add(DayPart.builder().date(part.date).type(part.type).danceGroups(unique(part.groupIds, "groupIds").stream()
                         .map(id -> ref(groupMap, id, "Show " + show.name + " verwijst naar een onbekende groep")).toList()).build());
             }
-            Show entity = Show.builder().name(show.name).date(show.date).dayParts(parts).build();
+            ShowConfiguration.validate(parts, show.appearances);
+            Show entity = Show.builder().name(show.name).dayParts(parts).appearances(Map.copyOf(show.appearances)).build();
             entity.setId((long) showIds.size()); school.addShow(entity);
         }
         return school;

agiledancers-be/src/main/java/nl/agilecc/agiledancers/service/ShowConfiguration.java

@@ -0,0 +1,33 @@
+package nl.agilecc.agiledancers.service;
+
+import nl.agilecc.agiledancers.model.DayPart;
+import nl.agilecc.agiledancers.model.specifications.DanceGroupType;
+import java.util.*;
+
+public final class ShowConfiguration {
+    private ShowConfiguration() {}
+    public static Map<DanceGroupType, Integer> defaults(int n) {
+        Map<DanceGroupType, Integer> counts = new EnumMap<>(DanceGroupType.class);
+        if (n > 0) for (var type : DanceGroupType.values()) counts.put(type, switch (type) {
+            case PRE_SCHOOLER -> 1;
+            case SHOW_CASE, PRE_EDUCATION -> n;
+            default -> Math.min(2, n);
+        });
+        return counts;
+    }
+    public static void validate(List<DayPart> parts, Map<DanceGroupType, Integer> counts) {
+        if (parts == null || parts.size() > 6 || parts.stream().anyMatch(p -> p == null || p.getDate() == null || p.getType() == null)
+                || parts.stream().map(p -> p.getDate() + ":" + p.getType()).distinct().count() != parts.size())
+            throw new ManagementException(ManagementException.Kind.INVALID_INPUT, "Configure zero to six dayparts with unique date/type combinations.");
+        if (counts == null) invalidCounts();
+        if (parts.isEmpty() && counts.isEmpty()) return;
+        if (counts.size() != DanceGroupType.values().length
+                || Arrays.stream(DanceGroupType.values()).anyMatch(t -> counts.get(t) == null || counts.get(t) < 1
+                || (!parts.isEmpty() && counts.get(t) > parts.size()))) invalidCounts();
+    }
+
+    private static void invalidCounts() {
+        throw new ManagementException(ManagementException.Kind.INVALID_INPUT,
+                "Every type needs an integer appearance count between 1 and the number of dayparts. Saved counts are retained when dayparts are removed.");
+    }
+}

agiledancers-be/src/main/java/nl/agilecc/agiledancers/solver/OrToolsSchedulingEngine.java

@@ -0,0 +1,51 @@
+package nl.agilecc.agiledancers.solver;
+import com.google.ortools.Loader;
+import com.google.ortools.sat.*;
+import jakarta.inject.Singleton;
+import nl.agilecc.agiledancers.service.*;
+import java.util.*;
+@Singleton
+public class OrToolsSchedulingEngine implements SchedulingEngine {
+    @Override
+    public SchoolManagementService.SchedulingResult solve(SchoolManagementService.SchedulingInput input) {
+        Loader.loadNativeLibraries();
+        CpModel model = new CpModel();
+        int n = input.dayParts(), groups = input.groupIds().size();
+        BoolVar[][] assigned = new BoolVar[groups][n];
+        for (int g = 0; g < groups; g++) {
+            for (int p = 0; p < n; p++) assigned[g][p] = model.newBoolVar("g" + g + "p" + p);
+            model.addEquality(LinearExpr.sum(assigned[g]), input.required().get(g));
+        }
+        IntVar[] loads = new IntVar[n];
+        for (int p = 0; p < n; p++) {
+            BoolVar[] column = new BoolVar[groups];
+            for (int g = 0; g < groups; g++) column[g] = assigned[g][p];
+            loads[p] = model.newIntVar(0, groups, "load" + p);
+            model.addEquality(loads[p], LinearExpr.sum(column));
+        }
+        IntVar max = model.newIntVar(0, groups, "max"), min = model.newIntVar(0, groups, "min");
+        model.addMaxEquality(max, loads);
+        model.addMinEquality(min, loads);
+        model.minimize(LinearExpr.weightedSum(new IntVar[]{max, min}, new long[]{1, -1}));
+        CpSolver solver = new CpSolver();
+        solver.getParameters().setMaxTimeInSeconds(1800);
+        // Quarkus owns process shutdown; do not install a native SIGINT handler.
+        solver.getParameters().setCatchSigintSignal(false);
+        // Single-worker search with a fixed seed makes identical inputs repeatable.
+        solver.getParameters().setNumSearchWorkers(1).setRandomSeed(0);
+        CpSolverStatus status = solver.solve(model);
+        if (status != CpSolverStatus.OPTIMAL && status != CpSolverStatus.FEASIBLE)
+            throw new ManagementException(ManagementException.Kind.INVALID_INPUT, switch (status) {
+                case INFEASIBLE -> "Scheduling is infeasible. Existing assignments were preserved.";
+                case UNKNOWN -> "The 30-minute limit was reached without a valid result. Existing assignments were preserved.";
+                default -> "Solver failed (" + status + "). Existing assignments were preserved.";
+            });
+        List<List<Long>> parts = new ArrayList<>();
+        for (int p = 0; p < n; p++) {
+            List<Long> ids = new ArrayList<>();
+            for (int g = 0; g < groups; g++) if (solver.booleanValue(assigned[g][p])) ids.add(input.groupIds().get(g));
+            parts.add(List.copyOf(ids));
+        }
+        return new SchoolManagementService.SchedulingResult(status == CpSolverStatus.OPTIMAL, List.copyOf(parts));
+    }
+}

agiledancers-be/src/main/resources/application.properties

@@ -1,2 +1,6 @@
 quarkus.application.name=agiledancers
 quarkus.http.host=0.0.0.0
+
+# Scheduling is synchronous with a 30-minute solver limit.
+quarkus.http.idle-timeout=31M
+quarkus.jackson.fail-on-unknown-properties=true

agiledancers-be/src/test/java/nl/agilecc/agiledancers/SchedulingTest.java

@@ -0,0 +1,109 @@
+package nl.agilecc.agiledancers;
+
+import nl.agilecc.agiledancers.model.*;
+import nl.agilecc.agiledancers.model.specifications.*;
+import nl.agilecc.agiledancers.service.*;
+import nl.agilecc.agiledancers.solver.OrToolsSchedulingEngine;
+import org.junit.jupiter.api.Test;
+import java.time.LocalDate;
+import java.util.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+class SchedulingTest {
+    private final SchoolManagementService service = new SchoolManagementService();
+    private final long school = service.createSchool("Studio").getId();
+    private List<DayPart> parts(int n) {
+        return java.util.stream.IntStream.range(0, n).mapToObj(i -> DayPart.builder()
+                .date(LocalDate.of(2027, 1, 1).plusDays(i)).type(DayPartType.AFTERNOON).danceGroups(List.of()).build()).toList();
+    }
+    private DanceGroup group(DanceGroupType type) {
+        return service.createGroup(school, "Group", type, 0, 99, Set.of());
+    }
+    private void run(Show show) {
+        var input = service.beginScheduling(school, show.getId());
+        try { service.finishScheduling(school, input, new OrToolsSchedulingEngine().solve(input)); }
+        finally { service.endScheduling(show.getId()); }
+    }
+    @Test void exactAppearancesAndOptimalBalanceIncludingEmptyParts() {
+        group(DanceGroupType.PRE_SCHOOLER);
+        var show = service.createShow(school, "Show", parts(6), null);
+        run(show);
+        var loads = show.getDayParts().stream().mapToInt(p -> p.getDanceGroups().size()).summaryStatistics();
+        assertEquals(1, loads.getSum()); assertEquals(0, loads.getMin()); assertEquals(1, loads.getMax());
+        for (var type : DanceGroupType.values()) group(type);
+        run(show);
+        for (var group : service.groups(school)) assertEquals(show.getAppearances().get(group.getType()).longValue(),
+                show.getDayParts().stream().filter(p -> p.getDanceGroups().contains(group)).count());
+        loads = show.getDayParts().stream().mapToInt(p -> p.getDanceGroups().size()).summaryStatistics();
+        assertTrue(loads.getMax() - loads.getMin() <= 1);
+        var snapshot = service.exportSchool(school);
+        assertEquals(snapshot, SchoolSnapshot.of(snapshot.restore()));
+    }
+    @Test void defaultsInitialConfigurationAndPreservationOnEdits() {
+        var show = service.createShow(school, "Show", List.of(), null);
+        assertTrue(show.getAppearances().isEmpty());
+        service.updateShow(school, show.getId(), "Show", parts(3), null);
+        assertEquals(3, show.getAppearances().get(DanceGroupType.PRE_EDUCATION));
+        assertEquals(1, show.getAppearances().get(DanceGroupType.PRE_SCHOOLER));
+        var counts = new EnumMap<>(show.getAppearances()); counts.put(DanceGroupType.PRE_SCHOOLER, 2);
+        service.updateShow(school, show.getId(), "Show", parts(4), counts);
+        assertEquals(counts, show.getAppearances());
+        assertThrows(ManagementException.class, () -> service.updateShow(school, show.getId(), "Show", parts(1), null));
+        assertEquals(4, show.getDayParts().size());
+        service.updateShow(school, show.getId(), "Show", List.of(), null);
+        assertEquals(counts, show.getAppearances());
+        service.updateShow(school, show.getId(), "Show", parts(4), null);
+        assertEquals(counts, show.getAppearances());
+    }
+    @Test void rejectsDuplicatePartsMissingCountsAndOutOfRangeCounts() {
+        var duplicate = List.of(parts(1).getFirst(), parts(1).getFirst());
+        assertThrows(ManagementException.class, () -> service.createShow(school, "Show", duplicate, null));
+        assertThrows(ManagementException.class, () -> service.createShow(school, "Show", parts(7), null));
+        assertThrows(ManagementException.class, () -> service.createShow(school, "Show", parts(2), Map.of()));
+        var counts = ShowConfiguration.defaults(2); counts.put(DanceGroupType.REGULAR, 3);
+        assertThrows(ManagementException.class, () -> service.createShow(school, "Show", parts(2), counts));
+        counts.put(DanceGroupType.REGULAR, 0);
+        assertThrows(ManagementException.class, () -> service.createShow(school, "Show", parts(2), counts));
+    }
+    @Test void duplicateRunsStaleResultsAndMalformedResultsPreserveAssignments() {
+        var group = group(DanceGroupType.REGULAR);
+        var show = service.createShow(school, "Show", parts(2), null); run(show);
+        var before = show.getDayParts().stream().map(DayPart::getDanceGroups).toList();
+        var input = service.beginScheduling(school, show.getId());
+        assertThrows(ManagementException.class, () -> service.beginScheduling(school, show.getId()));
+        var result = new OrToolsSchedulingEngine().solve(input);
+        service.updateGroup(school, group.getId(), "Renamed", group.getType(), 0, 99, Set.of());
+        assertDoesNotThrow(() -> service.finishScheduling(school, input, result));
+        group(DanceGroupType.PRE_SCHOOLER);
+        assertThrows(ManagementException.class, () -> service.finishScheduling(school, input, result));
+        assertEquals(before, show.getDayParts().stream().map(DayPart::getDanceGroups).toList());
+        service.endScheduling(show.getId());
+        var fresh = service.beginScheduling(school, show.getId());
+        assertThrows(ManagementException.class, () -> service.finishScheduling(school, fresh,
+                new SchoolManagementService.SchedulingResult(false, List.of(List.of(), List.of()))));
+        assertEquals(before, show.getDayParts().stream().map(DayPart::getDanceGroups).toList());
+        // Feasible results are accepted without requiring proof of optimality.
+        var valid = new OrToolsSchedulingEngine().solve(fresh);
+        assertDoesNotThrow(() -> service.finishScheduling(school, fresh, new SchoolManagementService.SchedulingResult(false, valid.assignments())));
+        service.endScheduling(show.getId());
+    }
+    @Test void staleDaypartCountChangesAndDeletedShowsAreRejected() {
+        group(DanceGroupType.REGULAR);
+        var show = service.createShow(school, "Show", parts(2), null);
+        var input = service.beginScheduling(school, show.getId());
+        var result = new OrToolsSchedulingEngine().solve(input);
+        service.updateShow(school, show.getId(), "Show", parts(3), null);
+        assertThrows(ManagementException.class, () -> service.finishScheduling(school, input, result));
+        service.deleteShow(school, show.getId());
+        assertThrows(ManagementException.class, () -> service.finishScheduling(school, input, result));
+        service.endScheduling(show.getId());
+    }
+    @Test void needsGroupsAndDayparts() {
+        var show = service.createShow(school, "Show", parts(1), null);
+        assertThrows(ManagementException.class, () -> service.beginScheduling(school, show.getId()));
+        group(DanceGroupType.REGULAR);
+        var empty = service.createShow(school, "Empty", List.of(), null);
+        assertThrows(ManagementException.class, () -> service.beginScheduling(school, empty.getId()));
+        assertTrue(show.getAppearances().values().stream().allMatch(n -> n == 1));
+    }
+}

agiledancers-be/src/test/java/nl/agilecc/agiledancers/SchoolManagementResourceTest.java

@@ -15,7 +15,7 @@ class SchoolManagementResourceTest {
     private static final Map<String, Object> DANCER = Map.of("name", "Sam", "birthDate", "2010-05-12");
     private static final Map<String, Object> GROUP = Map.of("category", "Teens", "type", "REGULAR",
             "startAge", 12, "endAge", 18, "styles", new String[]{"HIPHOP"});
-    private static final Map<String, Object> SHOW = Map.of("name", "Annual show", "date", "2027-06-12");
+    private static final Map<String, Object> SHOW = Map.of("name", "Annual show", "dayParts", new Object[]{Map.of("date", "2027-06-12", "type", "AFTERNOON")});
 
     @Test
     void managesSchoolAndItsResources() {
@@ -46,10 +46,10 @@ class SchoolManagementResourceTest {
             long showId = create(school + "/shows", SHOW);
             String show = school + "/shows/" + showId;
             given().get(show).then().statusCode(200)
-                    .body("dayParts.type", contains("MORNING", "AFTERNOON", "EVENING"))
+                    .body("dayParts.type", contains("AFTERNOON"))
                     .body("dayParts.danceGroupIds", everyItem(empty()));
-            put(show, Map.of("name", "Summer show", "date", "2027-07-01"))
+            put(show, Map.of("name", "Summer show", "dayParts", new Object[]{Map.of("date", "2027-07-01", "type", "EVENING")}))
-                    .statusCode(200).body("date", equalTo("2027-07-01"));
+                    .statusCode(200).body("dayParts.date", contains("2027-07-01"));
             given().get(school + "/shows").then().statusCode(200).body("id", contains((int) showId));
             given().get(school).then().statusCode(200).body("dancerIds", contains((int) dancerId))
                     .body("danceGroupIds", contains((int) groupId)).body("showIds", contains((int) showId));
@@ -152,6 +152,29 @@ class SchoolManagementResourceTest {
         }
     }
 
+    @Test
+    void schedulesAndValidatesTheNewShowConfiguration() {
+        String school = SCHOOLS + "/" + create(SCHOOLS, Map.of("name", "Scheduling school"));
+        try {
+            String show = school + "/shows/" + create(school + "/shows", SHOW);
+            given().post(show + "/schedule").then().statusCode(400);
+            long group = create(school + "/dance-groups", GROUP);
+            given().post(show + "/schedule").then().statusCode(200).body("optimal", equalTo(true));
+            given().get(show).then().body("dayParts[0].danceGroupIds", contains((int) group));
+            String before = given().get(show).asString();
+            String counts = "{\"SHOW_CASE\":1,\"PRE_EDUCATION\":1,\"SELECTION\":1,\"REGULAR\":%s,\"PRE_SCHOOLER\":1}";
+            for (String count : new String[]{"0", "2", "1.5", "null"}) {
+                String body = "{\"name\":\"Show\",\"dayParts\":[{\"date\":\"2027-06-12\",\"type\":\"AFTERNOON\"}],\"appearances\":" + counts.formatted(count) + "}";
+                put(show, body).statusCode(400);
+                given().get(show).then().body(equalTo(before));
+            }
+            String exported = given().get(school + "/export").then().statusCode(200).extract().asString();
+            given().contentType("application/json").body(exported).post(SCHOOLS + "/import?replaceId=" + school.substring(school.lastIndexOf('/') + 1))
+                    .then().statusCode(200);
+            given().get(school + "/export").then().body(equalTo(exported));
+        } finally { given().delete(school); }
+    }
+
     private static long create(String path, Object body) {
         return given().contentType("application/json").body(body).post(path).then()
                 .statusCode(201).header("Location", matchesPattern(".*/[0-9]+$"))

agiledancers-be/src/test/java/nl/agilecc/agiledancers/SchoolSnapshotResourceTest.java

@@ -12,11 +12,11 @@ class SchoolSnapshotResourceTest {
         long id = given().contentType("application/json").body("{\"name\":\"JSON school\"}").post(BASE)
                 .then().statusCode(201).extract().jsonPath().getLong("id");
         String json = given().get(BASE + "/" + id + "/export").then().statusCode(200)
-                .header("Content-Disposition", containsString(".json")).body("formatVersion", equalTo(1)).extract().asString();
+                .header("Content-Disposition", containsString(".json")).body("formatVersion", equalTo(2)).extract().asString();
         try {
             given().contentType("application/json").body(json).post(BASE + "/import/preview").then().statusCode(200)
                     .body("existingId", equalTo((int) id)).body("dancers", equalTo(0));
-            for (String bad : new String[]{"{", "null", json.replace("\"formatVersion\" : 1", "\"formatVersion\" : 2"),
+            for (String bad : new String[]{"{", "null", json.replace("\"formatVersion\" : 2", "\"formatVersion\" : 1"),
                     json.replace("\"name\" :", "\"unknown\" :"), json + " {}",
                     json.replace("\"dancers\" : [ ]", "\"dancers\" : null")}) {
                 given().contentType("application/json").body(bad).post(BASE + "/import?replaceId=" + id)

agiledancers-be/src/test/java/nl/agilecc/agiledancers/SchoolSnapshotTest.java

@@ -9,12 +9,12 @@ import static org.junit.jupiter.api.Assertions.*;
 
 class SchoolSnapshotTest {
     private SchoolSnapshot complete() {
-        return new SchoolSnapshot(1, UUID.randomUUID(), "Studio", List.of(new SchoolSnapshot.Person("a", "Sam", LocalDate.of(2010,1,1))),
+        return new SchoolSnapshot(2, UUID.randomUUID(), "Studio", List.of(new SchoolSnapshot.Person("a", "Sam", LocalDate.of(2010,1,1))),
                 List.of(new SchoolSnapshot.Trainer("c", "Alex")),
                 List.of(new SchoolSnapshot.Group("g", "Hiphop", DanceGroupType.REGULAR, 0, 99, List.of(DanceGroupStyle.HIPHOP), List.of("a"), "c"),
                         new SchoolSnapshot.Group("h", "Jazz", DanceGroupType.REGULAR, 0, 99, List.of(), List.of("a"), "c")),
-                List.of(new SchoolSnapshot.Performance("s", "Show", LocalDate.of(2027,1,1),
+                List.of(new SchoolSnapshot.Performance("s", "Show",
-                        List.of(new SchoolSnapshot.Part(DayPartType.MORNING, List.of("g", "h"))))));
+                        List.of(new SchoolSnapshot.Part(LocalDate.of(2027,1,1), DayPartType.MORNING, List.of("g", "h"))), ShowConfiguration.defaults(1))));
     }
     @Test void roundTripAfterRestartPreservesAllFieldsAndSharedRelationships() {
         var snapshot = complete();
@@ -56,7 +56,7 @@ class SchoolSnapshotTest {
     @Test void unresolvedReferenceLeavesExistingAndOtherSchoolsIntact() {
         var service = new SchoolManagementService(); var valid = complete();
         var original = service.importSchool(valid, null);
-        var bad = new SchoolSnapshot(1, valid.key(), valid.name(), List.of(), valid.coaches(), valid.groups(), valid.shows());
+        var bad = new SchoolSnapshot(2, valid.key(), valid.name(), List.of(), valid.coaches(), valid.groups(), valid.shows());
         assertThrows(ManagementException.class, () -> service.preview(bad));
         assertThrows(ManagementException.class, () -> service.importSchool(bad, original.getId()));
         assertEquals(SchoolSnapshot.of(valid.restore()), service.exportSchool(original.getId()));

agiledancers-be/src/test/java/nl/agilecc/agiledancers/service/SchedulingServiceTest.java

@@ -0,0 +1,67 @@
+package nl.agilecc.agiledancers.service;
+
+import nl.agilecc.agiledancers.model.*;
+import nl.agilecc.agiledancers.model.specifications.*;
+import nl.agilecc.agiledancers.solver.OrToolsSchedulingEngine;
+import org.junit.jupiter.api.Test;
+import java.time.LocalDate;
+import java.util.*;
+import java.util.concurrent.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+class SchedulingServiceTest {
+    @Test void failedAndNoResultRunsPreserveAssignmentsAndReleaseTheRunGuard() {
+        var schools = new SchoolManagementService();
+        long school = schools.createSchool("School").getId();
+        schools.createGroup(school, "Group", DanceGroupType.REGULAR, 0, 99, Set.of());
+        var show = schools.createShow(school, "Show", List.of(DayPart.builder().date(LocalDate.of(2027,1,1))
+                .type(DayPartType.MORNING).danceGroups(List.of()).build()), null);
+        var scheduling = new SchedulingService();
+        scheduling.schools = schools;
+        scheduling.engine = new OrToolsSchedulingEngine();
+        scheduling.schedule(school, show.getId());
+        var before = schools.exportSchool(school);
+        for (SchedulingEngine failure : List.<SchedulingEngine>of(
+                input -> { throw new IllegalStateException("Native failure"); },
+                input -> { throw new ManagementException(ManagementException.Kind.INVALID_INPUT, "No valid result before the limit"); },
+                input -> null)) {
+            scheduling.engine = failure;
+            assertThrows(ManagementException.class, () -> scheduling.schedule(school, show.getId()));
+            assertEquals(before, schools.exportSchool(school));
+            var next = schools.beginScheduling(school, show.getId());
+            schools.endScheduling(next.showId());
+        }
+    }
+
+    @Test void concurrentRunIsRejectedWhileEditsRemainPossibleAndInvalidateTheFirstResult() throws Exception {
+        var schools = new SchoolManagementService();
+        long school = schools.createSchool("School").getId();
+        schools.createGroup(school, "Group", DanceGroupType.REGULAR, 0, 99, Set.of());
+        var show = schools.createShow(school, "Show", List.of(DayPart.builder().date(LocalDate.of(2027,1,1))
+                .type(DayPartType.MORNING).danceGroups(List.of()).build()), null);
+        var scheduling = new SchedulingService(); scheduling.schools = schools;
+        var entered = new CountDownLatch(1); var release = new CountDownLatch(1);
+        scheduling.engine = input -> {
+            entered.countDown();
+            try { if (!release.await(10, TimeUnit.SECONDS)) throw new IllegalStateException("Test timeout"); }
+            catch (InterruptedException e) { Thread.currentThread().interrupt(); throw new IllegalStateException(e); }
+            return new OrToolsSchedulingEngine().solve(input);
+        };
+        try (var executor = Executors.newSingleThreadExecutor()) {
+            var first = executor.submit(() -> scheduling.schedule(school, show.getId()));
+            try {
+                assertTrue(entered.await(10, TimeUnit.SECONDS));
+                assertEquals(ManagementException.Kind.CONFLICT, assertThrows(ManagementException.class,
+                        () -> scheduling.schedule(school, show.getId())).getKind());
+                schools.createGroup(school, "New group", DanceGroupType.REGULAR, 0, 99, Set.of());
+            } finally { release.countDown(); }
+            var exception = assertThrows(ExecutionException.class, () -> first.get(10, TimeUnit.SECONDS));
+            assertInstanceOf(ManagementException.class, exception.getCause());
+            assertTrue(exception.getCause().getMessage().contains("inputs changed"));
+            assertTrue(show.getDayParts().getFirst().getDanceGroups().isEmpty());
+        }
+        scheduling.engine = new OrToolsSchedulingEngine();
+        scheduling.schedule(school, show.getId());
+        assertEquals(2, show.getDayParts().getFirst().getDanceGroups().size());
+    }
+}

agiledancers-fe/e2e/school-management.spec.ts

@@ -110,15 +110,28 @@ test('manages a school, shared memberships and shows through the real REST API',
   await tab(page, 'Shows');
   await page.getByRole('button', { name: 'Show toevoegen' }).click();
   await page.getByRole('dialog').getByLabel('Naam', { exact: true }).fill('Zomershow');
+  await page.getByRole('button', { name: 'Dagdeel toevoegen', exact: true }).click();
   await page.getByLabel('Datum', { exact: true }).fill('2027-06-12');
   await save(page);
-  await expect(page.getByText('Ochtend', { exact: true })).toBeVisible();
+  await expect(page.getByText('2027-06-12 · AFTERNOON:', { exact: false })).toBeVisible();
-  await expect(page.getByText('Middag', { exact: true })).toBeVisible();
-  await expect(page.getByText('Avond', { exact: true })).toBeVisible();
   await page.getByRole('button', { name: 'Zomershow bewerken' }).click();
   await page.getByLabel('Datum', { exact: true }).fill('2027-07-01');
   await save(page);
   await expect(page.locator('.date-tile')).toContainText('jul 2027');
+  page.once('dialog', (dialog) => dialog.accept());
+  await page.getByRole('button', { name: /Schedule groups/ }).click();
+  await expect(page.getByText('Planning voldoet aan alle optredensaantallen.')).toBeVisible();
+  await expect(page.getByRole('status').filter({ hasText: 'Optimale balans.' })).toBeVisible();
+  await page.getByRole('button', { name: 'Zomershow bewerken' }).click();
+  await page.getByRole('button', { name: 'Dagdeel toevoegen', exact: true }).click();
+  await page.getByLabel('Datum', { exact: true }).nth(1).fill('2027-07-02');
+  page.once('dialog', async (dialog) => {
+    expect(dialog.message()).toContain('Zomershow');
+    await dialog.dismiss();
+  });
+  await page.getByRole('button', { name: 'Opslaan', exact: true }).click();
+  await expect(page.getByRole('dialog')).toBeVisible();
+  await page.getByRole('button', { name: 'Annuleren', exact: true }).click();
 
   await tab(page, 'Overzicht');
   await page.setViewportSize({ width: 390, height: 844 });

agiledancers-fe/nginx/default.conf.template

@@ -5,6 +5,8 @@ server {
     index index.html;
 
     location /api/ {
+        proxy_read_timeout 1860s;
+        proxy_send_timeout 1860s;
         proxy_pass http://${BACKEND_UPSTREAM};
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;

agiledancers-fe/proxy.conf.json

@@ -2,6 +2,8 @@
   "/api/**": {
     "target": "http://127.0.0.1:8080",
     "secure": false,
+    "timeout": 1860000,
+    "proxyTimeout": 1860000,
     "changeOrigin": true
   }
 }

agiledancers-fe/src/app/core/api-models.ts

@@ -21,11 +21,17 @@ export interface DanceGroup {
   styles: GroupStyle[];
   dancerIds: number[];
 }
+export type DayPartType = 'MORNING' | 'AFTERNOON' | 'EVENING';
+export interface DayPart {
+  date: string;
+  type: DayPartType;
+  danceGroupIds: number[];
+}
 export interface Show {
   id: number;
   name: string;
-  date: string;
+  dayParts: DayPart[];
-  dayParts: { type: 'MORNING' | 'AFTERNOON' | 'EVENING'; danceGroupIds: number[] }[];
+  appearances: Partial<Record<GroupType, number>>;
 }
 export interface SchoolRequest {
   name: string;
@@ -43,7 +49,8 @@ export interface GroupRequest {
 }
 export interface ShowRequest {
   name: string;
-  date: string;
+  dayParts: { date: string; type: DayPartType }[];
+  appearances?: Partial<Record<GroupType, number>>;
 }
 export type ResourceKind = 'school' | 'dancer' | 'group' | 'show';
 export type EditorTarget =

agiledancers-fe/src/app/core/school-api.spec.ts

@@ -66,4 +66,11 @@ describe('SchoolApi contract', () => {
       .flush({ message: 'Invalid data' }, { status: 400, statusText: 'Bad Request' });
     expect(failure).toHaveBeenCalledOnce();
   });
+  it('schedules synchronously with room for the 30-minute solver limit', () => {
+    api.schedule(7, 3).subscribe();
+    const request = http.expectOne('/api/dance-schools/7/shows/3/schedule');
+    expect(request.request.method).toBe('POST');
+    expect(request.request.timeout).toBe(1860000);
+    request.flush({ optimal: false, message: 'Valid result; optimal balance not proven' });
+  });
 });

agiledancers-fe/src/app/core/school-api.ts

@@ -45,6 +45,13 @@ export class SchoolApi {
   saveShow(schoolId: number, body: ShowRequest, id?: number): Observable<Show> {
     return this.save(`${this.base}/${schoolId}/shows`, body, id);
   }
+  schedule(schoolId: number, showId: number): Observable<{ optimal: boolean; message: string }> {
+    return this.http.post<{ optimal: boolean; message: string }>(
+      `${this.base}/${schoolId}/shows/${showId}/schedule`,
+      null,
+      { timeout: 1860000 },
+    );
+  }
   delete(kind: ResourceKind, schoolId: number, id: number): Observable<void> {
     const collection = { school: '', dancer: '/dancers', group: '/dance-groups', show: '/shows' }[
       kind

agiledancers-fe/src/app/schools/school-page.html

@@ -114,7 +114,7 @@
           <p class="eyebrow">IN DE SPOTLIGHT</p>
           @if (upcoming(); as show) {
             <h2>{{ show.name }}</h2>
-            <p class="spotlight-date">{{ show.date | date: 'd MMMM yyyy' }}</p>
+            <p class="spotlight-date">{{ dateRange(show) }}</p>
             <p>Drie dagdelen. Eén gedeelde passie.</p>
             <a class="button light" [routerLink]="['/schools', context.school.id, 'shows']"
               >Shows bekijken <span aria-hidden="true">→</span></a
@@ -345,16 +345,39 @@
         @for (show of shows(); track show.id) {
           <article class="show-card">
             <div class="date-tile">
-              <strong>{{ show.date | date: 'dd' }}</strong
+              <strong>{{ firstDate(show) | date: 'dd' }}</strong
-              ><span>{{ show.date | date: 'MMM yyyy' }}</span>
+              ><span>{{ firstDate(show) | date: 'MMM yyyy' }}</span>
             </div>
             <div class="show-details">
               <h3>{{ show.name }}</h3>
-              <div class="tag-list">
+              <p>{{ dateRange(show) }}</p>
-                <span class="style-tag">Ochtend</span><span class="style-tag">Middag</span
+              @for (part of show.dayParts; track $index) {
-                ><span class="style-tag">Avond</span>
+                <p>{{ part.date }} · {{ part.type }}: {{ groupNamesFor(part.danceGroupIds) }}</p>
-              </div>
+              }
-              <p class="muted">Groepen indelen over dagdelen is nog niet beschikbaar.</p>
+              <p role="status">
+                {{
+                  scheduleValid(show)
+                    ? 'Planning voldoet aan alle optredensaantallen.'
+                    : 'Geen geldige planning. Plan de groepen opnieuw in.'
+                }}
+              </p>
+              <button
+                type="button"
+                class="button primary"
+                [disabled]="
+                  scheduling().includes(show.id) || !context.groups.length || !show.dayParts.length
+                "
+                (click)="schedule(show)"
+              >
+                {{
+                  scheduling().includes(show.id)
+                    ? 'Bezig met inplannen…'
+                    : 'Schedule groups — vervangt huidige toewijzingen'
+                }}
+              </button>
+              @if (!context.groups.length || !show.dayParts.length) {
+                <p>Inplannen vereist minstens één dansgroep en één dagdeel.</p>
+              }
             </div>
             <div class="row-actions">
               <button
@@ -385,7 +408,7 @@
           <div class="empty-state">
             <span class="empty-symbol" aria-hidden="true">✦</span>
             <h2>Het podium wacht op je</h2>
-            <p>Plan een show met een ochtend-, middag- en avonddeel.</p>
+            <p>Plan een show met maximaal zes gedateerde dagdelen.</p>
             <button class="button primary" type="button" (click)="editor.set({ kind: 'show' })">
               Eerste show plannen
             </button>
@@ -398,6 +421,7 @@
     <app-entity-editor
       [target]="target"
       [schoolId]="context.school.id"
+      [shows]="context.shows"
       (closed)="editor.set(null)"
       (saved)="saved()"
     />

agiledancers-fe/src/app/schools/school-page.ts

@@ -11,6 +11,7 @@ import {
   GROUP_TYPES,
   ResourceKind,
   SchoolData,
+  Show,
 } from '../core/api-models';
 import { apiError } from '../core/api-error';
 import { SchoolApi } from '../core/school-api';
@@ -51,6 +52,7 @@ export class SchoolPage implements OnInit {
   readonly editor = signal<EditorTarget | null>(null);
   readonly members = signal<DanceGroup | null>(null);
   readonly deleting = signal<DeleteTarget | null>(null);
+  readonly scheduling = signal<number[]>([]);
   readonly deleteBusy = signal(false);
   readonly deleteError = signal('');
   readonly search = signal('');
@@ -60,10 +62,14 @@ export class SchoolPage implements OnInit {
       .sort((a, b) => a.name.localeCompare(b.name, 'nl')),
   );
   readonly shows = computed(() =>
-    [...(this.data()?.shows ?? [])].sort((a, b) => a.date.localeCompare(b.date)),
+    [...(this.data()?.shows ?? [])].sort((a, b) =>
+      this.firstDate(a).localeCompare(this.firstDate(b)),
+    ),
   );
   readonly today = new Date().toLocaleDateString('en-CA');
-  readonly upcoming = computed(() => this.shows().find((show) => show.date >= this.today));
+  readonly upcoming = computed(() =>
+    this.shows().find((show) => this.lastDate(show) >= this.today),
+  );
   readonly tabs = [
     { value: 'overview', label: 'Overzicht' },
     { value: 'dancers', label: 'Dansers' },
@@ -98,6 +104,74 @@ export class SchoolPage implements OnInit {
         this.loading.set(false);
       });
   }
+  firstDate(show: Show): string {
+    return show.dayParts.map((p) => p.date).sort()[0] ?? '';
+  }
+  lastDate(show: Show): string {
+    return (
+      show.dayParts
+        .map((p) => p.date)
+        .sort()
+        .at(-1) ?? ''
+    );
+  }
+  dateRange(show: Show): string {
+    const first = this.firstDate(show),
+      last = this.lastDate(show);
+    return !first ? 'No dates configured' : first === last ? first : `${first} – ${last}`;
+  }
+  scheduleValid(show: Show): boolean {
+    const groups = this.data()?.groups ?? [];
+    return (
+      !!groups.length &&
+      !!show.dayParts.length &&
+      groups.every(
+        (g) =>
+          show.dayParts.filter((p) => p.danceGroupIds.includes(g.id)).length ===
+          show.appearances[g.type],
+      ) &&
+      show.dayParts.every(
+        (p) =>
+          new Set(p.danceGroupIds).size === p.danceGroupIds.length &&
+          p.danceGroupIds.every((id) => groups.some((g) => g.id === id)),
+      )
+    );
+  }
+  groupNamesFor(ids: number[]): string {
+    return (
+      ids.map((id) => this.data()?.groups.find((g) => g.id === id)?.category ?? '?').join(', ') ||
+      'Geen groepen'
+    );
+  }
+  async schedule(show: Show): Promise<void> {
+    const schoolId = this.data()?.school.id;
+    if (
+      schoolId === undefined ||
+      this.scheduling().includes(show.id) ||
+      !show.dayParts.length ||
+      !this.data()?.groups.length
+    )
+      return;
+    if (
+      !window.confirm(
+        `Groepen inplannen voor ${show.name}? Dit vervangt alle huidige toewijzingen.`,
+      )
+    )
+      return;
+    this.scheduling.update((ids) => [...ids, show.id]);
+    this.error.set('');
+    try {
+      const result = await firstValueFrom(this.api.schedule(schoolId, show.id));
+      this.notice.set(
+        result.optimal ? 'Optimale balans.' : 'Geldige planning; optimale balans niet bewezen.',
+      );
+      await this.reload();
+    } catch (error: unknown) {
+      this.error.set(apiError(error));
+    } finally {
+      this.scheduling.update((ids) => ids.filter((id) => id !== show.id));
+    }
+  }
   async reload(): Promise<void> {
     const id = this.data()?.school.id;
     if (id === undefined) return;
@@ -133,6 +207,17 @@ export class SchoolPage implements OnInit {
   }
   askDelete(target: DeleteTarget): void {
     this.deleteError.set('');
+    if (target.kind === 'group') {
+      const names =
+        this.data()
+          ?.shows.filter((s) => s.dayParts.some((p) => p.danceGroupIds.length))
+          .map((s) => s.name) ?? [];
+      if (names.length)
+        target = {
+          ...target,
+          explanation: `${target.explanation} De planning kan ongeldig worden van: ${names.join(', ')}.`,
+        };
+    }
     this.deleting.set(target);
   }
   membershipChanged(ids: number[]): void {

agiledancers-fe/src/app/shared/entity-editor.spec.ts

@@ -3,7 +3,7 @@ import { HttpErrorResponse } from '@angular/common/http';
 import { of, throwError } from 'rxjs';
 import { SchoolApi } from '../core/school-api';
 import { EntityEditor } from './entity-editor';
-import { EditorTarget } from '../core/api-models';
+import { EditorTarget, Show } from '../core/api-models';
 
 describe('EntityEditor', () => {
   const api = { saveSchool: vi.fn(), saveGroup: vi.fn(), saveDancer: vi.fn(), saveShow: vi.fn() };
@@ -14,10 +14,11 @@ describe('EntityEditor', () => {
       providers: [{ provide: SchoolApi, useValue: api }],
     });
   });
-  function editor(target: EditorTarget) {
+  function editor(target: EditorTarget, shows: Show[] = []) {
     const fixture = TestBed.createComponent(EntityEditor);
     fixture.componentRef.setInput('target', target);
     fixture.componentRef.setInput('schoolId', 7);
+    fixture.componentRef.setInput('shows', shows);
     fixture.componentInstance.ngOnInit();
     return fixture.componentInstance;
   }
@@ -66,4 +67,107 @@ describe('EntityEditor', () => {
     expect(component.error()).toContain('niet bereikbaar');
     expect(component.busy()).toBe(false);
   });
+  const show: Show = {
+    id: 3,
+    name: 'Summer',
+    dayParts: [
+      { date: '2027-06-01', type: 'AFTERNOON', danceGroupIds: [4] },
+      { date: '2027-06-02', type: 'AFTERNOON', danceGroupIds: [4] },
+    ],
+    appearances: { REGULAR: 2, SELECTION: 2, PRE_SCHOOLER: 1, SHOW_CASE: 2, PRE_EDUCATION: 2 },
+  };
+
+  it('initializes defaults for every type and rejects duplicate dated dayparts and fractional counts', () => {
+    const component = editor({ kind: 'show' });
+    component.name = 'Show';
+    expect(component.validDetails()).toBe(true);
+    component.addPart();
+    component.dayParts[0].date = '2027-06-01';
+    component.addPart();
+    component.dayParts[1].date = '2027-06-02';
+    component.addPart();
+    component.dayParts[2].date = '2027-06-03';
+    expect(component.appearances).toEqual({
+      REGULAR: 2,
+      SELECTION: 2,
+      PRE_SCHOOLER: 1,
+      SHOW_CASE: 3,
+      PRE_EDUCATION: 3,
+    });
+    expect(component.validDetails()).toBe(true);
+    component.dayParts[2].date = '2027-06-02';
+    expect(component.validDetails()).toBe(false);
+    component.dayParts[2].date = '2027-06-03';
+    component.appearances.PRE_SCHOOLER = 1.5;
+    expect(component.validDetails()).toBe(false);
+  });
+
+  it('preserves saved counts and requires explicit correction when reducing to one daypart', () => {
+    const component = editor({ kind: 'show', value: show });
+    component.addPart();
+    component.dayParts[2].date = '2027-06-03';
+    expect(component.appearances.SHOW_CASE).toBe(2);
+    component.removePart(2);
+    component.removePart(1);
+    expect(component.appearances.REGULAR).toBe(2);
+    expect(component.validDetails()).toBe(false);
+    component.setSingleCounts();
+    expect(component.validDetails()).toBe(true);
+  });
+
+  it('allows cancelling an invalidating edit and skips warnings for name-only edits', async () => {
+    api.saveShow.mockReturnValue(of(show));
+    const confirm = vi.spyOn(window, 'confirm').mockReturnValue(false);
+    try {
+      const component = editor({ kind: 'show', value: show });
+      component.appearances.REGULAR = 1;
+      await component.save();
+      expect(confirm).toHaveBeenCalledWith(expect.stringContaining('Summer'));
+      expect(api.saveShow).not.toHaveBeenCalled();
+      component.appearances.REGULAR = 2;
+      confirm.mockClear();
+      component.name = 'Renamed';
+      await component.save();
+      expect(confirm).not.toHaveBeenCalled();
+      expect(api.saveShow).toHaveBeenCalledOnce();
+    } finally {
+      confirm.mockRestore();
+    }
+  });
+  it('names affected shows before adding a group and allows cancellation', async () => {
+    const confirm = vi.spyOn(window, 'confirm').mockReturnValue(false);
+    try {
+      const component = editor({ kind: 'group' }, [show]);
+      component.name = 'New group';
+      await component.save();
+      expect(confirm).toHaveBeenCalledWith(expect.stringContaining('Summer'));
+      expect(api.saveGroup).not.toHaveBeenCalled();
+    } finally {
+      confirm.mockRestore();
+    }
+  });
+
+  it('displays one disabled appearance field for every type with one daypart', async () => {
+    // jsdom does not implement native dialog opening.
+    const descriptor = Object.getOwnPropertyDescriptor(HTMLDialogElement.prototype, 'showModal');
+    Object.defineProperty(HTMLDialogElement.prototype, 'showModal', {
+      configurable: true,
+      value: () => undefined,
+    });
+    try {
+      const fixture = TestBed.createComponent(EntityEditor);
+      fixture.componentRef.setInput('target', { kind: 'show' });
+      fixture.componentInstance.addPart();
+      fixture.detectChanges();
+      await fixture.whenStable();
+      fixture.detectChanges();
+      const element = fixture.nativeElement as HTMLElement;
+      const inputs = Array.from(element.querySelectorAll<HTMLInputElement>('input[type="number"]'));
+      expect(inputs).toHaveLength(5);
+      expect(inputs.every((input) => input.disabled && input.value === '1')).toBe(true);
+    } finally {
+      if (descriptor) Object.defineProperty(HTMLDialogElement.prototype, 'showModal', descriptor);
+      else Reflect.deleteProperty(HTMLDialogElement.prototype, 'showModal');
+    }
+  });
 });

agiledancers-fe/src/app/shared/entity-editor.ts

@@ -1,7 +1,15 @@
 import { Component, inject, input, OnInit, output, signal } from '@angular/core';
 import { FormsModule } from '@angular/forms';
 import { firstValueFrom, Observable } from 'rxjs';
-import { EditorTarget, GROUP_STYLES, GROUP_TYPES, GroupStyle, GroupType } from '../core/api-models';
+import {
+  EditorTarget,
+  GROUP_STYLES,
+  GROUP_TYPES,
+  GroupStyle,
+  GroupType,
+  DayPart,
+  Show,
+} from '../core/api-models';
 import { SchoolApi } from '../core/school-api';
 import { apiError } from '../core/api-error';
 import { DialogFrame } from './dialog-frame';
@@ -89,11 +97,69 @@ import { DialogFrame } from './dialog-frame';
             /></label>
           }
           @if (target().kind === 'show') {
-            <label>Datum<input type="date" name="showDate" [(ngModel)]="date" required /></label>
+            <fieldset>
-            <p class="form-hint">
+              <legend>Gedateerde dagdelen (maximaal zes)</legend>
-              De show krijgt automatisch een ochtend-, middag- en avonddeel. De groepsindeling volgt
+              @for (part of dayParts; track $index; let i = $index) {
-              later.
+                <div class="form-grid">
-            </p>
+                  <label
+                    >Datum<input
+                      type="date"
+                      [name]="'partDate' + i"
+                      [(ngModel)]="part.date"
+                      required
+                  /></label>
+                  <label
+                    >Dagdeel<select [name]="'partType' + i" [(ngModel)]="part.type" required>
+                      <option value="MORNING">Ochtend</option>
+                      <option value="AFTERNOON">Middag</option>
+                      <option value="EVENING">Avond</option>
+                    </select></label
+                  >
+                  <button type="button" class="text-button" (click)="removePart(i)">
+                    Dagdeel verwijderen
+                  </button>
+                </div>
+              }
+              <button
+                type="button"
+                class="button secondary"
+                [disabled]="dayParts.length >= 6"
+                (click)="addPart()"
+              >
+                Dagdeel toevoegen
+              </button>
+            </fieldset>
+            @if (dayParts.length) {
+              <fieldset>
+                <legend>Optredens per groepstype</legend>
+                @for (option of types; track option.value) {
+                  <label
+                    >{{ option.label
+                    }}<input
+                      type="number"
+                      [name]="'count' + option.value"
+                      [ngModel]="dayParts.length === 1 ? 1 : appearances[option.value]"
+                      (ngModelChange)="appearances[option.value] = $event"
+                      required
+                      min="1"
+                      [max]="dayParts.length"
+                      step="1"
+                      [disabled]="dayParts.length === 1"
+                  /></label>
+                }
+                <p class="form-hint">
+                  Bestaande aantallen blijven behouden bij wijzigingen. Corrigeer te hoge aantallen
+                  vóór opslaan.
+                </p>
+                @if (dayParts.length === 1 && !validCounts()) {
+                  <button type="button" class="button secondary" (click)="setSingleCounts()">
+                    Alle aantallen op één zetten
+                  </button>
+                }
+              </fieldset>
+            } @else {
+              <p class="form-hint">Zonder dagdelen blijft deze show ongepland.</p>
+            }
           }
         }
         <div class="dialog-actions">
@@ -120,6 +186,7 @@ import { DialogFrame } from './dialog-frame';
 export class EntityEditor implements OnInit {
   readonly target = input.required<EditorTarget>();
   readonly schoolId = input<number>();
+  readonly shows = input<Show[]>([]);
   readonly closed = output<void>();
   readonly saved = output<void>();
   readonly busy = signal(false);
@@ -128,6 +195,9 @@ export class EntityEditor implements OnInit {
   readonly styles = GROUP_STYLES;
   readonly today = new Date().toLocaleDateString('en-CA');
   private readonly api = inject(SchoolApi);
+  dayParts: DayPart[] = [];
+  appearances: Partial<Record<GroupType, number>> = {};
+  private countsInitialized = false;
   name = '';
   date = '';
   type: GroupType = 'REGULAR';
@@ -151,9 +221,48 @@ export class EntityEditor implements OnInit {
     } else {
       this.name = target.value.name;
       if (target.kind === 'dancer') this.date = target.value.birthDate;
-      if (target.kind === 'show') this.date = target.value.date;
+      if (target.kind === 'show') {
+        this.dayParts = target.value.dayParts.map((p) => ({ ...p }));
+        this.appearances = { ...target.value.appearances };
+        this.countsInitialized = Object.keys(this.appearances).length > 0;
+      }
     }
   }
+  addPart(): void {
+    if (this.dayParts.length >= 6) return;
+    const previous = this.dayParts.length;
+    this.dayParts.push({ date: '', type: 'AFTERNOON', danceGroupIds: [] });
+    if (!this.countsInitialized) {
+      for (const { value } of this.types) {
+        const defaultCount = (n: number) =>
+          value === 'PRE_SCHOOLER'
+            ? 1
+            : value === 'SHOW_CASE' || value === 'PRE_EDUCATION'
+              ? n
+              : Math.min(2, n);
+        if (
+          this.appearances[value] === undefined ||
+          this.appearances[value] === defaultCount(previous)
+        )
+          this.appearances[value] = defaultCount(this.dayParts.length);
+      }
+    }
+  }
+  removePart(index: number): void {
+    this.dayParts.splice(index, 1);
+    if (!this.countsInitialized && !this.dayParts.length) this.appearances = {};
+  }
+  setSingleCounts(): void {
+    for (const option of this.types) this.appearances[option.value] = 1;
+  }
+  validCounts(): boolean {
+    return this.types.every(
+      (o) =>
+        Number.isInteger(this.appearances[o.value]) &&
+        this.appearances[o.value]! >= 1 &&
+        this.appearances[o.value]! <= this.dayParts.length,
+    );
+  }
   toggleStyle(style: GroupStyle, checked: boolean): void {
     this.selectedStyles = checked
       ? [...this.selectedStyles, style]
@@ -162,7 +271,13 @@ export class EntityEditor implements OnInit {
   validDetails(): boolean {
     if (!this.name.trim()) return false;
     if (this.target().kind === 'dancer') return !!this.date && this.date <= this.today;
-    if (this.target().kind === 'show') return !!this.date;
+    if (this.target().kind === 'show')
+      return (
+        this.dayParts.length <= 6 &&
+        this.dayParts.every((p) => !!p.date && !!p.type) &&
+        new Set(this.dayParts.map((p) => p.date + ':' + p.type)).size === this.dayParts.length &&
+        (!this.dayParts.length || this.validCounts())
+      );
     if (this.target().kind === 'group')
       return (
         this.startAge !== null &&
@@ -176,6 +291,28 @@ export class EntityEditor implements OnInit {
   }
   async save(): Promise<void> {
     if (this.busy() || !this.validDetails()) return;
+    const current = this.target();
+    let affected: Show[] = [];
+    if (current.kind === 'group' && (!current.value || current.value.type !== this.type))
+      affected = this.shows();
+    if (
+      current.kind === 'show' &&
+      current.value &&
+      (JSON.stringify(current.value.dayParts.map((p) => ({ date: p.date, type: p.type }))) !==
+        JSON.stringify(this.dayParts.map((p) => ({ date: p.date, type: p.type }))) ||
+        JSON.stringify(current.value.appearances) !== JSON.stringify(this.appearances))
+    )
+      affected = [current.value];
+    const names = affected
+      .filter((s) => s.dayParts.some((p) => p.danceGroupIds.length))
+      .map((s) => s.name);
+    if (
+      names.length &&
+      !window.confirm(
+        `Deze wijziging kan de planning ongeldig maken van: ${names.join(', ')}. Doorgaan?`,
+      )
+    )
+      return;
     this.busy.set(true);
     this.error.set('');
     const target = this.target();
@@ -207,7 +344,15 @@ export class EntityEditor implements OnInit {
         );
         break;
       case 'show':
-        request = this.api.saveShow(schoolId!, { name: this.name.trim(), date: this.date }, id);
+        request = this.api.saveShow(
+          schoolId!,
+          {
+            name: this.name.trim(),
+            dayParts: this.dayParts.map((p) => ({ date: p.date, type: p.type })),
+            appearances: this.appearances,
+          },
+          id,
+        );
         break;
     }
     try {

skills/README.md

@@ -9,12 +9,13 @@ conversation, for example:
 
 | Skill | Purpose |
 | --- | --- |
+| [code-review](code-review/SKILL.md) | Review changes against documented coding standards and the originating spec. |
 | [grill-me](grill-me/SKILL.md) | Entry point for reviewing a plan or design through questions. |
 | [grilling](grilling/SKILL.md) | Interview instructions required by `grill-me`. |
 
 The skills are copied from [Matt Pocock's skills.sh listing](https://skills.sh/mattpocock/skills/grill-me)
 and its [upstream repository](https://github.com/mattpocock/skills).
-The exact upstream commit and paths are recorded in [upstream.json](upstream.json).
+The exact upstream revisions and paths are recorded in [upstream.json](upstream.json).
 The upstream [MIT license](LICENSE.mattpocock) is included.
 
 These project-local files are available to the agent from the next conversation

skills/code-review/SKILL.md

@@ -0,0 +1,89 @@
+---
+name: code-review
+description: "Review the changes since a fixed point (commit, branch, tag, or merge-base) along two axes: Standards (does the code follow this repo's documented coding standards?) and Spec (does the code match what the originating issue/spec asked for?). Runs both reviews in parallel sub-agents and reports them side by side. Use when the user wants to review a branch, a PR, work-in-progress changes, or asks to \"review since X\"."
+---
+
+Two-axis review of the diff between `HEAD` and a fixed point the user supplies:
+
+- **Standards**: does the code conform to this repo's documented coding standards?
+- **Spec**: does the code faithfully implement the originating issue / spec?
+
+Both axes run as **parallel sub-agents** so they don't pollute each other's context, then this skill aggregates their findings. Start every sub-agent with a fresh context window.
+
+The issue tracker should have been provided to you. If not, tell the user to run `/setup-matt-pocock-skills`.
+
+## Process
+
+### 1. Pin the fixed point
+
+Whatever the user said is the fixed point (a commit SHA, branch name, tag, `main`, `HEAD~5`, etc.). If they didn't specify one, ask for it.
+
+Capture the diff command once: `git diff <fixed-point>...HEAD` (three-dot, so the comparison is against the merge-base). Also note the list of commits via `git log <fixed-point>..HEAD --oneline`.
+
+Before going further, confirm the fixed point resolves (`git rev-parse <fixed-point>`) and the diff is non-empty. A bad ref or empty diff should fail here, not inside two parallel sub-agents.
+
+### 2. Identify the spec source
+
+Look for the originating spec, in this order:
+
+1. Issue references in the commit messages (`#123`, `Closes #45`, GitLab `!67`, etc.), fetched via the workflow in the tracker doc.
+2. A path the user passed as an argument.
+3. A spec file under `docs/`, `specs/`, or `.scratch/` matching the branch name or feature.
+4. If nothing is found, ask the user where the spec is. If they say there isn't one, the **Spec** sub-agent will skip and report "no spec available".
+
+### 3. Identify the standards sources
+
+Search the repo for every file that documents how code should be written. When `CODING_STANDARDS.md` or `CONTRIBUTING.md` exists, it must be on the list.
+
+On top of whatever the repo documents, the Standards axis always carries the **smell baseline** below: a fixed set of Fowler code smells (_Refactoring_, ch.3) that applies even when a repo documents nothing. Two rules bind it:
+
+- **The repo overrides.** A documented repo standard always wins; where it endorses something the baseline would flag, suppress the smell.
+- **Always a judgement call.** Each smell is a labelled heuristic ("possible Feature Envy"), never a hard violation. Like any standard here, skip anything tooling already enforces.
+
+Each smell reads *what it is* → *how to fix*; match it against the diff:
+
+- **Mysterious Name**: a function, variable, or type whose name doesn't reveal what it does or holds. → rename it; if no honest name comes, the design's murky.
+- **Duplicated Code**: the same logic shape appears in more than one hunk or file in the change. → extract the shared shape, call it from both.
+- **Feature Envy**: a method that reaches into another object's data more than its own. → move the method onto the data it envies.
+- **Data Clumps**: the same few fields or params keep travelling together (a type wanting to be born). → bundle them into one type, pass that.
+- **Primitive Obsession**: a primitive or string standing in for a domain concept that deserves its own type. → give the concept its own small type.
+- **Repeated Switches**: the same `switch`/`if`-cascade on the same type recurs across the change. → replace with polymorphism, or one map both sites share.
+- **Shotgun Surgery**: one logical change forces scattered edits across many files in the diff. → gather what changes together into one module.
+- **Divergent Change**: one file or module is edited for several unrelated reasons. → split so each module changes for one reason.
+- **Speculative Generality**: abstraction, parameters, or hooks added for needs the spec doesn't have. → delete it; inline back until a real need shows.
+- **Message Chains**: long `a.b().c().d()` navigation the caller shouldn't depend on. → hide the walk behind one method on the first object.
+- **Middle Man**: a class or function that mostly just delegates onward. → cut it, call the real target direct.
+- **Refused Bequest**: a subclass or implementer that ignores or overrides most of what it inherits. → drop the inheritance, use composition.
+
+### 4. Spawn both sub-agents in parallel
+
+Issue both sub-agent calls together, in the foreground, and aggregate the reports they return.
+
+**Standards sub-agent prompt** should include:
+
+- The full diff command and commit list.
+- The list of standards-source files you found in step 3, **plus the smell baseline from step 3** pasted in full (the sub-agent has no other access to it).
+- The brief: "Report, per file/hunk where relevant, (a) every place the diff violates a documented standard: cite the standard (file + the rule); and (b) any baseline smell you spot: name it and quote the hunk. Distinguish hard violations from judgement calls: documented-standard breaches can be hard, but baseline smells are always judgement calls, and a documented repo standard overrides the baseline. Skip anything tooling enforces. Under 400 words."
+
+**Spec sub-agent prompt** should include:
+
+- The diff command and commit list.
+- The path or fetched contents of the spec.
+- The brief: "Report: (a) requirements the spec asked for that are missing or partial; (b) behaviour in the diff that wasn't asked for (scope creep); (c) requirements that look implemented but where the implementation looks wrong. Quote the spec line for each finding. Under 400 words."
+
+If the spec is missing, skip the Spec sub-agent and note this in the final report.
+
+### 5. Aggregate
+
+Present the two reports under `## Standards` and `## Spec` headings, verbatim or lightly cleaned. Do **not** merge or rerank findings, because the two axes are deliberately separate (see _Why two axes_).
+
+End with a one-line summary: total findings per axis, and the worst issue _within each axis_ (if any). Don't pick a single winner across axes: that's the reranking the separation exists to prevent.
+
+## Why two axes
+
+A change can pass one axis and fail the other:
+
+- Code that follows every standard but implements the wrong thing → **Standards pass, Spec fail.**
+- Code that does exactly what the issue asked but breaks the project's conventions → **Spec pass, Standards fail.**
+
+Reporting them separately stops one axis from masking the other.

skills/code-review/agents/openai.yaml

@@ -0,0 +1,3 @@
+interface:
+  display_name: "Code Review"
+  short_description: "Review a diff on standards and spec"

skills/upstream.json

@@ -4,6 +4,11 @@
   "source": "https://skills.sh/mattpocock/skills/grill-me",
   "skills": {
     "grill-me": "skills/productivity/grill-me",
-    "grilling": "skills/productivity/grilling"
+    "grilling": "skills/productivity/grilling",
+    "code-review": {
+      "path": "skills/engineering/code-review",
+      "commit": "a496f5513d4a4cf889bc48e189e579f4b0bdf6aa",
+      "source": "https://www.skills.sh/mattpocock/skills/code-review"
+    }
   }
 }

specs/S3_define-coding-standards-to-fe

@@ -0,0 +1 @@
+Create a file (or append to it) CODING_STANDARDS.md and have the coding standards in there, for the review skill. 

specs/S7_define-coding-standards-to-be

@@ -0,0 +1 @@
+Create a file (or append to it) CODING_STANDARDS.md and have the coding standards in there, for the review skill. 

specs/in_review/S9_spread-dancegroups-via-ortools-setup

@@ -1,6 +1,6 @@
 # S9 — Schedule dance groups across show dayparts with OR-Tools
 
-Status: REFINED
+Status: IN_REVIEW
 
 Agreed after the grill-me review; shared understanding confirmed.
 
@@ -121,33 +121,43 @@ S10–S13 are intentionally empty placeholders and are to be refined separately.
 
 ## Acceptance criteria
 
-- [ ] Configure up to six dated dayparts, reject duplicate date/type combinations
+- [x] Configure up to six dated dayparts, reject duplicate date/type combinations
       and derive the displayed show date range from them.
-- [ ] Persist editable per-type counts with the agreed defaults, remove the
+- [x] Persist editable per-type counts with the agreed defaults, remove the
       backend type-level property and validate counts in frontend and backend.
-- [ ] With one daypart, every count is one and frontend fields are disabled.
+- [x] With one daypart, every count is one and frontend fields are disabled.
-- [ ] Daypart edits preserve configured counts and require correction of counts
+- [x] Daypart edits preserve configured counts and require correction of counts
       that exceed the new number of dayparts.
-- [ ] OR-Tools assigns every school group to exactly its type's required number
+- [x] OR-Tools assigns every school group to exactly its type's required number
       of distinct dayparts and minimizes the busiest/quietest appearance gap.
-- [ ] Scheduling requires groups and dayparts and replaces assignments only after
+- [x] Scheduling requires groups and dayparts and replaces assignments only after
       a successful, current result.
-- [ ] The synchronous request supports a 30-minute solver limit, accepts valid
+- [x] The synchronous request supports a 30-minute solver limit, accepts valid
       unproven results and communicates whether optimality was proven.
-- [ ] Failed, infeasible, stale and no-result runs preserve existing assignments
+- [x] Failed, infeasible, stale and no-result runs preserve existing assignments
       and explain why no replacement was saved.
-- [ ] Duplicate concurrent runs for a show are prevented in frontend and backend.
+- [x] Duplicate concurrent runs for a show are prevented in frontend and backend.
-- [ ] Potentially invalidating edits warn beforehand, identify affected shows,
+- [x] Potentially invalidating edits warn beforehand, identify affected shows,
       permit cancellation and expose invalid schedules afterward without
       automatically rescheduling.
-- [ ] New-format JSON round-trips dates, assignments and all type settings;
+- [x] New-format JSON round-trips dates, assignments and all type settings;
       legacy import support is not required.
-- [ ] Any repeatability work respects both the three-minute investigation limit
+- [x] Any repeatability work respects both the three-minute investigation limit
       and the ten-additional-statement implementation limit.
 
 ## Implementation handoff
 
-This specification records agreed behavior; it does not implement scheduling.
+This specification records the agreed behavior implemented on the current branch.
 The current application uses in-memory storage with JSON import/export for
 transfer. S9 adds the scheduling model, frontend controls, backend operation and
 JSON changes within that existing persistence approach.
+
+## Implementation validation
+
+- Backend: 29 tests, including real OR-Tools balancing, input validation, JSON
+  round-trips, concurrent scheduling, stale input rejection and failure preservation.
+- Frontend: 20 tests covering count validation, disabled single-daypart fields, edit cancellation,
+  API timeout contract, production build and lint checks.
+- Playwright: real REST workflow for dated dayparts, scheduling and cancellation.
+- Repeatability uses one solver-parameter statement (single worker, fixed seed);
+  no extended investigation was needed.