import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Objects;

/** Gitea 1.25 API adapter. Never include response bodies or tokens in errors. */
class ReleaseApi {
    record Tag(ReleaseVersion version, String sha, String object) {}

    final String server, token, base;

    ReleaseApi(Map<String, String> env) {
        server = Setup.required(env, "GITEA_SERVER_URL");
        var uri = URI.create(server);
        Pipeline.check(
                List.of("http", "https").contains(uri.getScheme())
                        && uri.getUserInfo() == null
                        && uri.getQuery() == null
                        && uri.getFragment() == null
                        && (uri.getPath().isEmpty() || uri.getPath().equals("/")),
                "Gitea must use a server-root URL");
        String repository = Setup.required(env, "CI_REPOSITORY");
        Pipeline.check(repository.matches("[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+"), "Invalid repository name");
        base = "/api/v1/repos/" + repository;
        token = Setup.required(env, "RELEASE_TOKEN");
    }

    Object request(String method, String path, Object body) throws Exception {
        return Setup.api(server, token, method, base + path, body);
    }

    String head() throws Exception {
        return sha(
                Json.object(Json.object(request("GET", "/branches/main", null)).get("commit"))
                        .get("id"));
    }

    static String sha(Object value) {
        String result = Objects.toString(value, "");
        Pipeline.check(result.matches("[0-9a-f]{40}"), "Invalid release commit SHA");
        return result;
    }

    List<Tag> tags() throws Exception {
        List<Tag> tags = new ArrayList<>();
        var seen = new java.util.HashSet<String>();
        for (int page = 1; ; page++) {
            var entries = (List<?>) request("GET", "/tags?limit=50&page=" + page, null);
            if (entries.isEmpty()) return tags;
            for (Object entry : entries) {
                var tag = Json.object(entry);
                String name = Objects.toString(tag.get("name"), "");
                Pipeline.check(
                        seen.add(name),
                        "Remote tag pagination repeated a tag; cannot establish a safe version baseline");
                // Unknown version-looking tags require explicit reconciliation, not a second baseline.
                if (!name.matches("v?[0-9].*")) continue;
                ReleaseVersion version = ReleaseVersion.parse(name);
                String commit = sha(Json.object(tag.get("commit")).get("sha"));
                String object = sha(tag.get("id"));
                tags.add(new Tag(version, commit, object));
            }
        }
    }

    void annotated(Tag tag) throws Exception {
        var data = Json.object(request("GET", "/git/tags/" + tag.object(), null));
        Pipeline.check(
                tag.version().toString().equals(data.get("tag"))
                        && tag.sha().equals(Json.object(data.get("object")).get("sha")),
                "Release tag must be annotated and point directly to its recorded commit");
    }

    void create(ReleaseVersion version, String commit, String run) throws Exception {
        request(
                "POST",
                "/tags",
                Map.of(
                        "tag_name",
                        version.toString(),
                        "target",
                        commit,
                        "message",
                        "Release " + version + "\nCommit: " + commit + "\nDeployment attempt: " + run));
        Tag tag = tags().stream()
                .filter(t -> t.version().equals(version))
                .findFirst()
                .orElseThrow();
        Pipeline.check(tag.sha().equals(commit), "Created release tag does not match selected commit");
        annotated(tag);
    }

    String verified(String commit) throws Exception {
        // A successful build.yaml main-push run includes verification AND successful image publication.
        // Do not accept another workflow, a branch build, or merely an existing image/tag.
        var seen = new java.util.HashSet<String>();
        for (int page = 1; ; page++) {
            var response = Json.object(request(
                    "GET",
                    "/actions/runs?head_sha=" + commit + "&event=push&branch=main&status=success&limit=50&page=" + page,
                    null));
            var runs = (List<?>) response.get("workflow_runs");
            if (runs.isEmpty()) break;
            boolean fresh = false;
            for (Object entry : runs) {
                var run = Json.object(entry);
                fresh |= seen.add(Objects.toString(run.get("id")));
                if (commit.equals(run.get("head_sha"))
                        && "push".equals(run.get("event"))
                        && List.of("main", "refs/heads/main").contains(Objects.toString(run.get("head_branch")))
                        && "completed".equals(run.get("status"))
                        && "success".equals(run.get("conclusion"))
                        && "build.yaml@refs/heads/main".equals(run.get("path"))) {
                    return Objects.toString(run.get("id"));
                }
            }
            // Older Gitea installations may ignore some list filters/pagination.
            // Validate each entry locally and stop if a page makes no progress.
            if (!fresh) break;
        }
        throw new IllegalArgumentException("No successful build.yaml main-push run verifies and publishes this SHA");
    }
}