import { Component, inject, input, OnInit, output, signal } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { firstValueFrom } from 'rxjs';
import { DanceGroup, Show } from '../core/api-models';
import { SchoolApi } from '../core/school-api';
import { apiError } from '../core/api-error';
import { DialogFrame } from './dialog-frame';

@Component({
  selector: 'app-schedule-editor',
  imports: [FormsModule, DialogFrame],
  template: `
    <app-dialog-frame
      [title]="show().name + ' — indeling'"
      [busy]="busy()"
      (dismissed)="closed.emit()"
    >
      <p>
        {{ !dirty() && current()?.finalized ? 'Definitief' : 'Concept' }} · preferredDayParts =
        {{ show().preferredDayParts }}
      </p>
      <p>
        Tussen twee dansen van dezelfde danser zijn twee andere optredens nodig. Je kunt een
        onvolledige indeling als concept opslaan.
      </p>
      @if (error()) {
        <p role="alert" class="alert error">{{ error() }}</p>
      }
      @if (dirty()) {
        <p role="status">
          Niet-opgeslagen wijzigingen. Sla het concept op om alle regels te controleren.
        </p>
      }
      @for (violation of current()?.violations ?? []; track $index) {
        <p class="alert error">{{ violation }}</p>
      }
      <fieldset [disabled]="busy()">
        @for (part of show().dayParts; track $index; let p = $index) {
          <fieldset>
            <legend>
              {{ part.date }} · {{ part.type }} ({{ assignments[p].length }} optredens)
            </legend>
            <ol>
              @for (id of assignments[p]; track $index; let i = $index) {
                <li>
                  {{ name(id) }}
                  <button
                    type="button"
                    [disabled]="i === 0"
                    (click)="reorder(p, i, -1)"
                    [attr.aria-label]="name(id) + ' omhoog'"
                  >
                    ↑
                  </button>
                  <button
                    type="button"
                    [disabled]="i === assignments[p].length - 1"
                    (click)="reorder(p, i, 1)"
                    [attr.aria-label]="name(id) + ' omlaag'"
                  >
                    ↓
                  </button>
                  <label
                    >Verplaatsen naar
                    <select [ngModel]="p" (ngModelChange)="move(p, i, +$event)">
                      @for (target of show().dayParts; track $index; let t = $index) {
                        <option [ngValue]="t">{{ target.date }} · {{ target.type }}</option>
                      }
                    </select>
                  </label>
                  <button type="button" (click)="remove(p, i)">Optreden verwijderen</button>
                </li>
              }
            </ol>
            <label
              >Groep toevoegen
              <select [ngModel]="null" (ngModelChange)="add(p, +$event)">
                <option [ngValue]="null">Kies een groep</option>
                @for (group of groups(); track group.id) {
                  @if (group.dancerIds.length && !assignments[p].includes(group.id)) {
                    <option [ngValue]="group.id">{{ group.category }}</option>
                  }
                }
              </select>
            </label>
          </fieldset>
        }
      </fieldset>
      <div class="dialog-actions">
        <button type="button" class="button secondary" [disabled]="busy()" (click)="closed.emit()">
          Gereed
        </button>
        <button
          type="button"
          class="button primary"
          [disabled]="busy() || !dirty()"
          (click)="save()"
        >
          Concept opslaan
        </button>
        <button
          type="button"
          class="button primary"
          [disabled]="busy() || dirty() || current()?.finalized || !!current()?.violations?.length"
          (click)="finalize()"
        >
          Definitief maken
        </button>
      </div>
    </app-dialog-frame>
  `,
})
export class ScheduleEditor implements OnInit {
  readonly show = input.required<Show>();
  readonly groups = input.required<DanceGroup[]>();
  readonly revision = input<number>();
  private originalRevision?: number;
  readonly schoolId = input.required<number>();
  readonly closed = output<void>();
  readonly saved = output<void>();
  readonly busy = signal(false);
  readonly dirty = signal(false);
  readonly error = signal('');
  readonly current = signal<Show | null>(null);
  private readonly api = inject(SchoolApi);
  assignments: number[][] = [];

  ngOnInit(): void {
    this.originalRevision = this.revision();
    this.current.set(this.show());
    this.assignments = this.show().dayParts.map((p) => [...p.danceGroupIds]);
  }
  name(id: number): string {
    return this.groups().find((g) => g.id === id)?.category ?? `Groep ${id}`;
  }
  reorder(p: number, i: number, delta: number): void {
    const list = this.assignments[p];
    [list[i], list[i + delta]] = [list[i + delta], list[i]];
    this.dirty.set(true);
  }
  move(p: number, i: number, target: number): void {
    if (target === p || this.assignments[target].includes(this.assignments[p][i])) return;
    this.assignments[target].push(this.assignments[p].splice(i, 1)[0]);
    this.dirty.set(true);
  }
  add(p: number, id: number): void {
    if (!id || this.assignments[p].includes(id)) return;
    this.assignments[p].push(id);
    this.dirty.set(true);
  }
  remove(p: number, i: number): void {
    this.assignments[p].splice(i, 1);
    this.dirty.set(true);
  }
  async save(): Promise<void> {
    await this.perform(false);
  }
  async finalize(): Promise<void> {
    await this.perform(true);
  }
  private async perform(finalize: boolean): Promise<void> {
    if (this.busy()) return;
    this.busy.set(true);
    this.error.set('');
    try {
      const result = await firstValueFrom(
        finalize
          ? this.api.finalize(this.schoolId(), this.show().id, this.originalRevision)
          : this.api.saveAssignments(
              this.schoolId(),
              this.show().id,
              this.assignments,
              this.originalRevision,
            ),
      );
      if (this.originalRevision !== undefined) this.originalRevision++;
      this.current.set(result);
      this.assignments = result.dayParts.map((p) => [...p.danceGroupIds]);
      this.dirty.set(false);
      this.saved.emit();
    } catch (error: unknown) {
      this.error.set(apiError(error));
    } finally {
      this.busy.set(false);
    }
  }
}