import {
  ChangeDetectionStrategy,
  Component,
  effect,
  inject,
  untracked,
} from '@angular/core';
import { RouterLink } from '@angular/router';
import {
  PiEmptyStateComponent,
  PiNoteComponent,
  PiProgressBarComponent,
  PiSkeletonComponent,
} from '@pi/ui';
import {
  EpicsFacade,
  ProjectFacade,
  provideEpicsFacade,
} from '@task-stream/web/tracker/application';
import { Epic } from '@task-stream/web/tracker/domain';
import { statusLook, typeLook } from '../ui/copy';

/** /p/:key/epics — the big pieces of work and how far each has got. */
@Component({
  selector: 'ts-epics-page',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [
    RouterLink,
    PiEmptyStateComponent,
    PiNoteComponent,
    PiProgressBarComponent,
    PiSkeletonComponent,
  ],
  providers: [provideEpicsFacade()],
  template: `
    <div class="ts-section-header">
      <p class="ts-muted">
        Una épica es un ticket que agrupa a otros. Cuelga tickets de ella desde
        su ficha («Subtareas») y aquí verás cuánto falta.
      </p>
    </div>

    @if (facade.error(); as error) {
      <pi-note
        gap="xs"
        status="error"
        appearance="fill"
        type="status"
        title="No se pudieron cargar las épicas"
        [text]="error"
      />
    } @else if (!facade.loaded()) {
      <pi-skeleton shape="text" [lines]="6" />
    } @else if (facade.epics().length) {
      <ul class="ts-epics">
        @for (epic of facade.epics(); track epic.issue.id) {
          <li class="ts-epic ts-panel" [style.--tone]="typeTone(epic)">
            <header class="ts-epic__head">
              <a
                class="ts-key"
                [routerLink]="['..', 'issues', epic.issue.key]"
                >{{ epic.issue.key }}</a
              >
              <a
                class="ts-epic__title"
                [routerLink]="['..', 'issues', epic.issue.key]"
                >{{ epic.issue.title }}</a
              >
              <span class="ts-pill" [style.--tone]="statusTone(epic)">{{
                statusLabel(epic)
              }}</span>
            </header>
            <pi-progress-bar
              [label]="summary(epic)"
              [value]="epic.progress.percent"
            />
          </li>
        }
      </ul>
    } @else {
      <pi-empty-state
        icon="flag"
        title="Aún no hay épicas"
        description="Abre un ticket grande y crea sus subtareas desde «Subtareas»: aparecerá aquí con su progreso."
      />
    }
  `,
  styles: `
    .ts-epics {
      display: grid;
      gap: 0.75rem;
      margin: 0;
      padding: 0;
      list-style: none;
    }
    .ts-epic {
      display: grid;
      gap: 0.75rem;
      padding: 1rem 1.125rem;
      border-left: 3px solid var(--tone, var(--ts-brand));
    }
    .ts-epic__head {
      display: grid;
      grid-template-columns: auto minmax(0, 1fr) auto;
      gap: 0.625rem;
      align-items: center;
    }
    .ts-epic__title {
      overflow: hidden;
      color: inherit;
      font-weight: 600;
      text-decoration: none;
      text-overflow: ellipsis;
      white-space: nowrap;
      &:hover {
        color: var(--ts-brand);
      }
    }
  `,
})
export class EpicsPage {
  protected readonly facade = inject(EpicsFacade);
  private readonly project = inject(ProjectFacade);

  constructor() {
    effect(() => {
      const projectId = this.project.project()?.id;
      if (projectId) untracked(() => this.facade.open(projectId));
    });
  }

  protected summary(epic: Epic): string {
    const { finished, total, percent, storyPoints, finishedStoryPoints } =
      epic.progress;
    const points = storyPoints
      ? ` · ${finishedStoryPoints}/${storyPoints} puntos`
      : '';
    return `${percent}% · ${finished} de ${total} tickets terminados${points}`;
  }

  protected typeTone = (epic: Epic) =>
    typeLook(this.project.workflow(), epic.issue.type).tone;
  protected statusTone = (epic: Epic) =>
    statusLook(this.project.workflow(), epic.issue.status).tone;
  protected statusLabel = (epic: Epic) =>
    statusLook(this.project.workflow(), epic.issue.status).label;
}