import {
  ChangeDetectionStrategy,
  Component,
  computed,
  input,
} from '@angular/core';
import { RouterLink } from '@angular/router';
import { AgendaItem } from '@task-stream/web/tracker/domain';

const DAY = 86_400_000;
const KIND: Record<AgendaItem['kind'], string> = {
  ISSUE: 'vence',
  SPRINT_END: 'fin de sprint',
  RELEASE: 'release',
};

/** My coming week: what is due, which sprints end, which releases land. */
@Component({
  selector: 'ts-week-agenda',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [RouterLink],
  host: {
    class: 'ts-panel',
    role: 'region',
    'aria-labelledby': 'agenda-title',
  },
  styleUrl: './home-panel.scss',
  template: `
    <header class="ts-panel__head">
      <h2 id="agenda-title">Tu semana</h2>
      <span class="ts-muted">{{ count() }} cosas en los próximos 7 días</span>
    </header>
    <ol class="ts-agenda">
      @for (day of days(); track day.date) {
        <li [class.is-today]="day.today" [class.is-empty]="!day.items.length">
          <p class="ts-agenda__day">
            <span>{{ day.weekday }}</span> <strong>{{ day.number }}</strong>
          </p>
          @for (item of day.items; track $index) {
            <a
              class="ts-agenda__item"
              [attr.data-kind]="item.kind"
              [routerLink]="link(item)"
              [attr.title]="item.projectKey + ' · ' + item.title"
            >
              <span class="ts-agenda__kind">{{ kindOf(item) }}</span>
              {{ item.issueKey ?? item.projectKey }}
              <span class="ts-agenda__title">{{ item.title }}</span>
            </a>
          } @empty {
            <span class="ts-agenda__none">—</span>
          }
        </li>
      }
    </ol>
  `,
  styles: `
    .ts-agenda {
      display: grid;
      grid-template-columns: repeat(7, minmax(0, 1fr));
      gap: 0.5rem;
      margin: 0;
      padding: 0;
      list-style: none;
      li {
        display: grid;
        align-content: start;
        gap: 0.25rem;
        min-height: 6rem;
        padding: 0.5rem;
        border-radius: 0.625rem;
        background: var(--ts-sunken);
      }
      li.is-today {
        outline: 2px solid var(--ts-brand);
        outline-offset: -2px;
      }
    }
    .ts-agenda__day {
      margin: 0 0 0.25rem;
      color: var(--ts-muted);
      font-size: 0.75rem;
      text-transform: capitalize;
      strong {
        color: var(--ts-ink);
        font-size: 1rem;
      }
    }
    .ts-agenda__item {
      display: grid;
      gap: 0.0625rem;
      padding: 0.25rem 0.375rem;
      border-left: 3px solid var(--ts-brand);
      border-radius: 0.375rem;
      background: var(--ts-surface);
      color: inherit;
      font-family: var(--ts-font-mono);
      font-size: 0.6875rem;
      text-decoration: none;
      &[data-kind='SPRINT_END'] {
        border-left-color: var(--ts-c-amber, #c98a12);
      }
      &[data-kind='RELEASE'] {
        border-left-color: var(--ts-c-green, #2e9e6a);
      }
      &:hover {
        background: var(--pi-color-primary-25);
      }
    }
    .ts-agenda__kind {
      color: var(--ts-muted);
      font-family: inherit;
    }
    .ts-agenda__title {
      overflow: hidden;
      font-family: var(--ts-font-body, inherit);
      font-size: 0.75rem;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    .ts-agenda__none {
      color: var(--ts-muted);
      font-size: 0.75rem;
    }
    @media (max-width: 720px) {
      .ts-agenda {
        grid-template-columns: minmax(0, 1fr);
        li {
          min-height: 0;
        }
        /* On a phone, only the days with something (and today). */
        li.is-empty:not(.is-today) {
          display: none;
        }
      }
    }
  `,
})
export class WeekAgendaComponent {
  readonly items = input.required<AgendaItem[]>();
  readonly now = input<Date>(new Date());

  protected readonly count = computed(() => this.items().length);
  protected readonly days = computed(() => {
    const now = this.now();
    const start = Date.UTC(now.getFullYear(), now.getMonth(), now.getDate());
    return Array.from({ length: 7 }, (_, n) => {
      const time = start + n * DAY;
      const date = new Date(time).toISOString().slice(0, 10);
      return {
        date,
        today: n === 0,
        weekday: new Date(time).toLocaleDateString('es', {
          weekday: 'short',
          timeZone: 'UTC',
        }),
        number: new Date(time).getUTCDate(),
        items: this.items().filter((i) => i.day === date),
      };
    });
  });

  protected kindOf(item: AgendaItem): string {
    return KIND[item.kind];
  }

  protected link(item: AgendaItem): unknown[] {
    return item.issueKey
      ? ['/p', item.projectKey, 'issues', item.issueKey]
      : [
          '/p',
          item.projectKey,
          item.kind === 'RELEASE' ? 'releases' : 'sprints',
        ];
  }
}