import {
  ChangeDetectionStrategy,
  Component,
  computed,
  effect,
  inject,
  input,
  signal,
  TemplateRef,
  viewChild,
} from '@angular/core';
import { form, FormField, required } from '@angular/forms/signals';
import { RouterLink } from '@angular/router';
import {
  PiActionButtonComponent,
  PiIconButtonComponent,
  PiIconComponent,
  PiLabelDirective,
  PiNoteComponent,
  PiSelectFieldComponent,
  PiSkeletonComponent,
  PiTextareaComponent,
  PiTextFieldComponent,
  type PiSelectFieldOption,
} from '@pi/ui';
import { DrawerService } from '@task-stream/web/shared/ui';
import {
  IssueFacade,
  ProjectFacade,
  provideIssueFacade,
} from '@task-stream/web/tracker/application';
import {
  Comment,
  IssueLink,
  IssueLinkType,
  IssuePriority,
  ReleaseStatus,
} from '@task-stream/web/tracker/domain';
import {
  clock,
  initials,
  LINK,
  options,
  PRIORITY,
  statusLook,
  timeAgo,
  typeLook,
} from '../ui/copy';

const NONE = '';

@Component({
  selector: 'ts-issue-page',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [
    RouterLink,
    FormField,
    PiActionButtonComponent,
    PiIconComponent,
    PiIconButtonComponent,
    PiLabelDirective,
    PiNoteComponent,
    PiSelectFieldComponent,
    PiSkeletonComponent,
    PiTextFieldComponent,
    PiTextareaComponent,
  ],
  providers: [provideIssueFacade()],
  styleUrl: './issue.page.scss',
  template: `
    <a class="ts-back" routerLink="../../board">← Tablero</a>

    @if (facade.issue(); as issue) {
      <div class="ts-issue">
        <section class="ts-issue__main">
          <header class="ts-issue__header">
            <div class="ts-issue__meta">
              <span class="ts-key">{{ issue.key }}</span>
              <span class="ts-type" [style.--tone]="type().tone">
                <pi-icon [icon]="type().icon" size="x-small" />
                {{ type().label }}
              </span>
              <span class="ts-pill" [style.--tone]="status().tone">{{
                status().label
              }}</span>
            </div>
            <div class="ts-issue__title-row">
              <h1>{{ issue.title }}</h1>
              @if (project.canContribute()) {
                <pi-icon-button
                  icon="edit"
                  color="grey"
                  appearance="ghost"
                  aria-label="Editar"
                  (execute)="openEdit()"
                />
              }
            </div>
          </header>

          @if (project.canContribute() && issue.allowedTransitions.length) {
            <div class="ts-transitions" role="group" aria-label="Mover a">
              <span class="ts-eyebrow">Mover a</span>
              @for (to of issue.allowedTransitions; track to) {
                <button
                  type="button"
                  class="ts-move"
                  [style.--tone]="statusTone(to)"
                  (click)="move(to)"
                >
                  {{ statusLabel(to) }}
                  <span aria-hidden="true">→</span>
                </button>
              }
            </div>
          }

          <article class="ts-block">
            <h2 class="ts-section">Descripción</h2>
            @if (issue.description) {
              <p class="ts-prewrap">{{ issue.description }}</p>
            } @else {
              <p class="ts-muted">Sin descripción.</p>
            }
            @if (issue.figmaUrl) {
              <a
                class="ts-figma"
                [href]="issue.figmaUrl"
                target="_blank"
                rel="noopener"
              >
                <pi-icon icon="figma" size="small" /> Ver el diseño en Figma
              </a>
            }
          </article>

          <article class="ts-block">
            <h2 class="ts-section">Relaciones</h2>
            @for (
              link of facade.outwardLinks();
              track link.issueId + link.type
            ) {
              <div class="ts-link">
                <span class="ts-link__kind">{{ linkLabel(link) }}</span>
                <a class="ts-key" [routerLink]="['..', link.issueKey]">{{
                  link.issueKey
                }}</a>
                @if (project.canContribute()) {
                  <pi-icon-button
                    icon="close"
                    color="grey"
                    appearance="ghost"
                    aria-label="Quitar"
                    (execute)="unlink(link)"
                  />
                }
              </div>
            }
            @for (
              link of facade.inwardLinks();
              track link.issueId + link.type
            ) {
              <div class="ts-link">
                <span class="ts-link__kind">{{ linkLabel(link) }}</span>
                <a class="ts-key" [routerLink]="['..', link.issueKey]">{{
                  link.issueKey
                }}</a>
              </div>
            }
            @if (!issue.links.length) {
              <p class="ts-muted">
                Sin relaciones. Vincula FE ↔ BE ↔ QA para seguir el trabajo de
                punta a punta.
              </p>
            }
            @if (project.canContribute()) {
              <form
                class="ts-inline-form"
                (submit)="$event.preventDefault(); link()"
                novalidate
              >
                <pi-select-field
                  [options]="linkTypeOptions"
                  [(value)]="linkType"
                />
                <pi-text-field
                  placeholder="Clave, p. ej. BE-3"
                  [(value)]="linkTarget"
                />
                <pi-action-button
                  size="small"
                  color="primary"
                  text="Relacionar"
                  [disabled]="!linkTarget().trim()"
                  (execute)="link()"
                />
              </form>
            }
          </article>

          <article class="ts-block">
            <h2 class="ts-section">
              Comentarios
              <span class="ts-mono">{{ facade.comments().length }}</span>
            </h2>
            @for (comment of facade.comments(); track comment.id) {
              <div class="ts-comment">
                <span class="ts-comment__avatar" aria-hidden="true">{{
                  initialsOf(comment.author.name)
                }}</span>
                <div class="ts-comment__body">
                  <div class="ts-comment__head">
                    <strong>{{ comment.author.name }}</strong>
                    <span class="ts-comment__when"
                      >{{ ago(comment.createdAt)
                      }}{{ comment.editedAt ? ' · editado' : '' }}</span
                    >
                    <span class="ts-spacer"></span>
                    @if (comment.author.id === facade.me()) {
                      <pi-icon-button
                        icon="edit"
                        color="grey"
                        appearance="ghost"
                        aria-label="Editar"
                        (execute)="openEditComment(comment)"
                      />
                    }
                    @if (
                      comment.author.id === facade.me() || project.canManage()
                    ) {
                      <pi-icon-button
                        icon="trash"
                        color="grey"
                        appearance="ghost"
                        aria-label="Eliminar"
                        (execute)="deleteComment(comment)"
                      />
                    }
                  </div>
                  <p class="ts-prewrap">{{ comment.body }}</p>
                </div>
              </div>
            }
            @if (project.canContribute()) {
              <form
                class="ts-form"
                (submit)="$event.preventDefault(); addComment()"
                novalidate
              >
                <pi-textarea
                  placeholder="Deja una decisión, una explicación, un paso para reproducir…"
                  [(value)]="commentBody"
                />
                <div>
                  <pi-action-button
                    color="primary"
                    text="Comentar"
                    [disabled]="!commentBody().trim()"
                    (execute)="addComment()"
                  />
                </div>
              </form>
            }
          </article>

          <article class="ts-block">
            <h2 class="ts-section">Historial</h2>
            <ol class="ts-log">
              @for (entry of facade.history(); track entry.id) {
                <li>
                  <time
                    class="ts-log__when"
                    [attr.datetime]="entry.occurredAt"
                    >{{ clock(entry.occurredAt) }}</time
                  >
                  <span class="ts-log__what">{{ entry.summary }}</span>
                  <span class="ts-log__ago">{{ ago(entry.occurredAt) }}</span>
                </li>
              }
            </ol>
          </article>
        </section>

        <aside class="ts-issue__side ts-panel">
          <p class="ts-eyebrow">Ficha</p>
          <pi-select-field
            [options]="assigneeOptions()"
            [disabled]="!project.canContribute()"
            [value]="issue.assignee?.id ?? ''"
            (valueChange)="assign($event)"
          >
            <pi-label>Asignado</pi-label>
          </pi-select-field>
          <pi-select-field
            [options]="releaseOptions()"
            [disabled]="!project.canContribute()"
            [value]="issue.release?.id ?? ''"
            (valueChange)="setRelease($event)"
          >
            <pi-label>Release</pi-label>
          </pi-select-field>
          <pi-select-field
            [options]="typeOptions()"
            [disabled]="!project.canContribute()"
            [value]="issue.type"
            (valueChange)="update({ type: $any($event) })"
          >
            <pi-label>Tipo</pi-label>
          </pi-select-field>
          <pi-select-field
            [options]="priorityOptions"
            [disabled]="!project.canContribute()"
            [value]="issue.priority"
            (valueChange)="update({ priority: $any($event) })"
          >
            <pi-label>Prioridad</pi-label>
          </pi-select-field>
          <pi-select-field
            [options]="areaOptions()"
            [disabled]="!project.canContribute()"
            [value]="issue.area ?? ''"
            (valueChange)="update({ area: $any($event || null) })"
          >
            <pi-label>Área</pi-label>
          </pi-select-field>

          <dl class="ts-facts">
            <dt>Reportado por</dt>
            <dd>{{ issue.reporter.name }}</dd>
            <dt>Creado</dt>
            <dd class="ts-mono">{{ ago(issue.createdAt) }}</dd>
            <dt>Actualizado</dt>
            <dd class="ts-mono">{{ ago(issue.updatedAt) }}</dd>
            @if (issue.labels.length) {
              <dt>Etiquetas</dt>
              <dd class="ts-labels">
                @for (label of issue.labels; track label) {
                  <span class="ts-label">#{{ label }}</span>
                }
              </dd>
            }
          </dl>
        </aside>
      </div>
    } @else if (facade.error(); as error) {
      <pi-note
        gap="xs"
        status="error"
        appearance="fill"
        type="status"
        title="No se pudo abrir el ticket"
        [text]="error"
      />
    } @else {
      <pi-skeleton shape="text" [lines]="8" />
    }

    <ng-template #reasonForm>
      <form
        class="ts-form"
        (submit)="$event.preventDefault(); confirmMove()"
        novalidate
      >
        <p class="ts-muted">
          Explica el motivo: quedará en el historial del ticket.
        </p>
        <pi-textarea
          [formField]="reason.text"
          placeholder="Qué ha fallado y cómo reproducirlo"
        >
          <pi-label [isRequired]="true">Motivo</pi-label>
        </pi-textarea>
        <pi-action-button
          size="w100"
          color="primary"
          text="Mover"
          [disabled]="reason().invalid()"
          (execute)="confirmMove()"
        />
      </form>
    </ng-template>

    <ng-template #editForm>
      <form
        class="ts-form"
        (submit)="$event.preventDefault(); saveEdit()"
        novalidate
      >
        <pi-text-field [formField]="edit.title">
          <pi-label [isRequired]="true">Título</pi-label>
        </pi-text-field>
        <pi-textarea [formField]="edit.description">
          <pi-label>Descripción</pi-label>
        </pi-textarea>
        <pi-text-field [formField]="edit.labels" placeholder="safari, checkout">
          <pi-label>Etiquetas (separadas por comas)</pi-label>
        </pi-text-field>
        <pi-text-field
          [formField]="edit.figmaUrl"
          placeholder="https://www.figma.com/design/…"
        >
          <pi-label>Frame de Figma</pi-label>
        </pi-text-field>
        <pi-action-button
          size="w100"
          color="primary"
          text="Guardar"
          [disabled]="edit().invalid()"
          (execute)="saveEdit()"
        />
      </form>
    </ng-template>

    <ng-template #commentEditForm>
      <form
        class="ts-form"
        (submit)="$event.preventDefault(); saveComment()"
        novalidate
      >
        <pi-textarea [formField]="commentEdit.body" />
        <pi-action-button
          size="w100"
          color="primary"
          text="Guardar"
          [disabled]="commentEdit().invalid()"
          (execute)="saveComment()"
        />
      </form>
    </ng-template>
  `,
})
export class IssuePage {
  /** Route param (`withComponentInputBinding`). */
  readonly issueKey = input.required<string>();

  protected readonly facade = inject(IssueFacade);
  protected readonly project = inject(ProjectFacade);
  private readonly drawer = inject(DrawerService);
  private readonly reasonForm =
    viewChild.required<TemplateRef<unknown>>('reasonForm');
  private readonly editForm =
    viewChild.required<TemplateRef<unknown>>('editForm');
  private readonly commentEditForm =
    viewChild.required<TemplateRef<unknown>>('commentEditForm');

  protected readonly type = computed(() =>
    typeLook(this.project.workflow(), this.facade.issue()?.type ?? ''),
  );
  protected readonly status = computed(() =>
    statusLook(this.project.workflow(), this.facade.issue()?.status ?? ''),
  );
  protected readonly ago = timeAgo;

  protected readonly assigneeOptions = computed<PiSelectFieldOption<string>[]>(
    () => [
      { value: NONE, label: 'Sin asignar' },
      ...this.project
        .members()
        .map((m) => ({ value: m.user.id, label: m.user.name })),
    ],
  );
  protected readonly releaseOptions = computed<PiSelectFieldOption<string>[]>(
    () => [
      { value: NONE, label: 'Sin release' },
      ...this.project
        .releases()
        .filter(
          (r) =>
            r.status === ReleaseStatus.PLANNED ||
            r.id === this.facade.issue()?.release?.id,
        )
        .map((r) => ({ value: r.id, label: r.name })),
    ],
  );
  protected readonly priorityOptions = options(PRIORITY);
  /** Active values, plus the ticket's own even if archived since. */
  protected readonly typeOptions = computed<PiSelectFieldOption<string>[]>(
    () => {
      const workflow = this.project.workflow();
      const current = this.facade.issue()?.type;
      return workflow.settings.issueTypes
        .filter((t) => !t.archived || t.id === current)
        .map((t) => ({ value: t.id, label: t.name }));
    },
  );
  protected readonly areaOptions = computed<PiSelectFieldOption<string>[]>(
    () => {
      const workflow = this.project.workflow();
      const current = this.facade.issue()?.area;
      return [
        { value: NONE, label: 'Sin área' },
        ...workflow.settings.areas
          .filter((a) => !a.archived || a.id === current)
          .map((a) => ({ value: a.id, label: a.name })),
      ];
    },
  );
  protected readonly linkTypeOptions = (
    Object.keys(LINK) as IssueLinkType[]
  ).map((value) => ({
    value,
    label: LINK[value].outward,
  }));

  // Inline forms: plain signals (a required validator would flag them red right after submitting).
  protected readonly linkType = signal<string | null>(IssueLinkType.RELATES_TO);
  protected readonly linkTarget = signal('');
  protected readonly commentBody = signal('');

  private pendingStatus: string | null = null;
  private readonly reasonModel = signal({ text: '' });
  protected readonly reason = form(this.reasonModel, (p) => required(p.text));

  private readonly editModel = signal({
    title: '',
    description: '',
    labels: '',
    figmaUrl: '',
  });
  protected readonly edit = form(this.editModel, (p) => required(p.title));

  private editingComment: string | null = null;
  private readonly commentEditModel = signal({ body: '' });
  protected readonly commentEdit = form(this.commentEditModel, (p) =>
    required(p.body),
  );

  constructor() {
    effect(() => this.facade.open(this.issueKey()));
  }

  protected statusLabel = (status: string) =>
    statusLook(this.project.workflow(), status).label;
  protected statusTone = (status: string) =>
    statusLook(this.project.workflow(), status).tone;
  protected readonly initialsOf = initials;
  protected readonly clock = clock;
  protected linkLabel = (link: IssueLink) =>
    link.direction === 'OUTWARD'
      ? LINK[link.type].outward
      : LINK[link.type].inward;

  protected move(to: string): void {
    if (this.project.workflow().requiresReason(to)) {
      this.pendingStatus = to;
      this.reasonModel.set({ text: '' });
      this.drawer.open(`Mover a «${this.statusLabel(to)}»`, this.reasonForm());
      return;
    }
    this.facade.changeStatus(to);
  }

  protected confirmMove(): void {
    if (!this.pendingStatus || this.reason().invalid()) return;
    this.facade.changeStatus(this.pendingStatus, this.reasonModel().text);
    this.pendingStatus = null;
    this.drawer.closeAll();
  }

  protected assign(assigneeId: string | null): void {
    this.facade.assign(assigneeId || null);
  }

  protected setRelease(releaseId: string | null): void {
    this.facade.setRelease(releaseId || null);
  }

  protected update(changes: {
    type?: string;
    priority?: IssuePriority;
    area?: string | null;
  }): void {
    this.facade.update(changes);
  }

  protected link(): void {
    const targetKey = this.linkTarget().trim();
    if (!targetKey) return;
    this.facade.link(
      (this.linkType() ?? IssueLinkType.RELATES_TO) as IssueLinkType,
      targetKey,
    );
    this.linkTarget.set('');
  }

  protected unlink(link: IssueLink): void {
    this.facade.unlink(link);
  }

  protected addComment(): void {
    const body = this.commentBody().trim();
    if (!body) return;
    this.facade.addComment(body);
    this.commentBody.set('');
  }

  protected openEditComment(comment: Comment): void {
    this.editingComment = comment.id;
    this.commentEditModel.set({ body: comment.body });
    this.drawer.open('Editar comentario', this.commentEditForm());
  }

  protected saveComment(): void {
    if (!this.editingComment || this.commentEdit().invalid()) return;
    this.facade.editComment(this.editingComment, this.commentEditModel().body);
    this.drawer.closeAll();
  }

  protected deleteComment(comment: Comment): void {
    if (confirm('¿Eliminar este comentario?'))
      this.facade.deleteComment(comment.id);
  }

  protected openEdit(): void {
    const issue = this.facade.issue();
    if (!issue) return;
    this.editModel.set({
      title: issue.title,
      description: issue.description ?? '',
      labels: issue.labels.join(', '),
      figmaUrl: issue.figmaUrl ?? '',
    });
    this.drawer.open(`Editar ${issue.key}`, this.editForm(), '36rem');
  }

  protected saveEdit(): void {
    if (this.edit().invalid()) return;
    const v = this.editModel();
    this.facade.update({
      title: v.title,
      description: v.description || null,
      labels: v.labels
        .split(',')
        .map((l) => l.trim())
        .filter(Boolean),
      figmaUrl: v.figmaUrl || null,
    });
    this.drawer.closeAll();
  }
}