import { Component, computed, inject, signal } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { ActivatedRoute, Router, RouterLink } from '@angular/router';
import {
  ApiClientService,
  type ApiErrorBody,
  type Permission,
  type RoleDto,
} from '@boilerplate/api-client';
import { adminPermissionGroups } from './admin-permissions';

@Component({
  standalone: true,
  imports: [FormsModule, RouterLink],
  template: `
    <a routerLink="/admin/roles">Zurueck zur Rollenliste</a>

    @if (error(); as currentError) {
      <section class="notice error">
        <strong>{{ messageFor(currentError) }}</strong>
        @if (currentError.requestId) {
          <small>Request-ID: {{ currentError.requestId }}</small>
        }
      </section>
    }

    @if (!loading()) {
      <form class="editor" (ngSubmit)="save()">
        <section>
          <h2>{{ isNew() ? 'Rolle anlegen' : 'Rolle bearbeiten' }}</h2>
          @if (role()?.system) {
            <span class="system">Systemrolle</span>
          }
          <label>
            Name
            <input
              name="name"
              [(ngModel)]="name"
              [readonly]="role()?.system"
              required
              maxlength="80"
            />
          </label>
          <label>
            Beschreibung
            <textarea name="description" [(ngModel)]="description" maxlength="255"></textarea>
          </label>
        </section>

        <section>
          <h3>Permissions</h3>
          <div class="groups">
            @for (group of groups; track group.title) {
              <fieldset>
                <legend>{{ group.title }}</legend>
                @for (permission of group.permissions; track permission.id) {
                  <label>
                    <input
                      type="checkbox"
                      [checked]="selectedPermissions().has(permission.id)"
                      [disabled]="role()?.name === 'admin'"
                      (change)="toggle(permission.id)"
                    />
                    <span>
                      <code>{{ permission.id }}</code>
                      {{ permission.label }}
                    </span>
                  </label>
                }
              </fieldset>
            }
          </div>
        </section>

        <div class="actions">
          <button type="submit" [disabled]="!name.trim()">Speichern</button>
          @if (role(); as currentRole) {
            @if (!currentRole.system) {
              <button type="button" class="danger" (click)="delete(currentRole)">Loeschen</button>
            }
          }
        </div>
      </form>
    } @else {
      <section class="notice">Rolle wird geladen.</section>
    }
  `,
  styles: [
    `
      a {
        display: inline-flex;
        margin-bottom: 16px;
        color: var(--color-primary-hover);
      }
      .notice,
      .editor {
        background: var(--color-surface);
        border: 1px solid var(--color-border);
        border-radius: 8px;
        padding: 16px;
      }
      .notice.error {
        border-color: var(--color-danger);
        color: var(--color-danger);
        margin-bottom: 16px;
      }
      .editor,
      section,
      .groups,
      fieldset,
      .actions {
        display: grid;
        gap: 14px;
      }
      h2,
      h3 {
        margin: 0;
      }
      label {
        display: grid;
        gap: 6px;
      }
      input,
      textarea,
      button {
        min-height: 44px;
      }
      input,
      textarea {
        border: 1px solid var(--color-border);
        border-radius: 6px;
        padding: 8px 10px;
      }
      textarea {
        min-height: 96px;
        resize: vertical;
      }
      button {
        border: 0;
        border-radius: 6px;
        background: var(--color-primary);
        color: var(--color-surface);
        padding: 0 14px;
      }
      button.danger {
        background: var(--color-danger);
      }
      button:disabled {
        opacity: 0.55;
      }
      fieldset {
        border: 1px solid var(--color-border);
        border-radius: 8px;
        padding: 12px;
      }
      fieldset label {
        grid-template-columns: 24px 1fr;
        align-items: start;
      }
      code {
        display: block;
        margin-bottom: 2px;
      }
      .system {
        width: fit-content;
        border: 1px solid var(--color-border);
        border-radius: 999px;
        padding: 4px 8px;
        color: var(--color-text-secondary);
      }
      @media (min-width: 900px) {
        .groups {
          grid-template-columns: 1fr 1fr;
        }
        .actions {
          grid-template-columns: auto auto;
          justify-content: start;
        }
      }
    `,
  ],
})
export class AdminRoleDetailPageComponent {
  private readonly api = inject(ApiClientService);
  private readonly route = inject(ActivatedRoute);
  private readonly router = inject(Router);
  readonly role = signal<RoleDto | null>(null);
  readonly loading = signal(false);
  readonly error = signal<ApiErrorBody | null>(null);
  readonly selectedPermissions = signal(new Set<Permission>());
  readonly groups = adminPermissionGroups;
  readonly isNew = computed(() => this.route.snapshot.paramMap.get('id') === 'new');
  name = '';
  description = '';

  constructor() {
    if (!this.isNew()) this.load();
  }

  load(): void {
    const id = this.route.snapshot.paramMap.get('id');
    if (!id) return;
    this.loading.set(true);
    this.error.set(null);
    this.api.adminRole(id).subscribe({
      next: (role) => {
        this.role.set(role);
        this.name = role.name;
        this.description = role.description;
        this.selectedPermissions.set(new Set(role.permissions.map((permission) => permission.id)));
        this.loading.set(false);
      },
      error: (error: { error?: ApiErrorBody }) => {
        this.error.set(error.error ?? this.genericError());
        this.loading.set(false);
      },
    });
  }

  toggle(permission: Permission): void {
    if (this.role()?.name === 'admin') return;
    const next = new Set(this.selectedPermissions());
    if (next.has(permission)) next.delete(permission);
    else next.add(permission);
    this.selectedPermissions.set(next);
  }

  save(): void {
    const body = {
      name: this.name,
      description: this.description,
      permissions: Array.from(this.selectedPermissions()),
    };
    const request = this.isNew()
      ? this.api.createAdminRole(body)
      : this.api.updateAdminRole(this.role()?.id ?? '', body);
    request.subscribe({
      next: (role) => {
        void this.router.navigate(['/admin/roles', role.id]);
      },
      error: (error: { error?: ApiErrorBody }) =>
        this.error.set(error.error ?? this.genericError()),
    });
  }

  delete(role: RoleDto): void {
    if (!confirm('Rolle wirklich loeschen?')) return;
    this.api.deleteAdminRole(role.id).subscribe({
      next: () => {
        void this.router.navigate(['/admin/roles']);
      },
      error: (error: { error?: ApiErrorBody }) =>
        this.error.set(error.error ?? this.genericError()),
    });
  }

  messageFor(error: ApiErrorBody): string {
    if (error.code === 'ROLE_STILL_ASSIGNED') return 'Diese Rolle ist noch Benutzern zugewiesen.';
    if (error.code === 'SYSTEM_ROLE_PROTECTED') return 'Diese Systemrolle ist geschuetzt.';
    if (error.code === 'LAST_ACTIVE_ADMIN_REQUIRED') {
      return 'Mindestens ein aktiver Administrator muss erhalten bleiben.';
    }
    return error.message;
  }

  private genericError(): ApiErrorBody {
    return {
      status: 0,
      code: 'UNKNOWN',
      message: 'Die Rolle konnte nicht verarbeitet werden.',
      requestId: '',
    };
  }
}