import { ChangeDetectionStrategy, Component, computed, inject, signal } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { Router, RouterLink } from '@angular/router';
import { MatIconModule } from '@angular/material/icon';
import { ApiService } from '../../core/api.service';
import { AuthService } from '../../core/auth.service';
import { errorText } from '../../core/models';
import { AuthFrameComponent } from './auth-frame.component';

const NAME = /^[a-z0-9]([a-z0-9._-]{0,62}[a-z0-9])?$/;

@Component({
  selector: 'app-register',
  imports: [FormsModule, RouterLink, MatIconModule, AuthFrameComponent],
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <app-auth-frame title="NEW MAILBOX" subtitle="Pick an address — you are logged in right away">
      @if (!loaded()) {
        <p class="text-slate-400 font-mono text-sm">Loading…</p>
      } @else if (!enabled()) {
        <p class="text-slate-300 font-rajdhani mb-4">Registration is closed on this server. Ask the administrator for a mailbox.</p>
        <a routerLink="/login" class="cyber-btn w-full py-2.5 rounded-xl font-bold text-sm"><mat-icon>arrow_back</mat-icon> BACK TO LOGIN</a>
      } @else {
        <form (ngSubmit)="submit()" class="space-y-4">
          <div>
            <label class="synth-label" for="local">Address</label>
            <div class="flex items-stretch gap-2">
              <input id="local" name="local" class="synth-input" [ngModel]="local()" (ngModelChange)="local.set($event.toLowerCase())"
                     required autocomplete="username" placeholder="name" aria-describedby="local-hint">
              <span class="flex items-center text-cyan-300 font-mono">&#64;</span>
              @if (domains().length > 1) {
                <select name="domain" class="synth-input !w-auto" [ngModel]="domain()" (ngModelChange)="domain.set($event)"
                        aria-label="Domain">
                  @for (d of domains(); track d) { <option [value]="d">{{ d }}</option> }
                </select>
              } @else {
                <span class="flex items-center px-3 rounded-[10px] bg-slate-900/70 border border-cyan-500/30 font-mono text-sm text-slate-200">
                  {{ domain() }}
                </span>
              }
            </div>
            <p id="local-hint" class="mt-1 text-[11px] font-mono" [class]="localValid() || !local() ? 'text-slate-500' : 'text-pink-400'">
              Letters, digits, dot, dash, underscore
            </p>
          </div>
          <div>
            <label class="synth-label" for="name">Your name (shown to recipients)</label>
            <input id="name" name="name" class="synth-input" [(ngModel)]="displayName" maxlength="100" autocomplete="name">
          </div>
          <div>
            <label class="synth-label" for="password">Password (8+ characters)</label>
            <div class="relative"><input id="password" name="password" [type]="show() ? 'text' : 'password'" class="synth-input pr-10" [ngModel]="password()"
                   (ngModelChange)="password.set($event)" required minlength="8" autocomplete="new-password">
            <button type="button" class="absolute right-2 top-1/2 -translate-y-1/2 text-slate-400 hover:text-cyan-300"
                    [attr.aria-label]="show() ? 'Hide password' : 'Show password'" (click)="show.set(!show())">
              <mat-icon>{{ show() ? 'visibility_off' : 'visibility' }}</mat-icon>
            </button></div>
          </div>
          <div>
            <label class="synth-label" for="password2">Password again</label>
            <div class="relative"><input id="password2" name="password2" [type]="show() ? 'text' : 'password'" class="synth-input pr-10" [ngModel]="password2()"
                   (ngModelChange)="password2.set($event)" required autocomplete="new-password">
            <button type="button" class="absolute right-2 top-1/2 -translate-y-1/2 text-slate-400 hover:text-cyan-300"
                    [attr.aria-label]="show() ? 'Hide password' : 'Show password'" (click)="show.set(!show())">
              <mat-icon>{{ show() ? 'visibility_off' : 'visibility' }}</mat-icon>
            </button></div>
          </div>
          @if (error()) {
            <p class="text-sm text-pink-400 font-rajdhani flex items-center gap-2" role="alert">
              <mat-icon class="!text-lg">error</mat-icon>{{ error() }}
            </p>
          }
          <button type="submit" class="cyber-btn w-full py-2.5 rounded-xl font-bold text-sm" [disabled]="busy()">
            <mat-icon>person_add</mat-icon> {{ busy() ? 'CREATING…' : 'CREATE MAILBOX' }}
          </button>
        </form>
        <p class="mt-6 text-center text-sm text-slate-400 font-rajdhani">
          Have a mailbox? <a routerLink="/login" class="text-cyan-300 hover:text-pink-400 font-semibold">Log in</a>
        </p>
      }
    </app-auth-frame>
  `
})
export class RegisterPage {
  private auth = inject(AuthService);
  private router = inject(Router);

  readonly loaded = signal(false);
  readonly enabled = signal(false);
  readonly show = signal(false);
  readonly domains = signal<string[]>([]);
  readonly domain = signal('');
  readonly local = signal('');
  readonly password = signal('');
  readonly password2 = signal('');
  displayName = '';
  readonly busy = signal(false);
  readonly error = signal('');
  readonly localValid = computed(() => NAME.test(this.local()));

  constructor() {
    inject(ApiService).config().subscribe({
      next: c => {
        this.enabled.set(c.registrationEnabled);
        this.domains.set(c.domains);
        this.domain.set(c.domains[0] ?? '');
        this.loaded.set(true);
      },
      error: e => { this.loaded.set(true); this.error.set(errorText(e)); }
    });
  }

  submit(): void {
    const problem = !this.localValid() ? 'The address: letters, digits, dot, dash, underscore'
      : this.password().length < 8 ? 'The password is shorter than 8 characters'
      : this.password() !== this.password2() ? 'The passwords do not match' : '';
    if (problem) {
      this.error.set(problem);
      return;
    }
    this.busy.set(true);
    this.error.set('');
    this.auth.register(`${this.local()}@${this.domain()}`, this.password(), this.displayName.trim()).subscribe({
      next: () => this.router.navigate(['/']),
      error: e => { this.busy.set(false); this.error.set(errorText(e)); }
    });
  }
}