import { Component, ChangeDetectionStrategy, Input, Injector, Signal, inject, effect, OnDestroy, OnInit } from '@angular/core';
import { AuthService } from '../../services/auth.service';
import { AdminAuthService } from '../../core/admin-auth/admin-auth.service';
import { TranslatePipe } from '../../i18n/translate.pipe';
import { QrLoginEngine } from '../../shared/qr-login/qr-login.engine';
import { QrLoginAdapter, QrLoginStatus } from '../../shared/qr-login/qr-login.model';
import { AuthSession } from '../../models/auth.model';

/**
 * The one QR-login dialog, reused as-is for both customer and admin login.
 * `mode` only decides which session service/storage backs it (AuthService's
 * customer session vs AdminAuthService's admin session) - the QR creation,
 * polling, expiry, and "return from Telegram app" logic (QrLoginEngine) and
 * the API call underneath it (TelegramSessionApiService) are identical for
 * both, by design: there is one Telegram QR/session backend, not two.
 */
@Component({
  selector: 'app-telegram-login',
  imports: [TranslatePipe],
  templateUrl: './telegram-login.component.html',
  styleUrls: ['./telegram-login.component.scss'],
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class TelegramLoginComponent implements OnInit, OnDestroy {
  @Input() mode: 'customer' | 'admin' = 'customer';

  private readonly customerAuth = inject(AuthService);
  private readonly adminAuth = inject(AdminAuthService);
  private readonly injector = inject(Injector);

  private engine!: QrLoginEngine<AuthSession>;

  showDialog = this.customerAuth.showLoginDialog;
  status = this.customerAuth.status;

  loginUrl!: Signal<string>;
  webSessionID!: Signal<string>;
  qrStatus!: Signal<QrLoginStatus>;
  encodedQrUrl!: Signal<string>;

  ngOnInit(): void {
    const service = this.mode === 'admin' ? this.adminAuth : this.customerAuth;
    this.showDialog = service.showLoginDialog;
    this.status = service.status;

    const adapter: QrLoginAdapter<AuthSession> = this.mode === 'admin'
      ? {
          createSession: () => this.adminAuth.createWebSession(),
          checkSessionOnce: id => this.adminAuth.checkSessionOnce(id),
          isSessionActive: session => !!session?.active,
          getAppLoginUrl: id => this.adminAuth.getAdminAppLoginUrl(id),
          onLoginComplete: () => this.adminAuth.onLoginComplete(),
        }
      : {
          createSession: () => this.customerAuth.createWebSession(),
          checkSessionOnce: id => this.customerAuth.checkSessionOnce(id),
          isSessionActive: session => !!session?.active,
          getAppLoginUrl: id => this.customerAuth.getTelegramAppLoginUrl(id),
          onLoginComplete: () => this.customerAuth.onTelegramLoginComplete(),
        };

    this.engine = new QrLoginEngine<AuthSession>(adapter);
    this.loginUrl = this.engine.loginUrl;
    this.webSessionID = this.engine.webSessionID;
    this.qrStatus = this.engine.qrStatus;
    this.encodedQrUrl = this.engine.encodedQrUrl;

    effect(() => this.engine.setActive(this.showDialog()), { injector: this.injector });
  }

  ngOnDestroy(): void {
    this.engine?.destroy();
  }

  close(): void {
    this.engine.setActive(false);
    (this.mode === 'admin' ? this.adminAuth : this.customerAuth).hideLogin();
  }

  openTelegramLogin(): void {
    this.engine.openAppLogin();
  }

  refreshQr(): void {
    this.engine.refresh();
  }
}