import {
  ChangeDetectionStrategy,
  Component,
  OnInit,
  HostListener,
  computed,
  inject,
  signal,
} from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormBuilder, ReactiveFormsModule, Validators } from '@angular/forms';
import { Router } from '@angular/router';
import { AuthService } from '../../core/services/auth.service';
import { BootstrapService } from '../../core/services/bootstrap.service';
import { MarkdownService } from '../../core/services/markdown.service';
import { LandingService } from './landing.service';
import { buildLoginFailureMessage } from './login-modal.service';
import { passwordMatchValidator } from '../setup/setup-create-admin.validators';

type ModalMode = 'closed' | 'login' | 'register';

@Component({
  selector: 'app-landing',
  standalone: true,
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [CommonModule, ReactiveFormsModule],
  templateUrl: './landing.component.html',
  styleUrls: ['./landing.component.css'],
})
export class LandingComponent implements OnInit {
  private readonly fb = inject(FormBuilder);
  private readonly auth = inject(AuthService);
  private readonly router = inject(Router);
  private readonly bootstrap = inject(BootstrapService);
  private readonly markdown = inject(MarkdownService);
  readonly landing = inject(LandingService);

  readonly mode = signal<ModalMode>('closed');
  readonly submitting = signal(false);
  readonly errorText = signal<string | null>(null);
  readonly errorCode = signal<string | null>(null);
  readonly retryAfterSeconds = signal<number | null>(null);

  readonly pageTitle = computed(() => this.bootstrap.payload()?.pageTitle ?? 'HIPCTF');
  readonly logo = computed(() => this.bootstrap.payload()?.logo ?? '');
  readonly welcomeHtml = computed(() => this.markdown.render(this.bootstrap.payload()?.welcomeMarkdown ?? ''));
  readonly registrationsEnabled = computed(
    () => this.bootstrap.payload()?.registrationsEnabled ?? false,
  );

  readonly loginForm = this.fb.nonNullable.group({
    username: this.fb.nonNullable.control('', [Validators.required]),
    password: this.fb.nonNullable.control('', [Validators.required]),
  });

  readonly registerForm = this.fb.nonNullable.group(
    {
      username: this.fb.nonNullable.control('', [
        Validators.required,
        Validators.minLength(3),
        Validators.maxLength(32),
        Validators.pattern(/^[a-zA-Z0-9_.-]+$/),
      ]),
      password: this.fb.nonNullable.control('', [Validators.required]),
      passwordConfirm: this.fb.nonNullable.control('', [Validators.required]),
    },
    { validators: passwordMatchValidator },
  );

  ngOnInit(): void {
    void this.landing.refresh();
    void this.bootstrap.refresh();
  }

  openLogin(): void {
    this.mode.set('login');
    this.clearError();
  }

  openRegister(): void {
    this.mode.set('register');
    this.clearError();
  }

  closeModal(): void {
    if (this.submitting()) return;
    this.mode.set('closed');
    this.clearError();
  }

  switchToLogin(): void {
    this.mode.set('login');
    this.clearError();
  }

  switchToRegister(): void {
    this.mode.set('register');
    this.clearError();
  }

  @HostListener('document:keydown.escape')
  onEscape(): void {
    this.closeModal();
  }

  loginError(): string | null {
    const c = this.loginForm.controls;
    if (!c.username.touched && !c.password.touched) return null;
    if (c.username.errors?.['required']) return 'Username is required';
    if (c.password.errors?.['required']) return 'Password is required';
    return null;
  }

  registerError(): string | null {
    const c = this.registerForm.controls;
    if (!c.username.touched && !c.password.touched && !c.passwordConfirm.touched && !this.registerForm.errors) {
      return null;
    }
    if (c.username.errors?.['required']) return 'Username is required';
    if (c.username.errors?.['minlength']) return 'Username must be at least 3 characters';
    if (c.username.errors?.['maxlength']) return 'Username must be at most 32 characters';
    if (c.username.errors?.['pattern']) {
      return 'Username may only contain letters, digits, dot, dash and underscore';
    }
    if (c.password.errors?.['required']) return 'Password is required';
    if (c.passwordConfirm.errors?.['required']) return 'Please confirm your password';
    if (this.registerForm.errors?.['passwordMismatch']) return 'Passwords do not match';
    return null;
  }

  async submitLogin(): Promise<void> {
    if (this.submitting()) return;
    this.loginForm.markAllAsTouched();
    if (this.loginForm.invalid) return;
    this.submitting.set(true);
    this.clearError();
    const { username, password } = this.loginForm.getRawValue();
    const result: { ok: true; accessToken: string; expiresIn: number; user: any } | {
      ok: false;
      status: number;
      code: string;
      message: string;
    } = await this.auth.login({ username, password });
    this.submitting.set(false);
    if (result.ok === true) {
      this.auth.setSession(result.accessToken, result.user);
      this.mode.set('closed');
      await this.router.navigateByUrl('/');
      return;
    }
    if (result.ok === false) {
      this.showFailure(result.code, result.message);
    }
  }

  async submitRegister(): Promise<void> {
    if (this.submitting()) return;
    this.registerForm.markAllAsTouched();
    if (this.registerForm.invalid) return;
    this.submitting.set(true);
    this.clearError();
    const { username, password, passwordConfirm } = this.registerForm.getRawValue();
    const result: { ok: true; accessToken: string; expiresIn: number; user: any } | {
      ok: false;
      status: number;
      code: string;
      message: string;
    } = await this.auth.register({ username, password, passwordConfirm });
    this.submitting.set(false);
    if (result.ok === true) {
      this.auth.setSession(result.accessToken, result.user);
      this.mode.set('closed');
      await this.router.navigateByUrl('/');
      return;
    }
    if (result.ok === false) {
      this.showFailure(result.code, result.message);
    }
  }

  private showFailure(code: string, message: string): void {
    this.errorCode.set(code);
    const built = buildLoginFailureMessage({ code, message });
    this.errorText.set(built.text);
    this.retryAfterSeconds.set(built.retryAfterSeconds ?? null);
  }

  private clearError(): void {
    this.errorCode.set(null);
    this.errorText.set(null);
    this.retryAfterSeconds.set(null);
  }
}