import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { BehaviorSubject, Observable, map, tap } from 'rxjs';
import { AuthResponse, UserInfo } from '../models/auth-response';

@Injectable({ providedIn: 'root' })
export class AuthService {
  private readonly ACCESS_TOKEN_KEY = 'indie_access_token';
  private readonly REFRESH_TOKEN_KEY = 'indie_refresh_token';
  private readonly USER_KEY = 'indie_user';

  private userSubject = new BehaviorSubject<UserInfo | null>(this.loadUser());
  user$ = this.userSubject.asObservable();

  constructor(private http: HttpClient) {}

  register(email: string): Observable<{ message: string }> {
    return this.http.post<{ message: string }>('/api/auth/register', { email });
  }

  login(email: string, password: string): Observable<AuthResponse> {
    return this.http.post<AuthResponse>('/api/auth/login', { email, password })
      .pipe(tap(res => this.setSession(res)));
  }

  refreshToken(refreshToken: string): Observable<AuthResponse> {
    return this.http.post<AuthResponse>('/api/auth/refresh', { refreshToken })
      .pipe(tap(res => this.setSession(res)));
  }

  logout(): Observable<void> {
    return this.http.post<void>('/api/auth/logout', {})
      .pipe(tap(() => this.clearSession()));
  }

  verifyEmail(token: string): Observable<{ message: string; setupToken?: string }> {
    return this.http.post<{ message: string; setupToken?: string }>('/api/auth/verify-email', { token });
  }

  resendVerification(email: string): Observable<{ message: string }> {
    return this.http.post<{ message: string }>('/api/auth/resend-verification', { email });
  }

  setPassword(setupToken: string, password: string, name: string): Observable<void> {
    return this.http.post<void>('/api/auth/set-password', { setupToken, password, name });
  }

  getAccessToken(): string | null {
    return localStorage.getItem(this.ACCESS_TOKEN_KEY);
  }

  getRefreshToken(): string | null {
    return localStorage.getItem(this.REFRESH_TOKEN_KEY);
  }

  getUser(): UserInfo | null {
    return this.userSubject.value;
  }

  isAuthenticated(): boolean {
    return !!this.getAccessToken();
  }

  clearSessionForLogout(): void {
    this.clearSession();
  }

  private setSession(res: AuthResponse): void {
    localStorage.setItem(this.ACCESS_TOKEN_KEY, res.accessToken);
    localStorage.setItem(this.REFRESH_TOKEN_KEY, res.refreshToken);
    localStorage.setItem(this.USER_KEY, JSON.stringify(res.user));
    this.userSubject.next(res.user);
  }

  private clearSession(): void {
    localStorage.removeItem(this.ACCESS_TOKEN_KEY);
    localStorage.removeItem(this.REFRESH_TOKEN_KEY);
    localStorage.removeItem(this.USER_KEY);
    this.userSubject.next(null);
  }

  private loadUser(): UserInfo | null {
    const data = localStorage.getItem(this.USER_KEY);
    return data ? JSON.parse(data) : null;
  }
}