import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable, BehaviorSubject } from 'rxjs';
import { User } from '../../models/user.model';

@Injectable({
  providedIn: 'root'
})
export class UserService {
  private baseUrl = 'http://localhost:8085/api/users';

  // Reactive session stream holding the active parsed user object or null if guest
  private currentSessionSubject = new BehaviorSubject<any>(null);
  public currentSession$ = this.currentSessionSubject.asObservable();

  constructor(private http: HttpClient) {
    // Automatically initialize stream status from storage on application startup boot phase
    this.loadInitialSession();
  }

  private loadInitialSession(): void {
    const activeSessionStr = localStorage.getItem('nexus_mock_session');
    if (activeSessionStr) {
      try {
        this.currentSessionSubject.next(JSON.parse(activeSessionStr));
      } catch (e) {
        console.error('Initial session recovery failed:', e);
      }
    }
  }

  // Notifies all reactive stream observers across the system that a new identity is confirmed
  updateSessionState(sessionData: any): void {
    localStorage.setItem('nexus_mock_session', JSON.stringify(sessionData));
    this.currentSessionSubject.next(sessionData);
  }

  // Clear tracking tokens and broadcast the null context downstream to trigger logout transitions
  clearSessionState(): void {
    localStorage.removeItem('nexus_mock_session');
    this.currentSessionSubject.next(null);
  }

  register(userData: User): Observable<User> {
    return this.http.post<User>(`${this.baseUrl}/register`, userData);
  }

  login(credentials: { email: any; password: any }): Observable<User> {
    return this.http.post<User>(`${this.baseUrl}/login`, {
      email: credentials.email,
      password: credentials.password
    });
  }

  getUserById(userId: number): Observable<User> {
    return this.http.get<User>(`${this.baseUrl}/${userId}`);
  }

// Initiates Stripe Checkout compiler sequences by fetching the dynamic mapping redirect URL
  createStripeSession(userId: number, amount: number): Observable<{ url: string }> {
    return this.http.post<{ url: string }>('http://localhost:8085/api/payment/create-checkout-session', {
      userId: userId,
      amount: amount
    });
  }

  // Requests the operational simulation pipeline wrapper to instantly verify balance records
  simulateWebhookPayment(userId: number, amount: number): Observable<any> {
    return this.http.post('http://localhost:8085/api/payment/simulate-success-webhook', {
      userId: userId,
      amount: amount
    });
  }
}