import { Injectable } from '@angular/core';
import { HttpClient, HttpParams } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Category, Item } from '../models';
import { environment } from '../../environments/environment';

@Injectable({
  providedIn: 'root'
})
export class ApiService {
  private readonly baseUrl = environment.apiUrl;
  private readonly qrBaseUrl = environment.apiUrl;

  constructor(private http: HttpClient) {}

  private normalizeItem(item: Item): Item {
    return {
      ...item,
      remainings: item.remainings || 'high'
    };
  }

  private normalizeItems(items: Item[] | null | undefined): Item[] {
    if (!items || !Array.isArray(items)) {
      return [];
    }
    return items.map(item => this.normalizeItem(item));
  }

  ping(): Observable<{ message: string }> {
    return this.http.get<{ message: string }>(`${this.baseUrl}/ping`);
  }

  getCategories(): Observable<Category[]> {
    return this.http.get<Category[]>(`${this.baseUrl}/category`);
  }

  getCategoryItems(categoryID: number, count: number = 50, skip: number = 0): Observable<Item[]> {
    const params = new HttpParams()
      .set('count', count.toString())
      .set('skip', skip.toString());
    return this.http.get<Item[]>(`${this.baseUrl}/category/${categoryID}`, { params })
      .pipe(map(items => this.normalizeItems(items)));
  }

  getItem(itemID: number): Observable<Item> {
    return this.http.get<Item>(`${this.baseUrl}/item/${itemID}`)
      .pipe(map(item => this.normalizeItem(item)));
  }

  searchItems(search: string, count: number = 50, skip: number = 0): Observable<{ items: Item[], total: number }> {
    const params = new HttpParams()
      .set('search', search)
      .set('count', count.toString())
      .set('skip', skip.toString());
    return this.http.get<{ items: Item[], total: number, count: number, skip: number }>(`${this.baseUrl}/searchitems`, { params })
      .pipe(
        map(response => ({
          items: this.normalizeItems(response?.items || []),
          total: response?.total || 0
        }))
      );
  }

  addToCart(itemID: number, quantity: number = 1): Observable<{ message: string }> {
    return this.http.post<{ message: string }>(`${this.baseUrl}/cart`, { itemID, quantity });
  }

  updateCartQuantity(itemID: number, quantity: number): Observable<{ message: string }> {
    return this.http.patch<{ message: string }>(`${this.baseUrl}/cart`, { itemID, quantity });
  }

  removeFromCart(itemIDs: number[]): Observable<{ message: string }> {
    return this.http.delete<{ message: string }>(`${this.baseUrl}/cart`, { body: itemIDs });
  }

  getCart(): Observable<Item[]> {
    return this.http.get<Item[]>(`${this.baseUrl}/cart`)
      .pipe(map(items => this.normalizeItems(items)));
  }

  // Review submission
  submitReview(reviewData: {
    itemID: number;
    rating: number;
    comment: string;
    username: string | null;
    userId: number | null;
    timestamp: string;
  }): Observable<{ message: string }> {
    return this.http.post<{ message: string }>(`${this.baseUrl}/comment`, reviewData);
  }

  // Payment - SBP Integration
  createPayment(paymentData: {
    amount: number;
    currency: string;
    siteuserID: string;
    siteorderID: string;
    redirectUrl: string;
    telegramUsername: string;
    items: Array<{ itemID: number; price: number; name: string }>;
  }): Observable<{
    qrId: string;
    qrStatus: string;
    qrExpirationDate: string;
    payload: string;
    qrUrl: string;
  }> {
    return this.http.post<{
      qrId: string;
      qrStatus: string;
      qrExpirationDate: string;
      payload: string;
      qrUrl: string;
    }>(`${this.baseUrl}/cart`, paymentData);
  }

  checkPaymentStatus(qrId: string): Observable<{
    additionalInfo: string;
    paymentPurpose: string;
    amount: number;
    code: string;
    createDate: string;
    currency: string;
    order: string;
    paymentStatus: string;
    qrId: string;
    transactionDate: string;
    transactionId: number;
    qrExpirationDate: string;
    phoneNumber: string;
  }> {
    return this.http.get<{
      additionalInfo: string;
      paymentPurpose: string;
      amount: number;
      code: string;
      createDate: string;
      currency: string;
      order: string;
      paymentStatus: string;
      qrId: string;
      transactionDate: string;
      transactionId: number;
      qrExpirationDate: string;
      phoneNumber: string;
    }>(`${this.qrBaseUrl}/qr/payment/${qrId}`);
  }

  submitPurchaseEmail(emailData: {
    email: string;
    telegramUserId: string | null;
    items: Array<{ itemID: number; name: string; price: number; currency: string }>;
  }): Observable<{ message: string }> {
    return this.http.post<{ message: string }>(`${this.baseUrl}/purchase-email`, emailData);
  }

  getRandomItems(count: number = 5, categoryID?: number): Observable<Item[]> {
    let params = new HttpParams().set('count', count.toString());
    if (categoryID) {
      params = params.set('category', categoryID.toString());
    }
    return this.http.get<Item[]>(`${this.baseUrl}/randomitems`, { params })
      .pipe(map(items => this.normalizeItems(items)));
  }
}