import { Component, inject, signal } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { Router, RouterLink } from '@angular/router';
import { HttpClient } from '@angular/common/http';
import { FastcheckService } from '../../fastcheck.service';
import { FASTCHECK_API } from '../../api';
import { TranslatePipe } from '../../translate/translate.pipe';

interface CreateFastcheckResponse {
  fastcheck: string;
  expiration: string;
  code: string;
  Status: boolean;
}

type PaymentMethod = 'sbp' | 'wechat' | 'visa' | 'master';
type Currency = 'RUB' | 'CNY' | 'USD' | 'EUR' | 'AMD';

@Component({
  selector: 'app-create-page',
  imports: [FormsModule, RouterLink, TranslatePipe],
  templateUrl: './create-page.html',
  styleUrl: './create-page.scss'
})
export class CreatePage {
  private http = inject(HttpClient);
  private store = inject(FastcheckService);
  private router = inject(Router);

  amount = signal<number>(10);
  note = signal<string>('');
  error = signal<string>('');
  loading = signal<boolean>(false);

  payment = signal<PaymentMethod>('sbp');
  currency = signal<Currency>('RUB');

  /** sessionID for the Authorization header. Comes from ?session=... or websession. */
  private get sessionId(): string {
    return new URLSearchParams(window.location.search).get('session') ?? '';
  }

  selectPayment(method: PaymentMethod, enabled: boolean): void {
    if (!enabled) return;
    this.payment.set(method);
  }

  selectCurrency(c: Currency, enabled: boolean): void {
    if (!enabled) return;
    this.currency.set(c);
  }

  createCheck(): void {
    const val = this.amount();
    if (!val || val <= 0) {
      this.error.set('Введите корректную сумму');
      return;
    }

    this.error.set('');
    this.loading.set(true);

    const headers: Record<string, string> = {};
    if (this.sessionId) {
      headers['Authorization'] = JSON.stringify({ sessionID: this.sessionId });
    }

    this.http
      .post<CreateFastcheckResponse>(
        `${FASTCHECK_API}/fastcheck`,
        { amount: val, currency: this.currency() },
        { headers }
      )
      .subscribe({
        next: (res) => {
          this.loading.set(false);
          if (res?.fastcheck) {
            this.store.setCreated({
              fastcheck: res.fastcheck,
              code: res.code,
              amount: val,
              expiration: res.expiration
            });
            this.router.navigate(['/']);
          } else {
            this.error.set('Не удалось создать платёж.');
          }
        },
        error: () => {
          this.loading.set(false);
          this.error.set('Ошибка при создании платежа. Попробуйте ещё раз.');
        }
      });
  }

  onAmountChange(value: number): void {
    this.amount.set(value);
    if (value > 0) this.error.set('');
  }

  onNoteChange(value: string): void {
    this.note.set(value);
  }
}