import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { CourierProviderCode } from './courier.constants';

export type XiaofeixiaSignType = 'MD5' | 'HMAC-SHA256';

export interface XiaofeixiaConfig {
  apiUrl: string;
  appId?: string;
  mchId: string;
  apiKey: string;
  signType: XiaofeixiaSignType;
}

export interface CourierIntegrationConfig {
  provider: CourierProviderCode;
  xiaofeixia: XiaofeixiaConfig;
}

@Injectable()
export class CourierConfigService {
  constructor(private readonly config: ConfigService) {}

  load(): CourierIntegrationConfig {
    const providerRaw = (this.config.get<string>('COURIER_PROVIDER') ?? 'xiaofeixia').toLowerCase();
    const provider = this.resolveProvider(providerRaw);

    return {
      provider,
      xiaofeixia: {
        apiUrl:
          this.config.get<string>('XIAOFEIXIA_API_URL') ??
          'https://beta.51xiaoju.cn/app/api/interface.do',
        appId: this.config.get<string>('XIAOFEIXIA_APP_ID') || undefined,
        mchId: this.config.get<string>('XIAOFEIXIA_MCH_ID') ?? '',
        apiKey: this.config.get<string>('XIAOFEIXIA_API_KEY') ?? '',
        signType: this.resolveSignType(this.config.get<string>('XIAOFEIXIA_SIGN_TYPE')),
      },
    };
  }

  private resolveProvider(raw: string): CourierProviderCode {
    switch (raw) {
      case 'xiaofeixia':
        return CourierProviderCode.XIAOFEIXIA;
      case 'sf':
        return CourierProviderCode.SF;
      case 'jd':
        return CourierProviderCode.JD;
      default:
        throw new Error(`Unsupported COURIER_PROVIDER: ${raw}`);
    }
  }

  private resolveSignType(raw?: string): XiaofeixiaSignType {
    if (raw?.toUpperCase() === 'HMAC-SHA256') {
      return 'HMAC-SHA256';
    }
    return 'MD5';
  }
}