import { Injectable, Logger } from '@nestjs/common';
import { HttpService } from '@nestjs/axios';
import { ConfigService } from '@nestjs/config';
import { publicEncrypt, constants } from 'crypto';
import { firstValueFrom } from 'rxjs';

@Injectable()
export class ExternalServicesService {
    private readonly logger = new Logger(ExternalServicesService.name);
    private readonly publicKey: string;
    private readonly coreApiUrl: string;

    constructor(
        private readonly httpService: HttpService,
        private readonly configService: ConfigService,
    ) {
        const b64Key = this.configService.get<string>('RSA_PUBLIC_KEY_BASE64');
        if (b64Key) {
            try {
                this.publicKey = Buffer.from(b64Key, 'base64').toString('utf-8');
            } catch (e) {
                this.logger.error('Failed to decode RSA Public Key', e);
            }
        } else {
            this.logger.warn('RSA_PUBLIC_KEY_BASE64 is missing');
        }

        this.coreApiUrl = this.configService.get<string>('CORE_API_URL') || 'http://localhost:8521';
    }

    async saveStripeKey(rawSecret: string, authHeader: string) {
        if (!this.publicKey) {
            throw new Error('RSA Public Key is not configured in Backoffice');
        }

        try {
            const encrypted = publicEncrypt(
                {
                    key: this.publicKey,
                    padding: constants.RSA_PKCS1_OAEP_PADDING,
                    oaepHash: 'sha256',
                },
                Buffer.from(rawSecret, 'utf-8')
            );

            const encryptedBase64 = encrypted.toString('base64');

            // Send to Core API
            const response = await firstValueFrom(
                this.httpService.post(
                    `${this.coreApiUrl}/api/v1/system/credentials`,
                    {
                        serviceName: 'stripe',
                        encryptedPayload: encryptedBase64,
                    },
                    {
                        headers: {
                            Authorization: authHeader,
                        },
                    }
                )
            );

            return response.data;
        } catch (error) {
            this.logger.error('Failed to save Stripe key', error);
            throw error;
        }
    }
}