paystack-client.ts

import { PaystackResponse, PaystackError } from "./types";
import { createPaystackConfig } from "./config";

const PAYSTACK_BASE_URL = 'https://api.paystack.co';
const USER_AGENT = process.env.USER_AGENT || 'Paystack-MCP-Server/0.0.1';

export class PaystackClient {
  private baseUrl: string;
  private secretKey: string;
  private userAgent: string;
  private timeout: number;

  constructor(
    secretKey: string,
    baseUrl: string = PAYSTACK_BASE_URL,
    userAgent: string = USER_AGENT,
    timeout: number = 30000
  ) {
    if (!secretKey) {
      throw new Error("Paystack secret key is required");
    }

    this.secretKey = secretKey;
    this.baseUrl = baseUrl;
    this.userAgent = userAgent;
    this.timeout = timeout;
  }

  /**
   * Make an HTTP request to Paystack API
   * @param method - HTTP method (GET, POST, PUT, DELETE, etc.)
   * @param endpoint - API endpoint path
   * @param data - Request body for POST/PUT/PATCH or query params for GET
   */

  async makeRequest<T>(
    method: string,
    endpoint: string,
    data?: any
  ): Promise<PaystackResponse<T>> {

    let url = `${this.baseUrl}${endpoint}`;

    const headers: Record<string, string> = {
      'Authorization': `Bearer ${this.secretKey}`,
      'User-Agent': this.userAgent,
      'Accept': 'application/json',
    };

    const options: RequestInit = {
      method: method.toUpperCase()
    };

    // Add Content-Type and body for requests with data
    if (data && ['POST', 'PUT', 'DELETE', 'PATCH'].includes(method.toUpperCase())) {
      headers['Content-Type'] = 'application/json';
      options.body = JSON.stringify(data);
    }
    options.headers = headers;

    try {
      const response = await fetch(url, options);

      // Parse response
      const responseText = await response.text();
      let responseData: PaystackResponse<T> | PaystackError;

      try {
        responseData = JSON.parse(responseText);
      } catch (parseError) {
        // Handle non-JSON responses gracefully (e.g., HTML error pages from API gateways)
        const responseSnippet = responseText.length > 200 
          ? responseText.substring(0, 200) + '...' 
          : responseText;
        const errorMessage = `Received non-JSON response from server (HTTP ${response.status}): ${responseSnippet}`;
        const nonJsonError = new Error(errorMessage);
        (nonJsonError as any).statusCode = response.status;
        (nonJsonError as any).responseText = responseText;
        throw nonJsonError;
      }
      return responseData as PaystackResponse<T>;
    } catch (error) {

      if (error !== null && (error as any).name === 'NetworkError') {
        const timeoutError = new Error(`Request timeout after ${this.timeout} ms`);
        (timeoutError as any).statusCode = 408;
        throw timeoutError;
      }
      throw error;
    }

}
}

/**
 * Create a PaystackClient instance with configuration
 */
export function createPaystackClient(cliApiKey?: string): PaystackClient {
  const config = createPaystackConfig(cliApiKey);
  return new PaystackClient(config.secretKey, config.baseURL, undefined, config.timeout);
}