import axios, { AxiosRequestConfig, type AxiosInstance } from 'axios';
import { HttpProxyAgent } from 'http-proxy-agent';
import { HttpsProxyAgent } from 'https-proxy-agent';
import { SocksProxyAgent } from 'socks-proxy-agent';
import type { ProxyInfo } from './types';

export class ProxyManager {
  /**
   * Determine if we should use Bun fetch (HTTP/HTTPS) or Axios (SOCKS)
   */
  static shouldUseBunFetch(proxy: ProxyInfo): boolean {
    return proxy.protocol === 'http' || proxy.protocol === 'https';
  }
  /**
   * Create proxy URL for both Bun fetch and Axios proxy agents
   */
  static createProxyUrl(proxy: ProxyInfo): string {
    const { protocol, host, port, username, password } = proxy;
    if (username && password) {
      return `${protocol}://${encodeURIComponent(username)}:${encodeURIComponent(password)}@${host}:${port}`;
    }
    return `${protocol}://${host}:${port}`;
  }

  /**
   * Create appropriate agent for Axios based on proxy type
   */
  static createProxyAgent(proxy: ProxyInfo) {
    this.validateConfig(proxy);

    const proxyUrl = this.createProxyUrl(proxy);
    switch (proxy.protocol) {
      case 'socks4':
      case 'socks5':
        // console.log(`Using SOCKS proxy: ${proxyUrl}`);
        return new SocksProxyAgent(proxyUrl);
      case 'http':
        return new HttpProxyAgent(proxyUrl);
      case 'https':
        return new HttpsProxyAgent(proxyUrl);
      default:
        throw new Error(`Unsupported proxy protocol: ${proxy.protocol}`);
    }
  }
  /**
   * Create Axios instance with proxy configuration
   */
  static createAxiosConfig(proxy: ProxyInfo): AxiosRequestConfig {
    const agent = this.createProxyAgent(proxy);
    return {
      httpAgent: agent,
      httpsAgent: agent,
    };
  }
  /**
   * Simple proxy config validation
   */
  static validateConfig(proxy: ProxyInfo): void {
    if (!proxy.host || !proxy.port) {
      throw new Error('Proxy host and port are required');
    }
    if (!['http', 'https', 'socks4', 'socks5'].includes(proxy.protocol)) {
      throw new Error(`Unsupported proxy protocol: ${proxy.protocol}`);
    }
  }
}