import { ProxyManager } from '../proxy-manager';
import type { HttpResponse, RequestConfig } from '../types';
import { HttpError } from '../types';
import type { RequestAdapter } from './types';

/**
 * Fetch adapter for HTTP/HTTPS proxies and non-proxy requests
 */
export class FetchAdapter implements RequestAdapter {
  canHandle(config: RequestConfig): boolean {
    // Fetch handles non-proxy requests and HTTP/HTTPS proxies
    if (typeof config.proxy === 'string') {
      return config.proxy.startsWith('http');
    }
    return !config.proxy || config.proxy.protocol === 'http' || config.proxy.protocol === 'https';
  }

  async request<T = any>(config: RequestConfig, signal: AbortSignal): Promise<HttpResponse<T>> {
    const { url, method = 'GET', headers, data, proxy } = config;

    // Prepare fetch options
    const fetchOptions: RequestInit = {
      method,
      headers,
      signal,
    };

    // Add body for non-GET requests
    if (data && method !== 'GET') {
      fetchOptions.body = typeof data === 'string' ? data : JSON.stringify(data);
      if (typeof data === 'object') {
        fetchOptions.headers = { 'Content-Type': 'application/json', ...fetchOptions.headers };
      }
    }

    // Add proxy if needed (using Bun's built-in proxy support)
    if (typeof proxy === 'string') {
      // If proxy is a URL string, use it directly
      (fetchOptions as any).proxy = proxy;
    } else if (proxy) {
      // If proxy is a ProxyInfo object, create a proxy URL
      (fetchOptions as any).proxy = ProxyManager.createProxyUrl(proxy);
    }
    const response = await fetch(url, fetchOptions);

    // Parse response based on content type
    let responseData: T;
    const contentType = response.headers.get('content-type') || '';

    if (contentType.includes('application/json')) {
      responseData = (await response.json()) as T;
    } else {
      responseData = (await response.text()) as T;
    }

    const httpResponse: HttpResponse<T> = {
      data: responseData,
      status: response.status,
      headers: Object.fromEntries(response.headers.entries()),
      ok: response.ok,
    };

    // Throw HttpError for non-2xx status codes
    if (!response.ok) {
      throw new HttpError(
        `Request failed with status ${response.status}`,
        response.status,
        httpResponse
      );
    }

    return httpResponse;
  }
}