import * as plugins from './plugins.js';
import * as types from './types.js';
import { SmartResponse } from './response.js';

// Keep-alive agents for connection pooling
const httpAgent = new plugins.agentkeepalive({
  keepAlive: true,
  maxFreeSockets: 10,
  maxSockets: 100,
  maxTotalSockets: 1000,
});

const httpAgentKeepAliveFalse = new plugins.agentkeepalive({
  keepAlive: false,
});

const httpsAgent = new plugins.agentkeepalive.HttpsAgent({
  keepAlive: true,
  maxFreeSockets: 10,
  maxSockets: 100,
  maxTotalSockets: 1000,
});

const httpsAgentKeepAliveFalse = new plugins.agentkeepalive.HttpsAgent({
  keepAlive: false,
});

/**
 * Tests if a URL is a unix socket
 */
export const isUnixSocket = (url: string): boolean => {
  const unixRegex = /^(http:\/\/|https:\/\/|)unix:/;
  return unixRegex.test(url);
};

/**
 * Parses socket path and route from unix socket URL
 */
export const parseUnixSocketUrl = (url: string): { socketPath: string; path: string } => {
  const parseRegex = /(.*):(.*)/;
  const result = parseRegex.exec(url);
  return {
    socketPath: result[1],
    path: result[2],
  };
};


/**
 * Core request function that handles all HTTP/HTTPS requests
 */
export async function coreRequest(
  urlArg: string,
  optionsArg: types.ICoreRequestOptions = {},
  requestDataFunc: ((req: plugins.http.ClientRequest) => void) | null = null
): Promise<plugins.http.IncomingMessage> {
  const done = plugins.smartpromise.defer<plugins.http.IncomingMessage>();

  // No defaults - let users explicitly set options to match fetch behavior

  // Parse URL
  const parsedUrl = plugins.smarturl.Smarturl.createFromUrl(urlArg, {
    searchParams: optionsArg.queryParams || {},
  });
  
  optionsArg.hostname = parsedUrl.hostname;
  if (parsedUrl.port) {
    optionsArg.port = parseInt(parsedUrl.port, 10);
  }
  optionsArg.path = parsedUrl.path;

  // Handle unix socket URLs
  if (isUnixSocket(urlArg)) {
    const { socketPath, path } = parseUnixSocketUrl(optionsArg.path);
    optionsArg.socketPath = socketPath;
    optionsArg.path = path;
  }

  // Determine agent based on protocol and keep-alive setting
  if (!optionsArg.agent) {
    // Only use keep-alive agents if explicitly requested
    if (optionsArg.keepAlive === true) {
      optionsArg.agent = parsedUrl.protocol === 'https:' ? httpsAgent : httpAgent;
    } else if (optionsArg.keepAlive === false) {
      optionsArg.agent = parsedUrl.protocol === 'https:' ? httpsAgentKeepAliveFalse : httpAgentKeepAliveFalse;
    }
    // If keepAlive is undefined, don't set any agent (more fetch-like behavior)
  }

  // Determine request module
  const requestModule = parsedUrl.protocol === 'https:' ? plugins.https : plugins.http;

  if (!requestModule) {
    throw new Error(`The request to ${urlArg} is missing a viable protocol. Must be http or https`);
  }

  // Perform the request
  const request = requestModule.request(optionsArg, async (response) => {
    // Handle hard timeout
    if (optionsArg.hardDataCuttingTimeout) {
      setTimeout(() => {
        response.destroy();
        done.reject(new Error('Request timed out'));
      }, optionsArg.hardDataCuttingTimeout);
    }

    // Always return the raw stream
    done.resolve(response);
  });

  // Write request body
  if (optionsArg.requestBody) {
    if (optionsArg.requestBody instanceof plugins.formData) {
      optionsArg.requestBody.pipe(request).on('finish', () => {
        request.end();
      });
    } else {
      // Write body as-is - caller is responsible for serialization
      const bodyData = typeof optionsArg.requestBody === 'string' 
        ? optionsArg.requestBody 
        : optionsArg.requestBody instanceof Buffer 
          ? optionsArg.requestBody
          : JSON.stringify(optionsArg.requestBody); // Still stringify for backward compatibility
      request.write(bodyData);
      request.end();
    }
  } else if (requestDataFunc) {
    requestDataFunc(request);
  } else {
    request.end();
  }

  // Handle request errors
  request.on('error', (e) => {
    console.error(e);
    request.destroy();
    done.reject(e);
  });

  // Get response and handle response errors
  const response = await done.promise;
  response.on('error', (err) => {
    console.error(err);
    response.destroy();
  });

  return response;
}

/**
 * Modern request function that returns a SmartResponse
 */
export async function request(
  urlArg: string,
  optionsArg: types.ICoreRequestOptions = {}
): Promise<SmartResponse> {
  const response = await coreRequest(urlArg, optionsArg);
  return new SmartResponse(response, urlArg);
}