// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

const {
  ArrayPrototypeIndexOf,
  ArrayPrototypePush,
  ArrayPrototypeShift,
  ArrayPrototypeSplice,
  ArrayPrototypeUnshift,
  FunctionPrototypeCall,
  JSONStringify,
  NumberParseInt,
  ObjectAssign,
  ObjectSetPrototypeOf,
  ReflectApply,
  ReflectConstruct,
  SymbolAsyncDispose,
} = primordials;

const {
  assertCrypto,
  kEmptyObject,
  promisify,
  once,
} = require('internal/util');
const { ERR_PROXY_TUNNEL } = require('internal/errors').codes;
assertCrypto();

const tls = require('tls');
const {
  kProxyConfig,
  checkShouldUseProxy,
  kWaitForProxyTunnel,
  getGlobalAgent,
} = require('internal/http');
const { Agent: HttpAgent } = require('_http_agent');
const {
  httpServerPreClose,
  Server: HttpServer,
  setupConnectionsTracking,
  storeHTTPOptions,
  _connectionListener,
} = require('_http_server');
const { ClientRequest } = require('_http_client');
let debug = require('internal/util/debuglog').debuglog('https', (fn) => {
  debug = fn;
});
const net = require('net');
const { URL, urlToHttpOptions, isURL } = require('internal/url');
const { validateObject } = require('internal/validators');
const { isIP } = require('internal/net');
const assert = require('internal/assert');
const { getOptionValue } = require('internal/options');

function Server(opts, requestListener) {
  if (!(this instanceof Server)) return new Server(opts, requestListener);

  let ALPNProtocols = ['http/1.1'];
  if (typeof opts === 'function') {
    requestListener = opts;
    opts = kEmptyObject;
  } else if (opts == null) {
    opts = kEmptyObject;
  } else {
    validateObject(opts, 'options');
    // Only one of ALPNProtocols and ALPNCallback can be set, so make sure we
    // only set a default ALPNProtocols if the caller has not set either of them
    if (opts.ALPNProtocols || opts.ALPNCallback)
      ALPNProtocols = undefined;
  }

  FunctionPrototypeCall(storeHTTPOptions, this, opts);
  FunctionPrototypeCall(tls.Server, this,
                        {
                          noDelay: true,
                          ALPNProtocols,
                          ...opts,
                        },
                        _connectionListener);

  this.httpAllowHalfOpen = false;

  if (requestListener) {
    this.addListener('request', requestListener);
  }

  this.addListener('tlsClientError', function addListener(err, conn) {
    if (!this.emit('clientError', err, conn))
      conn.destroy(err);
  });

  this.timeout = 0;
  this.maxHeadersCount = null;
  this.on('listening', setupConnectionsTracking);
}

ObjectSetPrototypeOf(Server.prototype, tls.Server.prototype);
ObjectSetPrototypeOf(Server, tls.Server);

Server.prototype.closeAllConnections = HttpServer.prototype.closeAllConnections;

Server.prototype.closeIdleConnections = HttpServer.prototype.closeIdleConnections;

Server.prototype.setTimeout = HttpServer.prototype.setTimeout;

Server.prototype.close = function close() {
  httpServerPreClose(this);
  ReflectApply(tls.Server.prototype.close, this, arguments);
  return this;
};

Server.prototype[SymbolAsyncDispose] = async function() {
  await FunctionPrototypeCall(promisify(this.close), this);
};

/**
 * Creates a new `https.Server` instance.
 * @param {{
 *   IncomingMessage?: IncomingMessage;
 *   ServerResponse?: ServerResponse;
 *   insecureHTTPParser?: boolean;
 *   maxHeaderSize?: number;
 *   }} [opts]
 * @param {Function} [requestListener]
 * @returns {Server}
 */
function createServer(opts, requestListener) {
  return new Server(opts, requestListener);
}

// When proxying a HTTPS request, the following needs to be done:
// https://datatracker.ietf.org/doc/html/rfc9110#CONNECT
// 1. Send a CONNECT request to the proxy server.
// 2. Wait for 200 connection established response to establish the tunnel.
// 3. Perform TLS handshake with the endpoint over the socket.
// 4. Tunnel the request using the established connection.
//
// This function computes the tunnel configuration for HTTPS requests.
// The handling of the tunnel connection is done in createConnection.
function getTunnelConfigForProxiedHttps(agent, reqOptions) {
  if (!agent[kProxyConfig]) {
    return null;
  }
  if ((reqOptions.protocol || agent.protocol) !== 'https:') {
    return null;
  }
  const shouldUseProxy = checkShouldUseProxy(agent[kProxyConfig], reqOptions);
  debug(`getTunnelConfigForProxiedHttps should use proxy for ${reqOptions.host}:${reqOptions.port}:`, shouldUseProxy);
  if (!shouldUseProxy) {
    return null;
  }
  const { auth, href } = agent[kProxyConfig];
  // The request is a HTTPS request, assemble the payload for establishing the tunnel.
  const ipType = isIP(reqOptions.host);
  // The request target must put IPv6 address in square brackets.
  // Here reqOptions is already processed by urlToHttpOptions so we'll add them back if necessary.
  // See https://www.rfc-editor.org/rfc/rfc3986#section-3.2.2
  const requestHost = ipType === 6 ? `[${reqOptions.host}]` : reqOptions.host;
  const requestPort = reqOptions.port || agent.defaultPort;
  const endpoint = `${requestHost}:${requestPort}`;
  // The ClientRequest constructor should already have validated the host and the port.
  // When the request options come from a string invalid characters would be stripped away,
  // when it's an object ERR_INVALID_CHAR would be thrown. Here we just assert in case
  // agent.createConnection() is called with invalid options.
  assert(!endpoint.includes('\r'));
  assert(!endpoint.includes('\n'));

  let payload = `CONNECT ${endpoint} HTTP/1.1\r\n`;
  // The parseProxyConfigFromEnv() method should have already validated the authorization header
  // value.
  if (auth) {
    payload += `proxy-authorization: ${auth}\r\n`;
  }
  if (agent.keepAlive || agent.maxSockets !== Infinity) {
    payload += 'proxy-connection: keep-alive\r\n';
  }
  payload += `host: ${endpoint}`;
  payload += '\r\n\r\n';

  const result = {
    __proto__: null,
    proxyTunnelPayload: payload,
    requestOptions: {  // Options used for the request sent after the tunnel is established.
      __proto__: null,
      servername: reqOptions.servername || ipType ? undefined : reqOptions.host,
      ...reqOptions,
    },
  };
  debug(`updated request for HTTPS proxy ${href} with`, result);
  return result;
};

function establishTunnel(agent, socket, options, tunnelConfig, afterSocket) {
  const { proxyTunnelPayload } = tunnelConfig;
  // By default, the socket is in paused mode. Read to look for the 200
  // connection established response.
  function read() {
    let chunk;
    while ((chunk = socket.read()) !== null) {
      if (onProxyData(chunk) !== -1) {
        break;
      }
    }
    socket.on('readable', read);
  }

  function cleanup() {
    socket.removeListener('end', onProxyEnd);
    socket.removeListener('error', onProxyError);
    socket.removeListener('readable', read);
    socket.setTimeout(0);  // Clear the timeout for the tunnel establishment.
  }

  function onProxyError(err) {
    debug('onProxyError', err);
    cleanup();
    afterSocket(err, socket);
  }

  // Read the headers from the chunks and check for the status code. If it fails we
  // clean up the socket and return an error. Otherwise we establish the tunnel.
  let buffer = '';
  function onProxyData(chunk) {
    const str = chunk.toString();
    debug('onProxyData', str);
    buffer += str;
    const headerEndIndex = buffer.indexOf('\r\n\r\n');
    if (headerEndIndex === -1) return headerEndIndex;
    const statusLine = buffer.substring(0, buffer.indexOf('\r\n'));
    const statusCode = statusLine.split(' ')[1];
    if (statusCode !== '200') {
      debug(`onProxyData receives ${statusCode}, cleaning up`);
      cleanup();
      const targetHost = proxyTunnelPayload.split('\r')[0].split(' ')[1];
      const message = `Failed to establish tunnel to ${targetHost} via ${agent[kProxyConfig].href}: ${statusLine}`;
      const err = new ERR_PROXY_TUNNEL(message);
      err.statusCode = NumberParseInt(statusCode);
      afterSocket(err, socket);
    } else {
      // https://datatracker.ietf.org/doc/html/rfc9110#CONNECT
      // RFC 9110 says that it can be 2xx but in the real world, proxy clients generally only
      // accepts 200.
      // Proxy servers are not supposed to send anything after the headers - the payload must be
      // be empty. So after this point we will proceed with the tunnel e.g. starting TLS handshake.
      debug('onProxyData receives 200, establishing tunnel');
      cleanup();

      // Reuse the tunneled socket to perform the TLS handshake with the endpoint,
      // then send the request.
      const { requestOptions } = tunnelConfig;
      tunnelConfig.requestOptions = null;
      requestOptions.socket = socket;
      let tunneldSocket;
      const onTLSHandshakeError = (err) => {
        debug('Propagate error event from tunneled socket to tunnel socket');
        afterSocket(err, tunneldSocket);
      };
      tunneldSocket = tls.connect(requestOptions, () => {
        debug('TLS handshake over tunnel succeeded');
        tunneldSocket.removeListener('error', onTLSHandshakeError);
        afterSocket(null, tunneldSocket);
      });
      tunneldSocket.on('free', () => {
        debug('Propagate free event from tunneled socket to tunnel socket');
        socket.emit('free');
      });
      tunneldSocket.on('error', onTLSHandshakeError);
    }
    return headerEndIndex;
  }

  function onProxyEnd() {
    cleanup();
    const err = new ERR_PROXY_TUNNEL('Connection to establish proxy tunnel ended unexpectedly');
    afterSocket(err, socket);
  }

  const proxyTunnelTimeout = tunnelConfig.requestOptions.timeout;
  debug('proxyTunnelTimeout', proxyTunnelTimeout, options.timeout);
  // It may be worth a separate timeout error/event.
  // But it also makes sense to treat the tunnel establishment timeout as
  // a normal timeout for the request.
  function onProxyTimeout() {
    debug('onProxyTimeout', proxyTunnelTimeout);
    cleanup();
    const err = new ERR_PROXY_TUNNEL(`Connection to establish proxy tunnel timed out after ${proxyTunnelTimeout}ms`);
    err.proxyTunnelTimeout = proxyTunnelTimeout;
    afterSocket(err, socket);
  }

  if (proxyTunnelTimeout && proxyTunnelTimeout > 0) {
    debug('proxy tunnel setTimeout', proxyTunnelTimeout);
    socket.setTimeout(proxyTunnelTimeout, onProxyTimeout);
  }

  socket.on('error', onProxyError);
  socket.on('end', onProxyEnd);
  socket.write(proxyTunnelPayload);

  read();
}

// HTTPS agents.
// See ProxyConfig in internal/http.js for how the connection should be handled
// when the agent is configured to use a proxy server.
function createConnection(...args) {
  // XXX: This signature (port, host, options) is different from all the other
  // createConnection() methods.
  let options, cb;
  if (args[0] !== null && typeof args[0] === 'object') {
    options = args[0];
  } else if (args[1] !== null && typeof args[1] === 'object') {
    options = { ...args[1] };
  } else if (args[2] === null || typeof args[2] !== 'object') {
    options = {};
  } else {
    options = { ...args[2] };
  }
  if (typeof args[0] === 'number') {
    options.port = args[0];
  }
  if (typeof args[1] === 'string') {
    options.host = args[1];
  }
  if (typeof args[args.length - 1] === 'function') {
    cb = args[args.length - 1];
  }

  debug('createConnection', options);

  if (options._agentKey) {
    const session = this._getSession(options._agentKey);
    if (session) {
      debug('reuse session for %j', options._agentKey);
      options = {
        session,
        ...options,
      };
    }
  }

  let socket;
  const tunnelConfig = getTunnelConfigForProxiedHttps(this, options);
  debug(`https createConnection should use proxy for ${options.host}:${options.port}:`, tunnelConfig);

  if (!tunnelConfig) {
    socket = tls.connect(options);
  } else {
    const connectOptions = {
      ...this[kProxyConfig].proxyConnectionOptions,
    };
    debug('Create proxy socket', connectOptions);
    const onError = (err) => {
      cleanupAndPropagate(err, socket);
    };
    const proxyTunnelTimeout = tunnelConfig.requestOptions.timeout;
    const onTimeout = () => {
      const err = new ERR_PROXY_TUNNEL(`Connection to establish proxy tunnel timed out after ${proxyTunnelTimeout}ms`);
      err.proxyTunnelTimeout = proxyTunnelTimeout;
      cleanupAndPropagate(err, socket);
    };
    const cleanupAndPropagate = once((err, currentSocket) => {
      debug('cleanupAndPropagate', err);
      socket.removeListener('error', onError);
      socket.removeListener('timeout', onTimeout);
      // An error occurred during tunnel establishment, in that case just destroy the socket.
      // and propagate the error to the callback.

      // When the error comes from unexpected status code, the stream is still in good shape,
      // in that case let req.onSocket handle the destruction instead.
      if (err && err.code === 'ERR_PROXY_TUNNEL' && !err.statusCode) {
        socket.destroy();
      }
      // This error should go to:
      // -> oncreate in Agent.prototype.createSocket
      // -> closure in Agent.prototype.addRequest or Agent.prototype.removeSocket
      if (cb) {
        cb(err, currentSocket);
      }
    });
    const onProxyConnection = () => {
      socket.removeListener('error', onError);
      establishTunnel(this, socket, options, tunnelConfig, cleanupAndPropagate);
    };
    if (this[kProxyConfig].protocol === 'http:') {
      socket = net.connect(connectOptions, onProxyConnection);
    } else {
      socket = tls.connect(connectOptions, onProxyConnection);
    }

    socket.on('error', onError);
    if (proxyTunnelTimeout) {
      socket.setTimeout(proxyTunnelTimeout, onTimeout);
    }
    socket[kWaitForProxyTunnel] = true;
  }

  if (options._agentKey) {
    // Cache new session for reuse
    socket.on('session', (session) => {
      this._cacheSession(options._agentKey, session);
    });

    // Evict session on error
    socket.once('close', (err) => {
      if (err)
        this._evictSession(options._agentKey);
    });
  }

  return socket;
}

/**
 * Creates a new `HttpAgent` instance.
 * @param {{
 *   keepAlive?: boolean;
 *   keepAliveMsecs?: number;
 *   maxSockets?: number;
 *   maxTotalSockets?: number;
 *   maxFreeSockets?: number;
 *   scheduling?: string;
 *   timeout?: number;
 *   maxCachedSessions?: number;
 *   servername?: string;
 *   defaultPort?: number;
 *   protocol?: string;
 *   proxyEnv?: object;
 *   }} [options]
 * @class
 */
function Agent(options) {
  if (!(this instanceof Agent))
    return new Agent(options);

  options = { __proto__: null, ...options };
  options.defaultPort ??= 443;
  options.protocol ??= 'https:';
  FunctionPrototypeCall(HttpAgent, this, options);

  this.maxCachedSessions = this.options.maxCachedSessions;
  if (this.maxCachedSessions === undefined)
    this.maxCachedSessions = 100;

  this._sessionCache = {
    map: {},
    list: [],
  };
}
ObjectSetPrototypeOf(Agent.prototype, HttpAgent.prototype);
ObjectSetPrototypeOf(Agent, HttpAgent);
Agent.prototype.createConnection = createConnection;

/**
 * Gets a unique name for a set of options.
 * @param {{
 *   host: string;
 *   port: number;
 *   localAddress: string;
 *   family: number;
 *   }} [options]
 * @returns {string}
 */
Agent.prototype.getName = function getName(options = kEmptyObject) {
  let name = FunctionPrototypeCall(HttpAgent.prototype.getName, this, options);

  name += ':';
  if (options.ca)
    name += options.ca;

  name += ':';
  if (options.cert)
    name += options.cert;

  name += ':';
  if (options.clientCertEngine)
    name += options.clientCertEngine;

  name += ':';
  if (options.ciphers)
    name += options.ciphers;

  name += ':';
  if (options.key)
    name += options.key;

  name += ':';
  if (options.pfx)
    name += options.pfx;

  name += ':';
  if (options.rejectUnauthorized !== undefined)
    name += options.rejectUnauthorized;

  name += ':';
  if (options.servername && options.servername !== options.host)
    name += options.servername;

  name += ':';
  if (options.minVersion)
    name += options.minVersion;

  name += ':';
  if (options.maxVersion)
    name += options.maxVersion;

  name += ':';
  if (options.secureProtocol)
    name += options.secureProtocol;

  name += ':';
  if (options.crl)
    name += options.crl;

  name += ':';
  if (options.honorCipherOrder !== undefined)
    name += options.honorCipherOrder;

  name += ':';
  if (options.ecdhCurve)
    name += options.ecdhCurve;

  name += ':';
  if (options.dhparam)
    name += options.dhparam;

  name += ':';
  if (options.secureOptions !== undefined)
    name += options.secureOptions;

  name += ':';
  if (options.sessionIdContext)
    name += options.sessionIdContext;

  name += ':';
  if (options.sigalgs)
    name += JSONStringify(options.sigalgs);

  name += ':';
  if (options.privateKeyIdentifier)
    name += options.privateKeyIdentifier;

  name += ':';
  if (options.privateKeyEngine)
    name += options.privateKeyEngine;

  return name;
};

Agent.prototype._getSession = function _getSession(key) {
  return this._sessionCache.map[key];
};

Agent.prototype._cacheSession = function _cacheSession(key, session) {
  // Cache is disabled
  if (this.maxCachedSessions === 0)
    return;

  // Fast case - update existing entry
  if (this._sessionCache.map[key]) {
    this._sessionCache.map[key] = session;
    return;
  }

  // Put new entry
  if (this._sessionCache.list.length >= this.maxCachedSessions) {
    const oldKey = ArrayPrototypeShift(this._sessionCache.list);
    debug('evicting %j', oldKey);
    delete this._sessionCache.map[oldKey];
  }

  ArrayPrototypePush(this._sessionCache.list, key);
  this._sessionCache.map[key] = session;
};

Agent.prototype._evictSession = function _evictSession(key) {
  const index = ArrayPrototypeIndexOf(this._sessionCache.list, key);
  if (index === -1)
    return;

  ArrayPrototypeSplice(this._sessionCache.list, index, 1);
  delete this._sessionCache.map[key];
};

const globalAgent = getGlobalAgent(getOptionValue('--use-env-proxy') ? process.env : undefined, Agent);

/**
 * Makes a request to a secure web server.
 * @param {...any} args
 * @returns {ClientRequest}
 */
function request(...args) {
  let options = {};

  if (typeof args[0] === 'string') {
    const urlStr = ArrayPrototypeShift(args);
    options = urlToHttpOptions(new URL(urlStr));
  } else if (isURL(args[0])) {
    options = urlToHttpOptions(ArrayPrototypeShift(args));
  }

  if (args[0] && typeof args[0] !== 'function') {
    ObjectAssign(options, ArrayPrototypeShift(args));
  }

  options._defaultAgent = module.exports.globalAgent;
  ArrayPrototypeUnshift(args, options);

  return ReflectConstruct(ClientRequest, args);
}

/**
 * Makes a GET request to a secure web server.
 * @param {string | URL} input
 * @param {{
 *   agent?: Agent | boolean;
 *   auth?: string;
 *   createConnection?: Function;
 *   defaultPort?: number;
 *   family?: number;
 *   headers?: object;
 *   hints?: number;
 *   host?: string;
 *   hostname?: string;
 *   insecureHTTPParser?: boolean;
 *   joinDuplicateHeaders?: boolean;
 *   localAddress?: string;
 *   localPort?: number;
 *   lookup?: Function;
 *   maxHeaderSize?: number;
 *   method?: string;
 *   path?: string;
 *   port?: number;
 *   protocol?: string;
 *   setHost?: boolean;
 *   socketPath?: string;
 *   timeout?: number;
 *   signal?: AbortSignal;
 *   uniqueHeaders?: Array;
 *   } | string | URL} [options]
 * @param {Function} [cb]
 * @returns {ClientRequest}
 */
function get(input, options, cb) {
  const req = request(input, options, cb);
  req.end();
  return req;
}

module.exports = {
  Agent,
  globalAgent,
  Server,
  createServer,
  get,
  request,
};