/**
 * mime类型的 map
 * @ author Cheng Liufeng
 * @ date 2014/8/30
 * 当请求静态服务器文件的类型 html, css, gif, jpg, png, javascript, json, plain text, 我们会在此文件进行映射
 */
exports.types = {
 "css": "text/css",
 "gif": "image/gif",
 "html": "text/html",
 "ico": "image/x-icon",
 "jpeg": "image/jpeg",
 "jpg": "image/jpeg",
 "js": "text/javascript",
 "json": "application/json",
 "pdf": "application/pdf",
 "png": "image/png",
 "svg": "image/svg+xml",
 "swf": "application/x-shockwave-flash",
 "tiff": "image/tiff",
 "txt": "text/plain",
 "wav": "audio/x-wav",
 "wma": "audio/x-ms-wma",
 "wmv": "video/x-ms-wmv",
 "xml": "text/xml"
};

/**
 * 聊天室服务端
 * 功能：实现了Node版的静态服务器
 * 实现了缓存，gzip压缩等
 * @ author Cheng Liufeng
 * @ date 2014/8/30
 */
 // 设置端口号
var PORT = 3000;
// 引入模块
var http = require('http');
var url = require('url');
var fs = require('fs');
var path = require('path');
var zlib = require('zlib');
// 引入文件
var mime = require('./mime').types;
var config = require('./config');
var chatServer = require('./utils/chat_server');
var server = http.createServer(function (req, res) {
 res.setHeader("Server","Node/V8");
 // 获取文件路径
 var pathName = url.parse(req.url).pathname;
 if(pathName.slice(-1) === "/"){
 pathName = pathName + "index.html"; //默认取当前默认下的index.html
 }
 // 安全处理（当使用Linux 的 curl命令访问时，存在安全隐患）
 var realPath = path.join("client", path.normalize(pathName.replace(/\.\./g, "")));
 // 检查文件路径是否存在
 path.exists(realPath, function(exists) {
 // 当文件不存在时的情况， 输出一个404错误
 if (!exists) {
  res.writeHead(404, "Not Found", {'Content-Type': 'text/plain'});
  res.write("The request url" + pathName +" is not found!");
  res.end();
 } else {   // 当文件存在时的处理逻辑
  fs.stat(realPath, function(err, stat) {
    // 获取文件扩展名
  var ext = path.extname(realPath);
  ext = ext "unknown";
  var contentType = mime[ext] || "text/plain";
  // 设置 Content-Type
  res.setHeader("Content-Type", contentType);
  var lastModified = stat.mtime.toUTCString();
  var ifModifiedSince = "If-Modified-Since".toLowerCase();
  res.setHeader("Last-Modified", lastModified);
  if (ext.match(config.Expires.fileMatch)) {
   var expires = new Date();
   expires.setTime(expires.getTime() + config.Expires.maxAge * 1000);
   res.setHeader("Expires", expires.toUTCString());
   res.setHeader("Cache-Control", "max-age=" + config.Expires.maxAge);
  }
  if (req.headers[ifModifiedSince] && lastModified == req.headers[ifModifiedSince]) {
   res.writeHead(304, "Not Modified");
   res.end();
  } else {
   // 使用流的方式去读取文件
   var raw = fs.createReadStream(realPath);
   var acceptEncoding = req.headers['accept-encoding'] || "";
   var matched = ext.match(config.Compress.match);
   if (matched && acceptEncoding.match(/\bgzip\b/)) {
   res.writeHead(200, "Ok", {'Content-Encoding': 'gzip'});
   raw.pipe(zlib.createGzip()).pipe(res);
   } else if (matched && acceptEncoding.match(/\bdeflate\b/)) {
   res.writeHead(200, "Ok", {'Content-Encoding': 'deflate'});
   raw.pipe(zlib.createDeflate()).pipe(res);
   } else {
   res.writeHead(200, "Ok");
   raw.pipe(res);
   }

//   fs.readFile(realPath, "binary", function(err, data) {
//   if(err) {
//    // file exists, but have some error while read
//    res.writeHead(500, {'Content-Type': 'text/plain'});
//    res.end(err);
//   } else {
//    // file exists, can success return
//    res.writeHead(200, {'Content-Type': contentType});
//    res.write(data, "binary");
//    res.end();
//   }
//   });
  }
  });
 }
 });
});

server.listen(PORT, function() {
 console.log("Server is listening on port " + PORT + "!");
});

chatServer.listen(server);