var sys       = require('util'),
    http      = require('http'),
    https     = require('https'),
    url       = require('url'),
    qs        = require('querystring'),
    multipart = require('./multipartform'),
    zlib      = require('zlib');
    
function mixin(target, source) {
  Object.keys(source).forEach(function(key) {
    target[key] = source[key];
  });
  
  return target;
}
    
function Request(uri, options) {
  this.url = url.parse(uri);
  this.options = options;
  this.headers = {
    'Accept': '*/*',
    'User-Agent': 'Restler for node.js',
    'Host': this.url.host
  };
  
  mixin(this.headers, options.headers || {});
  
  // set port and method defaults
  if (!this.url.port) this.url.port = (this.url.protocol == 'https:') ? '443' : '80';
  if (!this.options.method) this.options.method = (this.options.data) ? 'POST' : 'GET';
  if (typeof this.options.followRedirects == 'undefined') this.options.followRedirects = true;
  
  // stringify query given in options of not given in URL
  if (this.options.query && !this.url.query) {
    if (typeof this.options.query == 'object') 
      this.url.query = qs.stringify(this.options.query);
    else this.url.query = this.options.query;
  }
  
  this._applyBasicAuth();
  
  if (this.options.multipart) {
    this.headers['Content-Type'] = 'multipart/form-data; boundary=' + multipart.defaultBoundary;
  } else {
    if (typeof this.options.data == 'object') {
      this.options.data = qs.stringify(this.options.data);
      this.headers['Content-Type'] = 'application/x-www-form-urlencoded';
      this.headers['Content-Length'] = this.options.data.length;
    }
    if(typeof this.options.data == 'string') {
      var buffer = new Buffer(this.options.data, this.options.encoding || 'utf8');
      this.options.data = buffer;
      this.headers['Content-Length'] = buffer.length;
    }
  }
  
  var proto = (this.url.protocol == 'https:') ? https : http;
  
  this.request = proto.request({
    host: this.url.hostname,
    port: this.url.port,
    path: this._fullPath(),
    method: this.options.method,
    headers: this.headers
  });
  
  this._makeRequest();
}

Request.prototype = new process.EventEmitter();

mixin(Request.prototype, {
  _isRedirect: function(response) {
    return ([301, 302, 303].indexOf(response.statusCode) >= 0);
  },
  _fullPath: function() {
    var path = this.url.pathname || '/';
    if (this.url.hash) path += this.url.hash;
    if (this.url.query) path += '?' + this.url.query;
    return path;
  },
  _applyBasicAuth: function() {
    var authParts;
    
    if (this.url.auth) {
      authParts = this.url.auth.split(':');
      this.options.username = authParts[0];
      this.options.password = authParts[1];
    }
    
    if (this.options.username && this.options.password) {
      var b = new Buffer([this.options.username, this.options.password].join(':'));
      this.headers['Authorization'] = "Basic " + b.toString('base64');
    }
  },
  _responseHandler: function(response) {
    var self = this;
    
    if (this._isRedirect(response) && this.options.followRedirects == true) {
      try {
        var location = url.resolve(this.url, response.headers['location']);
        this.options.originalRequest = this;
        
        request(location, this.options);
      } catch(e) {
        self._respond('error', '', 'Failed to follow redirect');
      }
    } else {
      var body = '';
      
      response.setEncoding('binary');
      
      response.on('data', function(chunk) {
        body += chunk;
      });
      
      response.on('end', function() {
        self._decode(new Buffer(body, 'binary'), response, function(err, body) {
          if (err) {
            self._respond('error', '', 'Failed to decode response body');
            return;
          }
          self._encode(body, response, function(body) {
            self._fireEvents(body, response);
          });
        });
      });
    }
  },
  _decode: function(body, response, callback) {
    var encoder = response.headers['content-encoding'];
    if (encoder in decoders) {
      decoders[encoder].call(response, body, callback);
    } else {
      callback(null, body);
    }
  },
  _encode: function(body, response, callback) {
    var self = this;
    if (self.options.decoding == 'buffer') {
      callback(body);
    } else {
      body = body.toString(self.options.decoding);
      if (self.options.parser) {
        self.options.parser.call(response, body, callback);
      } else {
        callback(body);
      }
    }
  },
  _respond: function(type, data, response) {
    if (this.options.originalRequest) {
      this.options.originalRequest.emit(type, data, response);
    } else {
      this.emit(type, data, response);
    }
  },
  _fireEvents: function(body, response) {
    if (parseInt(response.statusCode) >= 400) this._respond('error', body, response);
    else this._respond('success', body, response);
        
    this._respond(response.statusCode.toString().replace(/\d{2}$/, 'XX'), body, response);
    this._respond(response.statusCode.toString(), body, response);
    this._respond('complete', body, response);
  },
  _makeRequest: function() {
    var self = this;
       
    this.request.on('response', function(response) {
  	  self._responseHandler(response);
  	}).on('error', function(err) {
  	  self._respond('error', null, err);
  	});
  },
  run: function() {
    var self = this;
    
    if (this.options.multipart) {
      multipart.write(this.request, this.options.data, function() {
        self.request.end();
      });
    } else {
      if (this.options.data) {
        this.request.write(this.options.data.toString(), this.options.encoding || 'utf8');
      }
      this.request.end();
    }
    
    return this;
  }
});

function shortcutOptions(options, method) {
  options = options || {};
  options.method = method;
  options.parser = (typeof options.parser !== "undefined") ? options.parser : parsers.auto;
  return options;
}
    
function request(url, options) {  
  var request = new Request(url, options);
  request.on('error', function() {}); 
 	return request.run();
}

function get(url, options) {
 return request(url, shortcutOptions(options, 'GET'));
}

function post(url, options) {
  return request(url, shortcutOptions(options, 'POST'));
}

function put(url, options) {
  return request(url, shortcutOptions(options, 'PUT'));
}

function del(url, options) {
  return request(url, shortcutOptions(options, 'DELETE'));
}

var parsers = {
  auto: function(data, callback) {
    var contentType = this.headers['content-type'];
    
    if (contentType) {
      for (var matcher in parsers.auto.matchers) {

        if (contentType.indexOf(matcher) == 0) {
          return parsers.auto.matchers[matcher].call(this, data, callback);
        }
      }
    }
    
    callback(data);
  },
  json: function(data, callback) {
    callback(data && JSON.parse(data));
  }
};

parsers.auto.matchers = {
  'application/json': parsers.json
};

try {
  var yaml = require('yaml');
  
  parsers.yaml = function(data, callback) {
    return callback(data && yaml.eval(data));
  };
  
  parsers.auto.matchers['application/yaml'] = parsers.yaml;
} catch(e) {}

try {
  var xml2js = require('xml2js');

  parsers.xml = function(data, callback) {
    if (data) {
      var parser = new xml2js.Parser();
      
      parser.on('end', function(result) {
          callback(result);
      });
      try {
          parser.parseString(data);
      } catch (e) {
          callback({error:'Oops, something went wrong.'});
      }
    } else {
      callback();
    }
  };
  
  parsers.auto.matchers['application/xml'] = parsers.xml;
} catch(e) { }

var decoders = {
  gzip: function(buf, callback) {
    zlib.gunzip(buf, callback);
  },
  deflate: function(buf, callback) {
    zlib.inflate(buf, callback);
  }
};


function Service(defaults) {
  if (defaults.baseURL) {
   this.baseURL = defaults.baseURL;
   delete defaults.baseURL; 
  }
  
  this.defaults = defaults;
}

mixin(Service.prototype, {
  request: function(path, options) {
    return request(this._url(path), this._withDefaults(options));
  },
  get: function(path, options) {
    return get(this._url(path), this._withDefaults(options));
  },
  put: function(path, options) {
    return put(this._url(path), this._withDefaults(options));
  },
  post: function(path, options) {
    return post(this._url(path), this._withDefaults(options));
  },
  del: function(path, options) {
    return del(this._url(path), this._withDefaults(options));
  },
  _url: function(path) {
    if (this.baseURL) return url.resolve(this.baseURL, path);
    else return path;
  },
  _withDefaults: function(options) {
    var o = mixin({}, this.defaults);
    return mixin(o, options);
  }
});

function service(constructor, defaults, methods) {
  constructor.prototype = new Service(defaults || {});
  mixin(constructor.prototype, methods);
  return constructor;
}

mixin(exports, {
  Request: Request,
  Service: Service,
  request: request,
  service: service,
  get: get,
  post: post,
  put: put,
  del: del,
  parsers: parsers,
  file: multipart.file,
  data: multipart.data
});