--- /dev/null
+var Negotiator = require('negotiator')
+var mime = require('mime-types')
+
+var slice = [].slice
+
+module.exports = Accepts
+
+function Accepts(req) {
+ if (!(this instanceof Accepts))
+ return new Accepts(req)
+
+ this.headers = req.headers
+ this.negotiator = Negotiator(req)
+}
+
+/**
+ * Check if the given `type(s)` is acceptable, returning
+ * the best match when true, otherwise `undefined`, in which
+ * case you should respond with 406 "Not Acceptable".
+ *
+ * The `type` value may be a single mime type string
+ * such as "application/json", the extension name
+ * such as "json" or an array `["json", "html", "text/plain"]`. When a list
+ * or array is given the _best_ match, if any is returned.
+ *
+ * Examples:
+ *
+ * // Accept: text/html
+ * this.types('html');
+ * // => "html"
+ *
+ * // Accept: text/*, application/json
+ * this.types('html');
+ * // => "html"
+ * this.types('text/html');
+ * // => "text/html"
+ * this.types('json', 'text');
+ * // => "json"
+ * this.types('application/json');
+ * // => "application/json"
+ *
+ * // Accept: text/*, application/json
+ * this.types('image/png');
+ * this.types('png');
+ * // => undefined
+ *
+ * // Accept: text/*;q=.5, application/json
+ * this.types(['html', 'json']);
+ * this.types('html', 'json');
+ * // => "json"
+ *
+ * @param {String|Array} type(s)...
+ * @return {String|Array|Boolean}
+ * @api public
+ */
+
+Accepts.prototype.type =
+Accepts.prototype.types = function (types) {
+ if (!Array.isArray(types)) types = slice.call(arguments);
+ var n = this.negotiator;
+ if (!types.length) return n.mediaTypes();
+ if (!this.headers.accept) return types[0];
+ var mimes = types.map(extToMime);
+ var accepts = n.mediaTypes(mimes.filter(validMime));
+ var first = accepts[0];
+ if (!first) return false;
+ return types[mimes.indexOf(first)];
+}
+
+/**
+ * Return accepted encodings or best fit based on `encodings`.
+ *
+ * Given `Accept-Encoding: gzip, deflate`
+ * an array sorted by quality is returned:
+ *
+ * ['gzip', 'deflate']
+ *
+ * @param {String|Array} encoding(s)...
+ * @return {String|Array}
+ * @api public
+ */
+
+Accepts.prototype.encoding =
+Accepts.prototype.encodings = function (encodings) {
+ if (!Array.isArray(encodings)) encodings = slice.call(arguments);
+ var n = this.negotiator;
+ if (!encodings.length) return n.encodings();
+ return n.encodings(encodings)[0] || false;
+}
+
+/**
+ * Return accepted charsets or best fit based on `charsets`.
+ *
+ * Given `Accept-Charset: utf-8, iso-8859-1;q=0.2, utf-7;q=0.5`
+ * an array sorted by quality is returned:
+ *
+ * ['utf-8', 'utf-7', 'iso-8859-1']
+ *
+ * @param {String|Array} charset(s)...
+ * @return {String|Array}
+ * @api public
+ */
+
+Accepts.prototype.charset =
+Accepts.prototype.charsets = function (charsets) {
+ if (!Array.isArray(charsets)) charsets = [].slice.call(arguments);
+ var n = this.negotiator;
+ if (!charsets.length) return n.charsets();
+ if (!this.headers['accept-charset']) return charsets[0];
+ return n.charsets(charsets)[0] || false;
+}
+
+/**
+ * Return accepted languages or best fit based on `langs`.
+ *
+ * Given `Accept-Language: en;q=0.8, es, pt`
+ * an array sorted by quality is returned:
+ *
+ * ['es', 'pt', 'en']
+ *
+ * @param {String|Array} lang(s)...
+ * @return {Array|String}
+ * @api public
+ */
+
+Accepts.prototype.lang =
+Accepts.prototype.langs =
+Accepts.prototype.language =
+Accepts.prototype.languages = function (langs) {
+ if (!Array.isArray(langs)) langs = slice.call(arguments);
+ var n = this.negotiator;
+ if (!langs.length) return n.languages();
+ if (!this.headers['accept-language']) return langs[0];
+ return n.languages(langs)[0] || false;
+}
+
+/**
+ * Convert extnames to mime.
+ *
+ * @param {String} type
+ * @return {String}
+ * @api private
+ */
+
+function extToMime(type) {
+ if (~type.indexOf('/')) return type;
+ return mime.lookup(type);
+}
+
+/**
+ * Check if mime is valid.
+ *
+ * @param {String} type
+ * @return {String}
+ * @api private
+ */
+
+function validMime(type) {
+ return typeof type === 'string';
+}