var path = require('path'); var fs = require('fs');

function Mime() {

// Map of extension -> mime type
this.types = Object.create(null);

// Map of mime type -> extension
this.extensions = Object.create(null);

}

/**

* Define mimetype -> extension mappings.  Each key is a mime-type that maps
* to an array of extensions associated with the type.  The first extension is
* used as the default extension for the type.
*
* e.g. mime.define({'audio/ogg', ['oga', 'ogg', 'spx']});
*
* @param map (Object) type definitions
*/

Mime.prototype.define = function (map) {

for (var type in map) {
  var exts = map[type];
  for (var i = 0; i < exts.length; i++) {
    if (process.env.DEBUG_MIME && this.types[exts]) {
      console.warn(this._loading.replace(/.*\//, ''), 'changes "' + exts[i] + '" extension type from ' +
        this.types[exts] + ' to ' + type);
    }

    this.types[exts[i]] = type;
  }

  // Default extension is the first one we encounter
  if (!this.extensions[type]) {
    this.extensions[type] = exts[0];
  }
}

};

/**

* Load an Apache2-style ".types" file
*
* This may be called multiple times (it's expected).  Where files declare
* overlapping types/extensions, the last file wins.
*
* @param file (String) path of file to load.
*/

Mime.prototype.load = function(file) {

this._loading = file;
// Read file and split into lines
var map = {},
    content = fs.readFileSync(file, 'ascii'),
    lines = content.split(/[\r\n]+/);

lines.forEach(function(line) {
  // Clean up whitespace/comments, and split into fields
  var fields = line.replace(/\s*#.*|^\s*|\s*$/g, '').split(/\s+/);
  map[fields.shift()] = fields;
});

this.define(map);

this._loading = null;

};

/**

* Lookup a mime type based on extension
*/

Mime.prototype.lookup = function(path, fallback) {

var ext = path.replace(/.*[\.\/\\]/, '').toLowerCase();

return this.types[ext] || fallback || this.default_type;

};

/**

* Return file extension associated with a mime type
*/

Mime.prototype.extension = function(mimeType) {

var type = mimeType.match(/^\s*([^;\s]*)(?:;|\s|$)/)[1].toLowerCase();
return this.extensions[type];

};

// Default instance var mime = new Mime();

// Define built-in types mime.define(require('./types.json'));

// Default type mime.default_type = mime.lookup('bin');

// // Additional API specific to the default instance //

mime.Mime = Mime;

/**

* Lookup a charset based on mime type.
*/

mime.charsets = {

lookup: function(mimeType, fallback) {
  // Assume text types are utf8
  return (/^text\//).test(mimeType) ? 'UTF-8' : fallback;
}

};

module.exports = mime;