File: //var/www/zaklada/html/node_modules/negotiator/lib/mediaType.js
/**
 * negotiator
 * Copyright(c) 2012 Isaac Z. Schlueter
 * Copyright(c) 2014 Federico Romero
 * Copyright(c) 2014-2015 Douglas Christopher Wilson
 * MIT Licensed
 */
'use strict';
/**
 * Module exports.
 * @public
 */
module.exports = preferredMediaTypes;
module.exports.preferredMediaTypes = preferredMediaTypes;
/**
 * Module variables.
 * @private
 */
var simpleMediaTypeRegExp = /^\s*([^\s\/;]+)\/([^;\s]+)\s*(?:;(.*))?$/;
/**
 * Parse the Accept header.
 * @private
 */
function parseAccept(accept) {
  var accepts = splitMediaTypes(accept);
  for (var i = 0, j = 0; i < accepts.length; i++) {
    var mediaType = parseMediaType(accepts[i].trim(), i);
    if (mediaType) {
      accepts[j++] = mediaType;
    }
  }
  // trim accepts
  accepts.length = j;
  return accepts;
}
/**
 * Parse a media type from the Accept header.
 * @private
 */
function parseMediaType(str, i) {
  var match = simpleMediaTypeRegExp.exec(str);
  if (!match) return null;
  var params = Object.create(null);
  var q = 1;
  var subtype = match[2];
  var type = match[1];
  if (match[3]) {
    var kvps = splitParameters(match[3]).map(splitKeyValuePair);
    for (var j = 0; j < kvps.length; j++) {
      var pair = kvps[j];
      var key = pair[0].toLowerCase();
      var val = pair[1];
      // get the value, unwrapping quotes
      var value = val && val[0] === '"' && val[val.length - 1] === '"'
        ? val.substr(1, val.length - 2)
        : val;
      if (key === 'q') {
        q = parseFloat(value);
        break;
      }
      // store parameter
      params[key] = value;
    }
  }
  return {
    type: type,
    subtype: subtype,
    params: params,
    q: q,
    i: i
  };
}
/**
 * Get the priority of a media type.
 * @private
 */
function getMediaTypePriority(type, accepted, index) {
  var priority = {o: -1, q: 0, s: 0};
  for (var i = 0; i < accepted.length; i++) {
    var spec = specify(type, accepted[i], index);
    if (spec && (priority.s - spec.s || priority.q - spec.q || priority.o - spec.o) < 0) {
      priority = spec;
    }
  }
  return priority;
}
/**
 * Get the specificity of the media type.
 * @private
 */
function specify(type, spec, index) {
  var p = parseMediaType(type);
  var s = 0;
  if (!p) {
    return null;
  }
  if(spec.type.toLowerCase() == p.type.toLowerCase()) {
    s |= 4
  } else if(spec.type != '*') {
    return null;
  }
  if(spec.subtype.toLowerCase() == p.subtype.toLowerCase()) {
    s |= 2
  } else if(spec.subtype != '*') {
    return null;
  }
  var keys = Object.keys(spec.params);
  if (keys.length > 0) {
    if (keys.every(function (k) {
      return spec.params[k] == '*' || (spec.params[k] || '').toLowerCase() == (p.params[k] || '').toLowerCase();
    })) {
      s |= 1
    } else {
      return null
    }
  }
  return {
    i: index,
    o: spec.i,
    q: spec.q,
    s: s,
  }
}
/**
 * Get the preferred media types from an Accept header.
 * @public
 */
function preferredMediaTypes(accept, provided) {
  // RFC 2616 sec 14.2: no header = */*
  var accepts = parseAccept(accept === undefined ? '*/*' : accept || '');
  if (!provided) {
    // sorted list of all types
    return accepts
      .filter(isQuality)
      .sort(compareSpecs)
      .map(getFullType);
  }
  var priorities = provided.map(function getPriority(type, index) {
    return getMediaTypePriority(type, accepts, index);
  });
  // sorted list of accepted types
  return priorities.filter(isQuality).sort(compareSpecs).map(function getType(priority) {
    return provided[priorities.indexOf(priority)];
  });
}
/**
 * Compare two specs.
 * @private
 */
function compareSpecs(a, b) {
  return (b.q - a.q) || (b.s - a.s) || (a.o - b.o) || (a.i - b.i) || 0;
}
/**
 * Get full type string.
 * @private
 */
function getFullType(spec) {
  return spec.type + '/' + spec.subtype;
}
/**
 * Check if a spec has any quality.
 * @private
 */
function isQuality(spec) {
  return spec.q > 0;
}
/**
 * Count the number of quotes in a string.
 * @private
 */
function quoteCount(string) {
  var count = 0;
  var index = 0;
  while ((index = string.indexOf('"', index)) !== -1) {
    count++;
    index++;
  }
  return count;
}
/**
 * Split a key value pair.
 * @private
 */
function splitKeyValuePair(str) {
  var index = str.indexOf('=');
  var key;
  var val;
  if (index === -1) {
    key = str;
  } else {
    key = str.substr(0, index);
    val = str.substr(index + 1);
  }
  return [key, val];
}
/**
 * Split an Accept header into media types.
 * @private
 */
function splitMediaTypes(accept) {
  var accepts = accept.split(',');
  for (var i = 1, j = 0; i < accepts.length; i++) {
    if (quoteCount(accepts[j]) % 2 == 0) {
      accepts[++j] = accepts[i];
    } else {
      accepts[j] += ',' + accepts[i];
    }
  }
  // trim accepts
  accepts.length = j + 1;
  return accepts;
}
/**
 * Split a string of parameters.
 * @private
 */
function splitParameters(str) {
  var parameters = str.split(';');
  for (var i = 1, j = 0; i < parameters.length; i++) {
    if (quoteCount(parameters[j]) % 2 == 0) {
      parameters[++j] = parameters[i];
    } else {
      parameters[j] += ';' + parameters[i];
    }
  }
  // trim parameters
  parameters.length = j + 1;
  for (var i = 0; i < parameters.length; i++) {
    parameters[i] = parameters[i].trim();
  }
  return parameters;
}