// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// Query String Utilities

var QueryString = exports;
var isString = require('../util').isString;
var isArray = require('../util').isArray;
var isBoolean = require('../util').isBoolean;
var isNumber = require('../util').isNumber;
var isObject = require('../util').isObject;
var isNull = require('../util').isNull;
var keys = require('../util').keys;
var map = require('../util').map;

// If obj.hasOwnProperty has been overridden, then calling
// obj.hasOwnProperty(prop) will break.
// See: https://github.com/joyent/node/issues/1707
function hasOwnProperty(obj, prop) {
  return Object.prototype.hasOwnProperty.call(obj, prop);
}


function charCode(c) {
  return c.charCodeAt(0);
}

QueryString.unescape = function(s) {
  return decodeURIComponent(s);
};


QueryString.escape = function(str) {
  return encodeURIComponent(str);
};

var stringifyPrimitive = function(v) {
  if (isString(v))
    return v;
  if (isBoolean(v))
    return v ? 'true' : 'false';
  if (isNumber(v))
    return isFinite(v) ? v : '';
  return '';
};


QueryString.stringify = QueryString.encode = function(obj, sep, eq, name) {
  sep = sep || '&';
  eq = eq || '=';
  if (isNull(obj)) {
    obj = undefined;
  }

  if (isObject(obj)) {
    return map(keys(obj), function(k) {
      var ks = QueryString.escape(stringifyPrimitive(k)) + eq;
      if (isArray(obj[k])) {
        return map(obj[k], function(v) {
          return ks + QueryString.escape(stringifyPrimitive(v));
        }).join(sep);
      } else {
        return ks + QueryString.escape(stringifyPrimitive(obj[k]));
      }
    }).join(sep);

  }

  if (!name) return '';
  return QueryString.escape(stringifyPrimitive(name)) + eq +
         QueryString.escape(stringifyPrimitive(obj));
};

// Parse a key=val string.
QueryString.parse = QueryString.decode = function(qs, sep, eq, options) {
  sep = sep || '&';
  eq = eq || '=';
  var obj = {};

  if (!isString(qs) || qs.length === 0) {
    return obj;
  }

  var regexp = /\+/g;
  qs = qs.split(sep);

  var maxKeys = 1000;
  if (options && isNumber(options.maxKeys)) {
    maxKeys = options.maxKeys;
  }

  var len = qs.length;
  // maxKeys <= 0 means that we should not limit keys count
  if (maxKeys > 0 && len > maxKeys) {
    len = maxKeys;
  }

  for (var i = 0; i < len; ++i) {
    var x = qs[i].replace(regexp, '%20'),
        idx = x.indexOf(eq),
        kstr, vstr, k, v;

    if (idx >= 0) {
      kstr = x.substr(0, idx);
      vstr = x.substr(idx + 1);
    } else {
      kstr = x;
      vstr = '';
    }

    try {
      k = decodeURIComponent(kstr);
      v = decodeURIComponent(vstr);
    } catch (e) {
      k = QueryString.unescape(kstr, true);
      v = QueryString.unescape(vstr, true);
    }

    if (!hasOwnProperty(obj, k)) {
      obj[k] = v;
    } else if (isArray(obj[k])) {
      obj[k].push(v);
    } else {
      obj[k] = [obj[k], v];
    }
  }

  return obj;
};