var $$UMFP; // reference to $UrlMatcherFactoryProvider

/**
 * @ngdoc object
 * @name ui.router.util.type:UrlMatcher
 *
 * @description
 * Matches URLs against patterns and extracts named parameters from the path or the search
 * part of the URL. A URL pattern consists of a path pattern, optionally followed by '?' and a list
 * of search parameters. Multiple search parameter names are separated by '&'. Search parameters
 * do not influence whether or not a URL is matched, but their values are passed through into
 * the matched parameters returned by {@link ui.router.util.type:UrlMatcher#methods_exec exec}.
 *
 * Path parameter placeholders can be specified using simple colon/catch-all syntax or curly brace
 * syntax, which optionally allows a regular expression for the parameter to be specified:
 *
 * * `':'` name - colon placeholder
 * * `'*'` name - catch-all placeholder
 * * `'{' name '}'` - curly placeholder
 * * `'{' name ':' regexp|type '}'` - curly placeholder with regexp or type name. Should the
 *   regexp itself contain curly braces, they must be in matched pairs or escaped with a backslash.
 *
 * Parameter names may contain only word characters (latin letters, digits, and underscore) and
 * must be unique within the pattern (across both path and search parameters). For colon
 * placeholders or curly placeholders without an explicit regexp, a path parameter matches any
 * number of characters other than '/'. For catch-all placeholders the path parameter matches
 * any number of characters.
 *
 * Examples:
 *
 * * `'/hello/'` - Matches only if the path is exactly '/hello/'. There is no special treatment for
 *   trailing slashes, and patterns have to match the entire path, not just a prefix.
 * * `'/user/:id'` - Matches '/user/bob' or '/user/1234!!!' or even '/user/' but not '/user' or
 *   '/user/bob/details'. The second path segment will be captured as the parameter 'id'.
 * * `'/user/{id}'` - Same as the previous example, but using curly brace syntax.
 * * `'/user/{id:[^/]*}'` - Same as the previous example.
 * * `'/user/{id:[0-9a-fA-F]{1,8}}'` - Similar to the previous example, but only matches if the id
 *   parameter consists of 1 to 8 hex digits.
 * * `'/files/{path:.*}'` - Matches any URL starting with '/files/' and captures the rest of the
 *   path into the parameter 'path'.
 * * `'/files/*path'` - ditto.
 * * `'/calendar/{start:date}'` - Matches "/calendar/2014-11-12" (because the pattern defined
 *   in the built-in  `date` Type matches `2014-11-12`) and provides a Date object in $stateParams.start
 *
 * @param {string} pattern  The pattern to compile into a matcher.
 * @param {Object} config  A configuration object hash:
 * @param {Object=} parentMatcher Used to concatenate the pattern/config onto
 *   an existing UrlMatcher
 *
 * * `caseInsensitive` - `true` if URL matching should be case insensitive, otherwise `false`, the default value (for backward compatibility) is `false`.
 * * `strict` - `false` if matching against a URL with a trailing slash should be treated as equivalent to a URL without a trailing slash, the default value is `true`.
 *
 * @property {string} prefix  A static prefix of this pattern. The matcher guarantees that any
 *   URL matching this matcher (i.e. any string for which {@link ui.router.util.type:UrlMatcher#methods_exec exec()} returns
 *   non-null) will start with this prefix.
 *
 * @property {string} source  The pattern that was passed into the constructor
 *
 * @property {string} sourcePath  The path portion of the source property
 *
 * @property {string} sourceSearch  The search portion of the source property
 *
 * @property {string} regex  The constructed regex that will be used to match against the url when
 *   it is time to determine which url will match.
 *
 * @returns {Object}  New `UrlMatcher` object
 */
function UrlMatcher(pattern, config, parentMatcher) {
  config = extend({ params: {} }, isObject(config) ? config : {});

  // Find all placeholders and create a compiled pattern, using either classic or curly syntax:
  //   '*' name
  //   ':' name
  //   '{' name '}'
  //   '{' name ':' regexp '}'
  // The regular expression is somewhat complicated due to the need to allow curly braces
  // inside the regular expression. The placeholder regexp breaks down as follows:
  //    ([:*])([\w\[\]]+)              - classic placeholder ($1 / $2) (search version has - for snake-case)
  //    \{([\w\[\]]+)(?:\:( ... ))?\}  - curly brace placeholder ($3) with optional regexp/type ... ($4) (search version has - for snake-case
  //    (?: ... | ... | ... )+         - the regexp consists of any number of atoms, an atom being either
  //    [^{}\\]+                       - anything other than curly braces or backslash
  //    \\.                            - a backslash escape
  //    \{(?:[^{}\\]+|\\.)*\}          - a matched set of curly braces containing other atoms
  var placeholder       = /([:*])([\w\[\]]+)|\{([\w\[\]]+)(?:\:((?:[^{}\\]+|\\.|\{(?:[^{}\\]+|\\.)*\})+))?\}/g,
      searchPlaceholder = /([:]?)([\w\[\]-]+)|\{([\w\[\]-]+)(?:\:((?:[^{}\\]+|\\.|\{(?:[^{}\\]+|\\.)*\})+))?\}/g,
      compiled = '^', last = 0, m,
      segments = this.segments = [],
      parentParams = parentMatcher ? parentMatcher.params : {},
      params = this.params = parentMatcher ? parentMatcher.params.$$new() : new $$UMFP.ParamSet(),
      paramNames = [];

  function addParameter(id, type, config, location) {
    paramNames.push(id);
    if (parentParams[id]) return parentParams[id];
    if (!/^\w+(-+\w+)*(?:\[\])?$/.test(id)) throw new Error("Invalid parameter name '" + id + "' in pattern '" + pattern + "'");
    if (params[id]) throw new Error("Duplicate parameter name '" + id + "' in pattern '" + pattern + "'");
    params[id] = new $$UMFP.Param(id, type, config, location);
    return params[id];
  }

  function quoteRegExp(string, pattern, squash, optional) {
    var surroundPattern = ['',''], result = string.replace(/[\\\[\]\^$*+?.()|{}]/g, "\\$&");
    if (!pattern) return result;
    switch(squash) {
      case false: surroundPattern = ['(', ')' + (optional ? "?" : "")]; break;
      case true:  surroundPattern = ['?(', ')?']; break;
      default:    surroundPattern = ['(' + squash + "|", ')?']; break;
    }
    return result + surroundPattern[0] + pattern + surroundPattern[1];
  }

  this.source = pattern;

  // Split into static segments separated by path parameter placeholders.
  // The number of segments is always 1 more than the number of parameters.
  function matchDetails(m, isSearch) {
    var id, regexp, segment, type, cfg, arrayMode;
    id          = m[2] || m[3]; // IE[78] returns '' for unmatched groups instead of null
    cfg         = config.params[id];
    segment     = pattern.substring(last, m.index);
    regexp      = isSearch ? m[4] : m[4] || (m[1] == '*' ? '.*' : null);
    type        = $$UMFP.type(regexp || "string") || inherit($$UMFP.type("string"), { pattern: new RegExp(regexp, config.caseInsensitive ? 'i' : undefined) });
    return {
      id: id, regexp: regexp, segment: segment, type: type, cfg: cfg
    };
  }

  var p, param, segment;
  while ((m = placeholder.exec(pattern))) {
    p = matchDetails(m, false);
    if (p.segment.indexOf('?') >= 0) break; // we're into the search part

    param = addParameter(p.id, p.type, p.cfg, "path");
    compiled += quoteRegExp(p.segment, param.type.pattern.source, param.squash, param.isOptional);
    segments.push(p.segment);
    last = placeholder.lastIndex;
  }
  segment = pattern.substring(last);

  // Find any search parameter names and remove them from the last segment
  var i = segment.indexOf('?');

  if (i >= 0) {
    var search = this.sourceSearch = segment.substring(i);
    segment = segment.substring(0, i);
    this.sourcePath = pattern.substring(0, last + i);

    if (search.length > 0) {
      last = 0;
      while ((m = searchPlaceholder.exec(search))) {
        p = matchDetails(m, true);
        param = addParameter(p.id, p.type, p.cfg, "search");
        last = placeholder.lastIndex;
        // check if ?&
      }
    }
  } else {
    this.sourcePath = pattern;
    this.sourceSearch = '';
  }

  compiled += quoteRegExp(segment) + (config.strict === false ? '\/?' : '') + '$';
  segments.push(segment);

  this.regexp = new RegExp(compiled, config.caseInsensitive ? 'i' : undefined);
  this.prefix = segments[0];
  this.$$paramNames = paramNames;
}

/**
 * @ngdoc function
 * @name ui.router.util.type:UrlMatcher#concat
 * @methodOf ui.router.util.type:UrlMatcher
 *
 * @description
 * Returns a new matcher for a pattern constructed by appending the path part and adding the
 * search parameters of the specified pattern to this pattern. The current pattern is not
 * modified. This can be understood as creating a pattern for URLs that are relative to (or
 * suffixes of) the current pattern.
 *
 * @example
 * The following two matchers are equivalent:
 * <pre>
 * new UrlMatcher('/user/{id}?q').concat('/details?date');
 * new UrlMatcher('/user/{id}/details?q&date');
 * </pre>
 *
 * @param {string} pattern  The pattern to append.
 * @param {Object} config  An object hash of the configuration for the matcher.
 * @returns {UrlMatcher}  A matcher for the concatenated pattern.
 */
UrlMatcher.prototype.concat = function (pattern, config) {
  // Because order of search parameters is irrelevant, we can add our own search
  // parameters to the end of the new pattern. Parse the new pattern by itself
  // and then join the bits together, but it's much easier to do this on a string level.
  var defaultConfig = {
    caseInsensitive: $$UMFP.caseInsensitive(),
    strict: $$UMFP.strictMode(),
    squash: $$UMFP.defaultSquashPolicy()
  };
  return new UrlMatcher(this.sourcePath + pattern + this.sourceSearch, extend(defaultConfig, config), this);
};

UrlMatcher.prototype.toString = function () {
  return this.source;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:UrlMatcher#exec
 * @methodOf ui.router.util.type:UrlMatcher
 *
 * @description
 * Tests the specified path against this matcher, and returns an object containing the captured
 * parameter values, or null if the path does not match. The returned object contains the values
 * of any search parameters that are mentioned in the pattern, but their value may be null if
 * they are not present in `searchParams`. This means that search parameters are always treated
 * as optional.
 *
 * @example
 * <pre>
 * new UrlMatcher('/user/{id}?q&r').exec('/user/bob', {
 *   x: '1', q: 'hello'
 * });
 * // returns { id: 'bob', q: 'hello', r: null }
 * </pre>
 *
 * @param {string} path  The URL path to match, e.g. `$location.path()`.
 * @param {Object} searchParams  URL search parameters, e.g. `$location.search()`.
 * @returns {Object}  The captured parameter values.
 */
UrlMatcher.prototype.exec = function (path, searchParams) {
  var m = this.regexp.exec(path);
  if (!m) return null;
  searchParams = searchParams || {};

  var paramNames = this.parameters(), nTotal = paramNames.length,
    nPath = this.segments.length - 1,
    values = {}, i, j, cfg, paramName;

  if (nPath !== m.length - 1) throw new Error("Unbalanced capture group in route '" + this.source + "'");

  function decodePathArray(string) {
    function reverseString(str) { return str.split("").reverse().join(""); }
    function unquoteDashes(str) { return str.replace(/\\-/g, "-"); }

    var split = reverseString(string).split(/-(?!\\)/);
    var allReversed = map(split, reverseString);
    return map(allReversed, unquoteDashes).reverse();
  }

  for (i = 0; i < nPath; i++) {
    paramName = paramNames[i];
    var param = this.params[paramName];
    var paramVal = m[i+1];
    // if the param value matches a pre-replace pair, replace the value before decoding.
    for (j = 0; j < param.replace; j++) {
      if (param.replace[j].from === paramVal) paramVal = param.replace[j].to;
    }
    if (paramVal && param.array === true) paramVal = decodePathArray(paramVal);
    values[paramName] = param.value(paramVal);
  }
  for (/**/; i < nTotal; i++) {
    paramName = paramNames[i];
    values[paramName] = this.params[paramName].value(searchParams[paramName]);
  }

  return values;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:UrlMatcher#parameters
 * @methodOf ui.router.util.type:UrlMatcher
 *
 * @description
 * Returns the names of all path and search parameters of this pattern in an unspecified order.
 *
 * @returns {Array.<string>}  An array of parameter names. Must be treated as read-only. If the
 *    pattern has no parameters, an empty array is returned.
 */
UrlMatcher.prototype.parameters = function (param) {
  if (!isDefined(param)) return this.$$paramNames;
  return this.params[param] || null;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:UrlMatcher#validate
 * @methodOf ui.router.util.type:UrlMatcher
 *
 * @description
 * Checks an object hash of parameters to validate their correctness according to the parameter
 * types of this `UrlMatcher`.
 *
 * @param {Object} params The object hash of parameters to validate.
 * @returns {boolean} Returns `true` if `params` validates, otherwise `false`.
 */
UrlMatcher.prototype.validates = function (params) {
  return this.params.$$validates(params);
};

/**
 * @ngdoc function
 * @name ui.router.util.type:UrlMatcher#format
 * @methodOf ui.router.util.type:UrlMatcher
 *
 * @description
 * Creates a URL that matches this pattern by substituting the specified values
 * for the path and search parameters. Null values for path parameters are
 * treated as empty strings.
 *
 * @example
 * <pre>
 * new UrlMatcher('/user/{id}?q').format({ id:'bob', q:'yes' });
 * // returns '/user/bob?q=yes'
 * </pre>
 *
 * @param {Object} values  the values to substitute for the parameters in this pattern.
 * @returns {string}  the formatted URL (path and optionally search part).
 */
UrlMatcher.prototype.format = function (values) {
  values = values || {};
  var segments = this.segments, params = this.parameters(), paramset = this.params;
  if (!this.validates(values)) return null;

  var i, search = false, nPath = segments.length - 1, nTotal = params.length, result = segments[0];

  function encodeDashes(str) { // Replace dashes with encoded "\-"
    return encodeURIComponent(str).replace(/-/g, function(c) { return '%5C%' + c.charCodeAt(0).toString(16).toUpperCase(); });
  }

  for (i = 0; i < nTotal; i++) {
    var isPathParam = i < nPath;
    var name = params[i], param = paramset[name], value = param.value(values[name]);
    var isDefaultValue = param.isOptional && param.type.equals(param.value(), value);
    var squash = isDefaultValue ? param.squash : false;
    var encoded = param.type.encode(value);

    if (isPathParam) {
      var nextSegment = segments[i + 1];
      if (squash === false) {
        if (encoded != null) {
          if (isArray(encoded)) {
            result += map(encoded, encodeDashes).join("-");
          } else {
            result += encodeURIComponent(encoded);
          }
        }
        result += nextSegment;
      } else if (squash === true) {
        var capture = result.match(/\/$/) ? /\/?(.*)/ : /(.*)/;
        result += nextSegment.match(capture)[1];
      } else if (isString(squash)) {
        result += squash + nextSegment;
      }
    } else {
      if (encoded == null || (isDefaultValue && squash !== false)) continue;
      if (!isArray(encoded)) encoded = [ encoded ];
      encoded = map(encoded, encodeURIComponent).join('&' + name + '=');
      result += (search ? '&' : '?') + (name + '=' + encoded);
      search = true;
    }
  }

  return result;
};

/**
 * @ngdoc object
 * @name ui.router.util.type:Type
 *
 * @description
 * Implements an interface to define custom parameter types that can be decoded from and encoded to
 * string parameters matched in a URL. Used by {@link ui.router.util.type:UrlMatcher `UrlMatcher`}
 * objects when matching or formatting URLs, or comparing or validating parameter values.
 *
 * See {@link ui.router.util.$urlMatcherFactory#methods_type `$urlMatcherFactory#type()`} for more
 * information on registering custom types.
 *
 * @param {Object} config  A configuration object which contains the custom type definition.  The object's
 *        properties will override the default methods and/or pattern in `Type`'s public interface.
 * @example
 * <pre>
 * {
 *   decode: function(val) { return parseInt(val, 10); },
 *   encode: function(val) { return val && val.toString(); },
 *   equals: function(a, b) { return this.is(a) && a === b; },
 *   is: function(val) { return angular.isNumber(val) isFinite(val) && val % 1 === 0; },
 *   pattern: /\d+/
 * }
 * </pre>
 *
 * @property {RegExp} pattern The regular expression pattern used to match values of this type when
 *           coming from a substring of a URL.
 *
 * @returns {Object}  Returns a new `Type` object.
 */
function Type(config) {
  extend(this, config);
}

/**
 * @ngdoc function
 * @name ui.router.util.type:Type#is
 * @methodOf ui.router.util.type:Type
 *
 * @description
 * Detects whether a value is of a particular type. Accepts a native (decoded) value
 * and determines whether it matches the current `Type` object.
 *
 * @param {*} val  The value to check.
 * @param {string} key  Optional. If the type check is happening in the context of a specific
 *        {@link ui.router.util.type:UrlMatcher `UrlMatcher`} object, this is the name of the
 *        parameter in which `val` is stored. Can be used for meta-programming of `Type` objects.
 * @returns {Boolean}  Returns `true` if the value matches the type, otherwise `false`.
 */
Type.prototype.is = function(val, key) {
  return true;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:Type#encode
 * @methodOf ui.router.util.type:Type
 *
 * @description
 * Encodes a custom/native type value to a string that can be embedded in a URL. Note that the
 * return value does *not* need to be URL-safe (i.e. passed through `encodeURIComponent()`), it
 * only needs to be a representation of `val` that has been coerced to a string.
 *
 * @param {*} val  The value to encode.
 * @param {string} key  The name of the parameter in which `val` is stored. Can be used for
 *        meta-programming of `Type` objects.
 * @returns {string}  Returns a string representation of `val` that can be encoded in a URL.
 */
Type.prototype.encode = function(val, key) {
  return val;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:Type#decode
 * @methodOf ui.router.util.type:Type
 *
 * @description
 * Converts a parameter value (from URL string or transition param) to a custom/native value.
 *
 * @param {string} val  The URL parameter value to decode.
 * @param {string} key  The name of the parameter in which `val` is stored. Can be used for
 *        meta-programming of `Type` objects.
 * @returns {*}  Returns a custom representation of the URL parameter value.
 */
Type.prototype.decode = function(val, key) {
  return val;
};

/**
 * @ngdoc function
 * @name ui.router.util.type:Type#equals
 * @methodOf ui.router.util.type:Type
 *
 * @description
 * Determines whether two decoded values are equivalent.
 *
 * @param {*} a  A value to compare against.
 * @param {*} b  A value to compare against.
 * @returns {Boolean}  Returns `true` if the values are equivalent/equal, otherwise `false`.
 */
Type.prototype.equals = function(a, b) {
  return a == b;
};

Type.prototype.$subPattern = function() {
  var sub = this.pattern.toString();
  return sub.substr(1, sub.length - 2);
};

Type.prototype.pattern = /.*/;

Type.prototype.toString = function() { return "{Type:" + this.name + "}"; };

/** Given an encoded string, or a decoded object, returns a decoded object */
Type.prototype.$normalize = function(val) {
  return this.is(val) ? val : this.decode(val);
};

/*
 * Wraps an existing custom Type as an array of Type, depending on 'mode'.
 * e.g.:
 * - urlmatcher pattern "/path?{queryParam[]:int}"
 * - url: "/path?queryParam=1&queryParam=2
 * - $stateParams.queryParam will be [1, 2]
 * if `mode` is "auto", then
 * - url: "/path?queryParam=1 will create $stateParams.queryParam: 1
 * - url: "/path?queryParam=1&queryParam=2 will create $stateParams.queryParam: [1, 2]
 */
Type.prototype.$asArray = function(mode, isSearch) {
  if (!mode) return this;
  if (mode === "auto" && !isSearch) throw new Error("'auto' array mode is for query parameters only");

  function ArrayType(type, mode) {
    function bindTo(type, callbackName) {
      return function() {
        return type[callbackName].apply(type, arguments);
      };
    }

    // Wrap non-array value as array
    function arrayWrap(val) { return isArray(val) ? val : (isDefined(val) ? [ val ] : []); }
    // Unwrap array value for "auto" mode. Return undefined for empty array.
    function arrayUnwrap(val) {
      switch(val.length) {
        case 0: return undefined;
        case 1: return mode === "auto" ? val[0] : val;
        default: return val;
      }
    }
    function falsey(val) { return !val; }

    // Wraps type (.is/.encode/.decode) functions to operate on each value of an array
    function arrayHandler(callback, allTruthyMode) {
      return function handleArray(val) {
        val = arrayWrap(val);
        var result = map(val, callback);
        if (allTruthyMode === true)
          return filter(result, falsey).length === 0;
        return arrayUnwrap(result);
      };
    }

    // Wraps type (.equals) functions to operate on each value of an array
    function arrayEqualsHandler(callback) {
      return function handleArray(val1, val2) {
        var left = arrayWrap(val1), right = arrayWrap(val2);
        if (left.length !== right.length) return false;
        for (var i = 0; i < left.length; i++) {
          if (!callback(left[i], right[i])) return false;
        }
        return true;
      };
    }

    this.encode = arrayHandler(bindTo(type, 'encode'));
    this.decode = arrayHandler(bindTo(type, 'decode'));
    this.is     = arrayHandler(bindTo(type, 'is'), true);
    this.equals = arrayEqualsHandler(bindTo(type, 'equals'));
    this.pattern = type.pattern;
    this.$normalize = arrayHandler(bindTo(type, '$normalize'));
    this.name = type.name;
    this.$arrayMode = mode;
  }

  return new ArrayType(this, mode);
};



/**
 * @ngdoc object
 * @name ui.router.util.$urlMatcherFactory
 *
 * @description
 * Factory for {@link ui.router.util.type:UrlMatcher `UrlMatcher`} instances. The factory
 * is also available to providers under the name `$urlMatcherFactoryProvider`.
 */
function $UrlMatcherFactory() {
  $$UMFP = this;

  var isCaseInsensitive = false, isStrictMode = true, defaultSquashPolicy = false;

  function valToString(val) { return val != null ? val.toString().replace(/\//g, "%2F") : val; }
  function valFromString(val) { return val != null ? val.toString().replace(/%2F/g, "/") : val; }
//  TODO: in 1.0, make string .is() return false if value is undefined by default.
//  function regexpMatches(val) { /*jshint validthis:true */ return isDefined(val) && this.pattern.test(val); }
  function regexpMatches(val) { /*jshint validthis:true */ return this.pattern.test(val); }

  var $types = {}, enqueue = true, typeQueue = [], injector, defaultTypes = {
    string: {
      encode: valToString,
      decode: valFromString,
      is: function(val) { return typeof val === "string"; },
      pattern: /[^/]*/
    },
    int: {
      encode: valToString,
      decode: function(val) { return parseInt(val, 10); },
      is: function(val) { return isDefined(val) && this.decode(val.toString()) === val; },
      pattern: /\d+/
    },
    bool: {
      encode: function(val) { return val ? 1 : 0; },
      decode: function(val) { return parseInt(val, 10) !== 0; },
      is: function(val) { return val === true || val === false; },
      pattern: /0|1/
    },
    date: {
      encode: function (val) {
        if (!this.is(val))
          return undefined;
        return [ val.getFullYear(),
          ('0' + (val.getMonth() + 1)).slice(-2),
          ('0' + val.getDate()).slice(-2)
        ].join("-");
      },
      decode: function (val) {
        if (this.is(val)) return val;
        var match = this.capture.exec(val);
        return match ? new Date(match[1], match[2] - 1, match[3]) : undefined;
      },
      is: function(val) { return val instanceof Date && !isNaN(val.valueOf()); },
      equals: function (a, b) { return this.is(a) && this.is(b) && a.toISOString() === b.toISOString(); },
      pattern: /[0-9]{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[1-2][0-9]|3[0-1])/,
      capture: /([0-9]{4})-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])/
    },
    json: {
      encode: angular.toJson,
      decode: angular.fromJson,
      is: angular.isObject,
      equals: angular.equals,
      pattern: /[^/]*/
    },
    any: { // does not encode/decode
      encode: angular.identity,
      decode: angular.identity,
      is: angular.identity,
      equals: angular.equals,
      pattern: /.*/
    }
  };

  function getDefaultConfig() {
    return {
      strict: isStrictMode,
      caseInsensitive: isCaseInsensitive
    };
  }

  function isInjectable(value) {
    return (isFunction(value) || (isArray(value) && isFunction(value[value.length - 1])));
  }

  /**
   * [Internal] Get the default value of a parameter, which may be an injectable function.
   */
  $UrlMatcherFactory.$$getDefaultValue = function(config) {
    if (!isInjectable(config.value)) return config.value;
    if (!injector) throw new Error("Injectable functions cannot be called at configuration time");
    return injector.invoke(config.value);
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#caseInsensitive
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Defines whether URL matching should be case sensitive (the default behavior), or not.
   *
   * @param {boolean} value `false` to match URL in a case sensitive manner; otherwise `true`;
   * @returns {boolean} the current value of caseInsensitive
   */
  this.caseInsensitive = function(value) {
    if (isDefined(value))
      isCaseInsensitive = value;
    return isCaseInsensitive;
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#strictMode
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Defines whether URLs should match trailing slashes, or not (the default behavior).
   *
   * @param {boolean=} value `false` to match trailing slashes in URLs, otherwise `true`.
   * @returns {boolean} the current value of strictMode
   */
  this.strictMode = function(value) {
    if (isDefined(value))
      isStrictMode = value;
    return isStrictMode;
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#defaultSquashPolicy
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Sets the default behavior when generating or matching URLs with default parameter values.
   *
   * @param {string} value A string that defines the default parameter URL squashing behavior.
   *    `nosquash`: When generating an href with a default parameter value, do not squash the parameter value from the URL
   *    `slash`: When generating an href with a default parameter value, squash (remove) the parameter value, and, if the
   *             parameter is surrounded by slashes, squash (remove) one slash from the URL
   *    any other string, e.g. "~": When generating an href with a default parameter value, squash (remove)
   *             the parameter value from the URL and replace it with this string.
   */
  this.defaultSquashPolicy = function(value) {
    if (!isDefined(value)) return defaultSquashPolicy;
    if (value !== true && value !== false && !isString(value))
      throw new Error("Invalid squash policy: " + value + ". Valid policies: false, true, arbitrary-string");
    defaultSquashPolicy = value;
    return value;
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#compile
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Creates a {@link ui.router.util.type:UrlMatcher `UrlMatcher`} for the specified pattern.
   *
   * @param {string} pattern  The URL pattern.
   * @param {Object} config  The config object hash.
   * @returns {UrlMatcher}  The UrlMatcher.
   */
  this.compile = function (pattern, config) {
    return new UrlMatcher(pattern, extend(getDefaultConfig(), config));
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#isMatcher
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Returns true if the specified object is a `UrlMatcher`, or false otherwise.
   *
   * @param {Object} object  The object to perform the type check against.
   * @returns {Boolean}  Returns `true` if the object matches the `UrlMatcher` interface, by
   *          implementing all the same methods.
   */
  this.isMatcher = function (o) {
    if (!isObject(o)) return false;
    var result = true;

    forEach(UrlMatcher.prototype, function(val, name) {
      if (isFunction(val)) {
        result = result && (isDefined(o[name]) && isFunction(o[name]));
      }
    });
    return result;
  };

  /**
   * @ngdoc function
   * @name ui.router.util.$urlMatcherFactory#type
   * @methodOf ui.router.util.$urlMatcherFactory
   *
   * @description
   * Registers a custom {@link ui.router.util.type:Type `Type`} object that can be used to
   * generate URLs with typed parameters.
   *
   * @param {string} name  The type name.
   * @param {Object|Function} definition   The type definition. See
   *        {@link ui.router.util.type:Type `Type`} for information on the values accepted.
   * @param {Object|Function} definitionFn (optional) A function that is injected before the app
   *        runtime starts.  The result of this function is merged into the existing `definition`.
   *        See {@link ui.router.util.type:Type `Type`} for information on the values accepted.
   *
   * @returns {Object}  Returns `$urlMatcherFactoryProvider`.
   *
   * @example
   * This is a simple example of a custom type that encodes and decodes items from an
   * array, using the array index as the URL-encoded value:
   *
   * <pre>
   * var list = ['John', 'Paul', 'George', 'Ringo'];
   *
   * $urlMatcherFactoryProvider.type('listItem', {
   *   encode: function(item) {
   *     // Represent the list item in the URL using its corresponding index
   *     return list.indexOf(item);
   *   },
   *   decode: function(item) {
   *     // Look up the list item by index
   *     return list[parseInt(item, 10)];
   *   },
   *   is: function(item) {
   *     // Ensure the item is valid by checking to see that it appears
   *     // in the list
   *     return list.indexOf(item) > -1;
   *   }
   * });
   *
   * $stateProvider.state('list', {
   *   url: "/list/{item:listItem}",
   *   controller: function($scope, $stateParams) {
   *     console.log($stateParams.item);
   *   }
   * });
   *
   * // ...
   *
   * // Changes URL to '/list/3', logs "Ringo" to the console
   * $state.go('list', { item: "Ringo" });
   * </pre>
   *
   * This is a more complex example of a type that relies on dependency injection to
   * interact with services, and uses the parameter name from the URL to infer how to
   * handle encoding and decoding parameter values:
   *
   * <pre>
   * // Defines a custom type that gets a value from a service,
   * // where each service gets different types of values from
   * // a backend API:
   * $urlMatcherFactoryProvider.type('dbObject', {}, function(Users, Posts) {
   *
   *   // Matches up services to URL parameter names
   *   var services = {
   *     user: Users,
   *     post: Posts
   *   };
   *
   *   return {
   *     encode: function(object) {
   *       // Represent the object in the URL using its unique ID
   *       return object.id;
   *     },
   *     decode: function(value, key) {
   *       // Look up the object by ID, using the parameter
   *       // name (key) to call the correct service
   *       return services[key].findById(value);
   *     },
   *     is: function(object, key) {
   *       // Check that object is a valid dbObject
   *       return angular.isObject(object) && object.id && services[key];
   *     }
   *     equals: function(a, b) {
   *       // Check the equality of decoded objects by comparing
   *       // their unique IDs
   *       return a.id === b.id;
   *     }
   *   };
   * });
   *
   * // In a config() block, you can then attach URLs with
   * // type-annotated parameters:
   * $stateProvider.state('users', {
   *   url: "/users",
   *   // ...
   * }).state('users.item', {
   *   url: "/{user:dbObject}",
   *   controller: function($scope, $stateParams) {
   *     // $stateParams.user will now be an object returned from
   *     // the Users service
   *   },
   *   // ...
   * });
   * </pre>
   */
  this.type = function (name, definition, definitionFn) {
    if (!isDefined(definition)) return $types[name];
    if ($types.hasOwnProperty(name)) throw new Error("A type named '" + name + "' has already been defined.");

    $types[name] = new Type(extend({ name: name }, definition));
    if (definitionFn) {
      typeQueue.push({ name: name, def: definitionFn });
      if (!enqueue) flushTypeQueue();
    }
    return this;
  };

  // `flushTypeQueue()` waits until `$urlMatcherFactory` is injected before invoking the queued `definitionFn`s
  function flushTypeQueue() {
    while(typeQueue.length) {
      var type = typeQueue.shift();
      if (type.pattern) throw new Error("You cannot override a type's .pattern at runtime.");
      angular.extend($types[type.name], injector.invoke(type.def));
    }
  }

  // Register default types. Store them in the prototype of $types.
  forEach(defaultTypes, function(type, name) { $types[name] = new Type(extend({name: name}, type)); });
  $types = inherit($types, {});

  /* No need to document $get, since it returns this */
  this.$get = ['$injector', function ($injector) {
    injector = $injector;
    enqueue = false;
    flushTypeQueue();

    forEach(defaultTypes, function(type, name) {
      if (!$types[name]) $types[name] = new Type(type);
    });
    return this;
  }];

  this.Param = function Param(id, type, config, location) {
    var self = this;
    config = unwrapShorthand(config);
    type = getType(config, type, location);
    var arrayMode = getArrayMode();
    type = arrayMode ? type.$asArray(arrayMode, location === "search") : type;
    if (type.name === "string" && !arrayMode && location === "path" && config.value === undefined)
      config.value = ""; // for 0.2.x; in 0.3.0+ do not automatically default to ""
    var isOptional = config.value !== undefined;
    var squash = getSquashPolicy(config, isOptional);
    var replace = getReplace(config, arrayMode, isOptional, squash);

    function unwrapShorthand(config) {
      var keys = isObject(config) ? objectKeys(config) : [];
      var isShorthand = indexOf(keys, "value") === -1 && indexOf(keys, "type") === -1 &&
                        indexOf(keys, "squash") === -1 && indexOf(keys, "array") === -1;
      if (isShorthand) config = { value: config };
      config.$$fn = isInjectable(config.value) ? config.value : function () { return config.value; };
      return config;
    }

    function getType(config, urlType, location) {
      if (config.type && urlType) throw new Error("Param '"+id+"' has two type configurations.");
      if (urlType) return urlType;
      if (!config.type) return (location === "config" ? $types.any : $types.string);
      return config.type instanceof Type ? config.type : new Type(config.type);
    }

    // array config: param name (param[]) overrides default settings.  explicit config overrides param name.
    function getArrayMode() {
      var arrayDefaults = { array: (location === "search" ? "auto" : false) };
      var arrayParamNomenclature = id.match(/\[\]$/) ? { array: true } : {};
      return extend(arrayDefaults, arrayParamNomenclature, config).array;
    }

    /**
     * returns false, true, or the squash value to indicate the "default parameter url squash policy".
     */
    function getSquashPolicy(config, isOptional) {
      var squash = config.squash;
      if (!isOptional || squash === false) return false;
      if (!isDefined(squash) || squash == null) return defaultSquashPolicy;
      if (squash === true || isString(squash)) return squash;
      throw new Error("Invalid squash policy: '" + squash + "'. Valid policies: false, true, or arbitrary string");
    }

    function getReplace(config, arrayMode, isOptional, squash) {
      var replace, configuredKeys, defaultPolicy = [
        { from: "",   to: (isOptional || arrayMode ? undefined : "") },
        { from: null, to: (isOptional || arrayMode ? undefined : "") }
      ];
      replace = isArray(config.replace) ? config.replace : [];
      if (isString(squash))
        replace.push({ from: squash, to: undefined });
      configuredKeys = map(replace, function(item) { return item.from; } );
      return filter(defaultPolicy, function(item) { return indexOf(configuredKeys, item.from) === -1; }).concat(replace);
    }

    /**
     * [Internal] Get the default value of a parameter, which may be an injectable function.
     */
    function $$getDefaultValue() {
      if (!injector) throw new Error("Injectable functions cannot be called at configuration time");
      var defaultValue = injector.invoke(config.$$fn);
      if (defaultValue !== null && defaultValue !== undefined && !self.type.is(defaultValue))
        throw new Error("Default value (" + defaultValue + ") for parameter '" + self.id + "' is not an instance of Type (" + self.type.name + ")");
      return defaultValue;
    }

    /**
     * [Internal] Gets the decoded representation of a value if the value is defined, otherwise, returns the
     * default value, which may be the result of an injectable function.
     */
    function $value(value) {
      function hasReplaceVal(val) { return function(obj) { return obj.from === val; }; }
      function $replace(value) {
        var replacement = map(filter(self.replace, hasReplaceVal(value)), function(obj) { return obj.to; });
        return replacement.length ? replacement[0] : value;
      }
      value = $replace(value);
      return !isDefined(value) ? $$getDefaultValue() : self.type.$normalize(value);
    }

    function toString() { return "{Param:" + id + " " + type + " squash: '" + squash + "' optional: " + isOptional + "}"; }

    extend(this, {
      id: id,
      type: type,
      location: location,
      array: arrayMode,
      squash: squash,
      replace: replace,
      isOptional: isOptional,
      value: $value,
      dynamic: undefined,
      config: config,
      toString: toString
    });
  };

  function ParamSet(params) {
    extend(this, params || {});
  }

  ParamSet.prototype = {
    $$new: function() {
      return inherit(this, extend(new ParamSet(), { $$parent: this}));
    },
    $$keys: function () {
      var keys = [], chain = [], parent = this,
        ignore = objectKeys(ParamSet.prototype);
      while (parent) { chain.push(parent); parent = parent.$$parent; }
      chain.reverse();
      forEach(chain, function(paramset) {
        forEach(objectKeys(paramset), function(key) {
            if (indexOf(keys, key) === -1 && indexOf(ignore, key) === -1) keys.push(key);
        });
      });
      return keys;
    },
    $$values: function(paramValues) {
      var values = {}, self = this;
      forEach(self.$$keys(), function(key) {
        values[key] = self[key].value(paramValues && paramValues[key]);
      });
      return values;
    },
    $$equals: function(paramValues1, paramValues2) {
      var equal = true, self = this;
      forEach(self.$$keys(), function(key) {
        var left = paramValues1 && paramValues1[key], right = paramValues2 && paramValues2[key];
        if (!self[key].type.equals(left, right)) equal = false;
      });
      return equal;
    },
    $$validates: function $$validate(paramValues) {
      var keys = this.$$keys(), i, param, rawVal, normalized, encoded;
      for (i = 0; i < keys.length; i++) {
        param = this[keys[i]];
        rawVal = paramValues[keys[i]];
        if ((rawVal === undefined || rawVal === null) && param.isOptional)
          break; // There was no parameter value, but the param is optional
        normalized = param.type.$normalize(rawVal);
        if (!param.type.is(normalized))
          return false; // The value was not of the correct Type, and could not be decoded to the correct Type
        encoded = param.type.encode(normalized);
        if (angular.isString(encoded) && !param.type.pattern.exec(encoded))
          return false; // The value was of the correct type, but when encoded, did not match the Type's regexp
      }
      return true;
    },
    $$parent: undefined
  };

  this.ParamSet = ParamSet;
}

// Register as a provider so it's available to other providers
angular.module('ui.router.util').provider('$urlMatcherFactory', $UrlMatcherFactory);
angular.module('ui.router.util').run(['$urlMatcherFactory', function($urlMatcherFactory) { }]);
