/* Copyright (c) 2006-2012 by OpenLayers Contributors (see authors.txt for 
 * full list of contributors). Published under the Clear BSD license.  
 * See http://svn.openlayers.org/trunk/openlayers/license.txt for the
 * full text of the license. */

/** 
 * Header: OpenLayers Base Types
 * OpenLayers custom string, number and function functions are described here.
 */

/**
 * Namespace: OpenLayers.String
 * Contains convenience functions for string manipulation.
 */
OpenLayers.String = {

    /**
     * APIFunction: startsWith
     * Test whether a string starts with another string. 
     * 
     * Parameters:
     * str - {String} The string to test.
     * sub - {String} The substring to look for.
     *  
     * Returns:
     * {Boolean} The first string starts with the second.
     */
    startsWith: function(str, sub) {
        return (str.indexOf(sub) == 0);
    },

    /**
     * APIFunction: contains
     * Test whether a string contains another string.
     * 
     * Parameters:
     * str - {String} The string to test.
     * sub - {String} The substring to look for.
     * 
     * Returns:
     * {Boolean} The first string contains the second.
     */
    contains: function(str, sub) {
        return (str.indexOf(sub) != -1);
    },
    
    /**
     * APIFunction: trim
     * Removes leading and trailing whitespace characters from a string.
     * 
     * Parameters:
     * str - {String} The (potentially) space padded string.  This string is not
     *     modified.
     * 
     * Returns:
     * {String} A trimmed version of the string with all leading and 
     *     trailing spaces removed.
     */
    trim: function(str) {
        return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
    },
    
    /**
     * APIFunction: camelize
     * Camel-case a hyphenated string. 
     *     Ex. "chicken-head" becomes "chickenHead", and
     *     "-chicken-head" becomes "ChickenHead".
     *
     * Parameters:
     * str - {String} The string to be camelized.  The original is not modified.
     * 
     * Returns:
     * {String} The string, camelized
     */
    camelize: function(str) {
        var oStringList = str.split('-');
        var camelizedString = oStringList[0];
        for (var i=1, len=oStringList.length; i<len; i++) {
            var s = oStringList[i];
            camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
        }
        return camelizedString;
    },
    
    /**
     * APIFunction: format
     * Given a string with tokens in the form ${token}, return a string
     *     with tokens replaced with properties from the given context
     *     object.  Represent a literal "${" by doubling it, e.g. "${${".
     *
     * Parameters:
     * template - {String} A string with tokens to be replaced.  A template
     *     has the form "literal ${token}" where the token will be replaced
     *     by the value of context["token"].
     * context - {Object} An optional object with properties corresponding
     *     to the tokens in the format string.  If no context is sent, the
     *     window object will be used.
     * args - {Array} Optional arguments to pass to any functions found in
     *     the context.  If a context property is a function, the token
     *     will be replaced by the return from the function called with
     *     these arguments.
     *
     * Returns:
     * {String} A string with tokens replaced from the context object.
     */
    format: function(template, context, args) {
        if(!context) {
            context = window;
        }

        // Example matching: 
        // str   = ${foo.bar}
        // match = foo.bar
        var replacer = function(str, match) {
            var replacement;

            // Loop through all subs. Example: ${a.b.c}
            // 0 -> replacement = context[a];
            // 1 -> replacement = context[a][b];
            // 2 -> replacement = context[a][b][c];
            var subs = match.split(/\.+/);
            for (var i=0; i< subs.length; i++) {
                if (i == 0) {
                    replacement = context;
                }

                replacement = replacement[subs[i]];
            }

            if(typeof replacement == "function") {
                replacement = args ?
                    replacement.apply(null, args) :
                    replacement();
            }

            // If replacement is undefined, return the string 'undefined'.
            // This is a workaround for a bugs in browsers not properly 
            // dealing with non-participating groups in regular expressions:
            // http://blog.stevenlevithan.com/archives/npcg-javascript
            if (typeof replacement == 'undefined') {
                return 'undefined';
            } else {
                return replacement; 
            }
        };

        return template.replace(OpenLayers.String.tokenRegEx, replacer);
    },

    /**
     * Property: tokenRegEx
     * Used to find tokens in a string.
     * Examples: ${a}, ${a.b.c}, ${a-b}, ${5}
     */
    tokenRegEx:  /\$\{([\w.]+?)\}/g,
    
    /**
     * Property: numberRegEx
     * Used to test strings as numbers.
     */
    numberRegEx: /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/,
    
    /**
     * APIFunction: isNumeric
     * Determine whether a string contains only a numeric value.
     *
     * Examples:
     * (code)
     * OpenLayers.String.isNumeric("6.02e23") // true
     * OpenLayers.String.isNumeric("12 dozen") // false
     * OpenLayers.String.isNumeric("4") // true
     * OpenLayers.String.isNumeric(" 4 ") // false
     * (end)
     *
     * Returns:
     * {Boolean} String contains only a number.
     */
    isNumeric: function(value) {
        return OpenLayers.String.numberRegEx.test(value);
    },
    
    /**
     * APIFunction: numericIf
     * Converts a string that appears to be a numeric value into a number.
     * 
     * Returns
     * {Number|String} a Number if the passed value is a number, a String
     *     otherwise. 
     */
    numericIf: function(value) {
        return OpenLayers.String.isNumeric(value) ? parseFloat(value) : value;
    }

};

/**
 * Namespace: OpenLayers.Number
 * Contains convenience functions for manipulating numbers.
 */
OpenLayers.Number = {

    /**
     * Property: decimalSeparator
     * Decimal separator to use when formatting numbers.
     */
    decimalSeparator: ".",
    
    /**
     * Property: thousandsSeparator
     * Thousands separator to use when formatting numbers.
     */
    thousandsSeparator: ",",
    
    /**
     * APIFunction: limitSigDigs
     * Limit the number of significant digits on a float.
     * 
     * Parameters:
     * num - {Float}
     * sig - {Integer}
     * 
     * Returns:
     * {Float} The number, rounded to the specified number of significant
     *     digits.
     */
    limitSigDigs: function(num, sig) {
        var fig = 0;
        if (sig > 0) {
            fig = parseFloat(num.toPrecision(sig));
        }
        return fig;
    },
    
    /**
     * APIFunction: format
     * Formats a number for output.
     * 
     * Parameters:
     * num  - {Float}
     * dec  - {Integer} Number of decimal places to round to.
     *        Defaults to 0. Set to null to leave decimal places unchanged.
     * tsep - {String} Thousands separator.
     *        Default is ",".
     * dsep - {String} Decimal separator.
     *        Default is ".".
     *
     * Returns:
     * {String} A string representing the formatted number.
     */
    format: function(num, dec, tsep, dsep) {
        dec = (typeof dec != "undefined") ? dec : 0; 
        tsep = (typeof tsep != "undefined") ? tsep :
            OpenLayers.Number.thousandsSeparator; 
        dsep = (typeof dsep != "undefined") ? dsep :
            OpenLayers.Number.decimalSeparator;

        if (dec != null) {
            num = parseFloat(num.toFixed(dec));
        }

        var parts = num.toString().split(".");
        if (parts.length == 1 && dec == null) {
            // integer where we do not want to touch the decimals
            dec = 0;
        }
        
        var integer = parts[0];
        if (tsep) {
            var thousands = /(-?[0-9]+)([0-9]{3})/; 
            while(thousands.test(integer)) { 
                integer = integer.replace(thousands, "$1" + tsep + "$2"); 
            }
        }
        
        var str;
        if (dec == 0) {
            str = integer;
        } else {
            var rem = parts.length > 1 ? parts[1] : "0";
            if (dec != null) {
                rem = rem + new Array(dec - rem.length + 1).join("0");
            }
            str = integer + dsep + rem;
        }
        return str;
    }
};

/**
 * Namespace: OpenLayers.Function
 * Contains convenience functions for function manipulation.
 */
OpenLayers.Function = {
    /**
     * APIFunction: bind
     * Bind a function to an object.  Method to easily create closures with
     *     'this' altered.
     * 
     * Parameters:
     * func - {Function} Input function.
     * object - {Object} The object to bind to the input function (as this).
     * 
     * Returns:
     * {Function} A closure with 'this' set to the passed in object.
     */
    bind: function(func, object) {
        // create a reference to all arguments past the second one
        var args = Array.prototype.slice.apply(arguments, [2]);
        return function() {
            // Push on any additional arguments from the actual function call.
            // These will come after those sent to the bind call.
            var newArgs = args.concat(
                Array.prototype.slice.apply(arguments, [0])
            );
            return func.apply(object, newArgs);
        };
    },
    
    /**
     * APIFunction: bindAsEventListener
     * Bind a function to an object, and configure it to receive the event
     *     object as first parameter when called. 
     * 
     * Parameters:
     * func - {Function} Input function to serve as an event listener.
     * object - {Object} A reference to this.
     * 
     * Returns:
     * {Function}
     */
    bindAsEventListener: function(func, object) {
        return function(event) {
            return func.call(object, event || window.event);
        };
    },
    
    /**
     * APIFunction: False
     * A simple function to that just does "return false". We use this to 
     * avoid attaching anonymous functions to DOM event handlers, which 
     * causes "issues" on IE<8.
     * 
     * Usage:
     * document.onclick = OpenLayers.Function.False;
     * 
     * Returns:
     * {Boolean}
     */
    False : function() {
        return false;
    },

    /**
     * APIFunction: True
     * A simple function to that just does "return true". We use this to 
     * avoid attaching anonymous functions to DOM event handlers, which 
     * causes "issues" on IE<8.
     * 
     * Usage:
     * document.onclick = OpenLayers.Function.True;
     * 
     * Returns:
     * {Boolean}
     */
    True : function() {
        return true;
    },
    
    /**
     * APIFunction: Void
     * A reusable function that returns ``undefined``.
     *
     * Returns:
     * {undefined}
     */
    Void: function() {}

};

/**
 * Namespace: OpenLayers.Array
 * Contains convenience functions for array manipulation.
 */
OpenLayers.Array = {

    /**
     * APIMethod: filter
     * Filter an array.  Provides the functionality of the
     *     Array.prototype.filter extension to the ECMA-262 standard.  Where
     *     available, Array.prototype.filter will be used.
     *
     * Based on well known example from http://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Array/filter
     *
     * Parameters:
     * array - {Array} The array to be filtered.  This array is not mutated.
     *     Elements added to this array by the callback will not be visited.
     * callback - {Function} A function that is called for each element in
     *     the array.  If this function returns true, the element will be
     *     included in the return.  The function will be called with three
     *     arguments: the element in the array, the index of that element, and
     *     the array itself.  If the optional caller parameter is specified
     *     the callback will be called with this set to caller.
     * caller - {Object} Optional object to be set as this when the callback
     *     is called.
     *
     * Returns:
     * {Array} An array of elements from the passed in array for which the
     *     callback returns true.
     */
    filter: function(array, callback, caller) {
        var selected = [];
        if (Array.prototype.filter) {
            selected = array.filter(callback, caller);
        } else {
            var len = array.length;
            if (typeof callback != "function") {
                throw new TypeError();
            }
            for(var i=0; i<len; i++) {
                if (i in array) {
                    var val = array[i];
                    if (callback.call(caller, val, i, array)) {
                        selected.push(val);
                    }
                }
            }        
        }
        return selected;
    }
    
};
