// namespaces
var dwv = dwv || {};
/** @namespace */
dwv.utils = dwv.utils || {};

/**
 * Capitalise the first letter of a string.
 * @param {String} string The string to capitalise the first letter.
 * @return {String} The new string.
 */
dwv.utils.capitaliseFirstLetter = function (string)
{
    var res = string;
    if ( string ) {
        res = string.charAt(0).toUpperCase() + string.slice(1);
    }
    return res;
};

/**
 * Split key/value string:
 *  key0=val00&key0=val01&key1=val10 returns
 *  { key0 : [val00, val01], key1 : val1 }
 * @param {String} inputStr The string to split.
 * @return {Object} The split string.
 */
dwv.utils.splitKeyValueString = function (inputStr)
{
    // result
    var result = {};
    // check input string
    if ( inputStr ) {
         // split key/value pairs
        var pairs = inputStr.split('&');
        for ( var i = 0; i < pairs.length; ++i )
        {
            var pair = pairs[i].split('=');
            // if the key does not exist, create it
            if ( !result[pair[0]] )
            {
                result[pair[0]] = pair[1];
            }
            else
            {
                // make it an array
                if ( !( result[pair[0]] instanceof Array ) ) {
                    result[pair[0]] = [result[pair[0]]];
                }
                result[pair[0]].push(pair[1]);
            }
        }
    }
    return result;
};

/**
 * Replace flags in a input string. Flags are keywords surrounded with curly
 * braces.
 * @param {String} inputStr The input string.
 * @param {Object} values A object of {value, unit}.
 * @example
 *    var values = {"length": { "value": 33, "unit": "cm" } };
 *    var str = "The length is: {length}.";
 *    var res = dwv.utils.replaceFlags(str, values); // "The length is: 33 cm."
 * @return {String} The result string.
 */
dwv.utils.replaceFlags = function (inputStr, values)
{
    var res = "";
    // check input string
    if (inputStr === null || typeof inputStr === "undefined") {
        return res;
    }
    res = inputStr;
    // check values
    if (values === null || typeof values === "undefined") {
        return res;
    }
    // loop through values keys
    var keys = Object.keys(values);
    for (var i = 0; i < keys.length; ++i) {
        var valueObj = values[keys[i]];
        if ( valueObj !== null && typeof valueObj !== "undefined" &&
            valueObj.value !== null && typeof valueObj.value !== "undefined") {
            // value string
            var valueStr = valueObj.value.toPrecision(4);
            // add unit if available
            // space or no space? Yes apart from degree...
            // check: https://en.wikipedia.org/wiki/Space_(punctuation)#Spaces_and_unit_symbols
            if (valueObj.unit !== null && typeof valueObj.unit !== "undefined" &&
                valueObj.unit.length !== 0) {
                if (valueObj.unit !== "degree") {
                    valueStr += " ";
                }
                valueStr += valueObj.unit;
            }
            // flag to replace
            var flag = '{' + keys[i] + '}';
            // replace
            res = res.replace(flag, valueStr);
        }
    }
    // return
    return res;
};

/**
 * Replace flags in a input string. Flags are keywords surrounded with curly
 * braces.
 * @param {String} inputStr The input string.
 * @param {Array} values An array of strings.
 * @example
 *    var values = ["a", "b"];
 *    var str = "The length is: {v0}. The size is: {v1}";
 *    var res = dwv.utils.replaceFlags2(str, values); // "The length is: a. The size is: b"
 * @return {String} The result string.
 */
dwv.utils.replaceFlags2 = function (inputStr, values)
{
    var res = inputStr;
    for ( var j = 0; j < values.length; ++j ) {
        res = res.replace("{v"+j+"}", values[j]);
    }
    return res;
};

dwv.utils.createDefaultReplaceFormat = function (values)
{
    var res = "";
    for ( var j = 0; j < values.length; ++j ) {
        if ( j !== 0 ) {
            res += ", ";
        }
        res += "{v"+j+"}";
    }
    return res;
};