iD.util = {};

iD.util.trueObj = function(arr) {
    var o = {};
    for (var i = 0, l = arr.length; i < l; i++) o[arr[i]] = true;
    return o;
};

iD.util.tagText = function(entity) {
    return d3.entries(entity.tags).map(function(e) {
        return e.key + '=' + e.value;
    }).join(', ');
};

iD.util.stringQs = function(str) {
    return str.split('&').reduce(function(obj, pair){
        var parts = pair.split('=');
        if (parts.length === 2) {
            obj[parts[0]] = (null === parts[1]) ? '' : decodeURIComponent(parts[1]);
        }
        return obj;
    }, {});
};

iD.util.qsString = function(obj, noencode) {
    return Object.keys(obj).sort().map(function(key) {
        return encodeURIComponent(key) + '=' + (
            noencode ? obj[key] : encodeURIComponent(obj[key]));
    }).join('&');
};

iD.util.prefixDOMProperty = function(property) {
    var prefixes = ['webkit', 'ms', 'moz', 'o'],
        i = -1,
        n = prefixes.length,
        s = document.body;

    if (property in s)
        return property;

    property = property.substr(0, 1).toUpperCase() + property.substr(1);

    while (++i < n)
        if (prefixes[i] + property in s)
            return prefixes[i] + property;

    return false;
};

iD.util.prefixCSSProperty = function(property) {
    var prefixes = ['webkit', 'ms', 'Moz', 'O'],
        i = -1,
        n = prefixes.length,
        s = document.body.style;

    if (property.toLowerCase() in s)
        return property.toLowerCase();

    while (++i < n)
        if (prefixes[i] + property in s)
            return '-' + prefixes[i].toLowerCase() + '-' + property.toLowerCase();

    return false;
};

iD.util.getStyle = function(selector) {
    for (var i = 0; i < document.styleSheets.length; i++) {
        var rules = document.styleSheets[i].rules || document.styleSheets[i].cssRules;
        for (var k = 0; k < rules.length; k++) {
            var selectorText = rules[k].selectorText && rules[k].selectorText.split(', ');
            if (_.contains(selectorText, selector)) {
                return rules[k];
            }
        }
    }
};

iD.util.getPrototypeOf = Object.getPrototypeOf || function(obj) { return obj.__proto__; };