'use strict';

exports.type = 'perItem';

exports.active = true;

exports.description = 'rounds numeric values to the fixed precision, removes default ‘px’ units';

exports.params = {
    floatPrecision: 3,
    leadingZero: true,
    defaultPx: true,
    convertToPx: true
};

var regNumericValues = /^([\-+]?\d*\.?\d+([eE][\-+]?\d+)?)(px|pt|pc|mm|cm|m|in|ft|em|ex|%)?$/,
    removeLeadingZero = require('../lib/svgo/tools').removeLeadingZero,
    absoluteLengths = { // relative to px
        cm: 96/2.54,
        mm: 9600/2.54,
        in: 96,
        pt: 4/3,
        pc: 16
    };

/**
 * Round numeric values to the fixed precision,
 * remove default 'px' units.
 *
 * @param {Object} item current iteration item
 * @param {Object} params plugin params
 * @return {Boolean} if false, item will be filtered out
 *
 * @author Kir Belevich
 */
exports.fn = function(item, params) {

    if (item.isElem()) {

        var match;

        item.eachAttr(function(attr) {
            match = attr.value.match(regNumericValues);

            // if attribute value matches regNumericValues
            if (match) {
                // round it to the fixed precision
                var num = +(+match[1]).toFixed(params.floatPrecision),
                    units = match[3] || '';

                // convert absolute values to pixels
                if (params.convertToPx && units && (units in absoluteLengths)) {
                    var pxNum = +(absoluteLengths[units] * match[1]).toFixed(params.floatPrecision);

                    if (String(pxNum).length < match[0].length)
                        num = pxNum,
                        units = 'px';
                }

                // and remove leading zero
                if (params.leadingZero) {
                    num = removeLeadingZero(num);
                }

                // remove default 'px' units
                if (params.defaultPx && units === 'px') {
                    units = '';
                }

                attr.value = num + units;
            }
        });

    }

};
