/**
 * @file Timeline preprocessor
 */
define(function(require) {

    var zrUtil = require('zrender/core/util');

    return function (option) {
        var timelineOpt = option && option.timeline;

        if (!zrUtil.isArray(timelineOpt)) {
            timelineOpt = timelineOpt ? [timelineOpt] : [];
        }

        zrUtil.each(timelineOpt, function (opt) {
            if (!opt) {
                return;
            }

            compatibleEC2(opt);
        });
    };

    function compatibleEC2(opt) {
        var type = opt.type;

        var ec2Types = {'number': 'value', 'time': 'time'};

        // Compatible with ec2
        if (ec2Types[type]) {
            opt.axisType = ec2Types[type];
            delete opt.type;
        }

        transferItem(opt);

        if (has(opt, 'controlPosition')) {
            var controlStyle = opt.controlStyle || (opt.controlStyle = {});
            if (!has(controlStyle, 'position')) {
                controlStyle.position = opt.controlPosition;
            }
            if (controlStyle.position === 'none' && !has(controlStyle, 'show')) {
                controlStyle.show = false;
                delete controlStyle.position;
            }
            delete opt.controlPosition;
        }

        var data = opt.data || (opt.data = []);

        zrUtil.each(data, function (dataItem) {
            if (zrUtil.isObject(dataItem) && !zrUtil.isArray(dataItem)) {
                if (!has(dataItem, 'value') && has(dataItem, 'name')) {
                    // In ec2, using name as value.
                    dataItem.value = dataItem.name;
                }
                transferItem(dataItem);
            }
        });
    }

    function transferItem(opt) {
        var itemStyle = opt.itemStyle || (opt.itemStyle = {});

        var itemStyleEmphasis = itemStyle.emphasis || (itemStyle.emphasis = {});
        var itemStyleNormal = itemStyle.normal || (itemStyle.normal = {});

        // Transfer to itemSytle.normal
        if (opt.symbol && !has(itemStyleNormal, 'symbol')) {
            itemStyleNormal.symbol = opt.symbol;
        }
        if (opt.symbolSize != null && !has(itemStyleNormal, 'symbolSize')) {
            itemStyleNormal.symbolSize = opt.symbolSize;
        }

        // Transfer label out
        var label = opt.label || (opt.label || {});
        var labelNormal = label.normal || (label.normal = {});
        var excludeLabelAttr = {normal: 1, emphasis: 1};

        zrUtil.each(label, function (value, name) {
            if (!excludeLabelAttr[name] && !has(labelNormal, name)) {
                labelNormal[name] = value;
            }
        });

        if (itemStyleEmphasis.label && !has(label, 'emphasis')) {
            label.emphasis = itemStyleEmphasis.label;
            delete itemStyleEmphasis.label;
        }
    }

    function has(obj, attr) {
        return obj.hasOwnProperty(attr);
    }

});