/*
title: Cycle Plot
category: custom
titleCN: Cycle Plot
difficulty: 3
*/


var rawData = [
    [2002, 14, 21, 25, 21, 26, 32, 27, 20, 10, 11, 5, 5],
    [2003, 18, 24, 28, 24, 33, 37, 30, 25, 13, 14, 6, 6],
    [2004, 22, 31, 36, 28, 37, 43, 35, 30, 13, 13, 7, 7],
    [2005, 25, 32, 38, 34, 39, 48, 38, 29, 14, 14, 8, 8],
    [2006, 29, 38, 47, 33, 44, 57, 41, 39, 16, 16, 9, 8],
    [2007, 29, 35, 49, 34, 43, 57, 41, 37, 20, 17, 9, 10],
    [2008, 22, 32, 37, 30, 35, 44, 38, 31, 16, 17, 8, 7],
    [2009, 25, 34, 41, 33, 39, 47, 44, 32, 17, 17, 9, 8],
    [2010, 26, 35, 46, 40, 47, 61, 47, 41, 20, 18, 9, 10],
    [2011, 29, 39, 55, 38, 55, 67, 53, 41, 19, 20, 11, 11],
    [2012, 38, 48, 60, 49, 57, 79, 62, 54, 26, 26, 13, 11]
];

var dataByMonth = [];
var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
rawData.forEach(function (entry, yearIndex) {
    entry.forEach(function (value, index) {
        if (index) {
            var monthIndex = index - 1;
            var monthItem = dataByMonth[monthIndex] = dataByMonth[monthIndex] || [];
            monthItem[0] = monthIndex;
            monthItem[yearIndex + 1] = value;
        }
    });
});
var averageByMonth = [];
dataByMonth.forEach(function (entry, index) {
    var sum = 0;
    entry.forEach(function (value, index) {
        index && (sum += value);
    });
    averageByMonth.push([index, sum / (entry.length - 1)]);
});

function renderTrendItem(params, api) {
    var categoryIndex = api.value(0);
    var unitBandWidth = api.size([0, 0])[0] * 0.85 / (rawData.length - 1);

    var points = rawData.map(function (entry, index) {
        var value = api.value(index + 1);
        var point = api.coord([categoryIndex, value]);
        point[0] += unitBandWidth * (index - rawData.length / 2);
        return point;
    });

    return {
        type: 'polyline',
        shape: {
            points: points
        },
        style: api.style({
            fill: null,
            stroke: api.visual('color'),
            lineWidth: 2
        })
    };
}

function renderAverageItem(param, api) {
    var bandWidth = api.size([0, 0])[0] * 0.85;
    var point = api.coord([api.value(0), api.value(1)]);

    return {
        type: 'line',
        shape: {
            x1: point[0] - bandWidth / 2,
            x2: point[0] + bandWidth / 2,
            y1: point[1],
            y2: point[1]
        },
        style: api.style({
            fill: null,
            stroke: api.visual('color'),
            lineWidth: 2
        })
    };
}

option = {
    tooltip: {
    },
    title: {
        text: 'Sales Trends by Year within Each Month',
        subtext: 'Sample of Cycle Plot',
        left: 'center'
    },
    legend: {
        top: 70,
        data: ['Trend by year (2002 - 2012)', 'Average']
    },
    dataZoom: [{
        type: 'slider',
        labelFormatter: ''
    }, {
        type: 'inside'
    }],
    grid: {
        bottom: 70,
        top: 120,
    },
    xAxis: {
        data: months
    },
    yAxis: {
        boundaryGap: [0, '20%']
    },
    series: [{
        type: 'custom',
        name: 'Average',
        renderItem: renderAverageItem,
        encode: {
            x: 0,
            y: 1
        },
        data: averageByMonth
    }, {
        type: 'custom',
        name: 'Trend by year (2002 - 2012)',
        renderItem: renderTrendItem,
        encode: {
            x: 0,
            y: rawData.map(function (entry, index) {
                return index + 1;
            })
        },
        data: dataByMonth
    }]
};