const dataPrev = {
    2020: [
        ['kr', 9],
        ['jp', 12],
        ['au', 8],
        ['de', 17],
        ['ru', 19],
        ['cn', 26],
        ['gb', 27],
        ['us', 46]
    ],
    2016: [
        ['kr', 13],
        ['jp', 7],
        ['au', 8],
        ['de', 11],
        ['ru', 20],
        ['cn', 38],
        ['gb', 29],
        ['us', 47]
    ],
    2012: [
        ['kr', 13],
        ['jp', 9],
        ['au', 14],
        ['de', 16],
        ['ru', 24],
        ['cn', 48],
        ['gb', 19],
        ['us', 36]
    ],
    2008: [
        ['kr', 9],
        ['jp', 17],
        ['au', 18],
        ['de', 13],
        ['ru', 29],
        ['cn', 33],
        ['gb', 9],
        ['us', 37]
    ],
    2004: [
        ['kr', 8],
        ['jp', 5],
        ['au', 16],
        ['de', 13],
        ['ru', 32],
        ['cn', 28],
        ['gb', 11],
        ['us', 37]
    ],
    2000: [
        ['kr', 7],
        ['jp', 3],
        ['au', 9],
        ['de', 20],
        ['ru', 26],
        ['cn', 16],
        ['gb', 1],
        ['us', 44]
    ]
};

const data = {
    2020: [
        ['kr', 6],
        ['jp', 27],
        ['au', 17],
        ['de', 10],
        ['ru', 20],
        ['cn', 38],
        ['gb', 22],
        ['us', 39]
    ],
    2016: [
        ['kr', 9],
        ['jp', 12],
        ['au', 8],
        ['de', 17],
        ['ru', 19],
        ['cn', 26],
        ['gb', 27],
        ['us', 46]
    ],
    2012: [
        ['kr', 13],
        ['jp', 7],
        ['au', 8],
        ['de', 11],
        ['ru', 20],
        ['cn', 38],
        ['gb', 29],
        ['us', 47]
    ],
    2008: [
        ['kr', 13],
        ['jp', 9],
        ['au', 14],
        ['de', 16],
        ['ru', 24],
        ['cn', 48],
        ['gb', 19],
        ['us', 36]
    ],
    2004: [
        ['kr', 9],
        ['jp', 17],
        ['au', 18],
        ['de', 13],
        ['ru', 29],
        ['cn', 33],
        ['gb', 9],
        ['us', 37]
    ],
    2000: [
        ['kr', 8],
        ['jp', 5],
        ['au', 16],
        ['de', 13],
        ['ru', 32],
        ['cn', 28],
        ['gb', 11],
        ['us', 37]
    ]
};

const countries = {
    kr: {
        name: 'South Korea',
        color: '#FE2371'
    },
    jp: {
        name: 'Japan',
        color: '#544FC5'
    },
    au: {
        name: 'Australia',
        color: '#2CAFFE'
    },
    de: {
        name: 'Germany',
        color: '#FE6A35'
    },
    ru: {
        name: 'Russia',
        color: '#6B8ABC'
    },
    cn: {
        name: 'China',
        color: '#1C74BD'
    },
    gb: {
        name: 'Great Britain',
        color: '#00A6A6'
    },
    us: {
        name: 'United States',
        color: '#D568FB'
    }
};

// Add upper case country code
for (const [key, value] of Object.entries(countries)) {
    value.ucCode = key.toUpperCase();
}


const getData = data => data.map(point => ({
    name: point[0],
    y: point[1],
    color: countries[point[0]].color
}));

const chart = Highcharts.chart('container', {
    chart: {
        type: 'column'
    },
    // Custom option for templates
    countries,
    title: {
        text: 'Summer Olympics 2020 - Top 5 countries by Gold medals',
        align: 'left'
    },
    subtitle: {
        text: 'Comparing to results from Summer Olympics 2016 - Source: <a ' +
            'href="https://olympics.com/en/olympic-games/tokyo-2020/medals"' +
            'target="_blank">Olympics</a>',
        align: 'left'
    },
    plotOptions: {
        series: {
            grouping: false,
            borderWidth: 0
        }
    },
    legend: {
        enabled: false
    },
    tooltip: {
        shared: true,
        headerFormat: '<span style="font-size: 15px">' +
            '{series.chart.options.countries.(point.key).name}' +
            '</span><br/>',
        pointFormat: '<span style="color:{point.color}">\u25CF</span> ' +
            '{series.name}: <b>{point.y} medals</b><br/>'
    },
    xAxis: {
        type: 'category',
        accessibility: {
            description: 'Countries'
        },
        max: 4,
        labels: {
            useHTML: true,
            animate: true,
            format: '{chart.options.countries.(value).ucCode}<br>' +
                '<span class="f32">' +
                '<span style="display:inline-block;height:32px;' +
                'vertical-align:text-top;" class="flag {value}">' +
                '</span></span>',
            style: {
                textAlign: 'center'
            }
        }
    },
    yAxis: [{
        title: {
            text: 'Gold medals'
        },
        showFirstLabel: false
    }],
    series: [{
        color: 'rgba(158, 159, 163, 0.5)',
        pointPlacement: -0.2,
        linkedTo: 'main',
        data: dataPrev[2020].slice(),
        name: '2016'
    }, {
        name: '2020',
        id: 'main',
        dataSorting: {
            enabled: true,
            matchByName: true
        },
        dataLabels: [{
            enabled: true,
            inside: true,
            style: {
                fontSize: '16px'
            }
        }],
        data: getData(data[2020]).slice()
    }],
    exporting: {
        allowHTML: true
    }
});

const locations = [
    {
        city: 'Tokyo',
        year: 2020
    }, {
        city: 'Rio',
        year: 2016
    }, {
        city: 'London',
        year: 2012
    }, {
        city: 'Beijing',
        year: 2008
    }, {
        city: 'Athens',
        year: 2004
    }, {
        city: 'Sydney',
        year: 2000
    }
];

locations.forEach(location => {
    const btn = document.getElementById(location.year);

    btn.addEventListener('click', () => {

        document.querySelectorAll('.buttons button.active')
            .forEach(active => {
                active.className = '';
            });
        btn.className = 'active';

        chart.update({
            title: {
                text: 'Summer Olympics ' + location.year +
                    ' - Top 5 countries by Gold medals'
            },
            subtitle: {
                text: 'Comparing to results from Summer Olympics ' +
                    (location.year - 4) +
                    ' - Source: <a href="https://olympics.com/en/olympic-games/' +
                    (location.city.toLowerCase()) +
                    '-' + (location.year) +
                    '/medals" target="_blank">Olympics</a>'
            },
            series: [{
                name: location.year - 4,
                data: dataPrev[location.year].slice()
            }, {
                name: location.year,
                data: getData(data[location.year]).slice()
            }]
        }, true, false, {
            duration: 800
        });
    });
});