const fullData = [
    { x: new Date('2025-06-20'), y: 3381.30 },
    { x: new Date('2025-06-22'), y: 3412.90 },
    { x: new Date('2025-06-23'), y: 3412.90 },
    { x: new Date('2025-06-24'), y: 3370.90 },
    { x: new Date('2025-06-25'), y: 3325.50 },
    { x: new Date('2025-06-26'), y: 3331.10 },
    { x: new Date('2025-06-27'), y: 3326.70 },
    { x: new Date('2025-06-28'), y: 3278.30 },
    { x: new Date('2025-06-30'), y: 3272.30 },
    { x: new Date('2025-07-01'), y: 3305.40 },
    { x: new Date('2025-07-02'), y: 3336.10 },
    { x: new Date('2025-07-03'), y: 3352.00 }];

const options = {
    chart: {
        type: 'area',
        height: 300,
        toolbar: { show: false },
        zoom: { enabled: false }
    },
    series: [{ name: '', data: fullData }],
    xaxis: {
        type: 'datetime'
    },
    yaxis: {
        tickAmount: 7,
        labels: {
            formatter: val => `${val.toLocaleString('id-ID')}`,
            offsetX: -17
        }
    },
    grid: {
        padding: {
            left: -10,
            right: 0
        }
    },
    tooltip: {
        x: { format: 'dd MMM yyyy' },
        y: {
            formatter: val => `US$${val.toLocaleString('id-ID')}`
        }
    },
    stroke: {
        curve: 'smooth',
        width: 2
    },
    fill: {
        type: 'gradient',
        gradient: {
            shadeIntensity: 1,
            opacityFrom: 0.8,
            opacityTo: 0,
            stops: [0, 90, 100]
        }
    },
    colors: ['#007bff'],
    legend: { show: false },
    dataLabels: { enabled: false }
};

const chart = new ApexCharts(document.querySelector("#chart"), options);
chart.render();

function updateChart(months) {
    const sortedData = [...fullData].sort((a, b) => a.x - b.x);
    const latestDate = sortedData[sortedData.length - 1].x;
    const start = new Date(latestDate);
    start.setMonth(start.getMonth() - months);

    const filtered = fullData.filter(item => item.x >= start && item.x <= latestDate);
    chart.updateSeries([{ name: '', data: filtered }]);
}

document.querySelectorAll('.filter-btn').forEach(btn => {
    btn.addEventListener('click', () => {
        document.querySelectorAll('.filter-btn').forEach(b => b.classList.remove('active'));
        btn.classList.add('active');
        const months = parseInt(btn.dataset.months);
        updateChart(months);
    });
});
updateChart(1);