<template>
	<div>
		<MkLoading v-if="fetching" />
		<div v-show="!fetching" :class="$style.root" class="_panel">
			<canvas ref="chartEl"></canvas>
		</div>
	</div>
</template>

<script lang="ts" setup>
import { markRaw, version as vueVersion, onMounted, onBeforeUnmount, nextTick, shallowRef, ref } from 'vue';
import { Chart } from "chart.js";
import tinycolor from "tinycolor2";
import gradient from "chartjs-plugin-gradient";
import * as os from "@/os";
import { defaultStore } from "@/store";
import { useChartTooltip } from "@/scripts/use-chart-tooltip";
import { chartVLine } from "@/scripts/chart-vline";
import { alpha } from "@/scripts/color";
import { initChart } from "@/scripts/init-chart";

initChart();

const chartEl = shallowRef<HTMLCanvasElement>(null);
const now = new Date();
let chartInstance: Chart = null;
const chartLimit = 7;
let fetching = ref(true);

const { handler: externalTooltipHandler } = useChartTooltip();

async function renderChart() {
	if (chartInstance) {
		chartInstance.destroy();
	}

	const getDate = (ago: number) => {
		const y = now.getFullYear();
		const m = now.getMonth();
		const d = now.getDate();

		return new Date(y, m, d - ago);
	};

	const format = (arr) => {
		return arr.map((v, i) => ({
			x: getDate(i).getTime(),
			y: v,
		}));
	};

	const raw = await os.api("charts/active-users", {
		limit: chartLimit,
		span: "day",
	});

	const vLineColor = defaultStore.state.darkMode
		? "rgba(255, 255, 255, 0.2)"
		: "rgba(0, 0, 0, 0.2)";

	const colorRead = "#eb6f92";
	const colorWrite = "#f6c177";

	const max = Math.max(...raw.read);

	chartInstance = new Chart(chartEl.value, {
		type: "bar",
		data: {
			datasets: [
				{
					parsing: false,
					label: "Read",
					data: format(raw.read).slice().reverse(),
					pointRadius: 0,
					borderWidth: 0,
					borderJoinStyle: "round",
					borderRadius: 4,
					backgroundColor: colorRead,
					barPercentage: 0.7,
					categoryPercentage: 0.5,
					fill: true,
				},
				{
					parsing: false,
					label: "Write",
					data: format(raw.write).slice().reverse(),
					pointRadius: 0,
					borderWidth: 0,
					borderJoinStyle: "round",
					borderRadius: 4,
					backgroundColor: colorWrite,
					barPercentage: 0.7,
					categoryPercentage: 0.5,
					fill: true,
				},
			],
		},
		options: {
			aspectRatio: 2.5,
			layout: {
				padding: {
					left: 0,
					right: 8,
					top: 0,
					bottom: 0,
				},
			},
			scales: {
				x: {
					type: "time",
					offset: true,
					time: {
						stepSize: 1,
						unit: "day",
						displayFormats: {
							day: "M/d",
							month: "Y/M",
						},
					},
					grid: {
						display: false,
					},
					ticks: {
						display: true,
						maxRotation: 0,
						autoSkipPadding: 8,
					},
				},
				y: {
					position: "left",
					suggestedMax: 10,
					grid: {
						display: true,
					},
					ticks: {
						display: true,
						//mirror: true,
					},
				},
			},
			interaction: {
				intersect: false,
				mode: "index",
			},
			plugins: {
				legend: {
					display: false,
				},
				tooltip: {
					enabled: false,
					mode: "index",
					animation: {
						duration: 0,
					},
					external: externalTooltipHandler,
				},
				gradient,
			},
		},
		plugins: [chartVLine(vLineColor)],
	});

	fetching.value = false;
}

onMounted(async () => {
	renderChart();
});
</script>

<style lang="scss" module>
.root {
	padding: 20px;
}
</style>
