<template>
	<div ref="rootEl">
		<MkLoading v-if="fetching" />
		<div v-else>
			<canvas ref="chartEl"></canvas>
		</div>
	</div>
</template>

<script lang="ts" setup>
import { nextTick, onMounted, ref, shallowRef, watch } from "vue";
import { Chart } from "chart.js";
import * as os from "@/os";
import { defaultStore } from "@/store";
import { useChartTooltip } from "@/scripts/use-chart-tooltip";
import { alpha } from "@/scripts/color";
import { initChart } from "@/scripts/init-chart";
import { $i } from "@/account";

initChart();

const props = defineProps<{
	src: string;
}>();

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

const { handler: externalTooltipHandler } = useChartTooltip({
	position: "middle",
});

const addArrays = (arr1: number[], arr2: number[], arr3: number[]) =>
	arr1.length === arr2.length && arr2.length === arr3.length
		? arr1.map((val, i) => val + arr2[i] + arr3[i])
		: null;

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

	const wide = rootEl.value.offsetWidth > 700;
	const narrow = rootEl.value.offsetWidth < 400;

	const weeks = wide ? 50 : narrow ? 10 : 25;
	const chartLimit = 7 * weeks;

	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) => {
			const dt = getDate(i);
			const iso = `${dt.getFullYear()}-${(dt.getMonth() + 1)
				.toString()
				.padStart(2, "0")}-${dt.getDate().toString().padStart(2, "0")}`;
			return {
				x: iso,
				y: dt.getDay(),
				d: iso,
				v,
			};
		});
	};

	let values;

	if (props.src === "active-users") {
		const raw = await os.api("charts/active-users", {
			limit: chartLimit,
			span: "day",
		});
		values = raw.readWrite;
	} else if (props.src === "notes") {
		const raw = await os.api("charts/notes", {
			limit: chartLimit,
			span: "day",
		});
		values = raw.local.inc;
	} else if (props.src === "ap-requests-inbox-received") {
		const raw = await os.api("charts/ap-request", {
			limit: chartLimit,
			span: "day",
		});
		values = raw.inboxReceived;
	} else if (props.src === "ap-requests-deliver-succeeded") {
		const raw = await os.api("charts/ap-request", {
			limit: chartLimit,
			span: "day",
		});
		values = raw.deliverSucceeded;
	} else if (props.src === "ap-requests-deliver-failed") {
		const raw = await os.api("charts/ap-request", {
			limit: chartLimit,
			span: "day",
		});
		values = raw.deliverFailed;
	} else if (props.src === "my-notes") {
		const raw = await os.api("charts/user/notes", {
			limit: chartLimit,
			span: "day",
			userId: $i.id,
		});
		values = addArrays(raw.diffs.normal, raw.diffs.reply, raw.diffs.renote);
	}

	fetching.value = false;

	await nextTick();

	const color = defaultStore.state.darkMode ? "#ebbcba" : "#d7827e";

	// 視覚上の分かりやすさのため上から最も大きい3つの値の平均を最大値とする
	const max =
		values
			.slice()
			.sort((a, b) => b - a)
			.slice(0, 3)
			.reduce((a, b) => a + b, 0) / 3;

	const min = Math.max(0, Math.min(...values) - 1);

	const marginEachCell = 4;

	chartInstance = new Chart(chartEl.value, {
		type: "matrix",
		data: {
			datasets: [
				{
					label: "Read & Write",
					data: format(values),
					pointRadius: 0,
					borderWidth: 0,
					borderJoinStyle: "round",
					borderRadius: 3,
					backgroundColor(c) {
						const value = c.dataset.data[c.dataIndex].v;
						let a = (value - min) / max;
						if (value !== 0) {
							// 0でない限りは完全に不可視にはしない
							a = Math.max(a, 0.05);
						}
						return alpha(color, a);
					},
					fill: true,
					width(c) {
						const a = c.chart.chartArea ?? {};
						return (a.right - a.left) / weeks - marginEachCell;
					},
					height(c) {
						const a = c.chart.chartArea ?? {};
						return (a.bottom - a.top) / 7 - marginEachCell;
					},
				},
			],
		},
		options: {
			aspectRatio: wide ? 6 : narrow ? 1.8 : 3.2,
			layout: {
				padding: {
					left: 8,
					right: 0,
					top: 0,
					bottom: 0,
				},
			},
			scales: {
				x: {
					type: "time",
					offset: true,
					position: "bottom",
					time: {
						unit: "week",
						round: "week",
						isoWeekday: 0,
						displayFormats: {
							day: "M/d",
							month: "Y/M",
							week: "M/d",
						},
					},
					grid: {
						display: false,
					},
					ticks: {
						display: true,
						maxRotation: 0,
						autoSkipPadding: 8,
					},
				},
				y: {
					offset: true,
					reverse: true,
					position: "right",
					grid: {
						display: false,
					},
					ticks: {
						maxRotation: 0,
						autoSkip: true,
						padding: 1,
						font: {
							size: 9,
						},
						callback: (value, index, values) =>
							["", "Mon", "", "Wed", "", "Fri", ""][value],
					},
				},
			},
			plugins: {
				legend: {
					display: false,
				},
				tooltip: {
					enabled: false,
					callbacks: {
						title(context) {
							const v =
								context[0].dataset.data[context[0].dataIndex];
							return v.d;
						},
						label(context) {
							const v = context.dataset.data[context.dataIndex];
							return ["Active: " + v.v];
						},
					},
					// mode: 'index',
					animation: {
						duration: 0,
					},
					external: externalTooltipHandler,
				},
			},
		},
	});
}

watch(
	() => props.src,
	() => {
		fetching.value = true;
		renderChart();
	},
);

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