<template>
	<svg class="mbcofsoe" viewBox="0 0 10 10" preserveAspectRatio="none">
		<template v-if="props.graduations === 'dots'">
			<circle
				v-for="(angle, i) in graduationsMajor"
				:cx="5 + Math.sin(angle) * (5 - graduationsPadding)"
				:cy="5 - Math.cos(angle) * (5 - graduationsPadding)"
				:r="0.125"
				:fill="
					(props.twentyfour ? h : h % 12) === i
						? nowColor
						: majorGraduationColor
				"
				:opacity="
					!props.fadeGraduations ||
					(props.twentyfour ? h : h % 12) === i
						? 1
						: Math.max(
								0,
								1 -
									angleDiff(hAngle, angle) / Math.PI -
									numbersOpacityFactor,
						  )
				"
			/>
		</template>
		<template v-else-if="props.graduations === 'numbers'">
			<text
				v-for="(angle, i) in texts"
				:x="5 + Math.sin(angle) * (5 - textsPadding)"
				:y="5 - Math.cos(angle) * (5 - textsPadding)"
				text-anchor="middle"
				dominant-baseline="middle"
				:font-size="(props.twentyfour ? h : h % 12) === i ? 1 : 0.7"
				:font-weight="
					(props.twentyfour ? h : h % 12) === i ? 'bold' : 'normal'
				"
				:fill="
					(props.twentyfour ? h : h % 12) === i
						? nowColor
						: 'currentColor'
				"
				:opacity="
					!props.fadeGraduations ||
					(props.twentyfour ? h : h % 12) === i
						? 1
						: Math.max(
								0,
								1 -
									angleDiff(hAngle, angle) / Math.PI -
									numbersOpacityFactor,
						  )
				"
			>
				{{ i === 0 ? (props.twentyfour ? "24" : "12") : i }}
			</text>
		</template>

		<!--
	<line
		:x1="5 - (Math.sin(sAngle) * (sHandLengthRatio * handsTailLength))"
		:y1="5 + (Math.cos(sAngle) * (sHandLengthRatio * handsTailLength))"
		:x2="5 + (Math.sin(sAngle) * ((sHandLengthRatio * 5) - handsPadding))"
		:y2="5 - (Math.cos(sAngle) * ((sHandLengthRatio * 5) - handsPadding))"
		:stroke="sHandColor"
		:stroke-width="thickness / 2"
		stroke-linecap="round"
	/>
	-->

		<line
			class="s"
			:class="{
				animate: !disableSAnimate && sAnimation !== 'none',
				elastic: sAnimation === 'elastic',
				easeOut: sAnimation === 'easeOut',
			}"
			:x1="5 - 0 * (sHandLengthRatio * handsTailLength)"
			:y1="5 + 1 * (sHandLengthRatio * handsTailLength)"
			:x2="5 + 0 * (sHandLengthRatio * 5 - handsPadding)"
			:y2="5 - 1 * (sHandLengthRatio * 5 - handsPadding)"
			:stroke="sHandColor"
			:stroke-width="thickness / 2"
			:style="`transform: rotateZ(${sAngle}rad)`"
			stroke-linecap="round"
		/>

		<line
			:x1="5 - Math.sin(mAngle) * (mHandLengthRatio * handsTailLength)"
			:y1="5 + Math.cos(mAngle) * (mHandLengthRatio * handsTailLength)"
			:x2="5 + Math.sin(mAngle) * (mHandLengthRatio * 5 - handsPadding)"
			:y2="5 - Math.cos(mAngle) * (mHandLengthRatio * 5 - handsPadding)"
			:stroke="mHandColor"
			:stroke-width="thickness"
			stroke-linecap="round"
		/>

		<line
			:x1="5 - Math.sin(hAngle) * (hHandLengthRatio * handsTailLength)"
			:y1="5 + Math.cos(hAngle) * (hHandLengthRatio * handsTailLength)"
			:x2="5 + Math.sin(hAngle) * (hHandLengthRatio * 5 - handsPadding)"
			:y2="5 - Math.cos(hAngle) * (hHandLengthRatio * 5 - handsPadding)"
			:stroke="hHandColor"
			:stroke-width="thickness"
			stroke-linecap="round"
		/>
	</svg>
</template>

<script lang="ts" setup>
import {
	computed,
	nextTick,
	onBeforeUnmount,
	onMounted,
	ref,
	shallowRef,
} from "vue";
import tinycolor from "tinycolor2";
import { globalEvents } from "@/events.js";

// https://stackoverflow.com/questions/1878907/how-can-i-find-the-difference-between-two-angles
const angleDiff = (a: number, b: number) => {
	const x = Math.abs(a - b);
	return Math.abs(((x + Math.PI) % (Math.PI * 2)) - Math.PI);
};

const graduationsPadding = 0.5;
const textsPadding = 0.6;
const handsPadding = 1;
const handsTailLength = 0.7;
const hHandLengthRatio = 0.75;
const mHandLengthRatio = 1;
const sHandLengthRatio = 1;
const numbersOpacityFactor = 0.35;

const props = withDefaults(
	defineProps<{
		thickness?: number;
		offset?: number;
		twentyfour?: boolean;
		graduations?: "none" | "dots" | "numbers";
		fadeGraduations?: boolean;
		sAnimation?: "none" | "elastic" | "easeOut";
	}>(),
	{
		numbers: false,
		thickness: 0.1,
		offset: 0 - new Date().getTimezoneOffset(),
		twentyfour: false,
		graduations: "dots",
		fadeGraduations: true,
		sAnimation: "elastic",
	},
);

const graduationsMajor = computed(() => {
	const angles: number[] = [];
	const times = props.twentyfour ? 24 : 12;
	for (let i = 0; i < times; i++) {
		const angle = (Math.PI * i) / (times / 2);
		angles.push(angle);
	}
	return angles;
});
const texts = computed(() => {
	const angles: number[] = [];
	const times = props.twentyfour ? 24 : 12;
	for (let i = 0; i < times; i++) {
		const angle = (Math.PI * i) / (times / 2);
		angles.push(angle);
	}
	return angles;
});

let enabled = true,
	majorGraduationColor = $ref<string>(),
	// let minorGraduationColor = $ref<string>();
	sHandColor = $ref<string>(),
	mHandColor = $ref<string>(),
	hHandColor = $ref<string>(),
	nowColor = $ref<string>(),
	h = $ref<number>(0),
	m = $ref<number>(0),
	s = $ref<number>(0),
	hAngle = $ref<number>(0),
	mAngle = $ref<number>(0),
	sAngle = $ref<number>(0),
	disableSAnimate = $ref(false),
	sOneRound = false;

function tick() {
	const now = new Date();
	now.setMinutes(
		now.getMinutes() + (new Date().getTimezoneOffset() + props.offset),
	);
	s = now.getSeconds();
	m = now.getMinutes();
	h = now.getHours();
	hAngle =
		(Math.PI * ((h % (props.twentyfour ? 24 : 12)) + (m + s / 60) / 60)) /
		(props.twentyfour ? 12 : 6);
	mAngle = (Math.PI * (m + s / 60)) / 30;
	if (sOneRound) {
		// 秒針が一周した際のアニメーションをよしなに処理する(これが無いと秒が59->0になったときに期待したアニメーションにならない)
		sAngle = (Math.PI * 60) / 30;
		window.setTimeout(() => {
			disableSAnimate = true;
			window.setTimeout(() => {
				sAngle = 0;
				window.setTimeout(() => {
					disableSAnimate = false;
				}, 100);
			}, 100);
		}, 700);
	} else {
		sAngle = (Math.PI * s) / 30;
	}
	sOneRound = s === 59;
}

tick();

function calcColors() {
	const computedStyle = getComputedStyle(document.documentElement);
	const dark = tinycolor(computedStyle.getPropertyValue("--bg")).isDark();
	const accent = tinycolor(
		computedStyle.getPropertyValue("--accent"),
	).toHexString();
	majorGraduationColor = dark
		? "rgba(255, 255, 255, 0.3)"
		: "rgba(0, 0, 0, 0.3)";
	// minorGraduationColor = dark ? 'rgba(255, 255, 255, 0.2)' : 'rgba(0, 0, 0, 0.2)';
	sHandColor = dark ? "rgba(255, 255, 255, 0.5)" : "rgba(0, 0, 0, 0.3)";
	mHandColor = tinycolor(
		computedStyle.getPropertyValue("--fg"),
	).toHexString();
	hHandColor = accent;
	nowColor = accent;
}

calcColors();

onMounted(() => {
	const update = () => {
		if (enabled) {
			tick();
			window.setTimeout(update, 1000);
		}
	};
	update();

	globalEvents.on("themeChanged", calcColors);
});

onBeforeUnmount(() => {
	enabled = false;

	globalEvents.off("themeChanged", calcColors);
});
</script>

<style lang="scss" scoped>
.mbcofsoe {
	display: block;

	> .s {
		will-change: transform;
		transform-origin: 50% 50%;

		&.animate.elastic {
			transition: transform 0.2s cubic-bezier(0.4, 2.08, 0.55, 0.44);
		}

		&.animate.easeOut {
			transition: transform 0.7s cubic-bezier(0, 0.7, 0.3, 1);
		}
	}
}
</style>
