/*!
 * The 2022 r/place Atlas
 * Copyright (c) 2017 Roland Rytz <roland@draemm.li>
 * Copyright (c) 2022 Place Atlas Initiative and contributors
 * Licensed under AGPL-3.0 (https://2022.place-atlas.stefanocoding.me/license.txt)
 */

const codeReference = {}
let canvasUrl = ""

const variantsEl = document.getElementById("variants")

for (const variation in variationsConfig) {
	codeReference[variationsConfig[variation].code] = variation
	const optionEl = document.createElement('option')
	optionEl.value = variation
	optionEl.textContent = variationsConfig[variation].name
	variantsEl.appendChild(optionEl)
}

const timelineSlider = document.getElementById("timeControlsSlider")
const timelineList = document.getElementById("timeControlsList")
const tooltip = document.getElementById("timeControlsTooltip")
const image = document.getElementById("image")
let abortController = new AbortController()
let currentUpdateIndex = 0
let updateTimeout = setTimeout(null, 0)
let tooltipDelayHide = setTimeout(null, 0)

let currentVariation = defaultVariation
let currentPeriod = defaultPeriod
window.currentVariation = currentVariation
window.currentPeriod = currentPeriod

let atlasDisplay = {}
window.atlasDisplay = atlasDisplay

const additionalLayers = []
const additionalLayerCanvas = document.createElement('canvas')

// SETUP
if (variationsConfig[currentVariation].versions.length === 1) bottomBar.classList.add('no-time-slider')

timelineSlider.max = variationsConfig[currentVariation].versions.length - 1
timelineSlider.value = currentPeriod
timelineList.children[0].value = defaultPeriod

timelineSlider.addEventListener("input", e => timelineParser(e.target.value))

timelineSlider.addEventListener("wheel", e => {
	if (e.deltaY < 0) e.target.valueAsNumber += 1
	else e.target.value -= 1
	timelineParser(e.target.value)
	e.stopPropagation()
}, { passive: true })

function timelineParser(value) {
	updateTooltip(parseInt(value), currentVariation)
	clearTimeout(updateTimeout)
	updateTimeout = setTimeout(() => {
		updateTime(parseInt(timelineSlider.value), currentVariation)
		setTimeout(() => {
			if (timelineSlider.value !== currentPeriod && abortController.signal.aborted) {
				updateTime(parseInt(timelineSlider.value), currentVariation)
			}
		}, 50)
	}, 25)
}

variantsEl.addEventListener("input", event => {
	updateTime(-1, event.target.value)
})

const dispatchTimeUpdateEvent = (period = currentPeriod, variation = currentVariation, atlas = atlas) => {
	const timeUpdateEvent = new CustomEvent('timeupdate', {
		detail: {
			period: period,
			variation: variation,
			periodString: formatPeriod(period, null, variation),
			atlas: atlas
		}
	})
	document.dispatchEvent(timeUpdateEvent)
}

async function updateBackground(newPeriod = currentPeriod, newVariation = currentVariation) {
	abortController.abort()
	const myAbortController = new AbortController()
	abortController = myAbortController
	currentUpdateIndex++
	const myUpdateIndex = currentUpdateIndex
	const variationConfig = variationsConfig[newVariation]

	variantsEl.value = currentVariation
	if (variationConfig.icon) {
		variantsEl.previousElementSibling.innerHTML = variationConfig.icon
		variantsEl.previousElementSibling.classList.remove('d-none')
		variantsEl.parentElement.classList.add('input-group')
	} else {
		variantsEl.previousElementSibling.innerHTML = ""
		variantsEl.previousElementSibling.classList.add('d-none')
		variantsEl.parentElement.classList.remove('input-group')
	}

	const configObject = variationConfig.versions[newPeriod]
	let layerUrls = []
	let layers = []

	if (typeof configObject.url === "string") {
		layerUrls.push(configObject.url)
	} else {
		layerUrls.push(...configObject.url)
	}
	const canvas = document.createElement('canvas')
	const context = canvas.getContext('2d')

	layers.length = layerUrls.length 
	await Promise.all(layerUrls.map(async (url, i) => {
		try {
			const imageBlob = await (await fetch(url, { signal: myAbortController.signal })).blob()
			const imageLayer = new Image()
			await new Promise(resolve => {
				imageLayer.onload = () => {
					context.canvas.width = Math.max(imageLayer.width, context.canvas.width)
					context.canvas.height = Math.max(imageLayer.height, context.canvas.height)
					layers[i] = imageLayer
					resolve()
				}
				imageLayer.src = URL.createObjectURL(imageBlob)
			})
		} catch (e) {
			const aborted = myAbortController.signal.aborted
			if (!aborted) throw e
		}
	}))

	if (myAbortController.signal.aborted || newPeriod !== currentPeriod || newVariation !== currentVariation || currentUpdateIndex !== myUpdateIndex) {
		return false
	}
	
	for (const imageLayer of layers) {
		context.drawImage(imageLayer, 0, 0)
	}

	context.drawImage(additionalLayerCanvas, 0, 0)

	if (myAbortController.signal.aborted || newPeriod !== currentPeriod || newVariation !== currentVariation || currentUpdateIndex !== myUpdateIndex) {
		return false
	}

	if (currentUpdateIndex !== myUpdateIndex) return [configObject, newPeriod, newVariation]
	const blob = await new Promise(resolve => canvas.toBlob(resolve))
	canvasUrl = URL.createObjectURL(blob)
	image.src = canvasUrl

	return true

}

let loadingTimeout = setTimeout(() => {}, 0)

async function updateTime(newPeriod = currentPeriod, newVariation = currentVariation, forceLoad = false) {
	if (newPeriod === currentPeriod && newVariation === currentVariation && !forceLoad) {
		return
	}
	document.body.dataset.canvasLoading = ""

	const loadingEl = document.getElementById("loading")
	const previouslyHidden = loadingEl.classList.contains("d-none")

	if (previouslyHidden) loadingEl.classList.add("opacity-0", "transition-opacity")
	clearTimeout(loadingTimeout)
	loadingTimeout = setTimeout(() => {
		loadingEl.classList.remove("d-none")
		if (previouslyHidden) setTimeout(() => {
			loadingEl.classList.remove("opacity-0")	
		}, 0)
	}, 2000)
	
	// const oldPeriod = currentPeriod
	const oldVariation = currentVariation

	if (!variationsConfig[newVariation]) newVariation = defaultVariation
	const variationConfig = variationsConfig[newVariation]

	if (newPeriod < 0) newPeriod = 0
	else if (newPeriod > variationConfig.versions.length - 1) newPeriod = variationConfig.versions.length - 1

	currentPeriod = newPeriod
	currentVariation = newVariation

	if (oldVariation !== newVariation) {
		timelineSlider.max = variationConfig.versions.length - 1
		if (!forceLoad) {
			currentPeriod = variationConfig.default
			newPeriod = currentPeriod
		}
		if (variationConfig.versions.length === 1) bottomBar.classList.add('no-time-slider')
		else bottomBar.classList.remove('no-time-slider')
	}
	timelineSlider.value = currentPeriod
	updateTooltip(newPeriod, newVariation)

	const updateBackgroundResult = await updateBackground(newPeriod, newVariation)

	if (!updateBackgroundResult) return

	dispatchTimeUpdateEvent(newPeriod, newVariation, atlas)
	delete document.body.dataset.canvasLoading
	clearTimeout(loadingTimeout)
	document.getElementById("loading").classList.add("d-none")
	document.getElementById("loading").classList.remove("opacity-0", "opacity-100", "transition-opacity")
	
	tooltip.dataset.forceVisible = ""
	clearTimeout(tooltipDelayHide)
	tooltipDelayHide = setTimeout(() => {
		delete tooltip.dataset.forceVisible
	}, 1000)

}

function generateAtlasDisplay(prevAtlas, prevAtlasOrder, newPeriod = currentPeriod, newVariation = currentVariation) {
	
	const newAtlas = {}
	const newAtlasOrderDisplayed = []
	const newAtlasOrderNotDisplayed = []

	for (const id of prevAtlasOrder) {

		newAtlasOrderNotDisplayed.push(id)
		const entry = prevAtlas[id]

		let chosenIndex

		const validPeriods2 = Object.keys(entry.path)

		periodCheck: for (const i in validPeriods2) {
			const validPeriods = validPeriods2[i].split(', ')
			for (const j in validPeriods) {
				const [start, end, variation] = parsePeriod(validPeriods[j])
				if (isOnPeriod(start, end, variation, newPeriod, newVariation)) {
					chosenIndex = i
					break periodCheck
				}
			}
		}

		if (chosenIndex === undefined) continue
		const pathChosen = Object.values(entry.path)[chosenIndex]
		const centerChosen = Object.values(entry.center)[chosenIndex]

		if (pathChosen === undefined) continue

		newAtlas[id] = {
			...entry,
			path: pathChosen,
			center: centerChosen,
		}

		newAtlasOrderNotDisplayed.pop()
		newAtlasOrderDisplayed.push(id)

	}

	return [newAtlas, [...newAtlasOrderDisplayed, ...newAtlasOrderNotDisplayed]]

}

function updateTooltip(period, variation) {
	const configObject = variationsConfig[variation].versions[period]

	// If timestamp is a number return a UTC formatted date, otherwise use exact timestamp label
	if (Array.isArray(configObject.timestamp)) {
		tooltip.querySelector('div').textContent = ""
		configObject.timestamp.forEach(timestamp => {
			if (tooltip.querySelector('div').textContent) tooltip.querySelector('div').innerHTML += "<br />"
			if (typeof timestamp === "number") tooltip.querySelector('div').innerHTML += new Date(timestamp * 1000).toUTCString()
			else tooltip.querySelector('div').innerHTML += timestamp
		})
	} else if (typeof configObject.timestamp === "number") tooltip.querySelector('div').textContent = new Date(configObject.timestamp * 1000).toUTCString()
	else tooltip.querySelector('div').textContent = configObject.timestamp

	// Clamps position of tooltip to prevent from going off screen
	const timelineSliderRect = timelineSlider.getBoundingClientRect()
	let min = -timelineSliderRect.left + 12
	let max = (window.innerWidth - tooltip.offsetWidth) - timelineSliderRect.left + 4
	tooltip.style.left = Math.min(Math.max((timelineSlider.offsetWidth) * (timelineSlider.value) / (timelineSlider.max) - tooltip.offsetWidth / 2, min), max) + "px"
}

tooltip.parentElement.addEventListener('mouseenter', () => updateTooltip(parseInt(timelineSlider.value), currentVariation))

window.addEventListener('resize', () => updateTooltip(parseInt(timelineSlider.value), currentVariation))

function isOnPeriod(start, end, variation, currentPeriod, currentVariation) {
	if (start > end) [start, end] = [end, start]
	return currentPeriod >= start && currentPeriod <= end && variation === currentVariation
}
window.isOnPeriod = isOnPeriod

function parsePeriod(periodString) {
	let variation = defaultVariation
	periodString = periodString + ""
	if (periodString.split(':').length > 1) {
		const split = periodString.split(':')
		variation = codeReference[split[0]]
		periodString = split[1]
	}
	if (periodString.search('-') + 1) {
		let [start, end] = periodString.split('-').map(i => parseInt(i))
		if (start > end) [start, end] = [end, start]
		return [start, end, variation]
	} else if (codeReference[periodString]) {
		variation = codeReference[periodString]
		const defaultPeriod = variationsConfig[variation].default
		return [defaultPeriod, defaultPeriod, variation]
	} else {
		const periodNew = parseInt(periodString)
		return [periodNew, periodNew, variation]
	}
}

function formatPeriod(targetStart, targetEnd, targetVariation, forUrl = false) {
	targetStart ??= currentPeriod
	targetEnd ??= targetStart
	targetVariation ??= currentVariation

	let periodString, variationString
	variationString = variationsConfig[targetVariation].code
	if (targetStart > targetEnd) [targetStart, targetEnd] = [targetEnd, targetStart]
	if (targetStart === targetEnd) {
		if (forUrl && targetVariation === defaultVariation && targetStart === variationsConfig[defaultVariation].default) {
			periodString = ""
		}
		else periodString = targetStart
	}
	else periodString = targetStart + "-" + targetEnd
	if (periodString && variationString) return variationsConfig[targetVariation].code + ":" + periodString
	if (variationString) return variationString

	return periodString
}

function setReferenceVal(reference, newValue) {
	if (reference === false || reference === "") return null
	else return reference ?? newValue
}

function formatHash(targetEntry, targetPeriod, targetVariation, targetX, targetY, targetZoom) {
	let hashData = window.location.hash.substring(1).split('/')

	targetEntry = setReferenceVal(targetEntry, hashData[0])
	targetPeriod = setReferenceVal(targetPeriod, currentPeriod)
	targetVariation = setReferenceVal(targetVariation, currentVariation)
	targetX = setReferenceVal(targetX, canvasCenter.x - scaleZoomOrigin[0])
	targetY = setReferenceVal(targetY, canvasCenter.y - scaleZoomOrigin[1])
	targetZoom = setReferenceVal(targetZoom, zoom)
	
	if (targetX) targetX = Math.round(targetX)
	if (targetY) targetY = Math.round(targetY)
	if (targetZoom) targetZoom = targetZoom.toFixed(3).replace(/\.?0+$/, '')

	const result = [targetEntry]
	const targetPeriodFormat = formatPeriod(targetPeriod, null, targetVariation, true)
	result.push(targetPeriodFormat, targetX, targetY, targetZoom)
	if (!result.some(el => el || el === 0)) return ''
	return '#' + result.join('/').replace(/\/+$/, '')
}

function downloadCanvas() {
	const linkEl = document.createElement("a")
	linkEl.download = "canvas.png"
	linkEl.href = canvasUrl
	linkEl.classList.add("d-none")
	document.body.appendChild(linkEl)
	linkEl.click()
	document.body.removeChild(linkEl)
}

function getNearestPeriod(entry, targetPeriod, targetVariation) {
	
	const pathKeys = Object.keys(entry.path)
	
	let nearestScore, nearestPeriod, nearestVariation, nearestKey

	function updateNearest(newScore, newPeriod, newVariation, newKey) {
		if (newScore >= nearestScore) return
		nearestScore = newScore
		nearestPeriod = newPeriod
		nearestVariation = newVariation
		nearestKey = newKey
	}

	checkPaths: for (const pathKey of pathKeys) {
		const pathPeriods = pathKey.split(', ')

		checkPathPeriod: for (const j in pathPeriods) {
			const [pathStart, pathEnd, pathVariation] = parsePeriod(pathPeriods[j])
			if (isOnPeriod(pathStart, pathEnd, pathVariation, targetPeriod, targetVariation)) {
				updateNearest(0, targetPeriod, targetVariation)
				break checkPaths
			} else if (pathVariation !== targetVariation) {
				updateNearest(Infinity, pathStart, pathVariation, pathKey)
				continue checkPathPeriod
			} else if (Math.abs(pathStart - targetPeriod) < Math.abs(pathEnd - targetPeriod)) {
				updateNearest(Math.abs(pathStart - targetPeriod), pathStart, pathVariation, pathKey)
			} else {
				updateNearest(Math.abs(pathEnd - targetPeriod), pathStart, pathVariation, pathKey)
			}
		}

	}

	return [ nearestPeriod, nearestVariation, nearestKey ]

}

const updateAdditionalLayer = () => {
	const layers = additionalLayers
	const canvas = additionalLayerCanvas
	const context = additionalLayerCanvas.getContext('2d')
	canvas.width = 0
	canvas.height = 0


	for (const layer of layers) {
		if (!layer.imageLayer) continue
		canvas.width = Math.max(layer.x + layer.imageLayer.width, canvas.width)
		canvas.height = Math.max(layer.y + layer.imageLayer.height, canvas.height)
	}

	for (const layer of layers) {
		if (!layer.imageLayer) continue
		context.drawImage(layer.imageLayer, layer.x, layer.y)
		console.log(layer.imageLayer)
	}
}