"use strict"
/**
	<youtube-embed> custom html element
	This acts as a preview for youtube's <iframe> embed player.
	It's gross and I hate it, but it's necessary,
	because their site is WAY too bloated for us to load it automatically.
	
	Usage:
	<youtube-embed href="https://youtu.be/URe5ihr2ow9"></youtube-embed>
	`href` can be any valid youtube video or youtube shorts url
	Known query parameters are:
	• t=, start= - start time (in seconds)
	• end= - end time (in seconds)
	• loop - enable looping
	
	When generating html, you may want to do something like this:
	<youtube-embed href="{url}">
		<a href="{url}">{url}</a>
	</youtube-embed>
	That way, it's still accessible if the custom element isn't installed.
**/
class Markup_YoutubeElement extends HTMLElement {
	constructor() {
		super()
		this.attachShadow({mode: 'open'})
		let e = this.constructor.template()
		for (let elem of e.querySelectorAll("[id]"))
			this["$"+elem.id] = elem
		this.$link.onclick = ev=>{
			ev.preventDefault()
			this.show_youtube(true)
		}
		this.$close.onclick = ev=>{
			this.show_youtube(false)
		}
		this.shadowRoot.append(e)
	}
	show_youtube(state) {
		this.$close.hidden = !state
		this.toggleAttribute('data-big', state)
		if (!this.$iframe == !state)
			return
		if (state) {
			this.$iframe = document.createElement('iframe')
			let src = `https://www.youtube-nocookie.com/embed/${this._id}?autoplay=1&rel=0`
			if (this._query)
				src += `&${this._query}`
			this.$iframe.src = src
			this.$iframe.allowFullscreen = true
			this.$link.replaceWith(this.$iframe)
		} else {
			this.$iframe.replaceWith(this.$link)
			this.$iframe.src = "about:blank"
			this.$iframe = null
		}
	}
	connectedCallback() {
		this.update_href(this.dataset.href)
	}
	disconnectedCallback() {
		this._id = null
	}
	update_href(url) {
		if (!url)
			return // todo: allow setting back to unloaded state?
		url = url.replace("/shorts/", "/watch?v=") // 🤮
		url = url.replace("://music.", "://www.") // i hope this works
		if (this._href == url)
			return
		this._href = url
		this.$title.textContent = url
		this.$author.textContent = ""
		this.$link.href = url
		
		let [, id, query] = /^https?:[/][/](?:www[.])?(?:youtube.com[/]watch[?]v=|youtu[.]be[/])([\w-]{11,})([&?].*)?$/.exec(url)
		if (query) {
			function parse_time(str) {
				let r = /^(?:([0-9.]+)h)?(?:([0-9.]+)m)?([0-9.]+)s?$/.exec(str)
				if (r) {
					let [_, h=0, m=0, s=0] = r
					return +h*3600 + +m*60 + +s
				}
				return str
			}
			function render_time(n) {
				if (!n)
					return "x"
				let s = n % 60 | 0
				n /= 60
				let m = n % 60 | 0
				n /= 60
				let h = n % 60 | 0
				if (h)
					return h+":"+m+":"+s
				return m+":"+s
			}
			let time = /[&?](?:t|start)=([^&?]+)/.exec(query)
			let end = /[&?]end=([^&?]+)/.exec(query)
			let loop = /[&?]loop(?:=|&|$)/.exec(query)
			query = ""
			if (time) {
				time = parse_time(time[1])
				query += "&start="+time
			}
			if (end) {
				end = parse_time(end[1])
				query += "&end="+end
			}
			//if (loop) query += "&loop=1&playlist="+id // this is broken now..
			let info = ""
			if (time && end)
				info = "at "+render_time(time)+" – "+render_time(end)
			else if (time)
				info = "at "+render_time(time)
			this.$how.textContent = info
		}
		this._query = query
		
		// display video info
		if (this._id == id)
			return
		this.$link.style.backgroundImage = `url(https://i.ytimg.com/vi/${id}/mqdefault.jpg)`
		this._id = id
		// only do one at a time
		let f = Markup_YoutubeElement.requests[id]
		if (!f) {
			// todo: cancel these when node is disconnected?
			Markup_YoutubeElement.requests[id] = f = fetch(`https://www.youtube.com/oembed?url=https%3A//youtube.com/watch%3Fv%3D${id}&format=json`).then(x=>x.json()).catch(x=>null)
		}
		f.then(data=>{
			if (this._id != id)
				return // if the video changed
			if (!data)
				data = {title: url, author_name: "(metadata request failed)"}
			this.$title.textContent = data.title
			this.$author.textContent = data.author_name
		})
	}
	attributeChangedCallback(name, old, value) {
		if (name=='data-href')
			this.update_href(value)
	}
}
// intern these?
Markup_YoutubeElement.requests = {}
Markup_YoutubeElement.observedAttributes = ['data-href']
{
	let template = ([html])=>{
		let temp = document.createElement('template')
		temp.innerHTML = html.replace(/\s*?\n\s*/g, "")
		return document.importNode.bind(document, temp.content, true)
	}
	Markup_YoutubeElement.template = template`
<a target=_blank id=link>
	<cite id=caption>
		<span id=title></span>
		<div></div>
		<span id=author></span>
	</cite>
</a>
<div id=how></div>
<button hidden id=close>❌ close</button>
<style>
	:host {
		display: flex !important;
		border: 2px solid gray;
		--height: 135px;
		flex-direction: column;
	}
	:host([data-big]) {
		--height: 270px;
	}
	#close {
		/*width: 25px;*/
		flex-shrink: 0;
	}
	iframe {
		min-width:0;
		flex-grow:1;
		border: none;
		height: var(--height);
	}
	#link {
		height: var(--height);
		padding: 4px;
		overflow-y: auto;
		background: no-repeat 0 / contain;
		overflow-wrap: break-word;
		white-space: pre-wrap;
		flex-grow: 1;
		box-sizing: border-box;
	}
	#caption {
		background: #0008;
		color: #FFF;
		font-family: sans-serif;
		display: inline;
	}
	#caption > span {
		padding: 0 0.25rem;
	}
	#caption > div {
		height: 5px;
	}
	#author {
		font-style: normal;
		font-weight: bold;
	}
	#how {
		padding-left: 2px;
		font-family: monospace;
	}
</style>
`
}

customElements.define('youtube-embed', Markup_YoutubeElement)