'use strict'

function call(method, params) {
	return m.request({
		method: "POST",
		url: `/api/${method}`,
		body: params,
	})
}

let BrowseModel = {
	path: undefined,
	subdirectories: [],
	entries: [],

	async reload(path) {
		if (this.path !== path) {
			this.path = path
			this.subdirectories = []
			this.entries = []
		}

		let resp = await call('browse', {path: path})
		this.subdirectories = resp.subdirectories
		this.entries = resp.entries
	},

	joinPath(parent, child) {
		if (!parent)
			return child
		if (!child)
			return parent
		return `${parent}/${child}`
	},

	getBrowseLinks() {
		if (this.path === undefined)
			return []

		let links = [{name: "Root", path: "", level: -1}], path
		for (const crumb of this.path.split('/').filter(s => !!s)) {
			path = this.joinPath(path, crumb)
			links.push({name: crumb, path: path, level: -1})
		}

		links[links.length - 1].level = 0

		for (const sub of this.subdirectories) {
			links.push(
				{name: sub, path: this.joinPath(this.path, sub), level: +1})
		}
		return links
	},
}

let BrowseLink = {
	view(vnode) {
		const link = vnode.attrs.link

		let c = 'selected'
		if (link.level < 0)
			c = 'parent'
		if (link.level > 0)
			c = 'child'

		return m('li', {
			class: c,
		}, m(m.route.Link, {
			href: `/browse/:key`,
			params: {key: link.path},
		}, link.name))
	},
}

let BrowseView = {
	// So that Page Up/Down, etc., work after changing directories.
	// Programmatically focusing a scrollable element requires setting tabindex,
	// and causes :focus-visible on page load, which we suppress in CSS.
	// I wish there was another way, but the workaround isn't particularly bad.
	// focus({focusVisible: true}) is FF 104+ only and experimental.
	oncreate(vnode) { vnode.dom.focus() },

	view(vnode) {
		return m('.browser[tabindex=0]', {
			key: BrowseModel.path,
		}, BrowseModel.entries.map(e => {
			return m(m.route.Link, {href: `/view/${e.sha1}`},
				m('img', {src: `/thumb/${e.sha1}`,
					width: e.thumbW, height: e.thumbH, title: e.name}))
		}))
	},
}

let Browse = {
	// Reload the model immediately, to improve responsivity.
	// But we don't need to: https://mithril.js.org/route.html#preloading-data
	// Also see: https://mithril.js.org/route.html#route-cancellation--blocking
	oninit(vnode) {
		let path = vnode.attrs.key || ""
		BrowseModel.reload(path)
	},

	view(vnode) {
		return m('.container', {}, [
			m('.header', {}, "Browser"),
			m('.body', {}, [
				m('ul.sidebar', BrowseModel.getBrowseLinks().map(link =>
					m(BrowseLink, {link}))),
				m(BrowseView),
			]),
		])
	},
}

let ViewModel = {
	sha1: undefined,
	paths: [],
	tags: {},

	async reload(sha1) {
		this.sha1 = sha1
		this.paths = []
		this.tags = {}

		let resp = await call('info', {sha1: sha1})
		this.paths = resp.paths
		this.tags = resp.tags
	},
}

let View = {
	oninit(vnode) {
		let sha1 = vnode.attrs.key || ""
		ViewModel.reload(sha1)
	},

	view(vnode) {
		const view = m('.view', [
			ViewModel.sha1 !== undefined
				? m('img', {src: `/image/${ViewModel.sha1}`})
				: "No image.",
		])
		const viewbar = m('.viewbar', [
			m('h2', "Locations"),
			m('ul', ViewModel.paths.map(sd => m('li', sd))),
			m('h2', "Tags"),
			Object.entries(ViewModel.tags).map(([group, tags]) => [
				m("h3", group),
				m("ul", Object.entries(tags).map(
					([tag, weight]) => m("li", `${tag}: ${weight}`))),
			]),
		])
		return m('.container', {}, [
			m('.header', {}, "View"),
			m('.body', {}, [
				view,
				viewbar,
			]),
		])
	},
}

window.addEventListener('load', () => {
	m.route(document.body, "/browse/", {
		// The path doesn't need to be escaped, perhaps change that (":key...").
		"/browse/": Browse,
		"/browse/:key": Browse,
		"/view/:key": View,

		"/similar/:sha1": undefined,
		"/tags": undefined,
		"/tags/:space": undefined,
		"/tags/:space/:tag": undefined,
	})
})