import {ElemJS, ejs} from "./basic.js"
import {Subscribable} from "./store/Subscribable.js"
import {store} from "./store/store.js"
import {Anchor} from "./Anchor.js"
import * as lsm from "./lsm.js"
import {resolveMxc} from "./functions.js"

const dateFormatter = Intl.DateTimeFormat("default", {hour: "numeric", minute: "numeric", day: "numeric", month: "short", year: "numeric"})

let sentIndex = 0

function getTxnId() {
	return Date.now() + (sentIndex++)
}

function eventSearch(list, event, min = 0, max = -1) {
	if (list.length === 0) return {success: false, i: 0}

	if (max === -1) max = list.length - 1
	let mid = Math.floor((max + min) / 2)
	// success condition
	if (list[mid] && list[mid].data.event_id === event.data.event_id) return {success: true, i: mid}
	// failed condition
	if (min >= max) {
		while (mid !== -1 && (!list[mid] || list[mid].data.origin_server_ts > event.data.origin_server_ts)) mid--
		return {
			success: false,
			i: mid + 1
		}
	}
	// recurse (below)
	if (list[mid].data.origin_server_ts > event.data.origin_server_ts) return eventSearch(list, event, min, mid-1)
	// recurse (above)
	else return eventSearch(list, event, mid+1, max)
}

class Event extends ElemJS {
	constructor(data) {
		super("div")
		this.class("c-message")
		this.data = null
		this.group = null
		this.update(data)
	}

	setGroup(group) {
		this.group = group
	}

	update(data) {
		this.data = data
		this.render()
	}

	removeEvent() {
		if (this.group) this.group.removeEvent(this)
		else this.remove()
	}

	render() {
		this.element.classList[this.data.pending ? "add" : "remove"]("c-message--pending")
		this.text(this.data.content.body)
	}
}

class Sender {
	constructor(roomID, mxid) {
		this.sender = store.rooms.get(roomID).value().members.get(mxid)
		this.sender.subscribe("changeSelf", this.update.bind(this))
		this.name = new ElemJS("div").class("c-message-group__name")
		this.avatar = new ElemJS("div").class("c-message-group__avatar")
		this.update()
	}

	update() {
		if (this.sender.exists()) {
			// name
			this.name.text(this.sender.value().content.displayname)

			// avatar
			this.avatar.clearChildren()
			if (this.sender.value().content.avatar_url) {
				this.avatar.child(
					ejs("img").class("c-message-group__icon").attribute("src", resolveMxc(this.sender.value().content.avatar_url, 32, "crop"))
				)
			} else {
				this.avatar.child(
					ejs("div").class("c-message-group__icon")
				)
			}
		}
	}
}

class EventGroup extends ElemJS {
	constructor(reactive, list) {
		super("div")
		this.class("c-message-group")
		this.reactive = reactive
		this.list = list
		this.data = {
			sender: list[0].data.sender,
			origin_server_ts: list[0].data.origin_server_ts
		}
		this.sender = new Sender(this.reactive.id, this.data.sender)
		this.child(
			this.sender.avatar,
			this.messages = ejs("div").class("c-message-group__messages").child(
				ejs("div").class("c-message-group__intro").child(
					this.sender.name,
					ejs("div").class("c-message-group__date").text(dateFormatter.format(this.data.origin_server_ts))
				),
				...this.list
			)
		)
	}

	addEvent(event) {
		const index = eventSearch(this.list, event).i
		event.setGroup(this)
		this.list.splice(index, 0, event)
		this.messages.childAt(index + 1, event)
	}

	removeEvent(event) {
		const search = eventSearch(this.list, event)
		if (!search.success) throw new Error(`Event ${event.data.event_id} not found in this group`)
		const index = search.i
		// actually remove the event
		this.list.splice(index, 1)
		event.remove() // should get everything else
		if (this.list.length === 0) this.reactive.removeGroup(this)
	}
}

class ReactiveTimeline extends ElemJS {
	constructor(id, list) {
		super("div")
		this.class("c-event-groups")
		this.id = id
		this.list = list
		this.render()
	}

	addEvent(event) {
		const search = eventSearch(this.list, event)
		// console.log(search, this.list.map(l => l.data.sender), event.data)
		if (!search.success && search.i >= 1) this.tryAddGroups(event, [search.i-1, search.i])
		else this.tryAddGroups(event, [search.i])
	}

	tryAddGroups(event, indices) {
		const success = indices.some(i => {
			if (!this.list[i]) {
				// if (printed++ < 100) console.log("tryadd success, created group")
				const group = new EventGroup(this, [event])
				this.list.splice(i, 0, group)
				this.childAt(i, group)
				return true
			} else if (this.list[i] && this.list[i].data.sender === event.data.sender) {
				// if (printed++ < 100) console.log("tryadd success, using existing group")
				this.list[i].addEvent(event)
				return true
			}
		})
		if (!success) console.log("tryadd failure", indices, this.list.map(l => l.data.sender), event.data)
	}

	removeGroup(group) {
		const index = this.list.indexOf(group)
		this.list.splice(index, 1)
		group.remove() // should get everything else
	}

	render() {
		this.clearChildren()
		this.list.forEach(group => this.child(group))
		this.anchor = new Anchor()
		this.child(this.anchor)
	}
}

class Timeline extends Subscribable {
	constructor(id) {
		super()
		Object.assign(this.events, {
			beforeChange: [],
			afterChange: []
		})
		Object.assign(this.eventDeps, {
			beforeChange: [],
			afterChange: []
		})
		this.id = id
		this.list = []
		this.map = new Map()
		this.reactiveTimeline = new ReactiveTimeline(id, [])
		this.latest = 0
		this.pending = new Set()
	}

	updateEvents(events) {
		this.broadcast("beforeChange")
		for (const eventData of events) {
			this.latest = Math.max(this.latest, eventData.origin_server_ts)
			let id = eventData.event_id
			if (eventData.sender === lsm.get("mx_user_id") && eventData.content && this.pending.has(eventData.content["chat.carbon.message.pending_id"])) {
				id = eventData.content["chat.carbon.message.pending_id"]
			}
			if (this.map.has(id)) {
				this.map.get(id).update(eventData)
			} else {
				const event = new Event(eventData)
				this.map.set(id, event)
				this.reactiveTimeline.addEvent(event)
			}
		}
		this.broadcast("afterChange")
	}

	removeEvent(id) {
		if (!this.map.has(id)) throw new Error(`Tried to delete event ID ${id} which does not exist`)
		this.map.get(id).removeEvent()
		this.map.delete(id)
	}

	getTimeline() {
		return this.reactiveTimeline
	}

	send(body) {
		const tx = getTxnId()
		const id = `pending$${tx}`
		this.pending.add(id)
		const content = {
			msgtype: "m.text",
			body,
			"chat.carbon.message.pending_id": id
		}
		const fakeEvent = {
			origin_server_ts: Date.now(),
			event_id: id,
			sender: lsm.get("mx_user_id"),
			content,
			pending: true
		}
		this.updateEvents([fakeEvent])
		return fetch(`${lsm.get("domain")}/_matrix/client/r0/rooms/${this.id}/send/m.room.message/${tx}?access_token=${lsm.get("access_token")}`, {
			method: "PUT",
			body: JSON.stringify(content),
			headers: {
				"Content-Type": "application/json"
			}
		})/*.then(() => {
			const subscription = () => {
				this.removeEvent(id)
				this.unsubscribe("afterChange", subscription)
			}
			this.subscribe("afterChange", subscription)
		})*/
	}
/*
	getGroupedEvents() {
		let currentSender = Symbol("N/A")
		let groups = []
		let currentGroup = []
		for (const event of this.list) {
			if (event.sender === currentSender) {
				currentGroup.push(event)
			} else {
				if (currentGroup.length) groups.push(currentGroup)
				currentGroup = [event]
				currentSender = event.sender
			}
		}
		if (currentGroup.length) groups.push(currentGroup)
		return groups
	}
	*/
}

export {Timeline}