import { createConsoleState } from '@modrinth/ui'

import {
	clear_log_buffer,
	get_live_log_buffer,
	get_logs,
	get_minecraft_latest_log_cursor,
} from '@/helpers/logs'

import { mergeLiveLogHistory } from './console-history'

type ConsoleState = ReturnType<typeof createConsoleState>

interface LogEntry {
	filename: string
	name?: string
	log_type: string
	output?: string | null
	age?: number
	live?: boolean
}

interface InstanceConsoleEntry {
	liveConsole: ConsoleState
	historicalConsole: ConsoleState
	historicalCache: Map<string, string>
	logList: LogEntry[] | null
	liveHistoryHydration: Promise<void> | null
}

const instances = new Map<string, InstanceConsoleEntry>()

function getOrCreate(instanceId: string): InstanceConsoleEntry {
	let entry = instances.get(instanceId)
	if (entry) return entry

	entry = {
		liveConsole: createConsoleState(),
		historicalConsole: createConsoleState(),
		historicalCache: new Map(),
		logList: null,
		liveHistoryHydration: null,
	}
	instances.set(instanceId, entry)
	return entry
}

async function hydrate(instanceId: string): Promise<void> {
	const entry = getOrCreate(instanceId)
	if (entry.liveConsole.output.value.length > 0) return

	if (entry.liveHistoryHydration) {
		return entry.liveHistoryHydration
	}

	const hydration = (async () => {
		const [latestLog, buffer] = await Promise.all([
			get_minecraft_latest_log_cursor(instanceId, 0)
				.then((result) => result.output)
				.catch(() => ''),
			get_live_log_buffer(instanceId),
		])

		if (entry.liveConsole.output.value.length > 0) return

		const history = mergeLiveLogHistory(latestLog, buffer)
		if (history) {
			await entry.liveConsole.addLegacyLog(history)
		}
	})()

	entry.liveHistoryHydration = hydration
	try {
		await hydration
	} finally {
		if (entry.liveHistoryHydration === hydration) {
			entry.liveHistoryHydration = null
		}
	}
}

async function getHistoricalLogs(instanceId: string): Promise<LogEntry[]> {
	const entry = getOrCreate(instanceId)
	if (entry.logList) return entry.logList

	const logs: LogEntry[] = await get_logs(instanceId, true)
	entry.logList = logs

	for (const log of logs) {
		if (log.output) {
			entry.historicalCache.set(log.filename, log.output)
		}
	}

	return logs
}

function getHistoricalContent(instanceId: string, filename: string): string | undefined {
	return instances.get(instanceId)?.historicalCache.get(filename)
}

function invalidate(instanceId: string): void {
	const entry = instances.get(instanceId)
	if (!entry) return
	entry.historicalCache.clear()
	entry.logList = null
}

async function clearLive(instanceId: string): Promise<void> {
	const entry = getOrCreate(instanceId)
	entry.liveConsole.clear()
	await clear_log_buffer(instanceId).catch(() => {})
}

async function destroy(instanceId: string): Promise<void> {
	instances.delete(instanceId)
	await clear_log_buffer(instanceId).catch(() => {})
}

export function useInstanceConsole(instanceId: string) {
	const entry = getOrCreate(instanceId)
	return {
		liveConsole: entry.liveConsole,
		historicalConsole: entry.historicalConsole,
		hydrate: () => hydrate(instanceId),
		getHistoricalLogs: () => getHistoricalLogs(instanceId),
		getHistoricalContent: (filename: string) => getHistoricalContent(instanceId, filename),
		invalidate: () => invalidate(instanceId),
		clearLive: () => clearLive(instanceId),
		destroy: () => destroy(instanceId),
	}
}