import { Guild, GuildScheduledEvent, GuildScheduledEventEditOptions, GuildScheduledEventSetStatusArg, GuildScheduledEventStatus, Message, MessageCreateOptions, MessageReaction, TextChannel } from "discord.js"
import { Emotes, NONE_OF_THAT } from "../constants"
import { logger, newRequestId } from "../logger"
import { getMembersWithRoleFromGuild } from "./roleFilter"
import { config } from "../configuration"
import { VoteMessage, isVoteEndedMessage, isVoteMessage } from "./messageIdentifiers"
import { createDateStringFromEvent } from "./dateHelper"
import { Maybe, voteMessageInputInformation as prepareVoteMessageInput } from "../interfaces"
import format from "date-fns/format"
import toDate from "date-fns/toDate"
import differenceInDays from "date-fns/differenceInDays"
import addDays from "date-fns/addDays"
import isAfter from "date-fns/isAfter"
import { ExtendedClient } from "../structures/client"
import { JellyfinHandler } from "../jellyfin/handler"

export type Vote = {
	emote: string, //todo habs nicht hinbekommen hier Emotes zu nutzen
	count: number,
	movie: string
}
export type VoteMessageInfo = {
	votes: Vote[],
	event: GuildScheduledEvent,
}
export default class VoteController {
	private client: ExtendedClient
	private yavinJellyfinHandler: JellyfinHandler

	public constructor(_client: ExtendedClient, _yavin: JellyfinHandler) {
		this.client = _client
		this.yavinJellyfinHandler = _yavin
	}

	public async handleNoneOfThatVote(messageReaction: MessageReaction, reactedUponMessage: VoteMessage, requestId: string, guildId: string) {
		if (!messageReaction.message.guild) return 'No guild'
		const guild = messageReaction.message.guild
		logger.debug(`${reactedUponMessage.id} is vote message`, { requestId, guildId })

		const watcherRoleMember = await getMembersWithRoleFromGuild(config.bot.announcement_role, messageReaction.message.guild)
		logger.info("ROLE MEMBERS " + JSON.stringify(watcherRoleMember), { requestId, guildId })

		const watcherRoleMemberCount = watcherRoleMember.size
		logger.info(`MEMBER COUNT: ${watcherRoleMemberCount}`, { requestId, guildId })

		const noneOfThatReactions = reactedUponMessage.reactions.cache.get(NONE_OF_THAT)?.users.cache.filter(x => x.id !== this.client.user?.id).size ?? 0

		const memberThreshold = (watcherRoleMemberCount / 2)
		logger.info(`Reroll ${noneOfThatReactions} > ${memberThreshold} ?`, { requestId, guildId })
		if (noneOfThatReactions > memberThreshold)
			logger.info(`No reroll`, { requestId, guildId })
		else {
			logger.info('Starting poll reroll', { requestId, guildId })
			await this.handleReroll(reactedUponMessage, guild.id, requestId)
			logger.info(`Finished handling NONE_OF_THAT vote`, { requestId, guildId })
		}
	}

	private async removeMessage(message: Message): Promise<Message<boolean>> {
		if (message.pinned) {
			await message.unpin()
		}
		return await message.delete()
	}

	/**
	 * returns true if a Vote object contains at least one vote
	 * @param {Vote} vote
	 */
	private hasAtLeastOneVote(vote: Vote): boolean {
		// subtracting the bots initial vote
		const overOneVote = (vote.count - 1) >= 1
		logger.debug(`${vote.movie} : ${vote.count} -> above: ${overOneVote}`)
		return overOneVote
	}

	public async generateRerollMovieList(voteInfo: VoteMessageInfo, guildId: string, requestId: string) {
		if (config.bot.reroll_retains_top_picks) {
			const votedOnMovies = voteInfo.votes.filter(this.hasAtLeastOneVote).filter(x => x.emote !== NONE_OF_THAT)
			logger.info(`Found ${votedOnMovies.length} with votes`, { requestId, guildId })
			const newMovieCount: number = config.bot.random_movie_count - votedOnMovies.length
			logger.info(`Fetching ${newMovieCount} from jellyfin`)
			const newMovies: string[] = await this.yavinJellyfinHandler.getRandomMovieNames(newMovieCount, guildId, requestId)
			// merge
			return newMovies.concat(votedOnMovies.map(x => x.movie))
		} else {
			// get movies from jellyfin to fill the remaining slots
			const newMovieCount: number = config.bot.random_movie_count
			logger.info(`Fetching ${newMovieCount} from jellyfin`)
			return await this.yavinJellyfinHandler.getRandomMovieNames(newMovieCount, guildId, requestId)
		}
	}

	public async handleReroll(voteMessage: VoteMessage, guildId: string, requestId: string) {
		// get the movies currently being voted on, their votes, the eventId and its date
		const voteInfo: VoteMessageInfo = await this.parseVoteInfoFromVoteMessage(voteMessage, requestId)
		if (!voteInfo.event.scheduledStartAt) {
			logger.info("Event does not have a start date, cancelling", { guildId: voteInfo.event.guildId, requestId })
			return
		}

		let movies: string[] = await this.generateRerollMovieList(voteInfo, guildId, requestId)

		const announcementChannel = this.client.getAnnouncementChannelForGuild(guildId)
		if (!announcementChannel) {
			logger.error(`No announcementChannel found for ${guildId}, can't post poll`)
			return
		}
		try {
			logger.info(`Trying to remove old vote Message`, { requestId, guildId })
			this.removeMessage(voteMessage)
		} catch (err) {
			// TODO: integrate failure DM to media Admin to inform about inability to delete old message
			logger.error(`Error during removeMessage: ${err}`)
		}
		const sentMessage = this.prepareAndSendVoteMessage({
			event: voteInfo.event,
			movies,
			announcementChannel,
			startDate: voteInfo.event.scheduledStartAt,
			pinAfterSending: true
		},
			guildId,
			requestId)
		logger.debug(`Sent reroll message: ${JSON.stringify(sentMessage)}`, { requestId, guildId })
	}

	private async fetchEventByEventId(guild: Guild, eventId: string, requestId: string): Promise<Maybe<GuildScheduledEvent>> {
		const guildEvent: GuildScheduledEvent = await guild.scheduledEvents.fetch(eventId)
		if (!guildEvent) logger.error(`GuildScheduledEvent with id${eventId} could not be found`, { requestId, guildId: guild.id })
		return guildEvent
	}

	public async parseVoteInfoFromVoteMessage(message: VoteMessage, requestId: string): Promise<VoteMessageInfo> {
		const lines = message.cleanContent.split('\n')
		let parsedIds = this.parseGuildIdAndEventIdFromWholeMessage(message.cleanContent)

		if (!message.guild)
			throw new Error(`Message ${message.id} not a guild message`)

		const event: Maybe<GuildScheduledEvent> = await this.fetchEventByEventId(message.guild, parsedIds.eventId, requestId)

		let votes: Vote[] = []
		for (const line of lines) {
			if (line.slice(0, 5).includes(':')) {
				const splitLine = line.split(":")
				const [emoji, movie] = splitLine
				const fetchedVoteFromMessage = message.reactions.cache.get(emoji)
				if (fetchedVoteFromMessage) {
					if (emoji === NONE_OF_THAT) {
						votes.push({ movie: NONE_OF_THAT, emote: NONE_OF_THAT, count: fetchedVoteFromMessage.count })
					} else
						votes.push({ movie: movie.trim(), emote: emoji, count: fetchedVoteFromMessage.count })
				} else {
					logger.error(`No vote reaction found for movie, assuming 0`, requestId)
					votes.push({ movie, emote: emoji, count: 0 })
				}
			}
		}
		return <VoteMessageInfo>{ event, votes }
	}
	public parseEventDateFromMessage(message: string, guildId: string, requestId: string): Date {
		logger.warn(`Falling back to RegEx parsing to get Event Date`, { guildId, requestId })
		const datematcher = RegExp(/((?:0[1-9]|[12][0-9]|3[01])\.(?:0[1-9]|1[012])\.)(?:\ um\ )((?:(?:[01][0-9]|[2][0-3])\:[0-5][0-9])|(?:[2][4]\:00))!/i)
		const result: RegExpMatchArray | null = message.match(datematcher)
		const timeFromResult = result?.at(-1)
		const dateFromResult = result?.at(1)?.concat(format(new Date(), 'yyyy')).concat(" " + timeFromResult) ?? ""
		return new Date(dateFromResult)
	}
	public parseGuildIdAndEventIdFromWholeMessage(message: string) {
		const idmatch = RegExp(/(?:http|https):\/\/discord\.com\/events\/(\d*)\/(\d*)/)
		const matches = message.match(idmatch)
		if (matches && matches.length == 3)
			return { guildId: matches[1], eventId: matches[2] }
		throw Error(`Could not find eventId in Vote Message`)
	}

	public async prepareAndSendVoteMessage(inputInfo: prepareVoteMessageInput, guildId: string, requestId: string) {
		const messageText = this.createVoteMessageText(inputInfo.event, inputInfo.movies, guildId, requestId)
		const sentMessage = await this.sendVoteMessage(messageText, inputInfo.movies.length, inputInfo.announcementChannel)
		if (inputInfo.pinAfterSending)
			sentMessage.pin()
		return sentMessage
	}

	public createVoteMessageText(event: GuildScheduledEvent, movies: string[], guildId: string, requestId: string): string {
		let message = `[Abstimmung] für https://discord.com/events/${guildId}/${event.id} \n<@&${config.bot.announcement_role}> Es gibt eine neue Abstimmung für die nächste Watchparty ${createDateStringFromEvent(event.scheduledStartAt, guildId, requestId)}! Stimme hierunter für den nächsten Film ab!\n`

		for (let i = 0; i < movies.length; i++) {
			message = message.concat(Emotes[i]).concat(": ").concat(movies[i]).concat("\n")
		}
		message = message.concat(NONE_OF_THAT).concat(": Wenn dir nichts davon gefällt.")

		return message
	}

	// TODO: Refactor into separate message controller
	public async sendVoteMessage(messageText: string, movieCount: number, announcementChannel: TextChannel) {

		const options: MessageCreateOptions = {
			allowedMentions: { parse: ["roles"] },
			content: messageText,
		}

		const sentMessage: Message<true> = await (await announcementChannel.fetch()).send(options)

		for (let i = 0; i < movieCount; i++) {
			sentMessage.react(Emotes[i])
		}
		sentMessage.react(NONE_OF_THAT)

		return sentMessage
	}

	public async closePoll(guild: Guild, requestId: string) {
		const guildId = guild.id
		logger.info("stopping poll", { guildId, requestId })

		const announcementChannel: Maybe<TextChannel> = this.client.getAnnouncementChannelForGuild(guildId)
		if (!announcementChannel) {
			logger.error("Could not find the textchannel. Unable to close poll.", { guildId, requestId })
			return
		}

		const messages: Message<true>[] = (await announcementChannel.messages.fetch()) //todo: fetch only pinned messages
			.map((value) => value)
			.filter(message => !isVoteEndedMessage(message) && isVoteMessage(message))
			.sort((a, b) => b.createdTimestamp - a.createdTimestamp)

		if (!messages || messages.length <= 0) {
			logger.info("Could not find any vote messages. Cancelling pollClose", { guildId, requestId })
			return
		}

		const lastMessage: Message<true> = messages[0]

		if (!isVoteMessage(lastMessage)) {
			logger.error(`Found message that is not a vote message, can't proceed`, { guildId, requestId })
			logger.debug(`Found messages: ${JSON.stringify(messages, null, 2)}`, { guildId, requestId })
			logger.debug(`Last message: ${JSON.stringify(lastMessage, null, 2)}`, { guildId, requestId })
		}
		else {
			const votes = (await this.getVotesByEmote(lastMessage, guildId, requestId))
				.sort((a, b) => b.count - a.count)

			logger.debug(`votes: ${JSON.stringify(votes, null, 2)}`, { guildId, requestId })

			logger.info("Deleting vote message")
			lastMessage.unpin()
			await lastMessage.delete()
			const event = await this.getOpenPollEvent(guild, guild.id, requestId)
			if (event && votes?.length > 0) {
				this.updateOpenPollEventWithVoteResults(event, votes, guild, guildId, requestId)
				this.sendVoteClosedMessage(event, votes[0].movie, guildId, requestId)
			}
		}
	}
	/**
	 * gets votes for the movies without the NONE_OF_THAT votes
	*/
	public async getVotesByEmote(message: VoteMessage, guildId: string, requestId: string): Promise<Vote[]> {
		const votes: Vote[] = []
		logger.debug(`Number of items in emotes: ${Object.values(Emotes).length}`, { guildId, requestId })
		for (let i = 0; i < Object.keys(Emotes).length / 2; i++) {
			const emote = Emotes[i]
			logger.debug(`Getting reaction for emote ${emote}`, { guildId, requestId })
			const reaction = message.reactions.resolve(emote)
			logger.debug(`Reaction for emote ${emote}: ${JSON.stringify(reaction, null, 2)}`, { guildId, requestId })
			if (reaction) {
				const vote: Vote = { emote: emote, count: reaction.count, movie: this.extractMovieFromMessageByEmote(message, emote) }
				votes.push(vote)
			}
		}
		return votes
	}
	public async getOpenPollEvent(guild: Guild, guildId: string, requestId: string): Promise<GuildScheduledEvent | null> {
		const voteEvents = (await guild.scheduledEvents.fetch())
			.map((value) => value)
			.filter(event => event.name.toLowerCase().includes("voting offen"))
		logger.debug(`Found events: ${JSON.stringify(voteEvents, null, 2)}`, { guildId, requestId })

		if (!voteEvents || voteEvents.length <= 0) {
			logger.error("Could not find vote event. Cancelling update!", { guildId, requestId })
			return null
		}
		return voteEvents[0]
	}
	public async updateOpenPollEventWithVoteResults(voteEvent: GuildScheduledEvent, votes: Vote[], guild: Guild, guildId: string, requestId: string) {
		logger.info(`Updating event with movie ${votes[0].movie}.`, { guildId, requestId })
		const options: GuildScheduledEventEditOptions<GuildScheduledEventStatus.Scheduled, GuildScheduledEventSetStatusArg<GuildScheduledEventStatus.Scheduled>> = {
			name: votes[0].movie,
			description: `!wp\nNummer 2: ${votes[1].movie} mit ${votes[1].count - 1} Stimmen\nNummer 3: ${votes[2].movie} mit ${votes[2].count - 1} Stimmen`
		}
		logger.debug(`Updating event: ${JSON.stringify(voteEvent, null, 2)}`, { guildId, requestId })
		logger.info("Updating event.", { guildId, requestId })
		voteEvent.edit(options)
	}
	public async sendVoteClosedMessage(event: GuildScheduledEvent, movie: string, guildId: string, requestId: string): Promise<Message<boolean>> {
		const date = event.scheduledStartAt ? format(event.scheduledStartAt, "dd.MM.") : "Fehler, Event hatte kein Datum"
		const time = event.scheduledStartAt ? format(event.scheduledStartAt, "HH:mm") : "Fehler, Event hatte keine Uhrzeit"
		const body = `[Abstimmung beendet] für https://discord.com/events/${event.guildId}/${event.id}\n<@&${config.bot.announcement_role}> Wir gucken ${movie} am ${date} um ${time}`
		const options: MessageCreateOptions = {
			content: body,
			allowedMentions: { parse: ["roles"] }
		}
		const announcementChannel = this.client.getAnnouncementChannelForGuild(guildId)
		logger.info("Sending vote closed message.", { guildId, requestId })
		if (!announcementChannel) {
			const errorMessageText = "Could not find announcement channel. Please fix!"
			logger.error(errorMessageText, { guildId, requestId })
			throw errorMessageText
		}
		return announcementChannel.send(options)
	}
	private extractMovieFromMessageByEmote(voteMessage: VoteMessage, emote: string): string {
		const lines = voteMessage.cleanContent.split("\n")
		const emoteLines = lines.filter(line => line.includes(emote))

		if (!emoteLines) {
			return ""
		}
		const movie = emoteLines[0].substring(emoteLines[0].indexOf(emote) + emote.length + 2) // plus colon and space

		return movie
	}
	public async checkForPollsToClose(guild: Guild): Promise<void> {
		const requestId = newRequestId()
		logger.info(`Automatic check for poll closing.`, { guildId: guild.id, requestId })
		const events = (await guild.scheduledEvents.fetch()).filter(event => event.name.toLocaleLowerCase().includes("voting offen")).map(event => event)
		if (events.length > 1) {
			logger.error("Handling more than one Event is not implemented yet. Found more than one poll to close")
			return
		} else if (events.length == 0) {
			logger.info("Could not find any events. Cancelling", { guildId: guild.id, requestId })
		}

		const updatedEvent = events[0]             //add two hours because of different timezones in discord api and Date.now()
		if (!updatedEvent.scheduledStartTimestamp) {
			logger.error("Event does not have a scheduled start time. Cancelling", { guildId: guild.id, requestId })
			return
		}

		const createDate: Date = toDate(updatedEvent.createdTimestamp)
		const eventDate: Date = toDate(updatedEvent.scheduledStartTimestamp)
		const difference: number = differenceInDays(createDate, eventDate)

		if (difference <= 2) {
			logger.info("Less than two days between event create and event start. Not closing poll.", { guildId: guild.id, requestId })
			return
		}

		const closePollDate: Date = addDays(eventDate, -2)

		if (isAfter(Date.now(), closePollDate)) {
			logger.info("Less than two days until event. Closing poll", { guildId: guild.id, requestId })
			this.closePoll(guild, requestId)
		} else {
			logger.info(`ScheduledStart: ${closePollDate}. Now: ${toDate(Date.now())}`, { guildId: guild.id, requestId })
		}
	}
}