import { addDays, differenceInDays, format, isAfter, toDate } from 'date-fns'
import { Guild, GuildScheduledEvent, GuildScheduledEventEditOptions, GuildScheduledEventSetStatusArg, GuildScheduledEventStatus, Message, MessageCreateOptions, TextChannel } from 'discord.js'
import { v4 as uuid } from 'uuid'
import { client } from '../..'
import { config } from '../configuration'
import { Emotes } from '../events/autoCreateVoteByWPEvent'
import { Maybe } from '../interfaces'
import { logger } from '../logger'
import { Command } from '../structures/command'
import { RunOptions } from '../types/commandTypes'

export default new Command({
  name: 'closepoll',
  description: 'Aktuelle Umfrage für nächste Watchparty beenden und Gewinner in Event eintragen.',
  options: [],
  run: async (interaction: RunOptions) => {
    const command = interaction.interaction
    const requestId = uuid()
    if (!command.guild) {
      logger.error("No guild found in interaction. Cancelling closing request", { requestId })
      command.followUp("Es gab leider ein Problem. Ich konnte deine Anfrage nicht bearbeiten :(")
      return
    }
    const guildId = command.guildId
    logger.info("Got command for closing poll!", { guildId, requestId })

    command.followUp("Alles klar, beende die Umfrage :)")
    closePoll(command.guild, requestId)
  }
})

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

  const announcementChannel: Maybe<TextChannel> = 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 => !message.cleanContent.includes("[Abstimmung beendet]") && message.cleanContent.includes("[Abstimmung]"))
    .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]

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

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


  const votes = await (await 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")
  await lastMessage.delete()
  const event = await getEvent(guild, guild.id, requestId)
  if (event) {
    updateEvent(event, votes, guild, guildId, requestId)
    sendVoteClosedMessage(event, votes[0].movie, guildId, requestId)
  }

  //lastMessage.unpin() //todo: uncomment when bot has permission to pin/unpin
}

async function sendVoteClosedMessage(event: GuildScheduledEvent, movie: string, guildId: string, requestId: string) {
  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 kein Datum"
  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 = client.getAnnouncementChannelForGuild(guildId)
  logger.info("Sending vote closed message.", { guildId, requestId })
  if (!announcementChannel) {
    logger.error("Could not find announcement channel. Please fix!", { guildId, requestId })
    return
  }
  announcementChannel.send(options)
}

async function updateEvent(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)
}

async function getEvent(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]
}

type Vote = {
  emote: string, //todo habs nicht hinbekommen hier Emotes zu nutzen
  count: number,
  movie: string
}

async function getVotesByEmote(message: Message, 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 = await 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: extractMovieFromMessageByEmote(message, emote) }
      votes.push(vote)
    }
  }
  return votes
}

function extractMovieFromMessageByEmote(message: Message, emote: string): string {
  const lines = message.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
}

export async function checkForPollsToClose(guild: Guild): Promise<void> {
  const requestId = uuid()
  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 })
    closePoll(guild, requestId)
  } else {
    logger.info(`ScheduledStart: ${closePollDate}. Now: ${toDate(Date.now())}`, { guildId: guild.id, requestId })
  }
}