const moment = require("moment");
const Eris = require("eris");

const bot = require("../bot");
const knex = require("../knex");
const utils = require("../utils");
const config = require("../cfg");
const attachments = require("./attachments");
const { formatters } = require("../formatters");

const ThreadMessage = require("./ThreadMessage");

const {THREAD_MESSAGE_TYPE, THREAD_STATUS, DISCORD_MESSAGE_ACTIVITY_TYPES} = require("./constants");

/**
 * @property {String} id
 * @property {Number} status
 * @property {String} user_id
 * @property {String} user_name
 * @property {String} channel_id
 * @property {Number} next_message_number
 * @property {String} scheduled_close_at
 * @property {String} scheduled_close_id
 * @property {String} scheduled_close_name
 * @property {Number} scheduled_close_silent
 * @property {String} alert_ids
 * @property {String} created_at
 */
class Thread {
  constructor(props) {
    utils.setDataModelProps(this, props);
  }

  /**
   * @param {Eris.MessageContent} text
   * @param {Eris.MessageFile|Eris.MessageFile[]} file
   * @returns {Promise<Eris.Message>}
   * @throws Error
   * @private
   */
  async _sendDMToUser(content, file = null) {
    // Try to open a DM channel with the user
    const dmChannel = await this.getDMChannel();
    if (! dmChannel) {
      throw new Error("Could not open DMs with the user. They may have blocked the bot or set their privacy settings higher.");
    }

    let firstMessage;

    if (typeof content === "string") {
      // Content is a string, chunk it and send it as individual messages.
      // Files (attachments) are only sent with the last message.
      const chunks = utils.chunk(content, 2000);
      for (const [i, chunk] of chunks.entries()) {
        let msg;
        if (i === chunks.length - 1) {
          // Only send embeds, files, etc. with the last message
          msg = await dmChannel.createMessage(chunk, file);
        } else {
          msg = await dmChannel.createMessage(chunk);
        }

        firstMessage = firstMessage || msg;
      }
    } else {
      // Content is a full message content object, send it as-is with the files (if any)
      firstMessage = await dmChannel.createMessage(content, file);
    }

    return firstMessage;
  }

  /**
   * @param {Eris.MessageContent} content
   * @param {Eris.MessageFile} file
   * @return {Promise<Eris.Message|null>}
   * @private
   */
  async _postToThreadChannel(content, file = null) {
    try {
      let firstMessage;

      if (typeof content === "string") {
        // Content is a string, chunk it and send it as individual messages.
        // Files (attachments) are only sent with the last message.
        const chunks = utils.chunk(content, 2000);
        for (const [i, chunk] of chunks.entries()) {
          let msg;
          if (i === chunks.length - 1) {
            // Only send embeds, files, etc. with the last message
            msg = await bot.createMessage(this.channel_id, chunk, file);
          }

          firstMessage = firstMessage || msg;
        }
      } else {
        // Content is a full message content object, send it as-is with the files (if any)
        firstMessage = await bot.createMessage(this.channel_id, content, file);
      }

      return firstMessage;
    } catch (e) {
      // Channel not found
      if (e.code === 10003) {
        console.log(`[INFO] Failed to send message to thread channel for ${this.user_name} because the channel no longer exists. Auto-closing the thread.`);
        this.close(true);
      } else {
        throw e;
      }
    }
  }

  /**
   * @param {Object} data
   * @returns {Promise<ThreadMessage>}
   * @private
   */
  async _addThreadMessageToDB(data) {
    if (data.message_type === THREAD_MESSAGE_TYPE.TO_USER) {
      data.message_number = await this._getAndIncrementNextMessageNumber();
    }

    const dmChannel = await this.getDMChannel();
    const insertedIds = await knex("thread_messages").insert({
      thread_id: this.id,
      created_at: moment.utc().format("YYYY-MM-DD HH:mm:ss"),
      is_anonymous: 0,
      dm_channel_id: dmChannel.id,
      ...data
    });

    const threadMessage = await knex("thread_messages")
      .where("id", insertedIds[0])
      .select();

    return new ThreadMessage(threadMessage[0]);
  }

  /**
   * @param {number} id
   * @param {object} data
   * @returns {Promise<void>}
   * @private
   */
  async _updateThreadMessage(id, data) {
    await knex("thread_messages")
      .where("id", id)
      .update(data);
  }

  /**
   * @param {number} id
   * @returns {Promise<void>}
   * @private
   */
  async _deleteThreadMessage(id) {
    await knex("thread_messages")
      .where("id", id)
      .delete();
  }

  /**
   * @returns {Promise<Number>}
   */
  async _getAndIncrementNextMessageNumber() {
    return knex.transaction(async trx => {
      const nextNumberRow = await trx("threads")
        .where("id", this.id)
        .select("next_message_number")
        .first();
      const nextNumber = nextNumberRow.next_message_number;

      await trx("threads")
        .where("id", this.id)
        .update({ next_message_number: nextNumber + 1 });

      return nextNumber;
    });
  }

  /**
   * @param {Eris.Member} moderator
   * @param {string} text
   * @param {Eris.MessageFile[]} replyAttachments
   * @param {boolean} isAnonymous
   * @returns {Promise<boolean>} Whether we were able to send the reply
   */
  async replyToUser(moderator, text, replyAttachments = [], isAnonymous = false) {
    const moderatorName = config.useNicknames && moderator.nick ? moderator.nick : moderator.user.username;
    const mainRole = utils.getMainRole(moderator);
    const roleName = mainRole ? mainRole.name : null;

    // Prepare attachments, if any
    const files = [];
    const attachmentLinks = [];

    if (replyAttachments.length > 0) {
      for (const attachment of replyAttachments) {
        await Promise.all([
          attachments.attachmentToDiscordFileObject(attachment).then(file => {
            files.push(file);
          }),
          attachments.saveAttachment(attachment).then(result => {
            attachmentLinks.push(result.url);
          })
        ]);
      }
    }

    let threadMessage = new ThreadMessage({
      message_type: THREAD_MESSAGE_TYPE.TO_USER,
      user_id: moderator.id,
      user_name: moderatorName,
      body: text,
      is_anonymous: (isAnonymous ? 1 : 0),
      role_name: roleName,
      attachments: attachmentLinks,
    });

    // Send the reply DM
    const dmContent = formatters.formatStaffReplyDM(threadMessage);
    let dmMessage;
    try {
      dmMessage = await this._sendDMToUser(dmContent, files);
    } catch (e) {
      await this.postSystemMessage(`Error while replying to user: ${e.message}`);
      return false;
    }

    // Save the log entry
    threadMessage = await this._addThreadMessageToDB({
      ...threadMessage.getSQLProps(),
      dm_message_id: dmMessage.id,
    });

    // Show the reply in the inbox thread
    const inboxContent = formatters.formatStaffReplyThreadMessage(threadMessage);
    const inboxMessage = await this._postToThreadChannel(inboxContent, files);
    if (inboxMessage) {
      await this._updateThreadMessage(threadMessage.id, { inbox_message_id: inboxMessage.id });
    }

    // Interrupt scheduled closing, if in progress
    if (this.scheduled_close_at) {
      await this.cancelScheduledClose();
      await this.postSystemMessage("Cancelling scheduled closing of this thread due to new reply");
    }

    return true;
  }

  /**
   * @param {Eris.Message} msg
   * @returns {Promise<void>}
   */
  async receiveUserReply(msg) {
    const fullUserName = `${msg.author.username}#${msg.author.discriminator}`;
    let messageContent = msg.content || "";

    // Prepare attachments
    const attachmentLinks = [];
    const smallAttachmentLinks = [];
    const attachmentFiles = [];

    for (const attachment of msg.attachments) {
      const savedAttachment = await attachments.saveAttachment(attachment);

      // Forward small attachments (<2MB) as attachments, link to larger ones
      if (config.relaySmallAttachmentsAsAttachments && attachment.size <= config.smallAttachmentLimit) {
        const file = await attachments.attachmentToDiscordFileObject(attachment);
        attachmentFiles.push(file);
        smallAttachmentLinks.push(savedAttachment.url);
      }

      attachmentLinks.push(savedAttachment.url);
    }

    // Handle special embeds (listening party invites etc.)
    if (msg.activity) {
      let applicationName = msg.application && msg.application.name;

      if (! applicationName && msg.activity.party_id.startsWith("spotify:")) {
        applicationName = "Spotify";
      }

      if (! applicationName) {
        applicationName = "Unknown Application";
      }

      let activityText;
      if (msg.activity.type === DISCORD_MESSAGE_ACTIVITY_TYPES.JOIN || msg.activity.type === DISCORD_MESSAGE_ACTIVITY_TYPES.JOIN_REQUEST) {
        activityText = "join a game";
      } else if (msg.activity.type === DISCORD_MESSAGE_ACTIVITY_TYPES.SPECTATE) {
        activityText = "spectate";
      } else if (msg.activity.type === DISCORD_MESSAGE_ACTIVITY_TYPES.LISTEN) {
        activityText = "listen along";
      } else {
        activityText = "do something";
      }

      messageContent += `\n\n*<This message contains an invite to ${activityText} on ${applicationName}>*`;
      messageContent = messageContent.trim();
    }

    // Save DB entry
    let threadMessage = new ThreadMessage({
      message_type: THREAD_MESSAGE_TYPE.FROM_USER,
      user_id: this.user_id,
      user_name: fullUserName,
      body: messageContent,
      is_anonymous: 0,
      dm_message_id: msg.id,
      dm_channel_id: msg.channel.id,
      attachments: attachmentLinks,
      small_attachments: smallAttachmentLinks,
    });

    threadMessage = await this._addThreadMessageToDB(threadMessage.getSQLProps());

    // Show user reply in the inbox thread
    const inboxContent = formatters.formatUserReplyThreadMessage(threadMessage);
    const inboxMessage = await this._postToThreadChannel(inboxContent, attachmentFiles);
    if (inboxMessage) {
      await this._updateThreadMessage(threadMessage.id, { inbox_message_id: inboxMessage.id });
    }

    if (config.reactOnSeen) {
      await msg.addReaction(config.reactOnSeenEmoji).catch(utils.noop);
    }

    // Interrupt scheduled closing, if in progress
    if (this.scheduled_close_at) {
      await this.cancelScheduledClose();
      await this.postSystemMessage(`<@!${this.scheduled_close_id}> Thread that was scheduled to be closed got a new reply. Cancelling.`);
    }

    if (this.alert_ids) {
      const ids = this.alert_ids.split(",");
      let mentions = "";

      ids.forEach(id => {
        mentions += `<@!${id}> `;
      });

      await this.deleteAlerts();
      await this.postSystemMessage(`${mentions}New message from ${this.user_name}`);
    }
  }

  /**
   * @returns {Promise<PrivateChannel>}
   */
  getDMChannel() {
    return bot.getDMChannel(this.user_id);
  }

  /**
   * @param {Eris.MessageContent} content
   * @param {Eris.MessageFile} file
   * @param {object} opts
   * @param {boolean} opts.saveToLog
   * @param {string} opts.logBody
   * @returns {Promise<void>}
   */
  async postSystemMessage(content, file = null, opts = {}) {
    const msg = await this._postToThreadChannel(content, file);
    if (msg && opts.saveToLog !== false) {
      await this._addThreadMessageToDB({
        message_type: THREAD_MESSAGE_TYPE.SYSTEM,
        user_id: null,
        user_name: "",
        body: msg.content || "<empty message>",
        is_anonymous: 0,
        inbox_message_id: msg.id,
      });
    }
  }

  /**
   * @param {Eris.MessageContent} content
   * @param {Eris.MessageFile} file
   * @param {object} opts
   * @param {boolean} opts.saveToLog
   * @param {string} opts.logBody
   * @returns {Promise<void>}
   */
  async sendSystemMessageToUser(content, file = null, opts = {}) {
    const msg = await this._sendDMToUser(content, file);
    if (opts.saveToLog !== false) {
      await this._addThreadMessageToDB({
        message_type: THREAD_MESSAGE_TYPE.SYSTEM_TO_USER,
        user_id: null,
        user_name: "",
        body: msg.content || "<empty message>",
        is_anonymous: 0,
        dm_message_id: msg.id,
      });
    }
  }

  /**
   * @param {Eris.MessageContent} content
   * @param {Eris.MessageFile} file
   * @return {Promise<Eris.Message|null>}
   */
  async postNonLogMessage(content, file = null) {
    return this._postToThreadChannel(content, file);
  }

  /**
   * @param {Eris.Message} msg
   * @returns {Promise<void>}
   */
  async saveChatMessageToLogs(msg) {
    // TODO: Save attachments?
    return this._addThreadMessageToDB({
      message_type: THREAD_MESSAGE_TYPE.CHAT,
      user_id: msg.author.id,
      user_name: `${msg.author.username}#${msg.author.discriminator}`,
      body: msg.content,
      is_anonymous: 0,
      dm_message_id: msg.id
    });
  }

  async saveCommandMessageToLogs(msg) {
    return this._addThreadMessageToDB({
      message_type: THREAD_MESSAGE_TYPE.COMMAND,
      user_id: msg.author.id,
      user_name: `${msg.author.username}#${msg.author.discriminator}`,
      body: msg.content,
      is_anonymous: 0,
      dm_message_id: msg.id
    });
  }

  /**
   * @param {Eris.Message} msg
   * @returns {Promise<void>}
   */
  async updateChatMessageInLogs(msg) {
    await knex("thread_messages")
      .where("thread_id", this.id)
      .where("dm_message_id", msg.id)
      .update({
        body: msg.content
      });
  }

  /**
   * @param {String} messageId
   * @returns {Promise<void>}
   */
  async deleteChatMessageFromLogs(messageId) {
    await knex("thread_messages")
      .where("thread_id", this.id)
      .where("dm_message_id", messageId)
      .delete();
  }

  /**
   * @returns {Promise<ThreadMessage[]>}
   */
  async getThreadMessages() {
    const threadMessages = await knex("thread_messages")
      .where("thread_id", this.id)
      .orderBy("created_at", "ASC")
      .orderBy("id", "ASC")
      .select();

    return threadMessages.map(row => new ThreadMessage(row));
  }

  /**
   * @param {number} messageNumber
   * @returns {Promise<ThreadMessage>}
   */
  async findThreadMessageByMessageNumber(messageNumber) {
    const data = await knex("thread_messages")
      .where("thread_id", this.id)
      .where("message_number", messageNumber)
      .first();

    return data ? new ThreadMessage(data) : null;
  }

  /**
   * @returns {Promise<void>}
   */
  async close(suppressSystemMessage = false, silent = false) {
    if (! suppressSystemMessage) {
      console.log(`Closing thread ${this.id}`);

      if (silent) {
        await this.postSystemMessage("Closing thread silently...");
      } else {
        await this.postSystemMessage("Closing thread...");
      }
    }

    // Update DB status
    await knex("threads")
      .where("id", this.id)
      .update({
        status: THREAD_STATUS.CLOSED
      });

    // Delete channel
    const channel = bot.getChannel(this.channel_id);
    if (channel) {
      console.log(`Deleting channel ${this.channel_id}`);
      await channel.delete("Thread closed");
    }
  }

  /**
   * @param {String} time
   * @param {Eris~User} user
   * @param {Number} silent
   * @returns {Promise<void>}
   */
  async scheduleClose(time, user, silent) {
    await knex("threads")
      .where("id", this.id)
      .update({
        scheduled_close_at: time,
        scheduled_close_id: user.id,
        scheduled_close_name: user.username,
        scheduled_close_silent: silent
      });
  }

  /**
   * @returns {Promise<void>}
   */
  async cancelScheduledClose() {
    await knex("threads")
      .where("id", this.id)
      .update({
        scheduled_close_at: null,
        scheduled_close_id: null,
        scheduled_close_name: null,
        scheduled_close_silent: null
      });
  }

  /**
   * @returns {Promise<void>}
   */
  async suspend() {
    await knex("threads")
      .where("id", this.id)
      .update({
        status: THREAD_STATUS.SUSPENDED,
        scheduled_suspend_at: null,
        scheduled_suspend_id: null,
        scheduled_suspend_name: null
      });
  }

  /**
   * @returns {Promise<void>}
   */
  async unsuspend() {
    await knex("threads")
      .where("id", this.id)
      .update({
        status: THREAD_STATUS.OPEN
      });
  }

  /**
   * @param {String} time
   * @param {Eris~User} user
   * @returns {Promise<void>}
   */
  async scheduleSuspend(time, user) {
    await knex("threads")
      .where("id", this.id)
      .update({
        scheduled_suspend_at: time,
        scheduled_suspend_id: user.id,
        scheduled_suspend_name: user.username
      });
  }

  /**
   * @returns {Promise<void>}
   */
  async cancelScheduledSuspend() {
    await knex("threads")
      .where("id", this.id)
      .update({
        scheduled_suspend_at: null,
        scheduled_suspend_id: null,
        scheduled_suspend_name: null
      });
  }

  /**
   * @param {String} userId
   * @returns {Promise<void>}
   */
  async addAlert(userId) {
    let alerts = await knex("threads")
      .where("id", this.id)
      .select("alert_ids")
      .first();
    alerts = alerts.alert_ids;

    if (alerts == null) {
      alerts = [userId]
    } else {
      alerts = alerts.split(",");
      if (! alerts.includes(userId)) {
        alerts.push(userId);
      }
    }

    alerts = alerts.join(",");
    await knex("threads")
      .where("id", this.id)
      .update({
        alert_ids: alerts
      });
  }

  /*
   * @param {String} userId
   * @returns {Promise<void>}
   */
  async removeAlert(userId) {
    let alerts = await knex("threads")
      .where("id", this.id)
      .select("alert_ids")
      .first();
    alerts = alerts.alert_ids;

    if (alerts != null) {
      alerts = alerts.split(",");

      for (let i = 0; i < alerts.length; i++) {
        if (alerts[i] === userId) {
          alerts.splice(i, 1);
        }
      }
    } else {
      return;
    }

    if (alerts.length === 0) {
      alerts = null;
    } else {
      alerts = alerts.join(",");
    }

    await knex("threads")
      .where("id", this.id)
      .update({
        alert_ids: alerts
      });
  }

  /**
   * @returns {Promise<void>}
   */
  async deleteAlerts() {
    await knex("threads")
      .where("id", this.id)
      .update({
        alert_ids: null
      })
  }

  /**
   * @param {Eris.Member} moderator
   * @param {ThreadMessage} threadMessage
   * @param {string} newText
   * @param {object} opts
   * @param {boolean} opts.quiet Whether to suppress edit notifications in the thread channel
   * @returns {Promise<void>}
   */
  async editStaffReply(moderator, threadMessage, newText, opts = {}) {
    const newThreadMessage = new ThreadMessage({
      ...threadMessage.getSQLProps(),
      body: newText,
    });

    const formattedThreadMessage = formatters.formatStaffReplyThreadMessage(newThreadMessage);
    const formattedDM = formatters.formatStaffReplyDM(newThreadMessage);

    await bot.editMessage(threadMessage.dm_channel_id, threadMessage.dm_message_id, formattedDM);
    await bot.editMessage(this.channel_id, threadMessage.inbox_message_id, formattedThreadMessage);

    if (! opts.quiet) {
      const threadNotification = formatters.formatStaffReplyEditNotificationThreadMessage(threadMessage, newText, moderator);
      await this.postSystemMessage(threadNotification);
    }

    await this._updateThreadMessage(threadMessage.id, { body: newText });
  }

  /**
   * @param {Eris.Member} moderator
   * @param {ThreadMessage} threadMessage
   * @param {object} opts
   * @param {boolean} opts.quiet Whether to suppress edit notifications in the thread channel
   * @returns {Promise<void>}
   */
  async deleteStaffReply(moderator, threadMessage, opts = {}) {
    await bot.deleteMessage(threadMessage.dm_channel_id, threadMessage.dm_message_id);
    await bot.deleteMessage(this.channel_id, threadMessage.inbox_message_id);

    if (! opts.quiet) {
      const threadNotification = formatters.formatStaffReplyDeletionNotificationThreadMessage(threadMessage, moderator);
      await this.postSystemMessage(threadNotification);
    }

    await this._deleteThreadMessage(threadMessage.id);
  }

  /**
   * @returns {Promise<String>}
   */
  getLogUrl() {
    return utils.getSelfUrl(`logs/${this.id}`);
  }
}

module.exports = Thread;