/**
 * Discord messageCreate handler – forwards staff replies to Gmail.
 */
const { mongoose } = require('../db-connection');
const { CONFIG } = require('../config');
const { extractRawEmail } = require('../utils');
const { getGmailClient, sendGmailReply } = require('../services/gmail');
const { updateTicketActivity } = require('../services/tickets');
const { getNotifyDm } = require('../services/staffSettings');

const Ticket = mongoose.model('Ticket');

/**
 * Handle a Discord message in a ticket channel → relay to Gmail (email tickets only).
 */
async function handleDiscordReply(m) {
  if (m.author.bot || m.interaction) return;

  const ticket = await Ticket.findOne({ discordThreadId: m.channel.id }).lean();
  if (!ticket) return;

  // Track whether last message is from staff or customer
  const memberForCheck = await m.guild.members.fetch(m.author.id).catch(() => null);
  const isStaffMember = memberForCheck && CONFIG.ROLE_ID_TO_PING && memberForCheck.roles.cache.has(CONFIG.ROLE_ID_TO_PING);
  Ticket.updateOne(
    { discordThreadId: m.channel.id },
    { $set: { lastMessageAuthorIsStaff: !!isStaffMember, lastActivity: new Date() } }
  ).catch(() => {});

  // DM the claimer if they have notifydm on and a non-staff user replied.
  if (ticket.claimerId && !isStaffMember && m.author.id !== ticket.claimerId) {
    const dmEnabled = await getNotifyDm(ticket.claimerId);
    if (dmEnabled) {
      const staffMember = await m.guild.members.fetch(ticket.claimerId).catch(() => null);
      if (staffMember) {
        const jumpLink = `https://discord.com/channels/${m.guild.id}/${m.channel.id}/${m.id}`;
        await staffMember
          .send(
            `New customer reply in **${m.channel.name}**:\n> ${m.content.slice(0, 300)}\n[Jump to message](${jumpLink})`
          )
          .catch(() => {});
      }
    }
  }

  const authorName =
    m.member?.displayName ||
    m.member?.nickname ||
    m.author.globalName ||
    m.author.username;

  if (ticket.gmailThreadId.startsWith('discord-')) {
    return;
  }

  // Email tickets: send reply via Gmail.
  try {
    const gmail = getGmailClient();
    const thread = await gmail.users.threads.get({
      userId: 'me',
      id: ticket.gmailThreadId
    });

    const last = [...thread.data.messages].reverse().find(msg => {
      const from =
        msg.payload.headers.find(h => h.name === 'From')?.value || '';
      return !from.toLowerCase().includes(CONFIG.MY_EMAIL);
    });

    if (!last) return;

    let recipient =
      last.payload.headers.find(h => h.name === 'From')?.value || '';
    const replyTo =
      last.payload.headers.find(h => h.name === 'Reply-To')?.value;
    if (replyTo) recipient = replyTo;

    const subject =
      last.payload.headers.find(h => h.name === 'Subject')?.value ||
      'Support';
    const msgId =
      last.payload.headers.find(h => h.name === 'Message-ID')?.value;

    const recipientEmail = extractRawEmail(recipient).toLowerCase();
    if (!recipientEmail || recipientEmail === CONFIG.MY_EMAIL) {
      console.warn('Bad recipient for reply:', recipientEmail);
      return;
    }

    await sendGmailReply(
      ticket.gmailThreadId,
      m.content,
      recipientEmail,
      subject,
      authorName,
      msgId,
      m.author.id
    );

    await updateTicketActivity(ticket.gmailThreadId);
  } catch (e) {
    console.error('REPLY ERROR:', e);
  }
}

module.exports = { handleDiscordReply };