/**
 * Syncs Zammad agent replies to Discord (for Discord tickets) and Gmail (for email tickets).
 * Polls Zammad ticket articles and pushes new customer-visible Agent replies to the right channel.
 */
const { mongoose } = require('../db-connection');
const { getZammadTicketArticles } = require('./zammad');
const { sendGmailReply } = require('./gmail');
const { htmlToTextWithBlocks } = require('../utils');

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

function bodyToText(body, contentType) {
  if (!body) return '';
  const isHtml = (contentType || '').toLowerCase().includes('html');
  return isHtml ? htmlToTextWithBlocks(body).trim() : String(body).trim();
}

/**
 * Run once: find open tickets with Zammad ID, fetch new agent (customer-visible) articles,
 * post to Discord or send via Gmail, then update lastSyncedZammadArticleId.
 * @param {import('discord.js').Client} client - Discord client (for posting to ticket channels)
 */
async function syncZammadReplies(client) {
  if (!client?.channels) return;

  const tickets = await Ticket.find({
    zammadTicketId: { $exists: true, $ne: null },
    status: 'open'
  })
    .select('gmailThreadId discordThreadId zammadTicketId lastSyncedZammadArticleId senderEmail subject')
    .lean();

  for (const ticket of tickets) {
    try {
      const articles = await getZammadTicketArticles(ticket.zammadTicketId);
      // Only agent replies that are customer-visible (not internal notes)
      const agentReplies = articles.filter(
        (a) => a.sender === 'Agent' && a.internal === false && a.body
      );
      if (agentReplies.length === 0) continue;

      const lastSynced = ticket.lastSyncedZammadArticleId || 0;
      const newReplies = agentReplies.filter((a) => a.id > lastSynced);
      const maxId = Math.max(lastSynced, ...agentReplies.map((a) => a.id));

      // First run: just advance cursor so we don't resend existing articles
      if (newReplies.length === 0) {
        if (maxId > lastSynced) {
          await Ticket.updateOne(
            { gmailThreadId: ticket.gmailThreadId },
            { $set: { lastSyncedZammadArticleId: maxId } }
          );
        }
        continue;
      }

      const isDiscordTicket = ticket.gmailThreadId.startsWith('discord-');

      for (const article of newReplies) {
        const text = bodyToText(article.body, article.content_type);
        if (!text) continue;

        const fromLabel = article.created_by || 'Support';

        if (isDiscordTicket && ticket.discordThreadId) {
          const channel = await client.channels.fetch(ticket.discordThreadId).catch(() => null);
          if (channel) {
            await channel.send(`**${fromLabel}** (via Zammad):\n${text}`).catch((err) => {
              console.error('Zammad sync: Discord send failed:', err.message);
            });
          }
        } else {
          // Email ticket: send reply via Gmail
          try {
            await sendGmailReply(
              ticket.gmailThreadId,
              text,
              ticket.senderEmail,
              ticket.subject || 'Support',
              fromLabel,
              null
            );
          } catch (err) {
            console.error('Zammad sync: Gmail send failed:', err.message);
          }
        }
      }

      await Ticket.updateOne(
        { gmailThreadId: ticket.gmailThreadId },
        { $set: { lastSyncedZammadArticleId: maxId } }
      );
    } catch (err) {
      console.error('Zammad sync error for ticket', ticket.gmailThreadId, err.message);
    }
  }
}

module.exports = { syncZammadReplies };