/**
 * /forward — forward this ticket's email thread to a third-party address.
 *
 * Builds a fresh outbound email to the target only; the original customer is
 * never looped in (see services/gmail.js forwardThread).
 */
const { MessageFlags } = require('discord.js');
const { findTicketForChannel } = require('../sharedHelpers');
const { forwardThread } = require('../../services/gmail');
const { logError, logTicketEvent } = require('../../services/debugLog');

const plural = (n, word) => `${n} ${word}${n === 1 ? '' : 's'}`;

async function handleForward(interaction) {
  const ticket = await findTicketForChannel(interaction);
  if (!ticket) return;

  // Discord-origin tickets have no Gmail thread to forward.
  if (ticket.gmailThreadId.startsWith('discord-')) {
    return interaction.reply({
      content: "This ticket has no email thread, so there's nothing to forward.",
      flags: MessageFlags.Ephemeral
    });
  }

  const target = interaction.options.getString('email');
  const note = interaction.options.getString('note') || '';

  // Defer: fetching the thread + downloading attachments can exceed the 3s window.
  await interaction.deferReply({ flags: MessageFlags.Ephemeral });

  try {
    const { messageCount, attachmentCount, skipped } = await forwardThread(
      ticket.gmailThreadId, target, note
    );

    logTicketEvent('Email thread forwarded', [
      { name: 'To', value: target },
      { name: 'Messages', value: String(messageCount) },
      { name: 'Forwarded by', value: interaction.user.tag }
    ], interaction).catch(() => {});

    const skippedNote = skipped ? ` (${plural(skipped, 'attachment')} skipped — over the size limit)` : '';
    return interaction.editReply({
      content: `Forwarded ${plural(messageCount, 'message')} (${plural(attachmentCount, 'attachment')}) to **${target}**.${skippedNote}`
    });
  } catch (err) {
    if (err.code === 'EBADRECIPIENT') {
      return interaction.editReply({ content: "That doesn't look like a valid email address." });
    }
    if (err.code === 'EEMPTY') {
      return interaction.editReply({ content: 'This thread has no messages to forward.' });
    }
    logError('handleForward', err, interaction).catch(() => {});
    return interaction.editReply({ content: `Failed to forward: ${err.message}` });
  }
}

module.exports = { handleForward };