/**
 * Escalation flows.
 *
 * runEscalation / runDeescalation are exported for handlers/buttons.js
 * (the tier-pick buttons share this code path). handleEscalate /
 * handleDeescalate are the slash-command entry points.
 */
const { EmbedBuilder, MessageFlags } = require('discord.js');
const { mongoose } = require('../../db-connection');
const { CONFIG } = require('../../config');
const { makeTicketName, resolveCreatorNickname } = require('../../services/tickets');
const { sendTicketNotificationEmail } = require('../../services/gmail');
const { getTicketActionRow } = require('../../utils/ticketComponents');
const { enqueueRename, enqueueMove, enqueueSend } = require('../../services/channelQueue');
const { pinMessage } = require('../../services/pinMessage');
const { logError } = require('../../services/debugLog');
const { findTicketForChannel, runDeferred } = require('../sharedHelpers');
const { fetchLoggingChannel } = require('./helpers');

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

/**
 * Run escalation to a target tier (1 = tier 2, 2 = tier 3). Caller must
 * validate ticket and currentTier < nextTier, and have already deferred.
 */
async function runEscalation(interaction, ticket, nextTier, reason) {
  const isDiscordTicket = ticket.gmailThreadId.startsWith('discord-');
  const categoryId = nextTier === 1
    ? (isDiscordTicket ? CONFIG.DISCORD_ESCALATED2_CHANNEL_ID : CONFIG.EMAIL_ESCALATED2_CHANNEL_ID)
    : (isDiscordTicket ? CONFIG.DISCORD_ESCALATED3_CHANNEL_ID : CONFIG.EMAIL_ESCALATED3_CHANNEL_ID);

  // Clear claim on escalation
  await Ticket.updateOne(
    { gmailThreadId: ticket.gmailThreadId },
    { $set: { escalated: true, escalationTier: nextTier, claimedBy: null, claimerId: null } }
  );
  ticket.escalated = true;
  ticket.escalationTier = nextTier;
  ticket.claimedBy = null;

  const creatorNickname = await resolveCreatorNickname(interaction.guild, ticket);
  const newName = makeTicketName('escalated', ticket, creatorNickname);
  enqueueRename(interaction.channel, newName).catch(err => logError('rename', err).catch(() => {}));

  if (!interaction.channel.isThread() && categoryId) {
    await enqueueMove(interaction.channel, categoryId);
  }

  const pendingEmbed = new EmbedBuilder()
    .setDescription('Ticket will be escalated in a few seconds.')
    .setColor(CONFIG.EMBED_COLOR_INFO);
  await interaction.editReply({ embeds: [pendingEmbed] });

  const creatorId = isDiscordTicket
    ? (ticket.gmailThreadId.split('-').pop() || '').trim()
    : null;
  const creatorMention = creatorId ? `<@${creatorId}>` : '';
  const roleMention = CONFIG.ROLE_ID_TO_PING ? `<@&${CONFIG.ROLE_ID_TO_PING}>` : 'a senior team member';
  const heyLine = creatorMention ? `Hey There ${creatorMention} 🥦` : 'Hey There 🥦';
  // Creator + role pings are intentional; still block @everyone/@here if somehow interpolated.
  await enqueueSend(interaction.channel, {
    content: `${heyLine}\n**Getting the senior ${roleMention} for you.**`,
    allowedMentions: { parse: ['users', 'roles'] }
  });

  const escalationBody = CONFIG.ESCALATION_MESSAGE
    .replace(/\\n/g, '\n')
    .replace(/\{support_name\}/g, CONFIG.SUPPORT_NAME);
  const escalatedEmbed = new EmbedBuilder()
    .setTitle(`🚨 Escalated to ${nextTier === 1 ? 'Tier 2' : 'Tier 3'} Support`)
    .setDescription(escalationBody)
    .setColor(CONFIG.EMBED_COLOR_ESCALATED)
    .setFooter({ text: `Escalated by ${interaction.member?.displayName || interaction.user.username}` });
  const updatedTicketForRow = { ...ticket, escalationTier: nextTier, escalated: true };
  const escalationRow = getTicketActionRow(updatedTicketForRow);
  const escalationMsg = await enqueueSend(interaction.channel, {
    content: null,
    embeds: [escalatedEmbed],
    components: [escalationRow]
  });

  if (CONFIG.PIN_ESCALATION_MESSAGE_ENABLED && escalationMsg) {
    await pinMessage(escalationMsg, interaction.client).catch(() => {});
  }

  if (!isDiscordTicket && ticket.gmailThreadId) {
    try {
      const escalatorName = interaction.member?.displayName || interaction.user.username;
      const tierLabel = nextTier === 1 ? 'tier 2' : 'tier 3';
      const emailBody = `${escalatorName} escalated this ticket to ${tierLabel}.${reason ? `\n\nReason: ${reason}` : ''}`;
      await sendTicketNotificationEmail(ticket, null, emailBody, interaction.user.id);
    } catch (emailErr) {
      console.error('Escalation email failed (non-fatal):', emailErr.message);
    }
  }

  if (nextTier === 2 && ticket.welcomeMessageId) {
    try {
      const welcomeMsg = await interaction.channel.messages.fetch(ticket.welcomeMessageId);
      await welcomeMsg.edit({ components: [getTicketActionRow(updatedTicketForRow)] });
    } catch (e) {
      console.error('Failed to update welcome message after escalate:', e.message);
    }
  }

  const logChan = await fetchLoggingChannel(interaction.client);
  if (logChan) {
    const ticketType = isDiscordTicket ? 'Discord' : 'Email';
    const tierLabel = nextTier === 1 ? 'tier 2' : 'tier 3';
    await enqueueSend(logChan,
      `${ticketType} ticket ${interaction.channel} escalated to ${tierLabel} by ${interaction.user.tag}.\nReason: ${reason}`
    );
  }
}

/** Run deescalation one step. Caller must validate ticket and currentTier >= 1. */
async function runDeescalation(interaction, ticket) {
  const currentTier = ticket.escalationTier ?? (ticket.escalated ? 1 : 0);
  const isDiscordTicket = ticket.gmailThreadId.startsWith('discord-');
  const newTier = currentTier - 1;

  await Ticket.updateOne(
    { gmailThreadId: ticket.gmailThreadId },
    { $set: { escalated: newTier > 0, escalationTier: newTier, claimedBy: null, claimerId: null } }
  );
  ticket.escalated = newTier > 0;
  ticket.escalationTier = newTier;
  ticket.claimedBy = null;

  const creatorNickname = await resolveCreatorNickname(interaction.guild, ticket);
  const state = newTier === 0 ? 'unclaimed' : 'escalated';
  enqueueRename(interaction.channel, makeTicketName(state, ticket, creatorNickname)).catch(err => logError('rename', err).catch(() => {}));

  if (!interaction.channel.isThread()) {
    try {
      if (newTier === 0) {
        const homeCategory = isDiscordTicket ? CONFIG.DISCORD_TICKET_CATEGORY_ID : CONFIG.TICKET_CATEGORY_ID;
        if (homeCategory) await enqueueMove(interaction.channel, homeCategory);
      } else if (newTier === 1) {
        const t2Category = isDiscordTicket
          ? CONFIG.DISCORD_ESCALATED2_CHANNEL_ID
          : CONFIG.EMAIL_ESCALATED2_CHANNEL_ID;
        if (t2Category) await enqueueMove(interaction.channel, t2Category);
      }
    } catch (e) {
      console.error('Move error (deescalate):', e);
    }
  }

  const tierLabel = newTier === 0 ? 'normal' : newTier === 1 ? 'tier 2' : 'tier 3';
  const deescalateEmbed = new EmbedBuilder()
    .setColor(0x00BFFF)
    .setTitle(`✅ De-escalated to ${tierLabel} Support`)
    .setFooter({ text: interaction.member?.displayName || interaction.user.username });
  await interaction.editReply({ embeds: [deescalateEmbed] });

  const logChan = await fetchLoggingChannel(interaction.client);
  if (logChan) {
    const ticketType = isDiscordTicket ? 'Discord' : 'Email';
    await enqueueSend(logChan,
      `${ticketType} ticket ${interaction.channel} de‑escalated to ${tierLabel} by ${interaction.user.tag}.`
    );
  }
}

async function handleEscalate(interaction) {
  const reason = null;
  const level = interaction.options.getString('level');
  const nextTier = level === '3' ? 2 : 1;

  const ticket = await findTicketForChannel(interaction);
  if (!ticket) return;

  const currentTier = ticket.escalationTier ?? (ticket.escalated ? 1 : 0);
  if (currentTier >= 2) {
    return interaction.reply({ content: 'This ticket is already at tier 3 support.', flags: MessageFlags.Ephemeral });
  }
  if (nextTier <= currentTier) {
    return interaction.reply({ content: 'Ticket is already at or past that tier.', flags: MessageFlags.Ephemeral });
  }

  const isDiscordTicket = ticket.gmailThreadId.startsWith('discord-');
  const categoryId = nextTier === 1
    ? (isDiscordTicket ? CONFIG.DISCORD_ESCALATED2_CHANNEL_ID : CONFIG.EMAIL_ESCALATED2_CHANNEL_ID)
    : (isDiscordTicket ? CONFIG.DISCORD_ESCALATED3_CHANNEL_ID : CONFIG.EMAIL_ESCALATED3_CHANNEL_ID);
  const configKey = nextTier === 1 ? 'ESCALATED2' : 'ESCALATED3';
  if (!categoryId && !interaction.channel.isThread()) {
    return interaction.reply({
      content: `${configKey} is not configured for ${isDiscordTicket ? 'Discord' : 'email'} tickets.`,
      flags: MessageFlags.Ephemeral
    });
  }

  await runDeferred(interaction, 'escalate', () =>
    runEscalation(interaction, ticket, nextTier, reason)
  );
}

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

  const currentTier = ticket.escalationTier ?? (ticket.escalated ? 1 : 0);
  if (currentTier === 0) {
    return interaction.reply({ content: 'This ticket is not escalated.', flags: MessageFlags.Ephemeral });
  }

  await runDeferred(interaction, 'de-escalate',
    () => runDeescalation(interaction, ticket),
    { flags: MessageFlags.Ephemeral }
  );
}

module.exports = { runEscalation, runDeescalation, handleEscalate, handleDeescalate };