/**
 * Zammad API service – create/close tickets, manage users, post articles.
 */
const axios = require('axios');
const { ZAMMAD } = require('../config');

const zammadHeaders = () =>
  ZAMMAD.URL && ZAMMAD.TOKEN
    ? { Authorization: `Token token=${ZAMMAD.TOKEN}`, 'Content-Type': 'application/json' }
    : null;

function baseUrl() {
  return ZAMMAD.URL ? ZAMMAD.URL.replace(/\/+$/, '') : '';
}

async function createZammadTicket({ subject, body, email, name, gameName, gameKey, group, discordUsername }) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN) {
    console.warn('Zammad not configured; skipping ticket create.');
    return null;
  }

  const url = `${baseUrl()}/api/v1/tickets`;
  const isDiscordTicket = Boolean(discordUsername);
  const firstname = isDiscordTicket ? '' : (name || 'Email Customer').split(' ')[0];
  const lastname = isDiscordTicket ? '' : (name || 'Email Customer').split(' ').slice(1).join(' ') || 'Customer';

  const payload = {
    title: subject || 'Support',
    group,
    customer: {
      email,
      firstname: firstname || '–',
      lastname: lastname || '–',
      role_ids: [3]
    },
    state: 'new',
    priority: '2 normal',
    article: {
      subject: subject || 'Support',
      body: `Email: ${email}\nGame: ${gameName}\n\nMessage:\n${body}`,
      type: 'note',
      internal: false,
      sender: 'Customer',
      from: isDiscordTicket ? `${discordUsername} <${email}>` : `${name} <${email}>`
    }
  };

  if (gameKey) payload.gameid = gameKey;
  if (discordUsername) payload.discordusername = String(discordUsername).slice(0, 120);

  const res = await axios.post(url, payload, {
    headers: {
      Authorization: `Token token=${ZAMMAD.TOKEN}`,
      'Content-Type': 'application/json'
    }
  });

  return res.data;
}

async function closeZammadTicket(zammadTicketId) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !zammadTicketId) return;
  const url = `${baseUrl()}/api/v1/tickets/${zammadTicketId}`;
  await axios.patch(url, { state: 'closed' }, {
    headers: {
      Authorization: `Token token=${ZAMMAD.TOKEN}`,
      'Content-Type': 'application/json'
    }
  });
}

async function updateZammadUserDiscordId(zammadUserId, discordId) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !zammadUserId || !discordId) return;
  const url = `${baseUrl()}/api/v1/users/${zammadUserId}`;
  await axios.patch(url, { discord_id: String(discordId) }, {
    headers: {
      Authorization: `Token token=${ZAMMAD.TOKEN}`,
      'Content-Type': 'application/json'
    }
  });
}

async function updateZammadUser(zammadUserId, attrs) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !zammadUserId || !attrs || Object.keys(attrs).length === 0) return;
  const url = `${baseUrl()}/api/v1/users/${zammadUserId}`;
  const body = {};
  if (attrs.discord_id != null) body.discord_id = String(attrs.discord_id);
  if (attrs.discord_username != null) body.discord_username = String(attrs.discord_username).slice(0, 120);
  if (Object.keys(body).length === 0) return;
  await axios.patch(url, body, {
    headers: {
      Authorization: `Token token=${ZAMMAD.TOKEN}`,
      'Content-Type': 'application/json'
    }
  });
}

async function searchZammadUsers(query) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !query) return [];
  try {
    const { data } = await axios.get(`${baseUrl()}/api/v1/users/search`, {
      params: { query: String(query).trim() },
      headers: zammadHeaders()
    });
    return Array.isArray(data) ? data : data?.users || [];
  } catch (e) {
    if (e.response?.status === 404) return [];
    throw e;
  }
}

async function createZammadUser({ email, firstname, lastname, login, discordId, discordUsername }) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !email) return null;
  const isDiscord = Boolean(discordUsername);
  const payload = {
    login: login || email,
    email: email.trim(),
    firstname: (firstname || '').trim() || (isDiscord ? '–' : 'Customer'),
    lastname: (lastname || '').trim() || (isDiscord ? '–' : 'User'),
    role_ids: [3]
  };
  if (discordId) payload.discord_id = String(discordId);
  if (discordUsername) payload.discord_username = String(discordUsername).slice(0, 120);
  const { data } = await axios.post(`${baseUrl()}/api/v1/users`, payload, { headers: zammadHeaders() });
  return data;
}

async function ensureZammadUserForDiscordUser(websiteUser, opts = {}) {
  if (!websiteUser?.email || !ZAMMAD.URL || !ZAMMAD.TOKEN) return null;
  const email = String(websiteUser.email).trim().toLowerCase();
  const discordId = websiteUser.discordID ? String(websiteUser.discordID) : null;
  const discordUsername = opts.discordUsername ? String(opts.discordUsername).slice(0, 120) : null;
  const firstname = (websiteUser.firstname || '').trim();
  const lastname = (websiteUser.lastname || '').trim();
  let zammadUser = null;
  try {
    const list = await searchZammadUsers(email);
    zammadUser = list.find((u) => (u.email || '').toLowerCase() === email) || null;
  } catch (e) {
    console.error('Zammad user search failed:', e.response?.data || e.message);
    return null;
  }
  if (!zammadUser) {
    try {
      zammadUser = await createZammadUser({
        email,
        firstname: firstname || (discordUsername ? '–' : 'Customer'),
        lastname: lastname || (discordUsername ? '–' : 'User'),
        login: email,
        discordId,
        discordUsername
      });
    } catch (e) {
      console.error('Zammad user create failed:', e.response?.data || e.message);
      return null;
    }
  }
  if (zammadUser?.id && (discordId || discordUsername)) {
    try {
      await updateZammadUser(zammadUser.id, {
        ...(discordId && { discord_id: discordId }),
        ...(discordUsername && { discord_username: discordUsername })
      });
    } catch (_) {
      /* custom attributes may not exist in Zammad */
    }
  }
  return zammadUser?.id ?? null;
}

async function getZammadTicketArticles(zammadTicketId) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !zammadTicketId) return [];
  const url = `${baseUrl()}/api/v1/ticket_articles/by_ticket/${zammadTicketId}`;
  const res = await axios.get(url, {
    headers: { Authorization: `Token token=${ZAMMAD.TOKEN}` }
  });
  return Array.isArray(res.data) ? res.data : [];
}

async function addZammadArticle(zammadTicketId, body, { from: fromDisplay } = {}) {
  if (!ZAMMAD.URL || !ZAMMAD.TOKEN || !zammadTicketId) return;
  const url = `${baseUrl()}/api/v1/ticket_articles`;
  const payload = {
    ticket_id: zammadTicketId,
    body: body || '',
    content_type: 'text/plain',
    type: 'note',
    internal: false,
    sender: 'Agent'
  };
  if (fromDisplay) {
    payload.subject = `Discord reply from ${fromDisplay}`;
  }
  await axios.post(url, payload, {
    headers: {
      Authorization: `Token token=${ZAMMAD.TOKEN}`,
      'Content-Type': 'application/json'
    }
  });
}

module.exports = {
  createZammadTicket,
  closeZammadTicket,
  updateZammadUserDiscordId,
  updateZammadUser,
  searchZammadUsers,
  createZammadUser,
  ensureZammadUserForDiscordUser,
  getZammadTicketArticles,
  addZammadArticle,
  zammadHeaders
};