// Discord OAuth callback handler
// User a /discord-connect endpointon megy → Discord auth → vissza a /discord-callback-re
// Itt lekérjük a Discord user ID-t és mentjük a Memberstack member metadata-ba

const { getStore } = require('@netlify/blobs');

function getStoreSafe(name) {
  const siteID = process.env.NETLIFY_SITE_ID;
  const token = process.env.NETLIFY_BLOBS_TOKEN;
  if (siteID && token) return getStore({ name, siteID, token, consistency: 'strong' });
  return getStore(name);
}

exports.handler = async (event) => {
  const { code, state } = event.queryStringParameters || {};

  if (!code) {
    return {
      statusCode: 400,
      headers: { 'Content-Type': 'text/html; charset=utf-8' },
      body: '<h1>Hiba</h1><p>Hiányzó OAuth kód. <a href='/profil'>Vissza a profilra</a></p>'
    };
  }

  const clientId = process.env.DISCORD_CLIENT_ID;
  const clientSecret = process.env.DISCORD_CLIENT_SECRET;
  const redirectUri = (process.env.URL || 'https://betsmart.bet') + '/.netlify/functions/discord-callback';

  if (!clientId || !clientSecret) {
    return {
      statusCode: 500,
      body: 'Discord OAuth nincs konfigurálva. Add hozzá a DISCORD_CLIENT_ID és DISCORD_CLIENT_SECRET env változókat.'
    };
  }

  try {
    // 1. Code → access token
    const tokenRes = await fetch('https://discord.com/api/v10/oauth2/token', {
      method: 'POST',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
      body: new URLSearchParams({
        client_id: clientId,
        client_secret: clientSecret,
        grant_type: 'authorization_code',
        code: code,
        redirect_uri: redirectUri
      })
    });

    if (!tokenRes.ok) {
      const t = await tokenRes.text();
      console.error('Token exchange failed:', t);
      return { statusCode: 500, body: 'OAuth token hiba' };
    }
    const tokenData = await tokenRes.json();

    // 2. Access token → user info
    const userRes = await fetch('https://discord.com/api/v10/users/@me', {
      headers: { 'Authorization': 'Bearer ' + tokenData.access_token }
    });
    if (!userRes.ok) {
      return { statusCode: 500, body: 'Discord user fetch hiba' };
    }
    const discordUser = await userRes.json();

    // 3. Mentés Blobs-ba: a 'state' a Memberstack member ID (a /discord-connect adta át)
    const memberId = state;
    if (memberId) {
      const store = getStoreSafe('subscriptions');
      const existing = (await store.get('sub:' + memberId, { type: 'json' })) || {};
      existing.discordId = discordUser.id;
      existing.discordUsername = discordUser.username;
      existing.discordLinkedAt = new Date().toISOString();
      await store.setJSON('sub:' + memberId, existing);

      // Ha van aktív Pro/Elite előfizetés, rögtön adjuk meg a VIP role-t
      if (existing.status === 'active' || existing.status === 'trialing') {
        const guildId = process.env.DISCORD_GUILD_ID;
        const vipRoleId = process.env.DISCORD_VIP_ROLE_ID;
        const botToken = process.env.DISCORD_BOT_TOKEN;
        if (guildId && vipRoleId && botToken) {
          // 1. lépés: a user csatlakozzon a szerverhez (ha még nem)
          await fetch(`https://discord.com/api/v10/guilds/${guildId}/members/${discordUser.id}`, {
            method: 'PUT',
            headers: {
              'Authorization': 'Bot ' + botToken,
              'Content-Type': 'application/json'
            },
            body: JSON.stringify({ access_token: tokenData.access_token })
          });
          // 2. lépés: VIP role
          await fetch(`https://discord.com/api/v10/guilds/${guildId}/members/${discordUser.id}/roles/${vipRoleId}`, {
            method: 'PUT',
            headers: { 'Authorization': 'Bot ' + botToken }
          });
        }
      }
    }

    // Sikeres - visszairányítjuk a profil oldalra
    return {
      statusCode: 302,
      headers: {
        'Location': '/profil.html?discord=connected'
      },
      body: ''
    };
  } catch (err) {
    console.error('Discord callback error:', err);
    return {
      statusCode: 500,
      headers: { 'Content-Type': 'text/html; charset=utf-8' },
      body: `<h1>Hiba</h1><p>${err.message}</p><a href='/profil'>Vissza</a>`
    };
  }
};