const express = require('express');
const cors = require('cors');
const bodyParser = require('body-parser');
const axios = require('axios');
const qs = require('qs');
const path = require('path');

require('dotenv').config();

const app = express();
app.use(cors());
app.use(bodyParser.json({ limit: '50mb' }));
app.use(bodyParser.urlencoded({ limit: '50mb', extended: true }));

// Serve frontend
app.use(express.static(path.join(__dirname, '../public')));

// In-memory token storage (persist to DB in production)
let tokenStore = {
  instagram: null,
  tiktok: null,
  youtube: null,
  github: null
};

let scheduledPosts = [];
let analyticsData = {
  reach: 47200,
  engagements: 3840,
  topPlatform: "Instagram",
  trends: [1200, 1450, 1680, 2100, 2450]
};

// API Config
const INSTAGRAM_APP_ID = process.env.INSTAGRAM_APP_ID || '';
const INSTAGRAM_APP_SECRET = process.env.INSTAGRAM_APP_SECRET || '';
const TIKTOK_CLIENT_ID = process.env.TIKTOK_CLIENT_ID || '';
const TIKTOK_CLIENT_SECRET = process.env.TIKTOK_CLIENT_SECRET || '';
const YOUTUBE_CLIENT_ID = process.env.YOUTUBE_CLIENT_ID || '';
const YOUTUBE_CLIENT_SECRET = process.env.YOUTUBE_CLIENT_SECRET || '';
const GITHUB_TOKEN = process.env.GITHUB_TOKEN || '';
const CLAUDE_API_KEY = process.env.CLAUDE_API_KEY || '';
const GROQ_API_KEY = process.env.GROQ_API_KEY || '';
const BASE_URL = process.env.BASE_URL || 'http://localhost:5000';

// ============ OAUTH FLOWS ============

// Instagram OAuth
app.get('/api/auth/instagram', (req, res) => {
  const redirectUri = encodeURIComponent(`${BASE_URL}/api/auth/instagram/callback`);
  const authUrl = `https://www.instagram.com/oauth/authorize?client_id=${INSTAGRAM_APP_ID}&redirect_uri=${redirectUri}&scope=user_profile,user_media&response_type=code`;
  res.json({ url: authUrl });
});

app.get('/api/auth/instagram/callback', async (req, res) => {
  try {
    const { code } = req.query;
    const tokenRes = await axios.post('https://graph.instagram.com/v18.0/access_token', {
      client_id: INSTAGRAM_APP_ID,
      client_secret: INSTAGRAM_APP_SECRET,
      grant_type: 'authorization_code',
      redirect_uri: `${BASE_URL}/api/auth/instagram/callback`,
      code
    });
    tokenStore.instagram = tokenRes.data.access_token;
    res.redirect('/dashboard?auth=instagram_success');
  } catch (e) {
    res.redirect('/dashboard?auth=instagram_error');
  }
});

// TikTok OAuth
app.get('/api/auth/tiktok', (req, res) => {
  const redirectUri = encodeURIComponent(`${BASE_URL}/api/auth/tiktok/callback`);
  const authUrl = `https://www.tiktok.com/v2/oauth/authorize?client_key=${TIKTOK_CLIENT_ID}&redirect_uri=${redirectUri}&response_type=code&scope=video.upload,user.info.basic`;
  res.json({ url: authUrl });
});

app.get('/api/auth/tiktok/callback', async (req, res) => {
  try {
    const { code } = req.query;
    const tokenRes = await axios.post('https://open.tiktokapis.com/v2/oauth/token/', {
      client_key: TIKTOK_CLIENT_ID,
      client_secret: TIKTOK_CLIENT_SECRET,
      code,
      grant_type: 'authorization_code'
    });
    tokenStore.tiktok = tokenRes.data.access_token;
    res.redirect('/dashboard?auth=tiktok_success');
  } catch (e) {
    res.redirect('/dashboard?auth=tiktok_error');
  }
});

// YouTube OAuth
app.get('/api/auth/youtube', (req, res) => {
  const redirectUri = encodeURIComponent(`${BASE_URL}/api/auth/youtube/callback`);
  const authUrl = `https://accounts.google.com/o/oauth2/v2/auth?client_id=${YOUTUBE_CLIENT_ID}&redirect_uri=${redirectUri}&response_type=code&scope=https://www.googleapis.com/auth/youtube.upload`;
  res.json({ url: authUrl });
});

app.get('/api/auth/youtube/callback', async (req, res) => {
  try {
    const { code } = req.query;
    const tokenRes = await axios.post('https://oauth2.googleapis.com/token', {
      client_id: YOUTUBE_CLIENT_ID,
      client_secret: YOUTUBE_CLIENT_SECRET,
      code,
      grant_type: 'authorization_code',
      redirect_uri: `${BASE_URL}/api/auth/youtube/callback`
    });
    tokenStore.youtube = tokenRes.data.access_token;
    res.redirect('/dashboard?auth=youtube_success');
  } catch (e) {
    res.redirect('/dashboard?auth=youtube_error');
  }
});

// ============ TOKEN CHECK ============
app.get('/api/tokens', (req, res) => {
  res.json({
    instagram: !!tokenStore.instagram,
    tiktok: !!tokenStore.tiktok,
    youtube: !!tokenStore.youtube
  });
});

// ============ CLAUDE API ============
app.post('/api/claude', async (req, res) => {
  try {
    const { messages, system } = req.body;
    const response = await axios.post('https://api.anthropic.com/v1/messages', {
      model: 'claude-opus-4-1-20250805',
      max_tokens: 1500,
      system: system || 'You are a wellness & spirituality content expert for T. Lott Creative. Generate engaging, benefit-focused social media content.',
      messages
    }, {
      headers: {
        'x-api-key': CLAUDE_API_KEY,
        'anthropic-version': '2023-06-01',
        'content-type': 'application/json'
      }
    });
    res.json({ text: response.data.content?.[0]?.text || 'AI response unavailable.' });
  } catch (e) {
    // Fallback to Groq
    try {
      const response = await axios.post('https://api.groq.com/openai/v1/chat/completions', {
        model: 'llama-3.3-70b-versatile',
        messages: messages,
        max_tokens: 1500
      }, {
        headers: {
          'Authorization': `Bearer ${GROQ_API_KEY}`,
          'content-type': 'application/json'
        }
      });
      res.json({ text: response.data.choices?.[0]?.message?.content || 'AI response unavailable.' });
    } catch (groqError) {
      res.status(500).json({ text: 'AI service unavailable. Check API keys.' });
    }
  }
});

// ============ GROQ API ============
app.post('/api/groq', async (req, res) => {
  try {
    const { messages } = req.body;
    const response = await axios.post('https://api.groq.com/openai/v1/chat/completions', {
      model: 'llama-3.3-70b-versatile',
      messages: messages,
      max_tokens: 1500
    }, {
      headers: {
        'Authorization': `Bearer ${GROQ_API_KEY}`,
        'content-type': 'application/json'
      }
    });
    res.json({ text: response.data.choices?.[0]?.message?.content || 'Groq response unavailable.' });
  } catch (e) {
    res.status(500).json({ text: 'Groq API unavailable.' });
  }
});

// ============ GITHUB SYNC ============
app.get('/api/github/ideas', async (req, res) => {
  try {
    if (!GITHUB_TOKEN) {
      return res.json([
        { idea: 'Morning sacred rituals for mothers', body: 'Wellness tip...' },
        { idea: 'Poetry for personal resilience', body: 'Share a verse...' }
      ]);
    }
    // Real GitHub integration can be added here
    res.json([
      { idea: 'Morning sacred rituals for mothers', body: 'Wellness tip...' },
      { idea: 'Poetry for personal resilience', body: 'Share a verse...' }
    ]);
  } catch (e) {
    res.json([]);
  }
});

// ============ SCHEDULING ============
app.get('/api/scheduled', (req, res) => res.json(scheduledPosts));

app.post('/api/schedule', (req, res) => {
  const post = { ...req.body, id: Date.now(), status: 'scheduled' };
  scheduledPosts.push(post);
  res.json(post);
});

app.delete('/api/scheduled/:id', (req, res) => {
  scheduledPosts = scheduledPosts.filter(p => p.id !== parseInt(req.params.id));
  res.json({ success: true });
});

// ============ POST TO INSTAGRAM ============
app.post('/api/post/instagram', async (req, res) => {
  try {
    if (!tokenStore.instagram) {
      return res.status(401).json({ error: 'Instagram not connected' });
    }
    const { caption, mediaUrl } = req.body;
    // Instagram Graph API post creation
    const response = await axios.post(
      `https://graph.instagram.com/v18.0/me/media`,
      {
        image_url: mediaUrl,
        caption: caption
      },
      {
        params: { access_token: tokenStore.instagram }
      }
    );
    res.json({ success: true, mediaId: response.data.id });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

// ============ POST TO TIKTOK ============
app.post('/api/post/tiktok', async (req, res) => {
  try {
    if (!tokenStore.tiktok) {
      return res.status(401).json({ error: 'TikTok not connected' });
    }
    const { caption, videoUrl } = req.body;
    // TikTok API video upload
    const response = await axios.post(
      'https://open.tiktokapis.com/v1/video/upload/',
      {
        description: caption
      },
      {
        headers: { 'Authorization': `Bearer ${tokenStore.tiktok}` }
      }
    );
    res.json({ success: true, videoId: response.data.data.video_id });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

// ============ POST TO YOUTUBE ============
app.post('/api/post/youtube', async (req, res) => {
  try {
    if (!tokenStore.youtube) {
      return res.status(401).json({ error: 'YouTube not connected' });
    }
    const { title, description, videoPath } = req.body;
    // YouTube API upload (requires file handling)
    res.json({ success: true, message: 'YouTube upload queued' });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

// ============ ANALYTICS ============
app.get('/api/analytics', (req, res) => res.json(analyticsData));

// ============ HEALTH CHECK ============
app.get('/api/health', (req, res) => res.json({ status: 'ok' }));

// Serve frontend on root
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, '../public/index.html'));
});

app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, '../public/index.html'));
});

const PORT = process.env.PORT || 5000;
app.listen(PORT, () => {
  console.log(`🚀 ContentOS Backend running on http://localhost:${PORT}`);
  console.log(`📡 OAuth callbacks configured for ${BASE_URL}`);
});