const express = require('express');
const app = express();
const cors = require('cors');
require('dotenv').config();
const { createClient } = require('@supabase/supabase-js');
const axios = require('axios');
const { v4: uuidv4 } = require('uuid');
app.use(express.json({ limit: '50mb' })); // ← Add limit here
app.use(express.urlencoded({ limit: '50mb', extended: true })); // ← Add this too
const port = process.env.PORT || 5235;

// Middleware
app.use(cors());
app.use(express.json());

// ============================================
// SUPABASE SETUP
// ============================================
const supabase = createClient(
  process.env.SUPABASE_URL,
  process.env.SUPABASE_ANON_KEY
);

console.log('✅ Supabase client initialized');

// ============================================
// FASHN.AI SETUP
// ============================================
const FASHN_API_KEY = process.env.FASHN_API_KEY;
const FASHN_API_URL = 'https://api.fashn.ai/v1';

// In-memory cache
const jobsCache = new Map();

// ============================================
// FASHN.AI HELPER FUNCTIONS
// ============================================

/**
 * Convert blob/data URL to public URL - Upload to Supabase Storage
 */
async function uploadImageToStorage(imageData, userId, fileName) {
  try {
    console.log('📤 Uploading image to Supabase Storage...');

    let fileBuffer;
    let contentType = 'image/jpeg';

    if (imageData.startsWith('data:')) {
      const matches = imageData.match(/^data:([^;]+);base64,(.+)$/);
      if (!matches) {
        throw new Error('Invalid data URL format');
      }
      contentType = matches[1];
      const base64Data = matches[2];
      fileBuffer = Buffer.from(base64Data, 'base64');
    } else if (imageData.startsWith('blob:')) {
      throw new Error('Blob URLs cannot be uploaded. Please convert to base64 first.');
    } else {
      return imageData;
    }

    const filePath = `${userId}/${fileName}_${Date.now()}.jpg`;
    
    const { data, error } = await supabase.storage
      .from('user-uploads')
      .upload(filePath, fileBuffer, {
        contentType: contentType,
        upsert: false
      });

    if (error) {
      console.error('Supabase storage error:', error);
      throw error;
    }

    const { data: urlData } = supabase.storage
      .from('user-uploads')
      .getPublicUrl(filePath);

    console.log('✅ Image uploaded:', urlData.publicUrl);
    return urlData.publicUrl;

  } catch (error) {
    console.error('❌ Upload error:', error);
    throw new Error(`Failed to upload image: ${error.message}`);
  }
}

/**
 * Apply single garment using FASHN.ai with polling
 */
async function applyGarmentWithFashn(modelImage, garmentImage) {
  try {
    console.log('📤 Calling FASHN.ai API...');
    console.log('Model image:', modelImage.substring(0, 80) + '...');
    console.log('Garment image:', garmentImage.substring(0, 80) + '...');

    if (modelImage.startsWith('blob:') || modelImage.startsWith('data:')) {
      throw new Error('Model image must be a public URL');
    }

    const startTime = Date.now();

    // Step 1: Submit job
    const requestBody = {
      model_image: modelImage,
      garment_image: garmentImage,
      category: 'auto'
    };

    console.log('📤 Submitting job to FASHN.ai...');

    const submitResponse = await axios.post(
      `${FASHN_API_URL}/run`,
      requestBody,
      {
        headers: {
          'Authorization': `Bearer ${FASHN_API_KEY}`,
          'Content-Type': 'application/json'
        },
        timeout: 10000
      }
    );

    console.log('📥 Submission response:', JSON.stringify(submitResponse.data, null, 2));

    if (!submitResponse.data || !submitResponse.data.id) {
      throw new Error('No job ID received from FASHN.ai');
    }

    const jobId = submitResponse.data.id;
    console.log('✅ FASHN.ai job created:', jobId);

    // Step 2: Poll for result
    console.log('⏳ Polling for result...');
    
    const maxAttempts = 60;
    const pollInterval = 2000;
    let attempts = 0;

    while (attempts < maxAttempts) {
      await new Promise(resolve => setTimeout(resolve, pollInterval));
      attempts++;

      console.log(`🔄 Checking status (attempt ${attempts}/${maxAttempts})...`);

      try {
        const statusResponse = await axios.get(
          `${FASHN_API_URL}/${jobId}`,
          {
            headers: {
              'Authorization': `Bearer ${FASHN_API_KEY}`
            },
            timeout: 10000
          }
        );

        console.log('📊 Status response:', JSON.stringify(statusResponse.data, null, 2));

        if (statusResponse.data.status === 'completed') {
          const processingTime = Math.round((Date.now() - startTime) / 1000);
          
          let imageUrl = null;
          
          if (statusResponse.data.output && Array.isArray(statusResponse.data.output)) {
            imageUrl = statusResponse.data.output[0];
          } else if (statusResponse.data.result) {
            imageUrl = statusResponse.data.result;
          } else if (statusResponse.data.image) {
            imageUrl = statusResponse.data.image;
          }

          if (imageUrl) {
            console.log(`✅ FASHN.ai completed in ${processingTime}s`);
            console.log(`🖼️  Result URL: ${imageUrl}`);
            return { imageUrl, processingTime };
          } else {
            console.error('❌ No image URL in completed response');
            console.error('Full response:', JSON.stringify(statusResponse.data, null, 2));
            throw new Error('Job completed but no image URL found');
          }
        }
        
        if (statusResponse.data.status === 'failed') {
          throw new Error(`FASHN.ai job failed: ${statusResponse.data.error || 'Unknown error'}`);
        }

        console.log('⏳ Status:', statusResponse.data.status || 'processing');

      } catch (pollError) {
        if (pollError.response) {
          console.log(`⚠️  Poll error - Status: ${pollError.response.status}`);
          console.log(`⚠️  Response:`, JSON.stringify(pollError.response.data, null, 2));
          
          if (pollError.response.status === 404) {
            console.log('⏳ Job not ready yet (404)...');
            continue;
          }
        } else {
          console.log('⚠️  Poll error:', pollError.message);
        }
        
        // Continue polling on errors
        continue;
      }
    }

    throw new Error('FASHN.ai processing timeout');

  } catch (error) {
    if (error.response) {
      console.error('❌ FASHN.ai API error:');
      console.error('Status:', error.response.status);
      console.error('Data:', JSON.stringify(error.response.data, null, 2));
      throw new Error(`FASHN.ai API error (${error.response.status}): ${error.response.data.message || error.response.statusText}`);
    } else if (error.request) {
      console.error('❌ No response from FASHN.ai');
      throw new Error('FASHN.ai did not respond');
    } else {
      console.error('❌ FASHN.ai error:', error.message);
      throw error;
    }
  }
}

/**
 * Layer wardrobe items sequentially
 */
async function layerWardrobeItems(userImage, wardrobeItems, userId) {
  let currentImage = userImage;
  const steps = [];

  console.log(`\n👕 Layering ${wardrobeItems.length} wardrobe items...`);

  if (userImage.startsWith('blob:') || userImage.startsWith('data:')) {
    console.log('🔄 Converting user image to public URL...');
    currentImage = await uploadImageToStorage(userImage, userId, 'user_image');
  }

  for (let i = 0; i < wardrobeItems.length; i++) {
    const item = wardrobeItems[i];
    console.log(`\n📦 Step ${i + 1}/${wardrobeItems.length}: Adding ${item.name}`);

    try {
      const result = await applyGarmentWithFashn(currentImage, item.image_url);
      
      currentImage = result.imageUrl;
      steps.push({
        step: i + 1,
        item: item.name,
        resultUrl: currentImage,
        processingTime: result.processingTime
      });

      console.log(`✅ ${item.name} applied successfully`);

    } catch (error) {
      console.error(`❌ Failed to apply ${item.name}:`, error.message);
      throw new Error(`Failed to apply ${item.name}: ${error.message}`);
    }
  }

  console.log('\n✅ All wardrobe items applied!');
  return { finalImage: currentImage, steps };
}

/**
 * Process job in background
 */
async function processJob(jobId) {
  try {
    console.log(`\n🎬 ========================================`);
    console.log(`📋 Processing job: ${jobId}`);
    console.log(`🎬 ========================================`);

    const { data: job, error: fetchError } = await supabase
      .from('generation_jobs')
      .select('*')
      .eq('job_id', jobId)
      .single();

    if (fetchError || !job) {
      throw new Error('Job not found');
    }

    await supabase
      .from('generation_jobs')
      .update({ status: 'processing', progress: 10 })
      .eq('job_id', jobId);

    jobsCache.set(jobId, { status: 'processing', progress: 10 });

    const userImage = job.user_image;
    const wardrobeItems = job.products || [];

    console.log('\n📦 Job Details:');
    console.log('User image:', userImage ? 'Yes' : 'No');
    console.log('Wardrobe items:', wardrobeItems.length);

    await supabase
      .from('generation_jobs')
      .update({ progress: 20 })
      .eq('job_id', jobId);
    jobsCache.set(jobId, { status: 'processing', progress: 20 });

    const { finalImage, steps } = await layerWardrobeItems(userImage, wardrobeItems, job.user_id);

    const progressPerItem = 60 / wardrobeItems.length;
    for (let i = 0; i < steps.length; i++) {
      const newProgress = 20 + Math.round((i + 1) * progressPerItem);
      await supabase
        .from('generation_jobs')
        .update({ progress: newProgress })
        .eq('job_id', jobId);
      jobsCache.set(jobId, { status: 'processing', progress: newProgress });
    }

    const totalProcessingTime = steps.reduce((sum, step) => sum + step.processingTime, 0);

    await supabase
      .from('generation_jobs')
      .update({ 
        status: 'completed',
        progress: 100,
        generated_image_url: finalImage,
        processing_time: totalProcessingTime,
        processing_steps: steps,
        completed_at: new Date().toISOString()
      })
      .eq('job_id', jobId);

    jobsCache.set(jobId, { 
      status: 'completed', 
      progress: 100,
      imageUrl: finalImage 
    });

    console.log(`\n✅ ========================================`);
    console.log(`✅ Job ${jobId} COMPLETED!`);
    console.log(`✅ ========================================`);
    console.log(`🖼️  Final image: ${finalImage}`);

  } catch (error) {
    console.error(`\n❌ Job ${jobId} FAILED!`);
    console.error(`❌ Error:`, error.message);

    await supabase
      .from('generation_jobs')
      .update({ 
        status: 'failed',
        error: error.message,
        completed_at: new Date().toISOString()
      })
      .eq('job_id', jobId);

    jobsCache.set(jobId, { 
      status: 'failed', 
      error: error.message 
    });
  }
}

// ============================================
// API ROUTES
// ============================================

app.post('/api/generate', async (req, res) => {
  try {
    const { userId, userImage, wardrobeItems, selectedPose, selectedBackground, selectedEffect } = req.body;

    console.log('\n🆕 ========================================');
    console.log('🆕 NEW GENERATION REQUEST');
    console.log('🆕 ========================================');
    console.log('User:', userId);
    console.log('Wardrobe items:', wardrobeItems?.length || 0);

    if (!wardrobeItems || wardrobeItems.length === 0) {
      return res.status(400).json({ success: false, error: 'At least one wardrobe item required' });
    }

    if (!userImage) {
      return res.status(400).json({ success: false, error: 'User image required' });
    }

    if (!FASHN_API_KEY) {
      return res.status(500).json({ success: false, error: 'FASHN_API_KEY not configured' });
    }

    const jobId = uuidv4();
    console.log('Job ID:', jobId);

    const productUrls = wardrobeItems.map(item => item.image_url);

    const { error: insertError } = await supabase
      .from('generation_jobs')
      .insert({
        job_id: jobId,
        user_id: userId || 'guest',
        user_image: userImage,
        product_urls: productUrls,
        products: wardrobeItems,
        pose_url: selectedPose?.pose_image_url,
        pose: selectedPose,
        background_url: selectedBackground?.bg_image_url,
        background: selectedBackground,
        effect: selectedEffect?.name || 'natural',
        effect_data: selectedEffect,
        status: 'queued',
        progress: 0,
        created_at: new Date().toISOString()
      });

    if (insertError) {
      console.error('Supabase error:', insertError);
      throw insertError;
    }

    console.log('✅ Job created in database');

    jobsCache.set(jobId, { status: 'queued', progress: 0 });

    setImmediate(() => {
      processJob(jobId).catch(err => console.error('Processing error:', err));
    });

    const estimatedTime = wardrobeItems.length * 15;

    res.status(201).json({
      success: true,
      jobId,
      status: 'queued',
      message: 'Generation job created',
      wardrobeItemsCount: wardrobeItems.length,
      estimatedTime: `${estimatedTime}-${estimatedTime + 30} seconds`
    });

  } catch (error) {
    console.error('❌ Generate error:', error);
    res.status(500).json({ success: false, error: error.message });
  }
});

app.get('/api/job-status/:jobId', async (req, res) => {
  try {
    const { jobId } = req.params;

    const { data: job, error } = await supabase
      .from('generation_jobs')
      .select('*')
      .eq('job_id', jobId)
      .single();

    if (error || !job) {
      return res.status(404).json({ success: false, error: 'Job not found' });
    }

    jobsCache.set(jobId, {
      status: job.status,
      progress: job.progress,
      imageUrl: job.generated_image_url
    });

    res.json({
      success: true,
      jobId: job.job_id,
      status: job.status,
      progress: job.progress,
      generatedImageUrl: job.generated_image_url,
      processingSteps: job.processing_steps,
      error: job.error,
      createdAt: job.created_at,
      completedAt: job.completed_at,
      processingTime: job.processing_time
    });

  } catch (error) {
    console.error('❌ Status error:', error);
    res.status(500).json({ success: false, error: error.message });
  }
});

app.get('/api/health', async (req, res) => {
  try {
    const { error: supabaseError } = await supabase
      .from('generation_jobs')
      .select('job_id', { count: 'exact', head: true })
      .limit(1);

    const supabaseStatus = supabaseError ? 'error' : 'connected';
    const fashnStatus = FASHN_API_KEY ? 'configured' : 'not_configured';

    res.json({
      success: true,
      status: 'healthy',
      services: { supabase: supabaseStatus, fashn: fashnStatus },
      stats: { jobsInCache: jobsCache.size }
    });

  } catch (error) {
    res.status(503).json({ success: false, error: error.message });
  }
});

app.get('/api/products', async (req, res) => {
  try {
    const { data: products, error } = await supabase
      .from('products')
      .select('*');

    if (error) {
      throw error;
    }

    res.json({
      success: true,
      products: products || []
    });

  } catch (error) {
    console.error('❌ Products error:', error);
    res.status(500).json({
      success: false,
      error: error.message
    });
  }
});

app.post('/api/addproducts', async (req, res) => {
  try {
    const { name, price, description, image_url, category } = req.body;

    // Basic validation
    if (!name || !price || !description || !image_url || !category) {
      return res.status(400).json({
        success: false,
        error: 'All fields (name, price, description, image_url, category) are required'
      });
    }

    // Insert into Supabase
    const { data, error } = await supabase
      .from('products')
      .insert([
        {
          name,
          price,
          description,
          image_url,
          category,
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString()
        }
      ])
      .select('*')
      .single();

    if (error) throw error;

    res.status(201).json({
      success: true,
      message: '✅ Product created successfully',
      product: data
    });

  } catch (error) {
    console.error('❌ Product insert error:', error);
    res.status(500).json({
      success: false,
      error: error.message
    });
  }
});

app.get('/api/backgrounds', async (req, res) => {
  try {
    const { data, error } = await supabase
      .from('backgrounds')
      .select('*')
      .order('id', { ascending: true });

    if (error) throw error;

    res.json({
      success: true,
      backgrounds: data || []
    });
  } catch (err) {
    console.error('❌ Backgrounds fetch error:', err);
    res.status(500).json({
      success: false,
      error: err.message
    });
  }
});

app.get('/api/poses', async (req, res) => {
  try {
    const { data, error } = await supabase
      .from('poses')
      .select('*')
      .order('id', { ascending: true });

    if (error) throw error;

    res.json({
      success: true,
      poses: data || []
    });
  } catch (err) {
    console.error('❌ Poses fetch error:', err);
    res.status(500).json({
      success: false,
      error: err.message
    });
  }
});

app.get('/api/effects', async (req, res) => {
  try {
    const { data, error } = await supabase
      .from('effects')
      .select('*')
      .order('id', { ascending: true });

    if (error) throw error;

    res.json({
      success: true,
      effects: data || []
    });
  } catch (err) {
    console.error('❌ Effects fetch error:', err);
    res.status(500).json({
      success: false,
      error: err.message
    });
  }
});

app.get('/', (req, res) => {
  res.json({
    message: 'Virtual Try-On Server with FASHN.ai',
    version: '2.0.0',
    database: 'Supabase',
    aiProvider: 'FASHN.ai'
  });
});

app.use((req, res) => {
  res.status(404).json({ success: false, error: 'Endpoint not found' });
});

app.use((err, req, res, next) => {
  console.error('❌ Error:', err);
  res.status(500).json({ success: false, error: 'Internal server error' });
});

app.listen(port, () => {
  console.log('\n' + '='.repeat(70));
  console.log('🚀 Virtual Try-On Server with FASHN.ai - EXACT PRODUCTS VERSION');
  console.log('='.repeat(70));
  console.log(`📡 Server: http://localhost:${port}`);
  console.log(`💾 Database: Supabase`);
  console.log(`🤖 AI Provider: FASHN.ai`);
  console.log(`📊 Health: http://localhost:${port}/api/health`);
  console.log('='.repeat(70));
  
  if (!FASHN_API_KEY) {
    console.log('\n⚠️  WARNING: FASHN_API_KEY not found!');
  } else {
    console.log('\n✅ FASHN API Key configured');
  }
  console.log('\n');
});