// backend/controllers/embeddingController.js
import { spawn } from 'child_process';
import path from 'path';
import fs from 'fs';
import pool from '../config/db.js';

export const generateEmbeddings = async (req, res) => {
  const { assistantId } = req.params;
  const userId = req.userId;

  try {
    // Retrieve file paths assigned to this assistant for the current user.
    const [filesResult] = await pool.execute(
      `SELECT f.file_path 
       FROM assistant_files af
       JOIN files f ON af.file_id = f.id
       WHERE af.assistant_id = ? AND f.user_id = ?`,
      [assistantId, userId]
    );

    if (filesResult.length === 0) {
      return res.status(400).json({ message: 'No files assigned to this assistant' });
    }

    // Create a directory for the assistant’s FAISS index:
    // e.g., documents/user_{userId}/assistant_{assistantId}
    const indexDir = path.join(process.cwd(), 'documents', `user_${userId}`, `assistant_${assistantId}`);
    fs.mkdirSync(indexDir, { recursive: true });

    // Define the output index file path (e.g., faiss_index.bin).
    const outputPath = path.join(indexDir, 'faiss_index.bin');

    // Prepare an array of file paths to pass to the Python script.
    const filePaths = filesResult.map(row => row.file_path);

    // Define the full path to the Python executable inside your venv.
    const pythonExecutable = "/root/intelaide-backend/python/bin/python3";

    // Build the full path to the generate_embeddings.py script.
    const pythonScriptPath = path.join(process.cwd(), 'python', 'create_embeds_from_files_mapping.py');


    // Spawn the Python process with the full path to the Python executable.
    const pythonProcess = spawn(pythonExecutable, [
      pythonScriptPath,
      '--files',
      ...filePaths,
      '--index_output',
      outputPath,
    ]);

//    console.log(`Filepaths: ${filePaths}`);
//    console.log(`Creating index: ${outputPath}`);


    let scriptOutput = '';
    let scriptError = '';

    pythonProcess.stdout.on('data', data => {
      scriptOutput += data.toString();
    });
    pythonProcess.stderr.on('data', data => {
      scriptError += data.toString();
    });

    pythonProcess.on('close', async (code) => {
      if (code !== 0) {
        console.error('Python script error:', scriptError);
        return res.status(500).json({ message: 'Error generating embeddings', error: scriptError });
      }
      // Update the assistant record with the FAISS index path and mark embeddings as completed.
      await pool.execute(
        'UPDATE ai_assistants SET faiss_index_path = ?, embedding_status = ? WHERE id = ? AND user_id = ?',
        [outputPath, 'completed', assistantId, userId]
      );
      res.json({ message: 'Embeddings generated successfully', output: scriptOutput });
    });

  } catch (error) {
    console.error('Error in generateEmbeddings:', error);
    res.status(500).json({ message: 'Error generating embeddings' });
  }
};

export default generateEmbeddings;