import sys
import pkg_resources
import torch
import os
from pathlib import Path
import psutil

def check_system_resources():
    """Check available system resources"""
    try:
        memory = psutil.virtual_memory()
        available_gb = memory.available / (1024 * 1024 * 1024)  # Convert to GB
        
        print("\n💾 System Resources:")
        print(f"- Available Memory: {available_gb:.1f}GB")
        
        if available_gb < 2:
            print("⚠️ Warning: Low available memory. This might affect performance.")
            print("  Consider closing other applications or increasing virtual memory.")
        
        # Check if running on CPU or GPU
        device = 'cuda' if torch.cuda.is_available() else 'cpu'
        print(f"- Using Device: {device.upper()}")
        
        if device == 'cpu':
            print("ℹ️ Note: Using CPU for computations. GPU would provide better performance.")
        
        return True
    except Exception as e:
        print(f"Error checking system resources: {str(e)}")
        return False

def check_setup():
    """Check if all dependencies are properly installed"""
    required = {
        'google-generativeai': '0.3.0',
        'faiss-cpu': '1.7.4',
        'langchain': '0.1.0',
        'python-dotenv': '1.0.0',
        'sentence-transformers': '2.2.2',
        'torch': '2.0.0',
        'streamlit': '1.30.0',
        'langchain-community': '0.0.13',
        'tqdm': '4.66.1',
        'numpy': '1.24.0',
        'psutil': '5.8.0'  # Added for system resource monitoring
    }
    
    missing = []
    for package, version in required.items():
        try:
            pkg_resources.require(f"{package}>={version}")
        except (pkg_resources.VersionConflict, pkg_resources.DistributionNotFound):
            missing.append(package)
    
    if missing:
        print("\n❌ Missing or incompatible packages:")
        for package in missing:
            print(f"  - {package}")
        print("\nTo fix: pip install -r requirements.txt")
        return False
    
    # Essential checks
    if not Path('.env').exists():
        print("\n❌ Configuration Missing:")
        print("Please create a .env file with your GOOGLE_API_KEY")
        return False
        
    if not Path('./documents').exists():
        print("\n❌ Study Materials Missing:")
        print("Please create a 'documents' folder and add your PDF study materials")
        return False
    
    # Check document sizes
    if Path('./documents').exists():
        total_size = 0
        for pdf in Path('./documents').glob('**/*.pdf'):
            total_size += pdf.stat().st_size
        
        total_size_mb = total_size / (1024 * 1024)  # Convert to MB
        if total_size_mb > 500:  # If total size > 500MB
            print(f"\n⚠️ Large Document Set ({total_size_mb:.1f}MB):")
            print("Consider splitting documents into smaller chunks or increasing available memory")
    
    print("\n✅ Basic setup verification complete")
    return True

def verify_model():
    """Verify the GTE embedding model is working"""
    try:
        from sentence_transformers import SentenceTransformer
        print("\n🔄 Loading GTE embedding model...")
        
        # Test with minimal memory usage using GTE model
        test_model = SentenceTransformer('thenlper/gte-large')
        test_text = "Test sentence for memory usage verification."
        _ = test_model.encode(test_text, show_progress_bar=False)
        
        print("✓ GTE embedding model verified")
        
        # Clear test objects
        del test_model
        import gc
        gc.collect()
        
        return True
    except Exception as e:
        print(f"\n❌ Error loading GTE embedding model: {str(e)}")
        return False

if __name__ == "__main__":
    print("\n🔍 Starting system verification...")
    check_system_resources()
    if check_setup():
        verify_model()