"""Reset ChromaDB SQLite index while preserving all collection data."""
import chromadb
from chromadb.config import Settings
import os
import sys


def reset_sqlite_index():
    """Reset SQLite index while preserving collection data.
    
    This script:
    1. Detects existing collection UUID folders
    2. Forces ChromaDB to rebuild the sqlite3 index
    3. Verifies collections are properly indexed
    4. Reports status
    """
    
    print("\n" + "=" * 70)
    print("🔧 ChromaDB SQLite Index Reset Tool")
    print("=" * 70)
    
    chroma_path = "./chroma_db"
    
    # Step 1: Verify collection folders exist
    print("\n📁 Step 1: Scanning for collection folders...")
    print("-" * 70)
    
    if not os.path.exists(chroma_path):
        print(f"❌ ERROR: {chroma_path} directory not found!")
        return False
    
    # Find all UUID folders
    uuid_folders = []
    try:
        for item in os.listdir(chroma_path):
            item_path = os.path.join(chroma_path, item)
            # Check if it's a directory and matches UUID pattern (36 chars, 4 hyphens)
            if os.path.isdir(item_path) and len(item) == 36 and item.count('-') == 4:
                uuid_folders.append(item)
    except Exception as e:
        print(f"❌ Error scanning directory: {e}")
        return False
    
    print(f"✅ Found {len(uuid_folders)} collection folder(s)")
    
    if len(uuid_folders) > 0:
        for i, folder in enumerate(uuid_folders, 1):
            folder_path = os.path.join(chroma_path, folder)
            # Check what files are in the collection
            files = os.listdir(folder_path)
            print(f"  {i}. {folder}")
            print(f"     Files: {', '.join(files)}")
    else:
        print("⚠️  WARNING: No collection folders found!")
    
    # Step 2: Check SQLite status
    print("\n📊 Step 2: Checking SQLite status...")
    print("-" * 70)
    
    sqlite_path = os.path.join(chroma_path, "chroma.sqlite3")
    if os.path.exists(sqlite_path):
        sqlite_size = os.path.getsize(sqlite_path)
        print(f"✅ chroma.sqlite3 exists (size: {sqlite_size:,} bytes)")
        
        if sqlite_size < 100000:  # Less than 100KB is likely empty
            print("⚠️  SQLite file is very small (likely empty/corrupted)")
    else:
        print("✅ chroma.sqlite3 does not exist (will be created)")
    
    # Step 3: Reset by creating new client
    print("\n🔄 Step 3: Rebuilding SQLite index...")
    print("-" * 70)
    
    try:
        print("Creating fresh ChromaDB PersistentClient...")
        client = chromadb.PersistentClient(
            path=chroma_path,
            settings=Settings(
                anonymized_telemetry=False,
                allow_reset=True
            )
        )
        print("✅ Client created successfully")
        
    except Exception as e:
        print(f"❌ ERROR creating client: {e}")
        return False
    
    # Step 4: Verify collections are indexed
    print("\n🔍 Step 4: Verifying collection index...")
    print("-" * 70)
    
    try:
        collections = client.list_collections()
        print(f"✅ ChromaDB found {len(collections)} collection(s)")
        
        if len(collections) > 0:
            print("\nIndexed Collections:")
            for i, collection in enumerate(collections, 1):
                doc_count = collection.count()
                metadata = collection.metadata
                print(f"\n  {i}. {collection.name}")
                print(f"     Document count: {doc_count}")
                print(f"     Metadata: {metadata}")
            
            print("\n✅ SUCCESS! All collections are properly indexed!")
            return True
        
        elif len(uuid_folders) > 0:
            # Collections folders exist but not indexed
            print("⚠️  WARNING: Collection folders exist but not indexed in SQLite")
            print("\nThis can happen if:")
            print("  - SQLite file was deleted and recreated without scanning folders")
            print("  - Collection data is corrupted")
            print("  - Permission issues prevent reading collection folders")
            
            print("\n📋 Troubleshooting steps:")
            print("  1. Check file permissions in chroma_db directory")
            print("  2. Try deleting chroma.sqlite3 and restarting application")
            print("  3. See docs/CHROMADB_RECOVERY.md for more options")
            
            return False
        
        else:
            print("✅ No collections currently indexed (database is clean)")
            return True
            
    except Exception as e:
        print(f"❌ ERROR reading collections: {e}")
        return False


def main():
    """Main entry point."""
    try:
        success = reset_sqlite_index()
        
        print("\n" + "=" * 70)
        if success:
            print("✅ RESET COMPLETE - Collections are properly indexed!")
            print("\n📝 Next steps:")
            print("  1. Start Streamlit: streamlit run streamlit_app.py")
            print("  2. Check 'Existing Collections' dropdown")
            print("  3. Load a collection and verify it works")
            exit_code = 0
        else:
            print("❌ RESET INCOMPLETE - See messages above for details")
            print("\n📝 Next steps:")
            print("  1. Review error messages above")
            print("  2. Check docs/CHROMADB_RECOVERY.md for solutions")
            print("  3. Contact support if issues persist")
            exit_code = 1
        
        print("=" * 70 + "\n")
        sys.exit(exit_code)
        
    except KeyboardInterrupt:
        print("\n\n⚠️  Script interrupted by user")
        sys.exit(1)
    except Exception as e:
        print(f"\n❌ FATAL ERROR: {e}")
        import traceback
        traceback.print_exc()
        sys.exit(1)


if __name__ == "__main__":
    main()