"""
Advanced ChromaDB clear script with selective deletion options.

Usage:
  python scripts/clear_db_advanced.py                    # Interactive - clear all
  python scripts/clear_db_advanced.py --force            # Clear all without confirmation
  python scripts/clear_db_advanced.py --group meet-sessions  # Clear specific group only
  python scripts/clear_db_advanced.py --meet-only        # Clear only meet-related signals
  python scripts/clear_db_advanced.py --test-only        # Clear only test collections
"""
import sys
import os
import argparse
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))

import chromadb
from backend.config import CHROMA_DB_PATH
from backend.db.chroma import get_group_ids


def clear_all(force=False):
    """Delete all collections."""
    client = chromadb.PersistentClient(path=CHROMA_DB_PATH)
    collections = client.list_collections()
    
    if not collections:
        print("✅ Database is already empty")
        return
    
    print(f"Found {len(collections)} collection(s) to delete:")
    total_docs = 0
    for coll in collections:
        count = coll.count()
        total_docs += count
        print(f"  - {coll.name}: {count} documents")
    
    print(f"\nTotal: {total_docs} documents across {len(collections)} collections")
    
    if not force:
        response = input("\nType 'yes' to confirm deletion: ")
        if response.lower() != 'yes':
            print("❌ Deletion cancelled")
            return
    
    print("\n🗑️  Deleting...")
    for coll in collections:
        client.delete_collection(coll.name)
        print(f"  ✅ Deleted: {coll.name}")
    
    print(f"\n✅ Deleted {len(collections)} collections, {total_docs} documents")


def clear_group(group_id: str, force=False):
    """Delete a specific group's collection."""
    client = chromadb.PersistentClient(path=CHROMA_DB_PATH)
    safe_name = f"ll_{group_id.replace('-', '_')}"[:63]
    
    try:
        coll = client.get_collection(safe_name)
        count = coll.count()
        
        print(f"Found collection '{safe_name}' with {count} documents")
        
        if not force:
            response = input(f"\nDelete collection '{safe_name}'? Type 'yes' to confirm: ")
            if response.lower() != 'yes':
                print("❌ Deletion cancelled")
                return
        
        client.delete_collection(safe_name)
        print(f"✅ Deleted collection '{safe_name}' ({count} documents)")
        
    except Exception as e:
        print(f"❌ Collection '{safe_name}' not found or error: {e}")


def clear_meet_only(force=False):
    """Delete only meet-related collections."""
    client = chromadb.PersistentClient(path=CHROMA_DB_PATH)
    collections = client.list_collections()
    
    # Identify meet collections (have lens=meet signals)
    meet_collections = []
    for coll in collections:
        try:
            # Sample first few docs to check if they're meet-related
            results = coll.get(limit=5)
            if results and results.get("metadatas"):
                for meta in results["metadatas"]:
                    if meta.get("lens") == "meet":
                        meet_collections.append(coll)
                        break
        except Exception:
            pass
    
    if not meet_collections:
        print("✅ No meet-related collections found")
        return
    
    print(f"Found {len(meet_collections)} meet-related collection(s):")
    total_docs = 0
    for coll in meet_collections:
        count = coll.count()
        total_docs += count
        print(f"  - {coll.name}: {count} documents")
    
    if not force:
        response = input("\nType 'yes' to confirm deletion: ")
        if response.lower() != 'yes':
            print("❌ Deletion cancelled")
            return
    
    print("\n🗑️  Deleting meet collections...")
    for coll in meet_collections:
        client.delete_collection(coll.name)
        print(f"  ✅ Deleted: {coll.name}")
    
    print(f"\n✅ Deleted {len(meet_collections)} collections, {total_docs} documents")


def clear_test_only(force=False):
    """Delete only test collections (names starting with 'test' or 'll_test')."""
    client = chromadb.PersistentClient(path=CHROMA_DB_PATH)
    collections = client.list_collections()
    
    test_collections = [c for c in collections if 'test' in c.name.lower()]
    
    if not test_collections:
        print("✅ No test collections found")
        return
    
    print(f"Found {len(test_collections)} test collection(s):")
    total_docs = 0
    for coll in test_collections:
        count = coll.count()
        total_docs += count
        print(f"  - {coll.name}: {count} documents")
    
    if not force:
        response = input("\nType 'yes' to confirm deletion: ")
        if response.lower() != 'yes':
            print("❌ Deletion cancelled")
            return
    
    print("\n🗑️  Deleting test collections...")
    for coll in test_collections:
        client.delete_collection(coll.name)
        print(f"  ✅ Deleted: {coll.name}")
    
    print(f"\n✅ Deleted {len(test_collections)} collections, {total_docs} documents")


def main():
    parser = argparse.ArgumentParser(
        description="Clear ChromaDB collections (signals + embeddings)",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  python scripts/clear_db_advanced.py                     # Clear all (interactive)
  python scripts/clear_db_advanced.py --force             # Clear all (no confirmation)
  python scripts/clear_db_advanced.py --group acme-dev    # Clear specific group
  python scripts/clear_db_advanced.py --meet-only         # Clear only meet signals
  python scripts/clear_db_advanced.py --test-only --force # Clear test data automatically
        """
    )
    
    parser.add_argument("--force", action="store_true", help="Skip confirmation prompt")
    parser.add_argument("--group", type=str, help="Delete only this specific group")
    parser.add_argument("--meet-only", action="store_true", help="Delete only meet-related collections")
    parser.add_argument("--test-only", action="store_true", help="Delete only test collections")
    
    args = parser.parse_args()
    
    print("=" * 60)
    print("ChromaDB Advanced Clear Script")
    print("=" * 60)
    print(f"Database path: {CHROMA_DB_PATH}")
    print()
    
    # Determine which clear operation to run
    if args.group:
        clear_group(args.group, force=args.force)
    elif args.meet_only:
        clear_meet_only(force=args.force)
    elif args.test_only:
        clear_test_only(force=args.force)
    else:
        clear_all(force=args.force)
    
    print("\n" + "=" * 60)


if __name__ == "__main__":
    main()