import argparse
from pathlib import Path
from typing import List

import chromadb


def _parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Local ChromaDB persistence demo")
    parser.add_argument(
        "--path",
        default="chroma_data",
        help="Local persistence directory",
    )
    parser.add_argument(
        "--collection",
        default="knowledge_base",
        help="Collection name",
    )
    parser.add_argument(
        "--query",
        default="Tell me about vector stores",
        help="Query text",
    )
    return parser.parse_args()


def _seed_collection(collection: chromadb.Collection) -> None:
    documents = [
        "Chroma is a lightweight, open-source vector database built for AI.",
        "Python is a high-level programming language used extensively in data science.",
        "The celestial body closest to Earth is the Moon.",
    ]
    metadatas = [
        {"category": "tech", "source": "docs"},
        {"category": "tech", "source": "wiki"},
        {"category": "science", "source": "space-facts"},
    ]
    ids = ["doc1", "doc2", "doc3"]
    collection.add(documents=documents, metadatas=metadatas, ids=ids)


def main() -> None:
    args = _parse_args()
    persist_path = Path(args.path).resolve()
    persist_path.mkdir(parents=True, exist_ok=True)

    print(f"Using local Chroma persistence at: {persist_path}")
    client = chromadb.PersistentClient(path=str(persist_path))

    collection = client.get_or_create_collection(name=args.collection)
    if collection.count() == 0:
        print("Seeding collection with sample documents...")
        _seed_collection(collection)
    print(f"Collection '{args.collection}' has {collection.count()} documents.")

    results = collection.query(query_texts=[args.query], n_results=2)
    print("\n--- Search Results ---")
    for doc, meta, distance in zip(
        results["documents"][0],
        results["metadatas"][0],
        results["distances"][0],
    ):
        print(f"Matched Document: {doc}")
        print(f"Metadata: {meta}")
        print(f"Distance Score (Lower is better): {distance:.4f}")
        print()
    print("----------------------")


if __name__ == "__main__":
    main()