import json
from pathlib import Path
from typing import Optional
from src.config import VECTORSTORE_DIR, PAPERS_DIR

def get_vectorstore_path(paper_id: str) -> Path:
    """Get the path where a vectorstore for a paper is saved."""
    return VECTORSTORE_DIR / f"{paper_id}.faiss"

def get_metadata_path(paper_id: str) -> Path:
    """Get the path where paper metadata is saved."""
    return VECTORSTORE_DIR / f"{paper_id}_metadata.json"

def save_paper_metadata(paper_id: str, filename: str, chunks_count: int):
    """Save paper metadata (filename, chunk count, etc.)."""
    metadata = {
        "paper_id": paper_id,
        "filename": filename,
        "chunks_count": chunks_count,
    }
    with open(get_metadata_path(paper_id), "w") as f:
        json.dump(metadata, f, indent=2)

def load_paper_metadata(paper_id: str) -> Optional[dict]:
    """Load paper metadata if it exists."""
    path = get_metadata_path(paper_id)
    if path.exists():
        with open(path, "r") as f:
            return json.load(f)
    return None

def list_saved_papers() -> list[dict]:
    """List all saved papers with their metadata."""
    papers = []
    for metadata_file in VECTORSTORE_DIR.glob("*_metadata.json"):
        with open(metadata_file, "r") as f:
            papers.append(json.load(f))
    return papers

def delete_paper(paper_id: str):
    """Delete a paper's vectorstore and metadata."""
    vectorstore_path = get_vectorstore_path(paper_id)
    metadata_path = get_metadata_path(paper_id)
    
    if vectorstore_path.exists():
        import shutil
        shutil.rmtree(vectorstore_path)
    if metadata_path.exists():
        metadata_path.unlink()