import mimetypes
from pathlib import Path

from fastapi import APIRouter, HTTPException
from fastapi.responses import FileResponse

from app.config import settings

router = APIRouter()


def _resolve_safe(key: str) -> Path:
    base = Path(settings.storage_dir).resolve()
    path = (base / key).resolve()
    if not path.is_relative_to(base):
        raise HTTPException(status_code=400, detail="Invalid path")
    return path


@router.get("/api/files/{key:path}")
def serve_file(key: str):
    path = _resolve_safe(key)
    if not path.exists() or not path.is_file():
        raise HTTPException(status_code=404, detail="File not found")
    media_type, _ = mimetypes.guess_type(str(path))
    return FileResponse(path, media_type=media_type or "application/octet-stream")