import os
from pathlib import Path

from fastapi import UploadFile

AVATARS_DIR = Path(os.getenv("DATABASE_PATH", "/data/skinspins.db")).parent / "avatars"
ALLOWED_TYPES = {"image/jpeg", "image/png", "image/webp", "image/gif"}
MAX_SIZE = 2 * 1024 * 1024  # 2 MB


async def save_avatar(file: UploadFile, user_id: str) -> tuple[str | None, str | None]:
    """Returns (url_path, error). url_path is like /avatars/user_id.jpg"""
    if file.content_type not in ALLOWED_TYPES:
        return None, "Only JPEG, PNG, WebP or GIF images are allowed."

    data = await file.read()
    if len(data) > MAX_SIZE:
        return None, "Image must be smaller than 2 MB."

    ext = file.content_type.split("/")[-1].replace("jpeg", "jpg")
    filename = f"{user_id}.{ext}"
    dest = AVATARS_DIR / filename

    # Remove any previous avatar for this user
    for old in AVATARS_DIR.glob(f"{user_id}.*"):
        old.unlink(missing_ok=True)

    dest.write_bytes(data)
    return f"/avatars/{filename}", None