"""Image <-> bytes/base64 helpers shared by adapters."""

from __future__ import annotations

import base64
import io

from PIL import Image


def to_jpeg_bytes(image: Image.Image, quality: int = 95) -> bytes:
    buf = io.BytesIO()
    image.convert("RGB").save(buf, format="JPEG", quality=quality)
    return buf.getvalue()


def to_png_bytes(image: Image.Image) -> bytes:
    buf = io.BytesIO()
    image.save(buf, format="PNG")
    return buf.getvalue()


def to_data_uri(image: Image.Image, fmt: str = "jpeg", quality: int = 90) -> str:
    """Encode an image as a data: URI for OpenAI-compatible image_url fields."""
    if fmt == "jpeg":
        raw = to_jpeg_bytes(image, quality=quality)
        mime = "image/jpeg"
    else:
        raw = to_png_bytes(image)
        mime = "image/png"
    b64 = base64.b64encode(raw).decode("ascii")
    return f"data:{mime};base64,{b64}"