import os
from io import BytesIO
from typing import Any, Dict

from fastapi import APIRouter, HTTPException, UploadFile, File
from fastapi.responses import FileResponse
from PIL import Image

router = APIRouter(prefix="/branding", tags=["branding"])

_BRANDING_DIR = os.path.join(os.getcwd(), "data", "branding")
_LOGO_PATH = os.path.join(_BRANDING_DIR, "logo.png")
_FAVICON_PATH = os.path.join(_BRANDING_DIR, "favicon.ico")


def _ensure_branding_dir() -> None:
    os.makedirs(_BRANDING_DIR, exist_ok=True)


def _resize_image(image: Image.Image, max_size: int = 300) -> Image.Image:
    image = image.convert("RGBA")
    image.thumbnail((max_size, max_size))
    return image


@router.get("/logo.png")
async def branding_logo() -> FileResponse:
    if not os.path.exists(_LOGO_PATH):
        raise HTTPException(status_code=404, detail="Logo not found")
    headers = {"Cache-Control": "public, max-age=300"}
    return FileResponse(_LOGO_PATH, media_type="image/png", headers=headers)


@router.get("/favicon.ico")
async def branding_favicon() -> FileResponse:
    if not os.path.exists(_FAVICON_PATH):
        raise HTTPException(status_code=404, detail="Favicon not found")
    headers = {"Cache-Control": "public, max-age=300"}
    return FileResponse(_FAVICON_PATH, media_type="image/x-icon", headers=headers)


async def save_branding_image(file: UploadFile) -> Dict[str, Any]:
    if not file.content_type or not file.content_type.startswith("image/"):
        raise HTTPException(status_code=400, detail="Please upload an image file.")
    content = await file.read()
    if not content:
        raise HTTPException(status_code=400, detail="Uploaded file is empty.")
    try:
        image = Image.open(BytesIO(content))
    except OSError as exc:
        raise HTTPException(status_code=400, detail="Image file could not be read.") from exc

    _ensure_branding_dir()
    image = _resize_image(image, 300)
    image.save(_LOGO_PATH, format="PNG")

    favicon = image.copy()
    favicon.thumbnail((64, 64))
    try:
        favicon.save(_FAVICON_PATH, format="ICO", sizes=[(32, 32), (64, 64)])
    except OSError:
        favicon.save(_FAVICON_PATH, format="ICO")

    return {"status": "ok", "width": image.width, "height": image.height}