"""Public, signed image files for generated-HTML backgrounds."""

from __future__ import annotations

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

from deerflow.html_runtime.public_images import (
    image_media_type,
    resolve_html_image_path,
    verify_html_image_token,
)

router = APIRouter(prefix="/api/public/html-images", tags=["html-images"])

_PUBLIC_HEADERS = {
    "Access-Control-Allow-Origin": "*",
    "Cross-Origin-Resource-Policy": "cross-origin",
    "X-Content-Type-Options": "nosniff",
    "Cache-Control": "public, max-age=86400",
}


@router.get("/{token}")
async def get_html_image(token: str) -> FileResponse:
    """Serve one raster image referenced by a generated HTML page."""
    try:
        thread_id, kind, filename = verify_html_image_token(token)
        path = resolve_html_image_path(thread_id, kind, filename)
    except (ValueError, FileNotFoundError):
        raise HTTPException(status_code=404, detail="HTML image not found") from None
    return FileResponse(
        path,
        media_type=image_media_type(filename),
        headers=_PUBLIC_HEADERS,
    )