import os
import mimetypes
from typing import Optional, Mapping

from fastapi import Response
from fastapi.responses import FileResponse
from starlette.background import BackgroundTask

from .common import templates


def with_tmpl(
        name: str,
        code: int = 200,
        headers: Optional[Mapping[str, str]] = None,
        background: Optional[BackgroundTask] = None,
        **context) -> Response:
    """Render a Jinja2 template and return Response object.
    `response_class` parameter is not needed

    Args:
        name (str): Template filename
        code (int, optional): HTTP response code
        headers (Optional[Mapping[str, str]], optional):
            Additional headers, passed to Response constructor
        background (Optional[BackgroundTask], optional):
            Background task, passed to Response constructor

    Returns:
        FastAPI's TemplateResponse object
    """

    return templates.TemplateResponse(
        name=name,
        context=context,
        status_code=code,
        headers=headers,
        background=background,
    )


def with_file(
        path: os.PathLike,
        mime: Optional[str] = None,
        code: int = 200,
        headers: Optional[Mapping[str, str]] = None,
        background: Optional[BackgroundTask] = None) -> FileResponse:
    """Send a file specified in `path`
    automatically guessing mimetype if `mime` is None

    Args:
        path (os.PathLike): File path
        mime (Optional[str], optional): File mimetype
        code (int, optional): HTTP response code
        headers (Optional[Mapping[str, str]], optional):
            Additional headers, passed to Response constructor
        background (Optional[BackgroundTask], optional):
            Background task, passed to Response constructor

    Returns:
        FileResponse: FastAPI's FileResponse object
    """

    return FileResponse(
        path=path,
        media_type=(
            mime or 
            mimetypes.guess_type(path)[0]
        ),
        status_code=code,
        headers=headers,
        background=background,
    )


# Alias
with_template = with_tmpl