# ========================================================================== #
#                                                                            #
#    KVMD - The main PiKVM daemon.                                           #
#                                                                            #
#    Copyright (C) 2018-2024  Maxim Devaev <mdevaev@gmail.com>               #
#                                                                            #
#    This program is free software: you can redistribute it and/or modify    #
#    it under the terms of the GNU General Public License as published by    #
#    the Free Software Foundation, either version 3 of the License, or       #
#    (at your option) any later version.                                     #
#                                                                            #
#    This program is distributed in the hope that it will be useful,         #
#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
#    GNU General Public License for more details.                            #
#                                                                            #
#    You should have received a copy of the GNU General Public License       #
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
#                                                                            #
# ========================================================================== #


import os
import contextlib

from typing import AsyncGenerator

import aiohttp
import aiohttp.multipart

from . import __version__


# =====
def make_user_agent(app: str) -> str:
    return f"{app}/{__version__}"


def raise_not_200(resp: aiohttp.ClientResponse) -> None:
    if resp.status == 200:
        return
    assert resp.reason is not None
    resp.release()
    raise aiohttp.ClientResponseError(
        resp.request_info,
        resp.history,
        status=resp.status,
        message=resp.reason,
        headers=resp.headers,
    )


async def raise_known_not_200(
    resp: aiohttp.ClientResponse,
    *ex_types: type[BaseException],
) -> None:

    if resp.status == 200:
        return

    assert resp.reason is not None
    try:
        error = ""
        error_msg = ""
        try:
            data = await resp.json()
            if (
                not data["ok"]
                and isinstance(data["result"]["error"], str)
                and isinstance(data["result"]["error_msg"], str)
            ):
                error = data["result"]["error"]
                error_msg = data["result"]["error_msg"]
        except Exception:
            pass
        if error:
            for ex_type in ex_types:
                if ex_type.__name__ == error:
                    raise ex_type(error_msg)
    finally:
        resp.release()

    raise aiohttp.ClientResponseError(
        resp.request_info,
        resp.history,
        status=resp.status,
        message=resp.reason,
        headers=resp.headers,
    )


def get_filename(resp: aiohttp.ClientResponse) -> str:
    try:
        disp = resp.headers["Content-Disposition"]
        parsed = aiohttp.multipart.parse_content_disposition(disp)
        return str(parsed[1]["filename"])
    except Exception:
        try:
            return os.path.basename(resp.url.path)
        except Exception:
            raise aiohttp.ClientError("Can't determine filename")


def get_mtime(resp: aiohttp.ClientResponse) -> float:
    try:
        date = resp.headers["Last-Modified"]
        parsed = aiohttp.helpers.parse_http_date(date)
        if parsed is not None:
            return parsed.timestamp()
    except Exception:
        pass
    raise aiohttp.ClientError("Can't determine mtime")


@contextlib.asynccontextmanager
async def download(
    url: str,
    verify: bool=True,
    timeout: float=10.0,
    read_timeout: (float | None)=None,
    app: str="KVMD",
) -> AsyncGenerator[aiohttp.ClientResponse]:

    async with aiohttp.ClientSession(
        headers={"User-Agent": make_user_agent(app)},
        timeout=aiohttp.ClientTimeout(
            connect=timeout,
            sock_connect=timeout,
            sock_read=(read_timeout if read_timeout is not None else timeout),
        ),
    ) as session:

        async with session.get(url, verify_ssl=verify) as resp:  # type: ignore
            raise_not_200(resp)
            yield resp
