"""Init file for Supervisor util for RESTful API."""

import asyncio
from collections.abc import Callable
import json
from typing import Any, cast

from aiohttp import web
from aiohttp.hdrs import AUTHORIZATION
from aiohttp.web_exceptions import HTTPUnauthorized
from aiohttp.web_request import Request
import voluptuous as vol
from voluptuous.humanize import humanize_error

from ..const import (
    HEADER_TOKEN,
    HEADER_TOKEN_OLD,
    JSON_DATA,
    JSON_ERROR_KEY,
    JSON_EXTRA_FIELDS,
    JSON_JOB_ID,
    JSON_MESSAGE,
    JSON_RESULT,
    REQUEST_FROM,
    RESULT_ERROR,
    RESULT_OK,
)
from ..coresys import CoreSys, CoreSysAttributes
from ..exceptions import APIError, BackupFileNotFoundError, DockerAPIError, HassioError
from ..jobs import JobSchedulerOptions, SupervisorJob
from ..utils import check_exception_chain, get_message_from_exception_chain
from ..utils.json import json_dumps, json_loads as json_loads_util
from ..utils.log_format import format_message
from . import const


def extract_supervisor_token(request: web.Request) -> str | None:
    """Extract Supervisor token from request."""
    if supervisor_token := request.headers.get(HEADER_TOKEN):
        return supervisor_token

    # Old Supervisor fallback
    if supervisor_token := request.headers.get(HEADER_TOKEN_OLD):
        return supervisor_token

    # API access only
    if supervisor_token := request.headers.get(AUTHORIZATION):
        return supervisor_token.split(" ")[-1]

    return None


def json_loads(data: Any) -> dict[str, Any]:
    """Extract json from string with support for '' and None."""
    if not data:
        return {}
    try:
        return json_loads_util(data)
    except json.JSONDecodeError as err:
        raise APIError("Invalid json") from err


def api_process(method):
    """Wrap function with true/false calls to rest api."""

    async def wrap_api(
        api: CoreSysAttributes, *args, **kwargs
    ) -> web.Response | web.StreamResponse:
        """Return API information."""
        try:
            answer = await method(api, *args, **kwargs)
        except BackupFileNotFoundError as err:
            return api_return_error(err, status=404)
        except APIError as err:
            return api_return_error(err, status=err.status, job_id=err.job_id)
        except HassioError as err:
            return api_return_error(err)

        if isinstance(answer, (dict, list)):
            return api_return_ok(data=answer)
        if isinstance(answer, web.Response):
            return answer
        if isinstance(answer, web.StreamResponse):
            return answer
        elif isinstance(answer, bool) and not answer:
            return api_return_error()
        return api_return_ok()

    return wrap_api


def require_home_assistant(method):
    """Ensure that the request comes from Home Assistant."""

    async def wrap_api(api: CoreSysAttributes, *args, **kwargs) -> Any:
        """Return API information."""
        coresys: CoreSys = api.coresys
        request: Request = args[0]
        if request[REQUEST_FROM] != coresys.homeassistant:
            raise HTTPUnauthorized()
        return await method(api, *args, **kwargs)

    return wrap_api


def api_process_raw(content, *, error_type=None):
    """Wrap content_type into function."""

    def wrap_method(method):
        """Wrap function with raw output to rest api."""

        async def wrap_api(
            api: CoreSysAttributes, *args, **kwargs
        ) -> web.Response | web.StreamResponse:
            """Return api information."""
            try:
                msg_data = await method(api, *args, **kwargs)
            except APIError as err:
                return api_return_error(
                    err,
                    error_type=error_type or const.CONTENT_TYPE_BINARY,
                    status=err.status,
                    job_id=err.job_id,
                )
            except HassioError as err:
                return api_return_error(
                    err, error_type=error_type or const.CONTENT_TYPE_BINARY
                )

            if isinstance(msg_data, (web.Response, web.StreamResponse)):
                return msg_data

            return web.Response(body=msg_data, content_type=content)

        return wrap_api

    return wrap_method


def api_return_error(
    error: HassioError | None = None,
    message: str | None = None,
    error_type: str | None = None,
    status: int = 400,
    *,
    job_id: str | None = None,
) -> web.Response:
    """Return an API error message."""
    if error and not message:
        message = get_message_from_exception_chain(error)
        if check_exception_chain(error, DockerAPIError):
            message = format_message(message)
    if not message:
        message = "Unknown error, see Supervisor logs (check with 'ha supervisor logs')"

    match error_type:
        case const.CONTENT_TYPE_TEXT:
            return web.Response(body=message, content_type=error_type, status=status)
        case const.CONTENT_TYPE_BINARY:
            return web.Response(
                body=message.encode(), content_type=error_type, status=status
            )
        case _:
            result: dict[str, Any] = {
                JSON_RESULT: RESULT_ERROR,
                JSON_MESSAGE: message,
            }
            if job_id:
                result[JSON_JOB_ID] = job_id
            if error and error.error_key:
                result[JSON_ERROR_KEY] = error.error_key
            if error and error.extra_fields:
                result[JSON_EXTRA_FIELDS] = error.extra_fields

    return web.json_response(
        result,
        status=status,
        dumps=json_dumps,
    )


def api_return_ok(data: dict[str, Any] | list[Any] | None = None) -> web.Response:
    """Return an API ok answer."""
    return web.json_response(
        {JSON_RESULT: RESULT_OK, JSON_DATA: data or {}},
        dumps=json_dumps,
    )


async def api_validate(
    schema: vol.Schema | vol.All,
    request: web.Request,
) -> dict[str, Any]:
    """Validate request data with schema."""
    data: dict[str, Any] = await request.json(loads=json_loads)
    try:
        data_validated = schema(data)
    except vol.Invalid as ex:
        raise APIError(humanize_error(data, ex)) from None

    return data_validated


async def background_task(
    coresys_obj: CoreSysAttributes,
    task_method: Callable,
    *args,
    **kwargs,
) -> tuple[asyncio.Task, str]:
    """Start task in background and return task and job ID.

    Args:
        coresys_obj: Instance that accesses coresys data using CoreSysAttributes
        task_method: The method to execute in the background. Must include a keyword arg 'validation_complete' of type asyncio.Event. Should set it after any initial validation has completed
        *args: Arguments to pass to task_method
        **kwargs: Keyword arguments to pass to task_method

    Returns:
        Tuple of (task, job_id)

    """
    event = asyncio.Event()
    job, task = cast(
        tuple[SupervisorJob, asyncio.Task],
        coresys_obj.sys_jobs.schedule_job(
            task_method,
            JobSchedulerOptions(),
            *args,
            validation_complete=event,
            **kwargs,
        ),
    )

    # Wait for provided event before returning
    # If the task fails validation it should raise before getting there
    event_task = coresys_obj.sys_create_task(event.wait())
    _, pending = await asyncio.wait(
        (task, event_task),
        return_when=asyncio.FIRST_COMPLETED,
    )
    # It seems task returned early (error or something), make sure to cancel
    # the event task to avoid "Task was destroyed but it is pending!" errors.
    if event_task in pending:
        event_task.cancel()
    return (task, job.uuid)