"""HTTP Support for Hass.io."""

from __future__ import annotations

from http import HTTPStatus
import logging
import os
import re
from typing import TYPE_CHECKING
from urllib.parse import quote, unquote

import aiohttp
from aiohttp import web
from aiohttp.client import ClientTimeout
from aiohttp.hdrs import (
    AUTHORIZATION,
    CACHE_CONTROL,
    CONTENT_ENCODING,
    CONTENT_LENGTH,
    CONTENT_TYPE,
    TRANSFER_ENCODING,
)
from aiohttp.web_exceptions import HTTPBadGateway

from homeassistant.components.http import (
    KEY_AUTHENTICATED,
    KEY_HASS,
    KEY_HASS_USER,
    HomeAssistantView,
)
from homeassistant.components.onboarding import async_is_onboarded

from .const import X_HASS_SOURCE

_LOGGER = logging.getLogger(__name__)

MAX_UPLOAD_SIZE = 1024 * 1024 * 1024

NO_TIMEOUT = re.compile(
    r"^(?:"
    r"|backups/.+/full"
    r"|backups/.+/partial"
    r"|backups/[^/]+/(?:upload|download)"
    r")$"
)

# fmt: off
# Onboarding can upload backups and restore it
PATHS_NOT_ONBOARDED = re.compile(
    r"^(?:"
    r"|backups/[a-f0-9]{8}(/info|/new/upload|/download|/restore/full|/restore/partial)?"
    r"|backups/new/upload"
    r")$"
)

# Authenticated users manage backups + download logs, changelog and documentation
PATHS_ADMIN = re.compile(
    r"^(?:"
    r"|backups/[a-f0-9]{8}(/info|/download|/restore/full|/restore/partial)?"
    r"|backups/new/upload"
    r"|audio/logs"
    r"|cli/logs"
    r"|core/logs"
    r"|dns/logs"
    r"|host/logs"
    r"|multicast/logs"
    r"|observer/logs"
    r"|supervisor/logs"
    r"|addons/[^/]+/(changelog|documentation|logs)"
    r")$"
)

# Unauthenticated requests come in for Supervisor panel + add-on images
PATHS_NO_AUTH = re.compile(
    r"^(?:"
    r"|app/.*"
    r"|(store/)?addons/[^/]+/(logo|icon)"
    r")$"
)

NO_STORE = re.compile(
    r"^(?:"
    r"|app/entrypoint.js"
    r")$"
)
# fmt: on

RESPONSE_HEADERS_FILTER = {
    TRANSFER_ENCODING,
    CONTENT_LENGTH,
    CONTENT_TYPE,
    CONTENT_ENCODING,
}


class HassIOView(HomeAssistantView):
    """Hass.io view to handle base part."""

    name = "api:hassio"
    url = "/api/hassio/{path:.+}"
    requires_auth = False

    def __init__(self, host: str, websession: aiohttp.ClientSession) -> None:
        """Initialize a Hass.io base view."""
        self._host = host
        self._websession = websession

    async def _handle(self, request: web.Request, path: str) -> web.StreamResponse:
        """Return a client request with proxy origin for Hass.io supervisor.

        Use cases:
        - Onboarding allows restoring backups
        - Load Supervisor panel and add-on logo unauthenticated
        - User upload/restore backups
        """
        # No bullshit
        if path != unquote(path):
            return web.Response(status=HTTPStatus.BAD_REQUEST)

        hass = request.app[KEY_HASS]
        is_admin = request[KEY_AUTHENTICATED] and request[KEY_HASS_USER].is_admin
        authorized = is_admin

        if is_admin:
            allowed_paths = PATHS_ADMIN

        elif not async_is_onboarded(hass):
            allowed_paths = PATHS_NOT_ONBOARDED

            # During onboarding we need the user to manage backups
            authorized = True

        else:
            # Either unauthenticated or not an admin
            allowed_paths = PATHS_NO_AUTH

        no_auth_path = PATHS_NO_AUTH.match(path)
        headers = {
            X_HASS_SOURCE: "core.http",
        }

        if no_auth_path:
            if request.method != "GET":
                return web.Response(status=HTTPStatus.METHOD_NOT_ALLOWED)

        else:
            if not allowed_paths.match(path):
                return web.Response(status=HTTPStatus.UNAUTHORIZED)

            if authorized:
                headers[AUTHORIZATION] = (
                    f"Bearer {os.environ.get('SUPERVISOR_TOKEN', '')}"
                )

            if request.method == "POST":
                headers[CONTENT_TYPE] = request.content_type
                # _stored_content_type is only computed once `content_type` is accessed
                if path == "backups/new/upload":
                    # We need to reuse the full content type that includes the boundary
                    if TYPE_CHECKING:
                        assert isinstance(request._stored_content_type, str)  # noqa: SLF001
                    headers[CONTENT_TYPE] = request._stored_content_type  # noqa: SLF001

        try:
            client = await self._websession.request(
                method=request.method,
                url=f"http://{self._host}/{quote(path)}",
                params=request.query,
                data=request.content if request.method != "GET" else None,
                headers=headers,
                timeout=_get_timeout(path),
            )

            # Stream response
            response = web.StreamResponse(
                status=client.status, headers=_response_header(client, path)
            )
            response.content_type = client.content_type

            if should_compress(response.content_type):
                response.enable_compression()
            await response.prepare(request)
            # In testing iter_chunked, iter_any, and iter_chunks:
            # iter_chunks was the best performing option since
            # it does not have to do as much re-assembly
            async for data, _ in client.content.iter_chunks():
                await response.write(data)

        except aiohttp.ClientError as err:
            _LOGGER.error("Client error on api %s request %s", path, err)
            raise HTTPBadGateway from err
        except TimeoutError as err:
            _LOGGER.error("Client timeout error on API request %s", path)
            raise HTTPBadGateway from err
        return response

    get = _handle
    post = _handle


def _response_header(response: aiohttp.ClientResponse, path: str) -> dict[str, str]:
    """Create response header."""
    headers = {
        name: value
        for name, value in response.headers.items()
        if name not in RESPONSE_HEADERS_FILTER
    }
    if NO_STORE.match(path):
        headers[CACHE_CONTROL] = "no-store, max-age=0"
    return headers


def _get_timeout(path: str) -> ClientTimeout:
    """Return timeout for a URL path."""
    if NO_TIMEOUT.match(path):
        return ClientTimeout(connect=10, total=None)
    return ClientTimeout(connect=10, total=300)


def should_compress(content_type: str) -> bool:
    """Return if we should compress a response."""
    if content_type.startswith("image/"):
        return "svg" in content_type
    if content_type.startswith("application/"):
        return (
            "json" in content_type
            or "xml" in content_type
            or "javascript" in content_type
        )
    return not content_type.startswith(("video/", "audio/", "font/"))