"""Provides an HTTP API for mobile_app."""
from __future__ import annotations

from contextlib import suppress
from http import HTTPStatus
import secrets

from aiohttp.web import Request, Response
import emoji
from nacl.secret import SecretBox
import voluptuous as vol

from homeassistant.components.http import HomeAssistantView
from homeassistant.components.http.data_validator import RequestDataValidator
from homeassistant.const import ATTR_DEVICE_ID, CONF_WEBHOOK_ID
from homeassistant.helpers import config_validation as cv
from homeassistant.util import slugify

from .const import (
    ATTR_APP_DATA,
    ATTR_APP_ID,
    ATTR_APP_NAME,
    ATTR_APP_VERSION,
    ATTR_DEVICE_NAME,
    ATTR_MANUFACTURER,
    ATTR_MODEL,
    ATTR_OS_NAME,
    ATTR_OS_VERSION,
    ATTR_SUPPORTS_ENCRYPTION,
    CONF_CLOUDHOOK_URL,
    CONF_REMOTE_UI_URL,
    CONF_SECRET,
    CONF_USER_ID,
    DOMAIN,
)
from .helpers import supports_encryption


class RegistrationsView(HomeAssistantView):
    """A view that accepts registration requests."""

    url = "/api/mobile_app/registrations"
    name = "api:mobile_app:register"

    @RequestDataValidator(
        vol.Schema(
            {
                vol.Optional(ATTR_APP_DATA, default={}): dict,
                vol.Required(ATTR_APP_ID): cv.string,
                vol.Required(ATTR_APP_NAME): cv.string,
                vol.Required(ATTR_APP_VERSION): cv.string,
                vol.Required(ATTR_DEVICE_NAME): cv.string,
                vol.Required(ATTR_MANUFACTURER): cv.string,
                vol.Required(ATTR_MODEL): cv.string,
                vol.Optional(ATTR_DEVICE_ID): cv.string,  # Added in 0.104
                vol.Required(ATTR_OS_NAME): cv.string,
                vol.Optional(ATTR_OS_VERSION): cv.string,
                vol.Required(ATTR_SUPPORTS_ENCRYPTION, default=False): cv.boolean,
            },
            # To allow future apps to send more data
            extra=vol.REMOVE_EXTRA,
        )
    )
    async def post(self, request: Request, data: dict) -> Response:
        """Handle the POST request for registration."""
        hass = request.app["hass"]

        webhook_id = secrets.token_hex()

        if hass.components.cloud.async_active_subscription():
            data[
                CONF_CLOUDHOOK_URL
            ] = await hass.components.cloud.async_create_cloudhook(webhook_id)

        data[CONF_WEBHOOK_ID] = webhook_id

        if data[ATTR_SUPPORTS_ENCRYPTION] and supports_encryption():
            data[CONF_SECRET] = secrets.token_hex(SecretBox.KEY_SIZE)

        data[CONF_USER_ID] = request["hass_user"].id

        if slugify(data[ATTR_DEVICE_NAME], separator=""):
            # if slug is not empty and would not only be underscores
            # use DEVICE_NAME
            pass
        elif emoji.emoji_count(data[ATTR_DEVICE_NAME]):
            # If otherwise empty string contains emoji
            # use descriptive name of the first emoji
            data[ATTR_DEVICE_NAME] = emoji.demojize(
                emoji.emoji_lis(data[ATTR_DEVICE_NAME])[0]["emoji"]
            ).replace(":", "")
        else:
            # Fallback to DEVICE_ID
            data[ATTR_DEVICE_NAME] = data[ATTR_DEVICE_ID]

        await hass.async_create_task(
            hass.config_entries.flow.async_init(
                DOMAIN, data=data, context={"source": "registration"}
            )
        )

        remote_ui_url = None
        with suppress(hass.components.cloud.CloudNotAvailable):
            remote_ui_url = hass.components.cloud.async_remote_ui_url()

        return self.json(
            {
                CONF_CLOUDHOOK_URL: data.get(CONF_CLOUDHOOK_URL),
                CONF_REMOTE_UI_URL: remote_ui_url,
                CONF_SECRET: data.get(CONF_SECRET),
                CONF_WEBHOOK_ID: data[CONF_WEBHOOK_ID],
            },
            status_code=HTTPStatus.CREATED,
        )