"""Provides functionality to notify people."""
import asyncio
from functools import partial
import logging
from typing import Optional

import voluptuous as vol

from homeassistant.const import CONF_NAME, CONF_PLATFORM
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers import config_per_platform, discovery
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.typing import HomeAssistantType
from homeassistant.loader import bind_hass
from homeassistant.setup import async_prepare_setup_platform
from homeassistant.util import slugify

# mypy: allow-untyped-defs, no-check-untyped-defs

_LOGGER = logging.getLogger(__name__)

# Platform specific data
ATTR_DATA = "data"

# Text to notify user of
ATTR_MESSAGE = "message"

# Target of the notification (user, device, etc)
ATTR_TARGET = "target"

# Title of notification
ATTR_TITLE = "title"
ATTR_TITLE_DEFAULT = "Home Assistant"

DOMAIN = "notify"

SERVICE_NOTIFY = "notify"

NOTIFY_SERVICES = "notify_services"
SERVICE = "service"
TARGETS = "targets"
FRIENDLY_NAME = "friendly_name"
TARGET_FRIENDLY_NAME = "target_friendly_name"

PLATFORM_SCHEMA = vol.Schema(
    {vol.Required(CONF_PLATFORM): cv.string, vol.Optional(CONF_NAME): cv.string},
    extra=vol.ALLOW_EXTRA,
)

NOTIFY_SERVICE_SCHEMA = vol.Schema(
    {
        vol.Required(ATTR_MESSAGE): cv.template,
        vol.Optional(ATTR_TITLE): cv.template,
        vol.Optional(ATTR_TARGET): vol.All(cv.ensure_list, [cv.string]),
        vol.Optional(ATTR_DATA): dict,
    }
)


@bind_hass
async def async_reload(hass, integration_name):
    """Register notify services for an integration."""
    if (
        NOTIFY_SERVICES not in hass.data
        or integration_name not in hass.data[NOTIFY_SERVICES]
    ):
        return

    tasks = [
        _async_setup_notify_services(hass, data)
        for data in hass.data[NOTIFY_SERVICES][integration_name]
    ]
    await asyncio.gather(*tasks)


async def _async_setup_notify_services(hass, data):
    """Create or remove the notify services."""
    notify_service = data[SERVICE]
    friendly_name = data[FRIENDLY_NAME]
    targets = data[TARGETS]

    async def _async_notify_message(service):
        """Handle sending notification message service calls."""
        await _async_notify_message_service(hass, service, notify_service, targets)

    if hasattr(notify_service, "targets"):
        target_friendly_name = data[TARGET_FRIENDLY_NAME]
        stale_targets = set(targets)

        for name, target in notify_service.targets.items():
            target_name = slugify(f"{target_friendly_name}_{name}")
            if target_name in stale_targets:
                stale_targets.remove(target_name)
            if target_name in targets:
                continue
            targets[target_name] = target
            hass.services.async_register(
                DOMAIN,
                target_name,
                _async_notify_message,
                schema=NOTIFY_SERVICE_SCHEMA,
            )

        for stale_target_name in stale_targets:
            del targets[stale_target_name]
            hass.services.async_remove(
                DOMAIN,
                stale_target_name,
            )

    friendly_name_slug = slugify(friendly_name)
    if hass.services.has_service(DOMAIN, friendly_name_slug):
        return

    hass.services.async_register(
        DOMAIN,
        friendly_name_slug,
        _async_notify_message,
        schema=NOTIFY_SERVICE_SCHEMA,
    )


async def _async_notify_message_service(hass, service, notify_service, targets):
    """Handle sending notification message service calls."""
    kwargs = {}
    message = service.data[ATTR_MESSAGE]
    title = service.data.get(ATTR_TITLE)

    if title:
        title.hass = hass
        kwargs[ATTR_TITLE] = title.async_render()

    if targets.get(service.service) is not None:
        kwargs[ATTR_TARGET] = [targets[service.service]]
    elif service.data.get(ATTR_TARGET) is not None:
        kwargs[ATTR_TARGET] = service.data.get(ATTR_TARGET)

    message.hass = hass
    kwargs[ATTR_MESSAGE] = message.async_render()
    kwargs[ATTR_DATA] = service.data.get(ATTR_DATA)

    await notify_service.async_send_message(**kwargs)


async def async_setup(hass, config):
    """Set up the notify services."""
    hass.data.setdefault(NOTIFY_SERVICES, {})

    async def async_setup_platform(
        integration_name, p_config=None, discovery_info=None
    ):
        """Set up a notify platform."""
        if p_config is None:
            p_config = {}

        platform = await async_prepare_setup_platform(
            hass, config, DOMAIN, integration_name
        )

        if platform is None:
            _LOGGER.error("Unknown notification service specified")
            return

        _LOGGER.info("Setting up %s.%s", DOMAIN, integration_name)
        notify_service = None
        try:
            if hasattr(platform, "async_get_service"):
                notify_service = await platform.async_get_service(
                    hass, p_config, discovery_info
                )
            elif hasattr(platform, "get_service"):
                notify_service = await hass.async_add_job(
                    platform.get_service, hass, p_config, discovery_info
                )
            else:
                raise HomeAssistantError("Invalid notify platform.")

            if notify_service is None:
                # Platforms can decide not to create a service based
                # on discovery data.
                if discovery_info is None:
                    _LOGGER.error(
                        "Failed to initialize notification service %s", integration_name
                    )
                return

        except Exception:  # pylint: disable=broad-except
            _LOGGER.exception("Error setting up platform %s", integration_name)
            return

        notify_service.hass = hass

        if discovery_info is None:
            discovery_info = {}

        target_friendly_name = (
            p_config.get(CONF_NAME) or discovery_info.get(CONF_NAME) or integration_name
        )
        friendly_name = (
            p_config.get(CONF_NAME) or discovery_info.get(CONF_NAME) or SERVICE_NOTIFY
        )

        data = {
            FRIENDLY_NAME: friendly_name,
            # The targets use a slightly different friendly name
            # selection pattern than the base service
            TARGET_FRIENDLY_NAME: target_friendly_name,
            SERVICE: notify_service,
            TARGETS: {},
        }
        hass.data[NOTIFY_SERVICES].setdefault(integration_name, [])
        hass.data[NOTIFY_SERVICES][integration_name].append(data)

        await _async_setup_notify_services(hass, data)

        hass.config.components.add(f"{DOMAIN}.{integration_name}")

        return True

    setup_tasks = [
        async_setup_platform(integration_name, p_config)
        for integration_name, p_config in config_per_platform(config, DOMAIN)
    ]

    if setup_tasks:
        await asyncio.wait(setup_tasks)

    async def async_platform_discovered(platform, info):
        """Handle for discovered platform."""
        await async_setup_platform(platform, discovery_info=info)

    discovery.async_listen_platform(hass, DOMAIN, async_platform_discovered)

    return True


class BaseNotificationService:
    """An abstract class for notification services."""

    hass: Optional[HomeAssistantType] = None

    def send_message(self, message, **kwargs):
        """Send a message.

        kwargs can contain ATTR_TITLE to specify a title.
        """
        raise NotImplementedError()

    async def async_send_message(self, message, **kwargs):
        """Send a message.

        kwargs can contain ATTR_TITLE to specify a title.
        """
        await self.hass.async_add_job(partial(self.send_message, message, **kwargs))