"""Discord platform for notify component."""
import logging
import os.path

import voluptuous as vol

from homeassistant.const import CONF_TOKEN
import homeassistant.helpers.config_validation as cv

from homeassistant.components.notify import (
    ATTR_DATA,
    ATTR_TARGET,
    PLATFORM_SCHEMA,
    BaseNotificationService,
)

_LOGGER = logging.getLogger(__name__)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({vol.Required(CONF_TOKEN): cv.string})

ATTR_IMAGES = "images"


def get_service(hass, config, discovery_info=None):
    """Get the Discord notification service."""
    token = config.get(CONF_TOKEN)
    return DiscordNotificationService(hass, token)


class DiscordNotificationService(BaseNotificationService):
    """Implement the notification service for Discord."""

    def __init__(self, hass, token):
        """Initialize the service."""
        self.token = token
        self.hass = hass

    def file_exists(self, filename):
        """Check if a file exists on disk and is in authorized path."""
        if not self.hass.config.is_allowed_path(filename):
            return False

        return os.path.isfile(filename)

    async def async_send_message(self, message, **kwargs):
        """Login to Discord, send message to channel(s) and log out."""
        import discord

        discord.VoiceClient.warn_nacl = False
        discord_bot = discord.Client()
        images = None

        if ATTR_TARGET not in kwargs:
            _LOGGER.error("No target specified")
            return None

        data = kwargs.get(ATTR_DATA) or {}

        if ATTR_IMAGES in data:
            images = list()

            for image in data.get(ATTR_IMAGES):
                image_exists = await self.hass.async_add_executor_job(
                    self.file_exists, image
                )

                if image_exists:
                    images.append(image)
                else:
                    _LOGGER.warning("Image not found: %s", image)

        # pylint: disable=unused-variable
        @discord_bot.event
        async def on_ready():
            """Send the messages when the bot is ready."""
            try:
                for channelid in kwargs[ATTR_TARGET]:
                    channelid = int(channelid)
                    channel = discord_bot.get_channel(channelid)

                    if channel is None:
                        _LOGGER.warning("Channel not found for id: %s", channelid)
                        continue

                    # Must create new instances of File for each channel.
                    files = None
                    if images:
                        files = list()
                        for image in images:
                            files.append(discord.File(image))

                    await channel.send(message, files=files)
            except (discord.errors.HTTPException, discord.errors.NotFound) as error:
                _LOGGER.warning("Communication error: %s", error)
            await discord_bot.logout()
            await discord_bot.close()

        # Using reconnect=False prevents multiple ready events to be fired.
        await discord_bot.start(self.token, reconnect=False)
