"""Config flow to configure the iCloud integration."""
import logging
import os

from pyicloud import PyiCloudService
from pyicloud.exceptions import (
    PyiCloudException,
    PyiCloudFailedLoginException,
    PyiCloudNoDevicesException,
    PyiCloudServiceNotActivatedException,
)
import voluptuous as vol

from homeassistant import config_entries
from homeassistant.const import CONF_PASSWORD, CONF_USERNAME
from homeassistant.helpers.storage import Store

from .const import (
    CONF_GPS_ACCURACY_THRESHOLD,
    CONF_MAX_INTERVAL,
    CONF_WITH_FAMILY,
    DEFAULT_GPS_ACCURACY_THRESHOLD,
    DEFAULT_MAX_INTERVAL,
    DEFAULT_WITH_FAMILY,
    DOMAIN,
    STORAGE_KEY,
    STORAGE_VERSION,
)

CONF_TRUSTED_DEVICE = "trusted_device"
CONF_VERIFICATION_CODE = "verification_code"

_LOGGER = logging.getLogger(__name__)


class IcloudFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
    """Handle a iCloud config flow."""

    VERSION = 1

    def __init__(self):
        """Initialize iCloud config flow."""
        self.api = None
        self._username = None
        self._password = None
        self._with_family = None
        self._max_interval = None
        self._gps_accuracy_threshold = None

        self._trusted_device = None
        self._verification_code = None

        self._existing_entry = None
        self._description_placeholders = None

    def _show_setup_form(self, user_input=None, errors=None, step_id="user"):
        """Show the setup form to the user."""

        if user_input is None:
            user_input = {}

        if step_id == "user":
            schema = {
                vol.Required(
                    CONF_USERNAME, default=user_input.get(CONF_USERNAME, "")
                ): str,
                vol.Required(
                    CONF_PASSWORD, default=user_input.get(CONF_PASSWORD, "")
                ): str,
                vol.Optional(
                    CONF_WITH_FAMILY,
                    default=user_input.get(CONF_WITH_FAMILY, DEFAULT_WITH_FAMILY),
                ): bool,
            }
        else:
            schema = {
                vol.Required(
                    CONF_PASSWORD, default=user_input.get(CONF_PASSWORD, "")
                ): str,
            }

        return self.async_show_form(
            step_id=step_id,
            data_schema=vol.Schema(schema),
            errors=errors or {},
            description_placeholders=self._description_placeholders,
        )

    async def _validate_and_create_entry(self, user_input, step_id):
        """Check if config is valid and create entry if so."""
        self._password = user_input[CONF_PASSWORD]

        extra_inputs = user_input

        # If an existing entry was found, meaning this is a password update attempt,
        # use those to get config values that aren't changing
        if self._existing_entry:
            extra_inputs = self._existing_entry

        self._username = extra_inputs[CONF_USERNAME]
        self._with_family = extra_inputs.get(CONF_WITH_FAMILY, DEFAULT_WITH_FAMILY)
        self._max_interval = extra_inputs.get(CONF_MAX_INTERVAL, DEFAULT_MAX_INTERVAL)
        self._gps_accuracy_threshold = extra_inputs.get(
            CONF_GPS_ACCURACY_THRESHOLD, DEFAULT_GPS_ACCURACY_THRESHOLD
        )

        # Check if already configured
        if self.unique_id is None:
            await self.async_set_unique_id(self._username)
            self._abort_if_unique_id_configured()

        try:
            self.api = await self.hass.async_add_executor_job(
                PyiCloudService,
                self._username,
                self._password,
                Store(self.hass, STORAGE_VERSION, STORAGE_KEY).path,
                True,
                None,
                self._with_family,
            )
        except PyiCloudFailedLoginException as error:
            _LOGGER.error("Error logging into iCloud service: %s", error)
            self.api = None
            errors = {CONF_PASSWORD: "invalid_auth"}
            return self._show_setup_form(user_input, errors, step_id)

        if self.api.requires_2fa:
            return await self.async_step_verification_code()

        if self.api.requires_2sa:
            return await self.async_step_trusted_device()

        try:
            devices = await self.hass.async_add_executor_job(
                getattr, self.api, "devices"
            )
            if not devices:
                raise PyiCloudNoDevicesException()
        except (PyiCloudServiceNotActivatedException, PyiCloudNoDevicesException):
            _LOGGER.error("No device found in the iCloud account: %s", self._username)
            self.api = None
            return self.async_abort(reason="no_device")

        data = {
            CONF_USERNAME: self._username,
            CONF_PASSWORD: self._password,
            CONF_WITH_FAMILY: self._with_family,
            CONF_MAX_INTERVAL: self._max_interval,
            CONF_GPS_ACCURACY_THRESHOLD: self._gps_accuracy_threshold,
        }

        # If this is a password update attempt, update the entry instead of creating one
        if step_id == "user":
            return self.async_create_entry(title=self._username, data=data)

        entry = await self.async_set_unique_id(self.unique_id)
        self.hass.config_entries.async_update_entry(entry, data=data)
        await self.hass.config_entries.async_reload(entry.entry_id)
        return self.async_abort(reason="reauth_successful")

    async def async_step_user(self, user_input=None):
        """Handle a flow initiated by the user."""
        errors = {}

        icloud_dir = Store(self.hass, STORAGE_VERSION, STORAGE_KEY)

        if not os.path.exists(icloud_dir.path):
            await self.hass.async_add_executor_job(os.makedirs, icloud_dir.path)

        if user_input is None:
            return self._show_setup_form(user_input, errors)

        return await self._validate_and_create_entry(user_input, "user")

    async def async_step_reauth(self, user_input=None):
        """Update password for a config entry that can't authenticate."""
        # Store existing entry data so it can be used later and set unique ID
        # so existing config entry can be updated
        if not self._existing_entry:
            await self.async_set_unique_id(user_input.pop("unique_id"))
            self._existing_entry = user_input.copy()
            self._description_placeholders = {"username": user_input[CONF_USERNAME]}
            user_input = None

        if user_input is None:
            return self._show_setup_form(step_id=config_entries.SOURCE_REAUTH)

        return await self._validate_and_create_entry(
            user_input, config_entries.SOURCE_REAUTH
        )

    async def async_step_trusted_device(self, user_input=None, errors=None):
        """We need a trusted device."""
        if errors is None:
            errors = {}

        trusted_devices = await self.hass.async_add_executor_job(
            getattr, self.api, "trusted_devices"
        )
        trusted_devices_for_form = {}
        for i, device in enumerate(trusted_devices):
            trusted_devices_for_form[i] = device.get(
                "deviceName", f"SMS to {device.get('phoneNumber')}"
            )

        if user_input is None:
            return await self._show_trusted_device_form(
                trusted_devices_for_form, user_input, errors
            )

        self._trusted_device = trusted_devices[int(user_input[CONF_TRUSTED_DEVICE])]

        if not await self.hass.async_add_executor_job(
            self.api.send_verification_code, self._trusted_device
        ):
            _LOGGER.error("Failed to send verification code")
            self._trusted_device = None
            errors[CONF_TRUSTED_DEVICE] = "send_verification_code"

            return await self._show_trusted_device_form(
                trusted_devices_for_form, user_input, errors
            )

        return await self.async_step_verification_code()

    async def _show_trusted_device_form(
        self, trusted_devices, user_input=None, errors=None
    ):
        """Show the trusted_device form to the user."""

        return self.async_show_form(
            step_id=CONF_TRUSTED_DEVICE,
            data_schema=vol.Schema(
                {
                    vol.Required(CONF_TRUSTED_DEVICE): vol.All(
                        vol.Coerce(int), vol.In(trusted_devices)
                    )
                }
            ),
            errors=errors or {},
        )

    async def async_step_verification_code(self, user_input=None, errors=None):
        """Ask the verification code to the user."""
        if errors is None:
            errors = {}

        if user_input is None:
            return await self._show_verification_code_form(user_input, errors)

        self._verification_code = user_input[CONF_VERIFICATION_CODE]

        try:
            if self.api.requires_2fa:
                if not await self.hass.async_add_executor_job(
                    self.api.validate_2fa_code, self._verification_code
                ):
                    raise PyiCloudException("The code you entered is not valid.")
            else:
                if not await self.hass.async_add_executor_job(
                    self.api.validate_verification_code,
                    self._trusted_device,
                    self._verification_code,
                ):
                    raise PyiCloudException("The code you entered is not valid.")
        except PyiCloudException as error:
            # Reset to the initial 2FA state to allow the user to retry
            _LOGGER.error("Failed to verify verification code: %s", error)
            self._trusted_device = None
            self._verification_code = None
            errors["base"] = "validate_verification_code"

            if self.api.requires_2fa:
                try:
                    self.api = await self.hass.async_add_executor_job(
                        PyiCloudService,
                        self._username,
                        self._password,
                        Store(self.hass, STORAGE_VERSION, STORAGE_KEY).path,
                        True,
                        None,
                        self._with_family,
                    )
                    return await self.async_step_verification_code(None, errors)
                except PyiCloudFailedLoginException as error_login:
                    _LOGGER.error("Error logging into iCloud service: %s", error_login)
                    self.api = None
                    errors = {CONF_PASSWORD: "invalid_auth"}
                    return self._show_setup_form(user_input, errors, "user")
            else:
                return await self.async_step_trusted_device(None, errors)

        return await self.async_step_user(
            {
                CONF_USERNAME: self._username,
                CONF_PASSWORD: self._password,
                CONF_WITH_FAMILY: self._with_family,
                CONF_MAX_INTERVAL: self._max_interval,
                CONF_GPS_ACCURACY_THRESHOLD: self._gps_accuracy_threshold,
            }
        )

    async def _show_verification_code_form(self, user_input=None, errors=None):
        """Show the verification_code form to the user."""

        return self.async_show_form(
            step_id=CONF_VERIFICATION_CODE,
            data_schema=vol.Schema({vol.Required(CONF_VERIFICATION_CODE): str}),
            errors=errors or {},
        )