"""Config flow for Android TV Remote integration."""
from __future__ import annotations

from collections.abc import Mapping
from typing import Any

from androidtvremote2 import (
    AndroidTVRemote,
    CannotConnect,
    ConnectionClosed,
    InvalidAuth,
)
import voluptuous as vol

from homeassistant import config_entries
from homeassistant.components import zeroconf
from homeassistant.const import CONF_HOST, CONF_MAC, CONF_NAME
from homeassistant.data_entry_flow import FlowResult
from homeassistant.helpers.device_registry import format_mac

from .const import DOMAIN
from .helpers import create_api

STEP_USER_DATA_SCHEMA = vol.Schema(
    {
        vol.Required("host"): str,
    }
)

STEP_PAIR_DATA_SCHEMA = vol.Schema(
    {
        vol.Required("pin"): str,
    }
)


class AndroidTVRemoteConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
    """Handle a config flow for Android TV Remote."""

    VERSION = 1

    def __init__(self) -> None:
        """Initialize a new AndroidTVRemoteConfigFlow."""
        self.api: AndroidTVRemote | None = None
        self.reauth_entry: config_entries.ConfigEntry | None = None
        self.host: str | None = None
        self.name: str | None = None
        self.mac: str | None = None

    async def async_step_user(
        self, user_input: dict[str, Any] | None = None
    ) -> FlowResult:
        """Handle the initial step."""
        errors: dict[str, str] = {}
        if user_input is not None:
            self.host = user_input["host"]
            assert self.host
            api = create_api(self.hass, self.host)
            try:
                self.name, self.mac = await api.async_get_name_and_mac()
                assert self.mac
                await self.async_set_unique_id(format_mac(self.mac))
                self._abort_if_unique_id_configured(updates={CONF_HOST: self.host})
                return await self._async_start_pair()
            except (CannotConnect, ConnectionClosed):
                # Likely invalid IP address or device is network unreachable. Stay
                # in the user step allowing the user to enter a different host.
                errors["base"] = "cannot_connect"
        return self.async_show_form(
            step_id="user",
            data_schema=STEP_USER_DATA_SCHEMA,
            errors=errors,
        )

    async def _async_start_pair(self) -> FlowResult:
        """Start pairing with the Android TV. Navigate to the pair flow to enter the PIN shown on screen."""
        assert self.host
        self.api = create_api(self.hass, self.host)
        await self.api.async_generate_cert_if_missing()
        await self.api.async_start_pairing()
        return await self.async_step_pair()

    async def async_step_pair(
        self, user_input: dict[str, Any] | None = None
    ) -> FlowResult:
        """Handle the pair step."""
        errors: dict[str, str] = {}
        if user_input is not None:
            try:
                pin = user_input["pin"]
                assert self.api
                await self.api.async_finish_pairing(pin)
                if self.reauth_entry:
                    await self.hass.config_entries.async_reload(
                        self.reauth_entry.entry_id
                    )
                    return self.async_abort(reason="reauth_successful")
                assert self.name
                return self.async_create_entry(
                    title=self.name,
                    data={
                        CONF_HOST: self.host,
                        CONF_NAME: self.name,
                        CONF_MAC: self.mac,
                    },
                )
            except InvalidAuth:
                # Invalid PIN. Stay in the pair step allowing the user to enter
                # a different PIN.
                errors["base"] = "invalid_auth"
            except ConnectionClosed:
                # Either user canceled pairing on the Android TV itself (most common)
                # or device doesn't respond to the specified host (device was unplugged,
                # network was unplugged, or device got a new IP address).
                # Attempt to pair again.
                try:
                    return await self._async_start_pair()
                except (CannotConnect, ConnectionClosed):
                    # Device doesn't respond to the specified host. Abort.
                    # If we are in the user flow we could go back to the user step to allow
                    # them to enter a new IP address but we cannot do that for the zeroconf
                    # flow. Simpler to abort for both flows.
                    return self.async_abort(reason="cannot_connect")
        return self.async_show_form(
            step_id="pair",
            data_schema=STEP_PAIR_DATA_SCHEMA,
            description_placeholders={CONF_NAME: self.name},
            errors=errors,
        )

    async def async_step_zeroconf(
        self, discovery_info: zeroconf.ZeroconfServiceInfo
    ) -> FlowResult:
        """Handle zeroconf discovery."""
        self.host = discovery_info.host
        self.name = discovery_info.name.removesuffix("._androidtvremote2._tcp.local.")
        self.mac = discovery_info.properties.get("bt")
        assert self.mac
        await self.async_set_unique_id(format_mac(self.mac))
        self._abort_if_unique_id_configured(
            updates={CONF_HOST: self.host, CONF_NAME: self.name}
        )
        self.context.update({"title_placeholders": {CONF_NAME: self.name}})
        return await self.async_step_zeroconf_confirm()

    async def async_step_zeroconf_confirm(
        self, user_input: dict[str, Any] | None = None
    ) -> FlowResult:
        """Handle a flow initiated by zeroconf."""
        if user_input is not None:
            try:
                return await self._async_start_pair()
            except (CannotConnect, ConnectionClosed):
                # Device became network unreachable after discovery.
                # Abort and let discovery find it again later.
                return self.async_abort(reason="cannot_connect")
        return self.async_show_form(
            step_id="zeroconf_confirm",
            description_placeholders={CONF_NAME: self.name},
        )

    async def async_step_reauth(self, entry_data: Mapping[str, Any]) -> FlowResult:
        """Handle configuration by re-auth."""
        self.host = entry_data[CONF_HOST]
        self.name = entry_data[CONF_NAME]
        self.mac = entry_data[CONF_MAC]
        self.reauth_entry = self.hass.config_entries.async_get_entry(
            self.context["entry_id"]
        )
        return await self.async_step_reauth_confirm()

    async def async_step_reauth_confirm(
        self, user_input: dict[str, Any] | None = None
    ) -> FlowResult:
        """Dialog that informs the user that reauth is required."""
        errors: dict[str, str] = {}
        if user_input is not None:
            try:
                return await self._async_start_pair()
            except (CannotConnect, ConnectionClosed):
                # Device is network unreachable. Abort.
                errors["base"] = "cannot_connect"
        return self.async_show_form(
            step_id="reauth_confirm",
            description_placeholders={CONF_NAME: self.name},
            errors=errors,
        )
