"""Support for MQTT message handling."""
from __future__ import annotations

import asyncio
from collections.abc import Callable
from dataclasses import dataclass
import datetime as dt
import logging
from typing import Any, cast

import jinja2
import voluptuous as vol

from homeassistant import config_entries
from homeassistant.components import websocket_api
from homeassistant.config_entries import ConfigEntry
from homeassistant.const import (
    CONF_DISCOVERY,
    CONF_PASSWORD,
    CONF_PAYLOAD,
    CONF_PORT,
    CONF_USERNAME,
    EVENT_HOMEASSISTANT_STOP,
    SERVICE_RELOAD,
)
from homeassistant.core import Event, HassJob, HomeAssistant, ServiceCall, callback
from homeassistant.data_entry_flow import BaseServiceInfo
from homeassistant.exceptions import TemplateError, Unauthorized
from homeassistant.helpers import config_validation as cv, event, template
from homeassistant.helpers.device_registry import DeviceEntry
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.typing import ConfigType

# Loading the config flow file will register the flow
from . import debug_info, discovery
from .client import (  # noqa: F401
    MQTT,
    async_publish,
    async_subscribe,
    publish,
    subscribe,
)
from .config import CONFIG_SCHEMA_BASE, DEFAULT_VALUES, DEPRECATED_CONFIG_KEYS
from .const import (  # noqa: F401
    ATTR_PAYLOAD,
    ATTR_QOS,
    ATTR_RETAIN,
    ATTR_TOPIC,
    CONF_BIRTH_MESSAGE,
    CONF_BROKER,
    CONF_COMMAND_TOPIC,
    CONF_DISCOVERY_PREFIX,
    CONF_QOS,
    CONF_STATE_TOPIC,
    CONF_TLS_VERSION,
    CONF_TOPIC,
    CONF_WILL_MESSAGE,
    CONFIG_ENTRY_IS_SETUP,
    DATA_CONFIG_ENTRY_LOCK,
    DATA_MQTT,
    DATA_MQTT_CONFIG,
    DATA_MQTT_RELOAD_NEEDED,
    DEFAULT_ENCODING,
    DEFAULT_QOS,
    DEFAULT_RETAIN,
    DOMAIN,
    MQTT_CONNECTED,
    MQTT_DISCONNECTED,
    PLATFORMS,
)
from .models import (  # noqa: F401
    MqttCommandTemplate,
    MqttValueTemplate,
    PublishPayloadType,
    ReceiveMessage,
    ReceivePayloadType,
)
from .util import _VALID_QOS_SCHEMA, valid_publish_topic, valid_subscribe_topic

_LOGGER = logging.getLogger(__name__)

SERVICE_PUBLISH = "publish"
SERVICE_DUMP = "dump"

MANDATORY_DEFAULT_VALUES = (CONF_PORT,)

ATTR_TOPIC_TEMPLATE = "topic_template"
ATTR_PAYLOAD_TEMPLATE = "payload_template"

MAX_RECONNECT_WAIT = 300  # seconds

CONNECTION_SUCCESS = "connection_success"
CONNECTION_FAILED = "connection_failed"
CONNECTION_FAILED_RECOVERABLE = "connection_failed_recoverable"

CONFIG_SCHEMA = vol.Schema(
    {
        DOMAIN: vol.All(
            cv.deprecated(CONF_BIRTH_MESSAGE),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_BROKER),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_DISCOVERY),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_PASSWORD),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_PORT),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_TLS_VERSION),  # Deprecated June 2020
            cv.deprecated(CONF_USERNAME),  # Deprecated in HA Core 2022.3
            cv.deprecated(CONF_WILL_MESSAGE),  # Deprecated in HA Core 2022.3
            CONFIG_SCHEMA_BASE,
        )
    },
    extra=vol.ALLOW_EXTRA,
)


# Service call validation schema
MQTT_PUBLISH_SCHEMA = vol.All(
    vol.Schema(
        {
            vol.Exclusive(ATTR_TOPIC, CONF_TOPIC): valid_publish_topic,
            vol.Exclusive(ATTR_TOPIC_TEMPLATE, CONF_TOPIC): cv.string,
            vol.Exclusive(ATTR_PAYLOAD, CONF_PAYLOAD): cv.string,
            vol.Exclusive(ATTR_PAYLOAD_TEMPLATE, CONF_PAYLOAD): cv.string,
            vol.Optional(ATTR_QOS, default=DEFAULT_QOS): _VALID_QOS_SCHEMA,
            vol.Optional(ATTR_RETAIN, default=DEFAULT_RETAIN): cv.boolean,
        },
        required=True,
    ),
    cv.has_at_least_one_key(ATTR_TOPIC, ATTR_TOPIC_TEMPLATE),
)


@dataclass
class MqttServiceInfo(BaseServiceInfo):
    """Prepared info from mqtt entries."""

    topic: str
    payload: ReceivePayloadType
    qos: int
    retain: bool
    subscribed_topic: str
    timestamp: dt.datetime


async def _async_setup_discovery(
    hass: HomeAssistant, conf: ConfigType, config_entry
) -> None:
    """Try to start the discovery of MQTT devices.

    This method is a coroutine.
    """
    await discovery.async_start(hass, conf[CONF_DISCOVERY_PREFIX], config_entry)


async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
    """Start the MQTT protocol service."""
    conf: ConfigType | None = config.get(DOMAIN)

    websocket_api.async_register_command(hass, websocket_subscribe)
    websocket_api.async_register_command(hass, websocket_mqtt_info)
    debug_info.initialize(hass)

    if conf:
        conf = dict(conf)
        hass.data[DATA_MQTT_CONFIG] = conf

    if not bool(hass.config_entries.async_entries(DOMAIN)):
        # Create an import flow if the user has yaml configured entities etc.
        # but no broker configuration. Note: The intention is not for this to
        # import broker configuration from YAML because that has been deprecated.
        hass.async_create_task(
            hass.config_entries.flow.async_init(
                DOMAIN,
                context={"source": config_entries.SOURCE_INTEGRATION_DISCOVERY},
                data={},
            )
        )
    return True


def _merge_basic_config(
    hass: HomeAssistant, entry: ConfigEntry, yaml_config: dict[str, Any]
) -> None:
    """Merge basic options in configuration.yaml config with config entry.

    This mends incomplete migration from old version of HA Core.
    """

    entry_updated = False
    entry_config = {**entry.data}
    for key in DEPRECATED_CONFIG_KEYS:
        if key in yaml_config and key not in entry_config:
            entry_config[key] = yaml_config[key]
            entry_updated = True

    for key in MANDATORY_DEFAULT_VALUES:
        if key not in entry_config:
            entry_config[key] = DEFAULT_VALUES[key]
            entry_updated = True

    if entry_updated:
        hass.config_entries.async_update_entry(entry, data=entry_config)


def _merge_extended_config(entry, conf):
    """Merge advanced options in configuration.yaml config with config entry."""
    # Add default values
    conf = {**DEFAULT_VALUES, **conf}
    return {**conf, **entry.data}


async def _async_config_entry_updated(hass: HomeAssistant, entry: ConfigEntry) -> None:
    """Handle signals of config entry being updated.

    Causes for this is config entry options changing.
    """
    mqtt_client = hass.data[DATA_MQTT]

    if (conf := hass.data.get(DATA_MQTT_CONFIG)) is None:
        conf = CONFIG_SCHEMA_BASE(dict(entry.data))

    mqtt_client.conf = _merge_extended_config(entry, conf)
    await mqtt_client.async_disconnect()
    mqtt_client.init_client()
    await mqtt_client.async_connect()

    await discovery.async_stop(hass)
    if mqtt_client.conf.get(CONF_DISCOVERY):
        await _async_setup_discovery(hass, mqtt_client.conf, entry)


async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
    """Load a config entry."""
    # Merge basic configuration, and add missing defaults for basic options
    _merge_basic_config(hass, entry, hass.data.get(DATA_MQTT_CONFIG, {}))

    # Bail out if broker setting is missing
    if CONF_BROKER not in entry.data:
        _LOGGER.error("MQTT broker is not configured, please configure it")
        return False

    # If user doesn't have configuration.yaml config, generate default values
    # for options not in config entry data
    if (conf := hass.data.get(DATA_MQTT_CONFIG)) is None:
        conf = CONFIG_SCHEMA_BASE(dict(entry.data))

    # User has configuration.yaml config, warn about config entry overrides
    elif any(key in conf for key in entry.data):
        shared_keys = conf.keys() & entry.data.keys()
        override = {k: entry.data[k] for k in shared_keys if conf[k] != entry.data[k]}
        if CONF_PASSWORD in override:
            override[CONF_PASSWORD] = "********"
        if override:
            _LOGGER.warning(
                "Deprecated configuration settings found in configuration.yaml. "
                "These settings from your configuration entry will override: %s",
                override,
            )

    # Merge advanced configuration values from configuration.yaml
    conf = _merge_extended_config(entry, conf)

    hass.data[DATA_MQTT] = MQTT(
        hass,
        entry,
        conf,
    )
    entry.add_update_listener(_async_config_entry_updated)

    await hass.data[DATA_MQTT].async_connect()

    async def async_stop_mqtt(_event: Event):
        """Stop MQTT component."""
        await hass.data[DATA_MQTT].async_disconnect()

    hass.bus.async_listen_once(EVENT_HOMEASSISTANT_STOP, async_stop_mqtt)

    async def async_publish_service(call: ServiceCall) -> None:
        """Handle MQTT publish service calls."""
        msg_topic = call.data.get(ATTR_TOPIC)
        msg_topic_template = call.data.get(ATTR_TOPIC_TEMPLATE)
        payload = call.data.get(ATTR_PAYLOAD)
        payload_template = call.data.get(ATTR_PAYLOAD_TEMPLATE)
        qos: int = call.data[ATTR_QOS]
        retain: bool = call.data[ATTR_RETAIN]
        if msg_topic_template is not None:
            try:
                rendered_topic = template.Template(
                    msg_topic_template, hass
                ).async_render(parse_result=False)
                msg_topic = valid_publish_topic(rendered_topic)
            except (jinja2.TemplateError, TemplateError) as exc:
                _LOGGER.error(
                    "Unable to publish: rendering topic template of %s "
                    "failed because %s",
                    msg_topic_template,
                    exc,
                )
                return
            except vol.Invalid as err:
                _LOGGER.error(
                    "Unable to publish: topic template '%s' produced an "
                    "invalid topic '%s' after rendering (%s)",
                    msg_topic_template,
                    rendered_topic,
                    err,
                )
                return

        if payload_template is not None:
            try:
                payload = MqttCommandTemplate(
                    template.Template(payload_template), hass=hass
                ).async_render()
            except (jinja2.TemplateError, TemplateError) as exc:
                _LOGGER.error(
                    "Unable to publish to %s: rendering payload template of "
                    "%s failed because %s",
                    msg_topic,
                    payload_template,
                    exc,
                )
                return

        await hass.data[DATA_MQTT].async_publish(msg_topic, payload, qos, retain)

    hass.services.async_register(
        DOMAIN, SERVICE_PUBLISH, async_publish_service, schema=MQTT_PUBLISH_SCHEMA
    )

    async def async_dump_service(call: ServiceCall) -> None:
        """Handle MQTT dump service calls."""
        messages = []

        @callback
        def collect_msg(msg):
            messages.append((msg.topic, msg.payload.replace("\n", "")))

        unsub = await async_subscribe(hass, call.data["topic"], collect_msg)

        def write_dump():
            with open(hass.config.path("mqtt_dump.txt"), "wt", encoding="utf8") as fp:
                for msg in messages:
                    fp.write(",".join(msg) + "\n")

        async def finish_dump(_):
            """Write dump to file."""
            unsub()
            await hass.async_add_executor_job(write_dump)

        event.async_call_later(hass, call.data["duration"], finish_dump)

    hass.services.async_register(
        DOMAIN,
        SERVICE_DUMP,
        async_dump_service,
        schema=vol.Schema(
            {
                vol.Required("topic"): valid_subscribe_topic,
                vol.Optional("duration", default=5): int,
            }
        ),
    )

    # setup platforms and discovery
    hass.data[DATA_CONFIG_ENTRY_LOCK] = asyncio.Lock()
    hass.data[CONFIG_ENTRY_IS_SETUP] = set()

    async def async_forward_entry_setup():
        """Forward the config entry setup to the platforms."""
        async with hass.data[DATA_CONFIG_ENTRY_LOCK]:
            for component in PLATFORMS:
                config_entries_key = f"{component}.mqtt"
                if config_entries_key not in hass.data[CONFIG_ENTRY_IS_SETUP]:
                    hass.data[CONFIG_ENTRY_IS_SETUP].add(config_entries_key)
                    await hass.config_entries.async_forward_entry_setup(
                        entry, component
                    )

    hass.async_create_task(async_forward_entry_setup())

    if conf.get(CONF_DISCOVERY):
        await _async_setup_discovery(hass, conf, entry)

    if DATA_MQTT_RELOAD_NEEDED in hass.data:
        hass.data.pop(DATA_MQTT_RELOAD_NEEDED)
        await hass.services.async_call(
            DOMAIN,
            SERVICE_RELOAD,
            {},
            blocking=False,
        )

    return True


@websocket_api.websocket_command(
    {vol.Required("type"): "mqtt/device/debug_info", vol.Required("device_id"): str}
)
@callback
def websocket_mqtt_info(hass, connection, msg):
    """Get MQTT debug info for device."""
    device_id = msg["device_id"]
    mqtt_info = debug_info.info_for_device(hass, device_id)

    connection.send_result(msg["id"], mqtt_info)


@websocket_api.websocket_command(
    {
        vol.Required("type"): "mqtt/subscribe",
        vol.Required("topic"): valid_subscribe_topic,
    }
)
@websocket_api.async_response
async def websocket_subscribe(hass, connection, msg):
    """Subscribe to a MQTT topic."""
    if not connection.user.is_admin:
        raise Unauthorized

    async def forward_messages(mqttmsg: ReceiveMessage):
        """Forward events to websocket."""
        try:
            payload = cast(bytes, mqttmsg.payload).decode(
                DEFAULT_ENCODING
            )  # not str because encoding is set to None
        except (AttributeError, UnicodeDecodeError):
            # Convert non UTF-8 payload to a string presentation
            payload = str(mqttmsg.payload)

        connection.send_message(
            websocket_api.event_message(
                msg["id"],
                {
                    "topic": mqttmsg.topic,
                    "payload": payload,
                    "qos": mqttmsg.qos,
                    "retain": mqttmsg.retain,
                },
            )
        )

    # Perform UTF-8 decoding directly in callback routine
    connection.subscriptions[msg["id"]] = await async_subscribe(
        hass, msg["topic"], forward_messages, encoding=None
    )

    connection.send_message(websocket_api.result_message(msg["id"]))


ConnectionStatusCallback = Callable[[bool], None]


@callback
def async_subscribe_connection_status(
    hass: HomeAssistant, connection_status_callback: ConnectionStatusCallback
) -> Callable[[], None]:
    """Subscribe to MQTT connection changes."""
    connection_status_callback_job = HassJob(connection_status_callback)

    async def connected():
        task = hass.async_run_hass_job(connection_status_callback_job, True)
        if task:
            await task

    async def disconnected():
        task = hass.async_run_hass_job(connection_status_callback_job, False)
        if task:
            await task

    subscriptions = {
        "connect": async_dispatcher_connect(hass, MQTT_CONNECTED, connected),
        "disconnect": async_dispatcher_connect(hass, MQTT_DISCONNECTED, disconnected),
    }

    @callback
    def unsubscribe():
        subscriptions["connect"]()
        subscriptions["disconnect"]()

    return unsubscribe


def is_connected(hass: HomeAssistant) -> bool:
    """Return if MQTT client is connected."""
    return hass.data[DATA_MQTT].connected


async def async_remove_config_entry_device(
    hass: HomeAssistant, config_entry: ConfigEntry, device_entry: DeviceEntry
) -> bool:
    """Remove MQTT config entry from a device."""
    # pylint: disable-next=import-outside-toplevel
    from . import device_automation

    await device_automation.async_removed_from_device(hass, device_entry.id)
    return True
