"""Config flow for Integration - Riemann sum integral integration."""

from collections.abc import Mapping
from typing import Any, cast, override

import voluptuous as vol

from homeassistant.components.counter import DOMAIN as COUNTER_DOMAIN
from homeassistant.components.input_number import DOMAIN as INPUT_NUMBER_DOMAIN
from homeassistant.components.sensor import DOMAIN as SENSOR_DOMAIN
from homeassistant.const import CONF_METHOD, CONF_NAME, EntityStateAttribute, UnitOfTime
from homeassistant.core import callback
from homeassistant.helpers import selector
from homeassistant.helpers.schema_config_entry_flow import (
    SchemaCommonFlowHandler,
    SchemaConfigFlowHandler,
    SchemaFlowFormStep,
    SchemaOptionsFlowHandler,
)

from .const import (
    CONF_MAX_SUB_INTERVAL,
    CONF_ROUND_DIGITS,
    CONF_SOURCE_SENSOR,
    CONF_UNIT_PREFIX,
    CONF_UNIT_TIME,
    DOMAIN,
    METHOD_LEFT,
    METHOD_RIGHT,
    METHOD_TRAPEZOIDAL,
)

UNIT_PREFIXES = [
    selector.SelectOptionDict(value="k", label="k (kilo)"),
    selector.SelectOptionDict(value="M", label="M (mega)"),
    selector.SelectOptionDict(value="G", label="G (giga)"),
    selector.SelectOptionDict(value="T", label="T (tera)"),
]
TIME_UNITS = [
    UnitOfTime.SECONDS,
    UnitOfTime.MINUTES,
    UnitOfTime.HOURS,
    UnitOfTime.DAYS,
]
INTEGRATION_METHODS = [
    METHOD_TRAPEZOIDAL,
    METHOD_LEFT,
    METHOD_RIGHT,
]
ALLOWED_DOMAINS = [COUNTER_DOMAIN, INPUT_NUMBER_DOMAIN, SENSOR_DOMAIN]


@callback
def entity_selector_compatible(
    handler: SchemaOptionsFlowHandler,
) -> selector.EntitySelector:
    """Return an entity selector which compatible entities."""
    current = handler.hass.states.get(handler.options[CONF_SOURCE_SENSOR])
    unit_of_measurement = (
        current.attributes.get(EntityStateAttribute.UNIT_OF_MEASUREMENT)
        if current
        else None
    )
    if unit_of_measurement is None:
        return selector.EntitySelector(
            selector.EntitySelectorConfig(domain=ALLOWED_DOMAINS)
        )

    entities = [
        ent.entity_id
        for ent in handler.hass.states.async_all(ALLOWED_DOMAINS)
        if ent.attributes.get(EntityStateAttribute.UNIT_OF_MEASUREMENT)
        == unit_of_measurement
        and ent.domain in ALLOWED_DOMAINS
    ]

    return selector.EntitySelector(
        selector.EntitySelectorConfig(include_entities=entities)
    )


async def _get_options_dict(handler: SchemaCommonFlowHandler | None) -> dict:
    if handler is None or not isinstance(
        handler.parent_handler, SchemaOptionsFlowHandler
    ):
        entity_selector = selector.EntitySelector(
            selector.EntitySelectorConfig(domain=ALLOWED_DOMAINS)
        )
    else:
        entity_selector = entity_selector_compatible(handler.parent_handler)

    return {
        vol.Required(CONF_SOURCE_SENSOR): entity_selector,
        vol.Required(CONF_METHOD, default=METHOD_TRAPEZOIDAL): selector.SelectSelector(
            selector.SelectSelectorConfig(
                options=INTEGRATION_METHODS, translation_key=CONF_METHOD
            ),
        ),
        vol.Optional(CONF_ROUND_DIGITS): selector.NumberSelector(
            selector.NumberSelectorConfig(
                min=0, max=6, mode=selector.NumberSelectorMode.BOX
            ),
        ),
        vol.Optional(CONF_MAX_SUB_INTERVAL): selector.DurationSelector(
            selector.DurationSelectorConfig(allow_negative=False)
        ),
    }


async def _get_options_schema(handler: SchemaCommonFlowHandler) -> vol.Schema:
    return vol.Schema(await _get_options_dict(handler))


async def _get_config_schema(handler: SchemaCommonFlowHandler) -> vol.Schema:
    options = await _get_options_dict(handler)
    return vol.Schema(
        {
            vol.Required(CONF_NAME): selector.TextSelector(),
            vol.Optional(CONF_UNIT_PREFIX): selector.SelectSelector(
                selector.SelectSelectorConfig(
                    options=UNIT_PREFIXES, mode=selector.SelectSelectorMode.DROPDOWN
                )
            ),
            vol.Required(
                CONF_UNIT_TIME, default=UnitOfTime.HOURS
            ): selector.SelectSelector(
                selector.SelectSelectorConfig(
                    options=TIME_UNITS,
                    mode=selector.SelectSelectorMode.DROPDOWN,
                    translation_key=CONF_UNIT_TIME,
                ),
            ),
            **options,
        }
    )


CONFIG_FLOW = {
    "user": SchemaFlowFormStep(_get_config_schema),
}

OPTIONS_FLOW = {
    "init": SchemaFlowFormStep(_get_options_schema),
}


class ConfigFlowHandler(SchemaConfigFlowHandler, domain=DOMAIN):
    """Handle a config or options flow for Integration."""

    MINOR_VERSION = 2

    config_flow = CONFIG_FLOW
    options_flow = OPTIONS_FLOW
    options_flow_reloads = True

    @override
    def async_config_entry_title(self, options: Mapping[str, Any]) -> str:
        """Return config entry title."""
        return cast(str, options["name"])
