"""Select sub-platform for grub_boot_switch.

Exposes the parent's targets table as a Home Assistant select entity.  The
options list is derived at code-gen time from the parent's `targets:` map, so
adding/removing entries there automatically updates the dropdown.
"""

import esphome.codegen as cg
import esphome.config_validation as cv
from esphome.components import select
from esphome.const import CONF_ID

from .. import (
    CONF_GRUB_BOOT_SWITCH_ID,
    CONF_TARGETS,
    GrubBootSwitch,
    grub_boot_switch_ns,
)

DEPENDENCIES = ["grub_boot_switch"]

BootTargetSelect = grub_boot_switch_ns.class_(
    "BootTargetSelect", select.Select, cg.Component
)

CONFIG_SCHEMA = select.select_schema(BootTargetSelect).extend(
    {
        cv.GenerateID(CONF_GRUB_BOOT_SWITCH_ID): cv.use_id(GrubBootSwitch),
    }
)


async def to_code(config):
    parent = await cg.get_variable(config[CONF_GRUB_BOOT_SWITCH_ID])

    # Reach back into the *full* validated config so we can pull the parent's
    # targets map.  CORE.config holds the post-validation tree.
    from esphome.core import CORE

    parent_cfg = CORE.config.get("grub_boot_switch", {})
    targets = parent_cfg.get(CONF_TARGETS, {})
    if not targets:
        raise cv.Invalid(
            "select platform requires the grub_boot_switch component to define `targets:`"
        )

    options = [label for _digit, label in sorted(targets.items())]

    var = await select.new_select(config, options=options)
    await cg.register_component(var, config)
    cg.add(var.set_parent(parent))