"""ESPHome external_component: GRUB boot switch over USB MSC.

Presents a synthetic 64 KB FAT12 disk to the attached host containing two
virtual files:

  switch_position           - one ASCII digit (0-9) reflecting the current
                              boot target.
  switch_position_grub.cfg  - GRUB snippet `set os_hw_switch=N\\n` consumed
                              by the user's /etc/grub.d/01_bootswitch hook.

The volume serial defaults to 0x55AA6922 to stay drop-in compatible with
the upstream stecman/hw-boot-selection firmware.
"""

from esphome import automation
import esphome.codegen as cg
import esphome.config_validation as cv
from esphome.const import CONF_ID
from esphome.components import esp32

DEPENDENCIES = ["esp32"]
CODEOWNERS = ["@adamksmith"]
MULTI_CONF = False

grub_boot_switch_ns = cg.esphome_ns.namespace("grub_boot_switch")
GrubBootSwitch = grub_boot_switch_ns.class_("GrubBootSwitch", cg.Component)

CONF_VOLUME_SERIAL = "volume_serial"
CONF_VOLUME_LABEL = "volume_label"
CONF_USB_VID = "usb_vid"
CONF_USB_PID = "usb_pid"
CONF_USB_MANUFACTURER = "usb_manufacturer"
CONF_USB_PRODUCT = "usb_product"
CONF_INITIAL_TARGET = "initial_target"
CONF_TARGETS = "targets"
CONF_GRUB_BOOT_SWITCH_ID = "grub_boot_switch_id"


def _validate_label(value):
    value = cv.string_strict(value)
    if len(value) > 11:
        raise cv.Invalid("volume_label must be 11 characters or fewer")
    return value


# targets: maps a digit (0-9) the firmware writes into switch_position to a
# human-readable label.  GRUB scripts react to the digit; the labels are only
# used by the select sub-platform exposed to Home Assistant.
TARGETS_SCHEMA = cv.Schema({cv.int_range(min=0, max=9): cv.string_strict})


CONFIG_SCHEMA = cv.All(
    cv.Schema(
        {
            cv.GenerateID(): cv.declare_id(GrubBootSwitch),
            cv.Optional(CONF_VOLUME_SERIAL, default=0x55AA6922): cv.hex_uint32_t,
            cv.Optional(CONF_VOLUME_LABEL, default="SWITCH"): _validate_label,
            cv.Optional(CONF_USB_VID, default=0x26BA): cv.hex_uint16_t,
            cv.Optional(CONF_USB_PID, default=0x8003): cv.hex_uint16_t,
            cv.Optional(CONF_USB_MANUFACTURER, default="Stecman"): cv.string,
            cv.Optional(CONF_USB_PRODUCT, default="Boot Switch"): cv.string,
            cv.Optional(CONF_INITIAL_TARGET, default=0): cv.int_range(min=0, max=9),
            cv.Optional(CONF_TARGETS, default={}): TARGETS_SCHEMA,
        }
    ).extend(cv.COMPONENT_SCHEMA),
    cv.only_with_framework("esp-idf"),
    cv.only_on_esp32,
)


async def to_code(config):
    var = cg.new_Pvariable(config[CONF_ID])
    await cg.register_component(var, config)

    cg.add(var.set_volume_serial(config[CONF_VOLUME_SERIAL]))
    cg.add(var.set_volume_label(config[CONF_VOLUME_LABEL]))
    cg.add(var.set_usb_ids(config[CONF_USB_VID], config[CONF_USB_PID]))
    cg.add(var.set_usb_strings(config[CONF_USB_MANUFACTURER], config[CONF_USB_PRODUCT]))
    cg.add(var.set_initial_target(config[CONF_INITIAL_TARGET]))

    for digit, label in sorted(config[CONF_TARGETS].items()):
        cg.add(var.add_target(digit, label))

    # esp_tinyusb is the supported MSC stack on ESP32-S3 USB-OTG.
    esp32.add_idf_component(
        name="espressif/esp_tinyusb",
        ref="~1.4.0",
    )

    # Move IDF console off USB-Serial-JTAG so TinyUSB can claim the peripheral.
    esp32.add_idf_sdkconfig_option("CONFIG_ESP_CONSOLE_UART_DEFAULT", True)
    esp32.add_idf_sdkconfig_option("CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG", False)

    # esp_tinyusb's tusb_msc_storage.c provides default tud_msc_* callbacks as
    # strong symbols. We provide our own callback-driven implementations, so
    # we tell the linker to allow multiple definitions and rely on link order
    # (main component first → our symbols win) to pick ours.
    esp32.add_idf_sdkconfig_option("CONFIG_TINYUSB_MSC_ENABLED", True)
    esp32.add_idf_sdkconfig_option("CONFIG_TINYUSB_CDC_ENABLED", False)

    cg.add_build_flag("-DCFG_TUSB_MCU=OPT_MCU_ESP32S3")
    cg.add_build_flag("-Wl,--allow-multiple-definition")