"""Tests for DriverChip.get_sequence's reset-delay handling."""

from collections.abc import Generator

import pytest

from esphome.components.mipi import (
    BRIGHTNESS,
    CONF_INVERT_COLORS,
    CONF_PIXEL_MODE,
    DriverChip,
)
from esphome.const import CONF_BRIGHTNESS

# A minimal config with no reset pin: enough for get_sequence(add_madctl=False) to run
# without needing a full display configuration.
_BASE_CONFIG = {CONF_PIXEL_MODE: "16bit", CONF_INVERT_COLORS: False}


@pytest.fixture(autouse=True)
def _remove_test_models() -> Generator[None]:
    """Unregister chips created by a test."""
    existing = set(DriverChip.models)
    yield
    for name in set(DriverChip.models) - existing:
        del DriverChip.models[name]


def test_get_sequence_defaults_to_10ms_reset_delay() -> None:
    """A model with no reset_delay default falls back to a 10ms settling delay."""
    chip = DriverChip("TEST-GET-SEQUENCE-DEFAULT")

    sequence = chip.get_sequence(_BASE_CONFIG, add_madctl=False, add_reset=True)

    # SWRESET ({1, 0}) is prepended (no reset pin configured), followed by the
    # 10ms settling delay, flattened to {10, 255}.
    assert sequence[:4] == (1, 0, 10, 255)


def test_get_sequence_uses_model_reset_delay_default() -> None:
    """A model's own reset_delay default overrides the base 10ms default."""
    chip = DriverChip("TEST-GET-SEQUENCE-CUSTOM-DELAY", reset_delay=99)

    sequence = chip.get_sequence(_BASE_CONFIG, add_madctl=False, add_reset=True)

    assert sequence[:4] == (1, 0, 99, 255)


@pytest.mark.parametrize("reset_delay", [0, 256])
def test_get_sequence_rejects_out_of_range_reset_delay(reset_delay: int) -> None:
    """reset_delay outside 1-255ms is rejected.

    This matches the 1-255ms range map_sequence() already allows for a
    "delay N" entry in a custom init sequence.
    """
    chip = DriverChip("TEST-GET-SEQUENCE-BAD-DELAY", reset_delay=reset_delay)

    with pytest.raises(ValueError, match="reset_delay must be between 1 and 255ms"):
        chip.get_sequence(_BASE_CONFIG, add_madctl=False, add_reset=True)


def test_get_sequence_skips_reset_delay_validation_without_add_reset() -> None:
    """An out-of-range reset_delay is only checked when add_reset is requested.

    mipi_dsi calls get_sequence with add_reset=False and never uses
    reset_delay, so an invalid default there should not raise.
    """
    chip = DriverChip("TEST-GET-SEQUENCE-NO-RESET", reset_delay=999)

    chip.get_sequence(_BASE_CONFIG, add_madctl=False, add_reset=False)


def _has_brightness_command(sequence: tuple[int, ...], value: int) -> bool:
    """True if the flattened sequence holds a one-byte brightness (0x51) command."""
    return any(
        sequence[i : i + 3] == (BRIGHTNESS, 1, value) for i in range(len(sequence) - 2)
    )


@pytest.mark.parametrize("brightness", [0, 0x80])
def test_get_sequence_adds_configured_brightness(brightness: int) -> None:
    """A configured brightness is sent at startup, including zero."""
    chip = DriverChip("TEST-GET-SEQUENCE-BRIGHTNESS")

    sequence = chip.get_sequence(
        {**_BASE_CONFIG, CONF_BRIGHTNESS: brightness}, add_madctl=False
    )

    assert _has_brightness_command(sequence, brightness)


def test_get_sequence_omits_brightness_when_not_set() -> None:
    """No brightness command is sent when neither config nor model sets one."""
    chip = DriverChip("TEST-GET-SEQUENCE-NO-BRIGHTNESS")

    sequence = chip.get_sequence(_BASE_CONFIG, add_madctl=False)

    assert not any(_has_brightness_command(sequence, v) for v in range(256))