import importlib.util
import logging
from pathlib import Path
import sys
from types import ModuleType
from unittest.mock import Mock

import pytest

from esphome import const, cpp_helpers as ch
from esphome.core import CoroPriority, coroutine_with_priority
from esphome.cpp_helpers import ComponentSourcePool, register_component_source


@pytest.mark.asyncio
async def test_gpio_pin_expression__conf_is_none(monkeypatch):
    actual = await ch.gpio_pin_expression(None)

    assert actual is None


@pytest.mark.asyncio
async def test_register_component(monkeypatch):
    base_mock = Mock()
    base_mock.__str__ = lambda self: "foo.bar"
    base_mock.type = Mock()
    base_mock.type.__str__ = lambda self: "foo::Bar"
    var = Mock(base=base_mock)

    app_mock = Mock(register_component_=Mock(return_value=var))
    monkeypatch.setattr(ch, "App", app_mock)

    core_mock = Mock(component_ids=["foo.bar"], data={})
    monkeypatch.setattr(ch, "CORE", core_mock)

    add_mock = Mock()
    monkeypatch.setattr(ch, "add", add_mock)

    actual = await ch.register_component(var, {})

    assert actual is var
    assert add_mock.call_count == 1
    app_mock.register_component_.assert_called_once()
    assert app_mock.register_component_.call_args.args[0] is var
    assert core_mock.component_ids == []


@pytest.mark.asyncio
async def test_register_component__no_component_id(monkeypatch):
    var = Mock(base="foo.eek")

    core_mock = Mock(component_ids=["foo.bar"])
    monkeypatch.setattr(ch, "CORE", core_mock)

    with pytest.raises(ValueError, match="Component ID foo.eek was not declared to"):
        await ch.register_component(var, {})


@pytest.mark.asyncio
async def test_register_component__with_setup_priority(monkeypatch):
    base_mock = Mock()
    base_mock.__str__ = lambda self: "foo.bar"
    base_mock.type = Mock()
    base_mock.type.__str__ = lambda self: "foo::Bar"
    var = Mock(base=base_mock)

    app_mock = Mock(register_component_=Mock(return_value=var))
    monkeypatch.setattr(ch, "App", app_mock)

    core_mock = Mock(component_ids=["foo.bar"], data={})
    monkeypatch.setattr(ch, "CORE", core_mock)

    add_mock = Mock()
    monkeypatch.setattr(ch, "add", add_mock)

    actual = await ch.register_component(
        var,
        {
            const.CONF_SETUP_PRIORITY: "123",
            const.CONF_UPDATE_INTERVAL: "456",
        },
    )

    assert actual is var
    add_mock.assert_called()
    assert add_mock.call_count == 3
    app_mock.register_component_.assert_called_once()
    assert app_mock.register_component_.call_args.args[0] is var
    assert core_mock.component_ids == []


def test_register_component_source_empty_name(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setattr(ch, "CORE", Mock(data={}))
    assert register_component_source("") == 0


def test_register_component_source_deduplicates(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    monkeypatch.setattr(ch, "CORE", Mock(data={}))
    idx1 = register_component_source("wifi")
    idx2 = register_component_source("api")
    idx3 = register_component_source("wifi")
    assert idx1 == 1
    assert idx2 == 2
    assert idx3 == 1  # deduplicated


def test_generate_source_table_code_empty() -> None:
    from esphome.cpp_helpers import _generate_source_table_code

    assert _generate_source_table_code("TBL", "lookup", {}) == ""


def test_generate_source_table_code_non_empty() -> None:
    from esphome.cpp_helpers import _generate_source_table_code

    code = _generate_source_table_code("TBL", "lookup", {"wifi": 1, "api": 2})
    assert "PROGMEM" in code
    assert "wifi" in code
    assert "api" in code
    assert "lookup" in code
    assert "index == 0" in code
    assert "progmem_read_ptr" in code
    assert "index > 2" in code


@pytest.mark.asyncio
async def test_generate_component_source_table_empty_pool(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    """Test that _generate_component_source_table does nothing with an empty pool."""
    from esphome.cpp_helpers import _generate_component_source_table

    monkeypatch.setattr(ch, "CORE", Mock(data={}))
    add_global_mock = Mock()
    monkeypatch.setattr(ch, "add_global", add_global_mock)
    await _generate_component_source_table()
    add_global_mock.assert_not_called()


def test_register_component_source_overflow_warns(
    monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
) -> None:
    # Pre-fill pool to max
    pool = ComponentSourcePool(
        sources={f"comp_{i}": i + 1 for i in range(0xFF)},
        table_registered=True,
    )
    monkeypatch.setattr(
        ch, "CORE", Mock(data={ch._COMPONENT_SOURCE_DOMAIN: pool}, testing_mode=False)
    )
    with caplog.at_level(logging.WARNING):
        idx = register_component_source("overflow_component")
    assert idx == 0
    assert "Too many unique component source names" in caplog.text
    assert "overflow_component" in caplog.text


def test_register_component_source_overflow_suppressed_in_testing_mode(
    monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
) -> None:
    # Pre-fill pool to max
    pool = ComponentSourcePool(
        sources={f"comp_{i}": i + 1 for i in range(0xFF)},
        table_registered=True,
    )
    monkeypatch.setattr(
        ch, "CORE", Mock(data={ch._COMPONENT_SOURCE_DOMAIN: pool}, testing_mode=True)
    )
    with caplog.at_level(logging.WARNING):
        idx = register_component_source("overflow_component")
    assert idx == 0
    assert "Too many unique component source names" not in caplog.text


def _define_value(name: str) -> str | None:
    for define in ch.CORE.defines:
        if define.name == name:
            # Values are codegen expressions (IntLiteral); compare rendered.
            return str(define.value)
    return None


def test_slot_counter_emits_requested_count() -> None:
    """Each request bumps the count; the self-scheduled FINAL job emits it."""
    request = ch.slot_counter("TEST_SLOT_COUNT")
    request()
    request()
    ch.CORE.flush_tasks()
    assert _define_value("TEST_SLOT_COUNT") == "2"


def test_slot_counter_keyed_emits_largest_count() -> None:
    """Keyed requests size storage every key declares at the same capacity:
    the define is the busiest key's count, not the total over all keys."""
    request = ch.slot_counter("TEST_SLOT_COUNT_KEYED")
    request("rx_a")
    request("rx_a")
    request("rx_a")
    request("rx_b")
    assert ch.get_slot_count("TEST_SLOT_COUNT_KEYED") == 3
    ch.CORE.flush_tasks()
    assert _define_value("TEST_SLOT_COUNT_KEYED") == "3"


def test_slot_counter_rejects_mixed_keyed_and_unkeyed_requests() -> None:
    """A keyed and an unkeyed request for one define cannot be sized together."""
    request = ch.slot_counter("TEST_SLOT_COUNT_MIXED")
    request("rx_a")
    with pytest.raises(ValueError, match="TEST_SLOT_COUNT_MIXED"):
        request()
    unkeyed = ch.slot_counter("TEST_SLOT_COUNT_MIXED_2")
    unkeyed()
    with pytest.raises(ValueError, match="TEST_SLOT_COUNT_MIXED_2"):
        unkeyed("rx_a")


def test_slot_counter_without_requests_emits_nothing() -> None:
    """No requests, no job, no define — the guarded storage compiles out."""
    ch.slot_counter("TEST_SLOT_COUNT_UNUSED")
    ch.CORE.flush_tasks()
    assert _define_value("TEST_SLOT_COUNT_UNUSED") is None


def test_slot_counter_request_from_final_job_still_emits() -> None:
    """The FIRST request for a define may come from a FINAL job: its emit job
    is scheduled mid-drain and flush_tasks() loops until the heap is empty.
    Later requests do not get this guarantee — see the companion test."""
    request = ch.slot_counter("TEST_SLOT_COUNT_LATE")

    @coroutine_with_priority(CoroPriority.FINAL)
    async def late_requester() -> None:
        request()

    ch.CORE.add_job(late_requester)
    ch.CORE.flush_tasks()
    assert _define_value("TEST_SLOT_COUNT_LATE") == "1"


def test_slot_counter_request_after_emit_raises() -> None:
    """The boundary of FINAL-time requests: once the define was emitted, a
    further request would silently undersize the storage, so it fails loudly."""
    request = ch.slot_counter("TEST_SLOT_COUNT_TOO_LATE")
    request()
    ch.CORE.flush_tasks()
    assert _define_value("TEST_SLOT_COUNT_TOO_LATE") == "1"
    with pytest.raises(ValueError, match="TEST_SLOT_COUNT_TOO_LATE"):
        request()


def _load_module(
    monkeypatch: pytest.MonkeyPatch, name: str, path: Path, source: str
) -> ModuleType:
    path.write_text(source, encoding="utf-8")
    spec = importlib.util.spec_from_file_location(name, path)
    module = importlib.util.module_from_spec(spec)
    monkeypatch.setitem(sys.modules, name, module)
    spec.loader.exec_module(module)
    return module


@pytest.mark.parametrize(
    ("wrapper", "expected"),
    [
        # A plain wrapper returns the coroutine, so its frame is gone when
        # register_component looks for the source; an async one is still on the stack.
        ("def new_component(config):\n    return ", "fake_dev"),
        ("async def new_component(config):\n    return await ", "fake_bus"),
    ],
)
@pytest.mark.asyncio
async def test_new_bus_component_source_is_the_caller(
    monkeypatch: pytest.MonkeyPatch, tmp_path: Path, wrapper: str, expected: str
) -> None:
    bus = _load_module(
        monkeypatch,
        "esphome.components.fake_bus",
        tmp_path / "fake_bus.py",
        "from esphome import cpp_helpers as ch\n"
        "async def register_device(var, config):\n"
        "    pass\n"
        f"{wrapper}ch.new_bus_component(register_device, config)\n",
    )
    dev = _load_module(
        monkeypatch,
        "esphome.components.fake_dev",
        tmp_path / "fake_dev.py",
        "async def to_code(new_component, config):\n"
        "    return await new_component(config)\n",
    )
    base = Mock()
    base.__str__ = lambda self: "foo.bar"
    var = Mock(base=base)
    monkeypatch.setattr(ch, "new_Pvariable", Mock(return_value=var))
    monkeypatch.setattr(ch, "CORE", Mock(component_ids=["foo.bar"], data={}))
    monkeypatch.setattr(ch, "add", Mock())
    monkeypatch.setattr(ch, "App", Mock())
    source = Mock(return_value=1)
    monkeypatch.setattr(ch, "register_component_source", source)
    result = await dev.to_code(bus.new_component, {const.CONF_ID: "foo.bar"})
    assert result is var
    source.assert_called_once_with(expected)