"""Tests for the long-lived gateway heap-trim helper."""

from unittest.mock import Mock

import pytest

import hermes_cli.mem_trim as mem_trim


@pytest.fixture(autouse=True)
def _reset_trim_state(monkeypatch):
    monkeypatch.setattr(mem_trim, "_last_trim_monotonic", 0.0)
    monkeypatch.setattr(mem_trim, "_probe_done", True)
    monkeypatch.setattr(mem_trim, "_malloc_trim", None)
    monkeypatch.setattr(mem_trim, "_trim_call_count", 0)


def test_unsupported_allocator_is_noop_without_gc(monkeypatch):
    collect = Mock()
    monkeypatch.setattr(mem_trim.gc, "collect", collect)

    assert mem_trim.trim_memory(force=True, reason="test") is False
    collect.assert_not_called()


def test_config_kill_switch_overrides_force_from_config_file(monkeypatch, tmp_path):
    from hermes_constants import reset_hermes_home_override, set_hermes_home_override

    hermes_home = tmp_path / "hermes"
    hermes_home.mkdir()
    (hermes_home / "config.yaml").write_text(
        "context:\n  memory_trim:\n    enabled: false\n",
        encoding="utf-8",
    )
    trim = Mock(return_value=1)
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    token = set_hermes_home_override(hermes_home)

    try:
        assert mem_trim.trim_memory(force=True) is False
        trim.assert_not_called()
    finally:
        reset_hermes_home_override(token)


def test_default_config_declares_memory_trim_controls():
    from hermes_cli.config import DEFAULT_CONFIG

    context = DEFAULT_CONFIG["context"]
    assert isinstance(context, dict)
    settings = context["memory_trim"]
    assert isinstance(settings, dict)
    assert isinstance(settings["enabled"], bool)
    assert isinstance(settings["cooldown_seconds"], float)


def test_collect_memory_snapshot_parses_linux_proc_status(monkeypatch):
    # No ``sys.platform`` pin: the only platform check lives inside
    # ``_read_proc_status``, which is replaced below — the subject here is
    # the /proc/self/status parser, which is host-independent.
    monkeypatch.setattr(
        mem_trim,
        "_read_proc_status",
        lambda: "Name:\tpython\nVmRSS:\t1234 kB\nRssAnon:\t567 kB\n",
    )
    monkeypatch.setattr(mem_trim.threading, "active_count", lambda: 9)

    assert mem_trim.collect_memory_snapshot(history_bytes=42) == {
        "rss_kib": 1234,
        "rss_anon_kib": 567,
        "thread_count": 9,
        "history_bytes": 42,
    }


def test_success_collects_then_trims(monkeypatch):
    calls = []
    monkeypatch.setattr(mem_trim.gc, "collect", lambda: calls.append("gc"))
    monkeypatch.setattr(
        mem_trim, "_malloc_trim", lambda pad: calls.append(("trim", pad)) or 1
    )
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)

    assert mem_trim.trim_memory(reason="turn", cooldown_seconds=60) is True
    assert calls == ["gc", ("trim", 0)]
    assert mem_trim._last_trim_monotonic == 100.0


def test_success_logs_memory_snapshot_and_trim_result(monkeypatch, caplog):
    monkeypatch.setattr(mem_trim.gc, "collect", lambda: None)
    monkeypatch.setattr(mem_trim, "_malloc_trim", lambda _pad: 1)
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)
    snapshots = iter(
        (
            {"rss_kib": 4096, "rss_anon_kib": 3072, "thread_count": 3},
            {"rss_kib": 2048, "rss_anon_kib": 1024, "thread_count": 3},
        )
    )
    monkeypatch.setattr(mem_trim, "collect_memory_snapshot", lambda: next(snapshots))

    with caplog.at_level("INFO", logger="hermes_cli.mem_trim"):
        assert mem_trim.trim_memory(reason="test turn") is True

    assert "reason=test turn" in caplog.text
    assert "malloc_trim=1" in caplog.text
    assert "rss_kib=4096->2048" in caplog.text


def test_force_logs_even_when_periodic_log_sampling_skips(monkeypatch, caplog):
    monkeypatch.setattr(mem_trim.gc, "collect", lambda: None)
    monkeypatch.setattr(mem_trim, "_malloc_trim", lambda _pad: 1)
    monkeypatch.setattr(mem_trim, "_config_settings", lambda: (True, 0.0, 99, 1.0))
    # Two ticks: the forced call comes after the 5s force floor so it runs
    # (the floor exists to coalesce burst closes, not to mute logging).
    _ticks = iter([100.0, 110.0])
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: next(_ticks, 110.0))
    monkeypatch.setattr(
        mem_trim,
        "collect_memory_snapshot",
        lambda: {"rss_kib": 4096, "rss_anon_kib": 3072, "thread_count": 3},
    )

    with caplog.at_level("INFO", logger="hermes_cli.mem_trim"):
        assert mem_trim.trim_memory(reason="periodic") is True
        assert mem_trim.trim_memory(force=True, reason="close") is True

    messages = [record.getMessage() for record in caplog.records]
    assert not any("reason=periodic" in message for message in messages)
    assert any("reason=close" in message for message in messages)


def test_cooldown_suppresses_repeated_collection(monkeypatch):
    collect = Mock()
    trim = Mock(return_value=1)
    monkeypatch.setattr(mem_trim.gc, "collect", collect)
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    monkeypatch.setattr(mem_trim, "_last_trim_monotonic", 95.0)
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)

    assert mem_trim.trim_memory(cooldown_seconds=60) is False
    collect.assert_not_called()
    trim.assert_not_called()
    assert mem_trim.trim_memory(force=True, cooldown_seconds=60) is True


def test_config_cooldown_controls_rate_limit(monkeypatch):
    trim = Mock(return_value=1)
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    monkeypatch.setattr(mem_trim, "_last_trim_monotonic", 1.0)
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)
    monkeypatch.setattr(
        "hermes_cli.config.load_config_readonly",
        lambda: {
            "context": {
                "memory_trim": {"enabled": True, "cooldown_seconds": 120.0}
            }
        },
    )

    assert mem_trim.trim_memory() is False
    trim.assert_not_called()


def test_legacy_environment_switch_does_not_control_behavior(monkeypatch):
    trim = Mock(return_value=1)
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    monkeypatch.setenv("HERMES_DISABLE_MEMORY_TRIM", "1")
    monkeypatch.setattr(
        "hermes_cli.config.load_config_readonly",
        lambda: {"context": {"memory_trim": {"enabled": True}}},
    )

    assert mem_trim.trim_memory(force=True) is True
    trim.assert_called_once_with(0)


def test_libc_failure_is_fail_open_and_rate_limited(monkeypatch):
    trim = Mock(side_effect=RuntimeError("boom"))
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)

    assert mem_trim.trim_memory(reason="test", cooldown_seconds=60) is False
    assert mem_trim._last_trim_monotonic == 100.0
    assert mem_trim.trim_memory(cooldown_seconds=60) is False
    assert trim.call_count == 1


def test_force_floor_coalesces_burst_closes(monkeypatch):
    """A delegate batch closes N child agents back-to-back, each forcing a
    trim — the short force floor must coalesce the burst instead of stacking
    N uncooled full gc.collect() passes in the same process."""
    collect = Mock()
    trim = Mock(return_value=1)
    monkeypatch.setattr(mem_trim.gc, "collect", collect)
    monkeypatch.setattr(mem_trim, "_malloc_trim", trim)
    monkeypatch.setattr(mem_trim, "_config_settings", lambda: (True, 0.0, 1, 0.0))
    monkeypatch.setattr(
        mem_trim,
        "collect_memory_snapshot",
        lambda: {"rss_kib": 4096, "rss_anon_kib": 3072, "thread_count": 3},
    )
    monkeypatch.setattr(mem_trim, "_last_trim_monotonic", 0.0)

    # t=100: first forced close runs.
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 100.0)
    assert mem_trim.trim_memory(force=True, reason="agent close") is True
    assert trim.call_count == 1

    # t=101..103: three more child closes inside the floor — all coalesced.
    for t in (101.0, 102.0, 103.0):
        monkeypatch.setattr(mem_trim.time, "monotonic", lambda t=t: t)
        assert mem_trim.trim_memory(force=True, reason="agent close") is False
    assert trim.call_count == 1, "burst closes must not stack forced trims"

    # t=106: past the floor — the parent's final close-trim still fires.
    monkeypatch.setattr(mem_trim.time, "monotonic", lambda: 106.0)
    assert mem_trim.trim_memory(force=True, reason="agent close") is True
    assert trim.call_count == 2