#
# This file is part of gunicorn released under the MIT license.
# See the NOTICE for more information.

import os
import signal
from unittest import mock

import pytest

from gunicorn.companion.control import CommandError
from gunicorn.companion.manager import (
    CompanionManager,
    reset_child_signals,
    set_parent_death_signal,
)
from gunicorn.companion.config import CompanionConfig
from gunicorn.companion.process import State


def make_manager(*names):
    configs = [CompanionConfig(name=n, target=lambda: None) for n in names]
    return CompanionManager(configs, log=mock.Mock())


def test_manager_builds_one_process_per_config():
    manager = make_manager("rq", "scheduler")
    assert set(manager.processes) == {"rq", "scheduler"}
    assert manager.processes["rq"].state == State.STOPPED


def test_resolve_target_accepts_callable():
    fn = lambda: None
    assert CompanionManager._resolve_target(fn) is fn


def test_resolve_target_import_string():
    # os.getpid is a real "module:attr" target.
    assert CompanionManager._resolve_target("os:getpid") is __import__("os").getpid


def test_resolve_target_rejects_bad_string():
    with pytest.raises(ValueError):
        CompanionManager._resolve_target("no_colon")


def test_log_exit_reports_signal_or_status():
    manager = make_manager("rq")
    process = manager.processes["rq"]
    process.last_exit_signal, process.last_exit_code = 9, None
    manager._log_exit(process)
    process.last_exit_signal, process.last_exit_code = None, 1
    manager._log_exit(process)
    messages = [call.args[0] for call in manager.log.info.call_args_list]
    assert any("signal" in message for message in messages)
    assert any("status" in message for message in messages)


def test_reset_child_signals_restores_defaults():
    with mock.patch("signal.signal") as signal_signal:
        reset_child_signals()
    restored = {call.args[0]: call.args[1] for call in signal_signal.call_args_list}
    # The stop signal must reach the default disposition, not the manager's
    # inherited handler, so a forked companion actually terminates on SIGTERM.
    assert restored[signal.SIGTERM] is signal.SIG_DFL
    assert restored[signal.SIGINT] is signal.SIG_DFL


def test_set_parent_death_signal_noop_off_linux():
    with mock.patch("sys.platform", "darwin"):
        assert set_parent_death_signal(signal.SIGTERM) is False


def test_set_parent_death_signal_arms_on_linux():
    libc = mock.Mock()
    libc.prctl.return_value = 0
    with mock.patch("sys.platform", "linux"), \
            mock.patch("ctypes.CDLL", return_value=libc):
        assert set_parent_death_signal(signal.SIGTERM) is True
    libc.prctl.assert_called_once()


def test_parent_gone_detects_reparenting():
    manager = make_manager("rq")
    manager.parent_pid = 4242
    with mock.patch("os.getppid", return_value=4242):
        assert manager._parent_gone() is False
    with mock.patch("os.getppid", return_value=1):
        assert manager._parent_gone() is True


def test_close_manager_fds_closes_control_and_pipe():
    manager = make_manager("rq")
    manager.control = mock.Mock()
    manager._wakeup_pipe = (7, 8)
    with mock.patch("os.close") as os_close:
        manager._close_manager_fds()
    manager.control.listener.close.assert_called_once_with()
    assert os_close.call_count == 2


def test_close_manager_fds_noop_when_unset():
    manager = make_manager("rq")
    manager._close_manager_fds()  # control and pipe are None: must not raise


def test_apply_environment_sets_cwd_and_env():
    config = CompanionConfig(name="rq", target=lambda: None,
                             cwd="/tmp", env={"COMPANION_X": "1"})
    with mock.patch("os.chdir") as chdir, \
            mock.patch.dict("os.environ", {}, clear=False):
        CompanionManager._apply_environment(config)
        chdir.assert_called_once_with("/tmp")
        import os
        assert os.environ["COMPANION_X"] == "1"


def test_apply_environment_noop_without_cwd_env():
    config = CompanionConfig(name="rq", target=lambda: None)
    with mock.patch("os.chdir") as chdir:
        CompanionManager._apply_environment(config)
        chdir.assert_not_called()


def test_open_output_inherit_returns_none():
    assert CompanionManager._open_output(None) is None
    assert CompanionManager._open_output("inherit") is None


def test_open_output_path_opens_append():
    with mock.patch("os.open", return_value=9) as open_mock:
        fd = CompanionManager._open_output("/var/log/rq.log")
    assert fd == 9
    flags = open_mock.call_args.args[1]
    assert flags & os.O_APPEND and flags & os.O_CREAT


def test_redirect_output_files():
    config = CompanionConfig(name="rq", target=lambda: None,
                             stdout="/o.log", stderr="/e.log")
    with mock.patch("os.open", side_effect=[10, 11]), \
            mock.patch("os.dup2") as dup2, \
            mock.patch("os.close") as close:
        CompanionManager._redirect_output(config)
    dup2.assert_any_call(10, 1)
    dup2.assert_any_call(11, 2)
    # The opened fds are closed after being duped onto 1/2, no leak.
    close.assert_any_call(10)
    close.assert_any_call(11)


def test_redirect_output_stderr_to_stdout():
    config = CompanionConfig(name="rq", target=lambda: None,
                             stdout="/o.log", stderr="stdout")
    with mock.patch("os.open", return_value=10), \
            mock.patch("os.dup2") as dup2, \
            mock.patch("os.close") as close:
        CompanionManager._redirect_output(config)
    dup2.assert_any_call(10, 1)
    dup2.assert_any_call(1, 2)
    close.assert_called_once_with(10)


def test_redirect_output_inherit_noop():
    config = CompanionConfig(name="rq", target=lambda: None)
    with mock.patch("os.dup2") as dup2:
        CompanionManager._redirect_output(config)
    dup2.assert_not_called()


def test_reap_records_exit_code():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.pid = 4321
    # exit code 1 -> status 1<<8; second call drains the queue.
    with mock.patch("os.waitpid", side_effect=[(4321, 1 << 8), (0, 0)]):
        reaped = manager.reap_processes()
    assert reaped == [proc]
    assert proc.last_exit_code == 1
    assert proc.last_exit_signal is None
    assert proc.exit_count == 1
    assert proc.pid is None


def test_reap_records_signal():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.pid = 4321
    with mock.patch("os.waitpid", side_effect=[(4321, 9), (0, 0)]):
        manager.reap_processes()
    assert proc.last_exit_signal == 9
    assert proc.last_exit_code is None


def test_reap_no_children():
    manager = make_manager("rq")
    with mock.patch("os.waitpid", side_effect=ChildProcessError):
        assert manager.reap_processes() == []


def test_status_lists_all_companions():
    manager = make_manager("rq", "scheduler")
    entries = manager.status(now=100.0)
    assert {e["name"] for e in entries} == {"rq", "scheduler"}
    assert all("state" in e and "description" in e for e in entries)


def test_handle_command_status():
    manager = make_manager("rq")
    resp = manager.handle_command({"cmd": "status"})
    assert resp["ok"] is True
    assert resp["companions"][0]["name"] == "rq"


def test_handle_command_start_routes():
    manager = make_manager("rq")
    with mock.patch.object(manager, "start_process",
                           return_value=(True, "rq started")) as start_mock:
        resp = manager.handle_command({"cmd": "start", "name": "rq"})
    start_mock.assert_called_once_with("rq")
    assert resp == {"ok": True, "message": "rq started"}


def test_handle_command_stop_and_restart_route():
    manager = make_manager("rq")
    with mock.patch.object(manager, "stop_process", return_value=(True, "s")) as stop_mock, \
            mock.patch.object(manager, "restart_process", return_value=(True, "r")) as restart_mock:
        manager.handle_command({"cmd": "stop", "name": "rq"})
        manager.handle_command({"cmd": "restart", "name": "rq"})
    stop_mock.assert_called_once_with("rq")
    restart_mock.assert_called_once_with("rq")


def test_handle_command_missing_name():
    manager = make_manager("rq")
    with pytest.raises(CommandError):
        manager.handle_command({"cmd": "start"})


def test_handle_command_unknown():
    manager = make_manager("rq")
    with pytest.raises(CommandError):
        manager.handle_command({"cmd": "reread"})


def make_config(name, **kwargs):
    return CompanionConfig(name=name, target=lambda: None, **kwargs)


def test_reread_adds_new():
    manager = make_manager("rq")
    new = [make_config("rq"), make_config("scheduler")]
    with mock.patch("os.fork", return_value=10):
        result = manager.reread_config(new)
    assert result["added"] == ["scheduler"]
    assert "scheduler" in manager.processes
    assert manager.processes["scheduler"].state == State.STARTING


def test_reread_removes_missing():
    manager = make_manager("rq", "scheduler")
    manager.processes["scheduler"].state = State.RUNNING
    manager.processes["scheduler"].pid = 11
    with mock.patch("os.kill"):
        result = manager.reread_config([make_config("rq")])
    assert result["removed"] == ["scheduler"]
    assert "scheduler" not in manager.processes


def test_reread_restarts_changed():
    manager = make_manager("rq")
    manager.processes["rq"].state = State.RUNNING
    manager.processes["rq"].pid = 12
    changed = make_config("rq", env={"X": "1"})  # different hash
    with mock.patch("os.kill"):
        result = manager.reread_config([changed])
    assert result["restarted"] == ["rq"]
    assert manager.processes["rq"].config is changed
    assert manager.processes["rq"].state == State.STOPPING


def test_reread_changed_manual_stop_keeps_stopped():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.manual_stop = True
    proc.state = State.STOPPED
    changed = make_config("rq", env={"X": "1"})
    result = manager.reread_config([changed])
    assert result["unchanged"] == ["rq"]
    assert proc.config is changed and proc.state == State.STOPPED


def test_reread_unchanged_noop():
    manager = make_manager("rq")
    same = manager.processes["rq"].config
    result = manager.reread_config([same])
    assert result["unchanged"] == ["rq"]
    assert result["restarted"] == []


def test_reread_duplicate_name_keeps_old():
    manager = make_manager("rq")
    result = manager.reread_config([make_config("rq"), make_config("rq")])
    assert result["ok"] is False and result["kept_old_config"] is True
    assert "duplicate" in result["error"]


def test_reread_validation_failure_mutates_nothing():
    manager = make_manager("rq")
    original_config = manager.processes["rq"].config
    original_names = set(manager.processes)
    # This batch would change "rq" and add "scheduler", but the duplicate
    # "scheduler" makes the whole reread invalid: nothing must be applied.
    bad = [make_config("rq", env={"X": "1"}), make_config("scheduler"),
           make_config("scheduler")]
    with mock.patch("os.fork") as fork, mock.patch("os.kill") as kill:
        result = manager.reread_config(bad)
    assert result["ok"] is False and result["kept_old_config"] is True
    assert set(manager.processes) == original_names
    assert manager.processes["rq"].config is original_config
    fork.assert_not_called()
    kill.assert_not_called()


def test_handle_command_reread_no_loader():
    manager = make_manager("rq")
    with pytest.raises(CommandError):
        manager.handle_command({"cmd": "reread"})


def test_handle_command_reread_runs_loader():
    manager = make_manager("rq")
    manager.config_loader = lambda: [manager.processes["rq"].config]
    resp = manager.handle_command({"cmd": "reread"})
    assert resp["ok"] is True and resp["unchanged"] == ["rq"]


def test_handle_command_reread_bad_config():
    manager = make_manager("rq")
    def boom():
        raise ValueError("duplicate companion name rq")
    manager.config_loader = boom
    resp = manager.handle_command({"cmd": "reread"})
    assert resp["ok"] is False and resp["kept_old_config"] is True


def test_start_process_stopped_spawns():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    with mock.patch("os.fork", return_value=70) as fork:
        ok, _ = manager.start_process("rq")
    fork.assert_called_once()
    assert ok and proc.state == State.STARTING and proc.manual_stop is False


def test_start_process_backoff_cancels_retry():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.next_retry_at = 999.0
    proc.manual_stop = True
    with mock.patch("os.fork", return_value=71):
        ok, _ = manager.start_process("rq")
    assert ok and proc.state == State.STARTING
    assert proc.next_retry_at is None and proc.manual_stop is False


def test_start_process_running_is_noop():
    manager = make_manager("rq")
    manager.processes["rq"].state = State.RUNNING
    with mock.patch("os.fork") as fork:
        ok, _ = manager.start_process("rq")
    assert ok
    fork.assert_not_called()


def test_start_process_stopping_rejected():
    manager = make_manager("rq")
    manager.processes["rq"].state = State.STOPPING
    ok, msg = manager.start_process("rq")
    assert not ok and "stopping" in msg


def test_start_process_unknown():
    manager = make_manager("rq")
    ok, _ = manager.start_process("nope")
    assert not ok


def test_stop_process_running_signals_and_stopping():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.RUNNING
    proc.pid = 80
    proc.config.stop_timeout = 60
    with mock.patch("os.kill") as kill:
        ok, _ = manager.stop_process("rq", now=200.0)
    kill.assert_called_once_with(80, signal.SIGTERM)
    assert ok and proc.state == State.STOPPING
    assert proc.manual_stop is True and proc.stop_deadline == 260.0


def test_stop_process_backoff_to_stopped():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.next_retry_at = 999.0
    with mock.patch("os.kill") as kill:
        ok, _ = manager.stop_process("rq")
    kill.assert_not_called()
    assert ok and proc.state == State.STOPPED
    assert proc.next_retry_at is None and proc.manual_stop is True


def test_stop_process_already_stopped():
    manager = make_manager("rq")
    with mock.patch("os.kill") as kill:
        ok, _ = manager.stop_process("rq")
    kill.assert_not_called()
    assert ok and manager.processes["rq"].manual_stop is True


def test_stop_process_unknown():
    manager = make_manager("rq")
    ok, _ = manager.stop_process("nope")
    assert not ok


def test_stop_during_restart_cancels_pending_restart():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.STOPPING
    proc.pid = 70
    proc.restart_pending = True
    with mock.patch("os.kill") as kill:
        ok, _ = manager.stop_process("rq")
    kill.assert_not_called()
    assert ok and proc.manual_stop is True and proc.restart_pending is False
    # On exit the companion now settles STOPPED instead of being respawned.
    with mock.patch.object(manager, "spawn_process") as spawn:
        manager.handle_exit(proc)
    spawn.assert_not_called()
    assert proc.state == State.STOPPED


def test_safe_kill_ignores_dead_process():
    with mock.patch("os.kill", side_effect=ProcessLookupError):
        CompanionManager._safe_kill(123, signal.SIGTERM)  # must not raise


def test_stop_process_survives_dead_companion():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.RUNNING
    proc.pid = 80
    with mock.patch("os.kill", side_effect=ProcessLookupError):
        ok, _ = manager.stop_process("rq", now=1.0)
    assert ok and proc.state == State.STOPPING


def test_signal_number_resolves_name():
    assert CompanionManager._signal_number("SIGKILL") == signal.SIGKILL
    assert CompanionManager._signal_number(9) == 9


def test_signal_number_rejects_bad():
    with pytest.raises(ValueError):
        CompanionManager._signal_number("SIGTRM")


def test_restart_process_running_stops_with_reload_timeout():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.RUNNING
    proc.pid = 90
    proc.config.reload_timeout = 30
    proc.manual_stop = True
    with mock.patch("os.kill") as kill:
        ok, _ = manager.restart_process("rq", now=300.0)
    kill.assert_called_once_with(90, signal.SIGTERM)
    assert ok and proc.state == State.STOPPING
    assert proc.restart_pending is True and proc.stop_deadline == 330.0
    assert proc.manual_stop is False


def test_restart_pending_reap_respawns_immediately():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.STOPPING
    proc.restart_pending = True
    proc.pid = 91
    with mock.patch("os.waitpid", side_effect=[(91, 0), (0, 0)]), \
            mock.patch("os.fork", return_value=92):
        manager.reap_processes()
    assert proc.state == State.STARTING
    assert proc.pid == 92
    assert proc.restart_pending is False
    assert proc.restart_count == 1


def test_restart_process_stopped_starts_now():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    with mock.patch("os.fork", return_value=93), mock.patch("os.kill") as kill:
        ok, _ = manager.restart_process("rq")
    kill.assert_not_called()
    assert ok and proc.state == State.STARTING


def test_restart_process_backoff_starts_now():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.next_retry_at = 999.0
    with mock.patch("os.fork", return_value=94):
        ok, _ = manager.restart_process("rq")
    assert ok and proc.state == State.STARTING and proc.next_retry_at is None


def test_restart_process_stopping_rejected():
    manager = make_manager("rq")
    manager.processes["rq"].state = State.STOPPING
    ok, msg = manager.restart_process("rq")
    assert not ok and "stopping" in msg


def test_manual_stop_preserved_through_exit():
    # stop a running companion, then reap its child: it must settle in STOPPED
    # with manual_stop still set so it is not auto-restarted.
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.RUNNING
    proc.pid = 60
    with mock.patch("os.kill"):
        manager.stop_process("rq", now=10.0)
    with mock.patch("os.waitpid", side_effect=[(60, 0), (0, 0)]), \
            mock.patch("os.fork") as fork:
        manager.reap_processes()
    fork.assert_not_called()
    assert proc.state == State.STOPPED and proc.manual_stop is True


def test_start_clears_manual_stop():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.manual_stop = True
    with mock.patch("os.fork", return_value=61):
        manager.start_process("rq")
    assert proc.manual_stop is False


def test_spawn_does_not_touch_manual_stop():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.manual_stop = True
    with mock.patch("os.fork", return_value=62):
        manager.spawn_process(proc)
    assert proc.manual_stop is True


def test_handle_exit_unexpected_backoff():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.restart_delay = 5
    manager.handle_exit(proc, now=100.0)
    assert proc.state == State.BACKOFF
    assert proc.next_retry_at == 105.0


def test_handle_exit_manual_stop_stays_stopped():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.manual_stop = True
    manager.handle_exit(proc, now=100.0)
    assert proc.state == State.STOPPED
    assert proc.next_retry_at is None


def test_retry_backoff_respawns_when_due():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.next_retry_at = 100.0
    with mock.patch("os.fork", return_value=555):
        retried = manager.retry_backoff(now=101.0)
    assert retried == [proc]
    assert proc.restart_count == 1
    assert proc.state == State.STARTING
    assert proc.pid == 555


def test_retry_backoff_waits_until_due():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.next_retry_at = 100.0
    assert manager.retry_backoff(now=99.0) == []
    assert proc.state == State.BACKOFF


def test_reap_unexpected_exit_enters_backoff():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.pid = 4321
    with mock.patch("os.waitpid", side_effect=[(4321, 1 << 8), (0, 0)]):
        manager.reap_processes()
    assert proc.state == State.BACKOFF
    assert proc.next_retry_at is not None


def test_promote_running_after_startsecs():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.config.startsecs = 1
    proc.state = State.STARTING
    proc.started_at = 100.0
    promoted = manager.promote_running(now=101.5)
    assert promoted == [proc]
    assert proc.state == State.RUNNING


def test_promote_running_too_early():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.config.startsecs = 5
    proc.state = State.STARTING
    proc.started_at = 100.0
    assert manager.promote_running(now=102.0) == []
    assert proc.state == State.STARTING


def test_promote_running_ignores_non_starting():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    proc.state = State.BACKOFF
    proc.started_at = 100.0
    assert manager.promote_running(now=999.0) == []
    assert proc.state == State.BACKOFF


def test_spawn_parent_records_pid_and_starting():
    manager = make_manager("rq")
    proc = manager.processes["rq"]
    with mock.patch("os.fork", return_value=4321):
        pid = manager.spawn_process(proc)
    assert pid == 4321
    assert proc.pid == 4321
    assert proc.state == State.STARTING
    assert proc.started_at is not None
    assert proc.manual_stop is False


def test_lifecycle_running_crash_backoff_retry():
    manager = make_manager("rq")
    process = manager.processes["rq"]
    assert process.state == State.STOPPED
    with mock.patch("os.fork", return_value=100):
        manager.spawn_process(process)
    assert process.state == State.STARTING
    manager.promote_running(now=process.started_at + process.config.startsecs)
    assert process.state == State.RUNNING
    manager.handle_exit(process, now=1000.0)
    assert process.state == State.BACKOFF
    assert process.next_retry_at == 1000.0 + process.restart_delay
    with mock.patch("os.fork", return_value=101):
        manager.retry_backoff(now=process.next_retry_at)
    assert process.state == State.STARTING


def test_lifecycle_stop_to_stopped():
    manager = make_manager("rq")
    process = manager.processes["rq"]
    with mock.patch("os.fork", return_value=200):
        manager.spawn_process(process)
    manager.promote_running(now=process.started_at + process.config.startsecs)
    with mock.patch("os.kill") as kill:
        manager.stop_process("rq", now=500.0)
    assert process.state == State.STOPPING
    assert process.manual_stop is True
    kill.assert_called_once()
    manager.handle_exit(process, now=501.0)
    assert process.state == State.STOPPED


def test_lifecycle_restart_respawns_after_exit():
    manager = make_manager("rq")
    process = manager.processes["rq"]
    with mock.patch("os.fork", return_value=300):
        manager.spawn_process(process)
    manager.promote_running(now=process.started_at + process.config.startsecs)
    with mock.patch("os.kill"):
        manager.restart_process("rq", now=600.0)
    assert process.state == State.STOPPING
    assert process.restart_pending is True
    with mock.patch("os.fork", return_value=301):
        manager.handle_exit(process, now=601.0)
    assert process.state == State.STARTING
    assert process.restart_pending is False