import pytest

from agent_todos.timebox import BoxState, TimeBox


def test_timebox_default_state_is_open():
    tb = TimeBox(id=None, todo_id=None, duration_seconds=1500)
    assert tb.state == BoxState.open
    assert tb.accumulated_seconds == 0
    assert tb.last_started_at is None
    assert tb.interruptions == []


def test_transitions_from_open():
    tb = TimeBox(id=None, todo_id=None, duration_seconds=600)
    # open can go to running (start) or be abandoned immediately
    assert tb.can(BoxState.running) is True
    assert tb.can(BoxState.abandoned) is True
    assert tb.can(BoxState.completed) is False  # nothing was worked on
    assert tb.can(BoxState.expired) is False


def test_transitions_from_running():
    tb = TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.running)
    assert tb.can(BoxState.paused) is True
    assert tb.can(BoxState.interrupted) is True
    assert tb.can(BoxState.completed) is True
    assert tb.can(BoxState.abandoned) is True
    assert tb.can(BoxState.expired) is True
    assert tb.can(BoxState.open) is False  # cannot rewind to fresh
    assert tb.can(BoxState.running) is False  # no self-loops


def test_transitions_from_paused():
    tb = TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.paused)
    assert tb.can(BoxState.running) is True  # resume
    assert tb.can(BoxState.interrupted) is True
    assert tb.can(BoxState.completed) is True
    assert tb.can(BoxState.abandoned) is True
    assert tb.can(BoxState.expired) is True
    assert tb.can(BoxState.open) is False


def test_transitions_from_interrupted():
    # interrupted is paused-with-a-reason: still recoverable to running
    tb = TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.interrupted)
    assert tb.can(BoxState.running) is True
    assert tb.can(BoxState.completed) is True
    assert tb.can(BoxState.abandoned) is True
    assert tb.can(BoxState.expired) is True
    assert tb.can(BoxState.open) is False


def test_terminal_states_accept_no_transitions():
    for terminal in (BoxState.completed, BoxState.abandoned, BoxState.expired):
        tb = TimeBox(id=None, todo_id=None, duration_seconds=600, state=terminal)
        for s in BoxState:
            assert tb.can(s) is False


def test_elapsed_math_paused_uses_accumulated_only():
    tb = TimeBox(
        id=None,
        todo_id=None,
        duration_seconds=600,
        state=BoxState.paused,
        accumulated_seconds=120,
    )
    assert tb.elapsed_seconds() == 120
    assert tb.remaining_seconds() == 480


def test_remaining_is_floor_zero():
    tb = TimeBox(
        id=None,
        todo_id=None,
        duration_seconds=600,
        state=BoxState.paused,
        accumulated_seconds=1200,
    )
    assert tb.remaining_seconds() == 0


def test_percent_progress_clamps_to_100():
    tb = TimeBox(
        id=None,
        todo_id=None,
        duration_seconds=600,
        state=BoxState.paused,
        accumulated_seconds=900,
    )
    assert tb.progress_percent() == 100


def test_duration_must_be_positive():
    with pytest.raises(ValueError):
        TimeBox(id=None, todo_id=None, duration_seconds=0)
    with pytest.raises(ValueError):
        TimeBox(id=None, todo_id=None, duration_seconds=-5)


def test_has_active_nonterminal_state():
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.open).has_active_state() is True
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.running).has_active_state() is True
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.paused).has_active_state() is True
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.interrupted).has_active_state() is True
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.completed).has_active_state() is False
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.abandoned).has_active_state() is False
    assert TimeBox(id=None, todo_id=None, duration_seconds=600, state=BoxState.expired).has_active_state() is False