from datetime import date
from types import SimpleNamespace

from app.crud.subject import derive_subject_status, should_generate_visits_after_subject_update
from app.crud.visit import (
    build_early_termination_visit_changes,
    build_visit_schedule_dates,
    get_last_planned_visit_window_start_date,
    sort_visits_for_display,
    validate_early_termination_date,
)
from app.schemas.study import StudyUpdate


def test_build_visit_schedule_dates_uses_per_visit_windows():
    baseline_date = date(2026, 5, 8)

    visits = build_visit_schedule_dates(
        [
            {
                "visit_code": "基线访视",
                "baseline_offset_days": 0,
                "window_before_days": 0,
                "window_after_days": 0,
            },
            {
                "visit_code": "V1",
                "baseline_offset_days": 7,
                "window_before_days": 2,
                "window_after_days": 2,
            },
            {
                "visit_code": "V2",
                "baseline_offset_days": 15,
                "window_before_days": 2,
                "window_after_days": 2,
            },
            {
                "visit_code": "V3",
                "baseline_offset_days": 23,
                "window_before_days": 3,
                "window_after_days": 3,
            },
        ],
        baseline_date,
    )

    assert [
        (visit["visit_code"], visit["baseline_offset_days"], visit["planned_date"], visit["window_start"], visit["window_end"])
        for visit in visits
    ] == [
        ("基线访视", 0, date(2026, 5, 8), date(2026, 5, 8), date(2026, 5, 8)),
        ("V1", 7, date(2026, 5, 15), date(2026, 5, 13), date(2026, 5, 17)),
        ("V2", 15, date(2026, 5, 23), date(2026, 5, 21), date(2026, 5, 25)),
        ("V3", 23, date(2026, 5, 31), date(2026, 5, 28), date(2026, 6, 3)),
    ]


def test_build_visit_schedule_dates_keeps_visit_structure_without_baseline_date():
    visits = build_visit_schedule_dates(
        [
            {
                "visit_code": "基线访视",
                "baseline_offset_days": 0,
                "window_before_days": 0,
                "window_after_days": 0,
            },
            {
                "visit_code": "V1",
                "baseline_offset_days": 7,
                "window_before_days": 2,
                "window_after_days": 2,
            },
        ],
        None,
    )

    assert [
        (visit["visit_code"], visit["planned_date"], visit["window_start"], visit["window_end"])
        for visit in visits
    ] == [
        ("基线访视", None, None, None),
        ("V1", None, None, None),
    ]


def test_study_update_allows_multiple_visits_with_same_baseline_offset():
    payload = StudyUpdate(
        visit_schedule=[
            {
                "visit_code": "筛选访视",
                "baseline_offset_days": 0,
                "window_before_days": 0,
                "window_after_days": 0,
            },
            {
                "visit_code": "基线访视",
                "baseline_offset_days": 0,
                "window_before_days": 0,
                "window_after_days": 0,
            },
        ]
    )

    assert [item.visit_code for item in payload.visit_schedule or []] == ["筛选访视", "基线访视"]


def test_sort_visits_for_display_follows_configured_visit_order_without_dates():
    visits = [
        SimpleNamespace(visit_code="V1", planned_date=None),
        SimpleNamespace(visit_code="V2", planned_date=None),
        SimpleNamespace(visit_code="基线访视", planned_date=None),
    ]
    visit_schedule = [
        {"visit_code": "基线访视"},
        {"visit_code": "V1"},
        {"visit_code": "V2"},
    ]

    assert [visit.visit_code for visit in sort_visits_for_display(visits, visit_schedule)] == ["基线访视", "V1", "V2"]


def test_sort_visits_for_display_does_not_infer_business_order():
    visits = [
        SimpleNamespace(visit_code="基线访视", planned_date=None),
        SimpleNamespace(visit_code="V1", planned_date=None),
        SimpleNamespace(visit_code="V2", planned_date=None),
    ]
    visit_schedule = [
        {"visit_code": "V1"},
        {"visit_code": "V2"},
        {"visit_code": "基线访视"},
    ]

    assert [visit.visit_code for visit in sort_visits_for_display(visits, visit_schedule)] == ["V1", "V2", "基线访视"]


def test_sort_visits_places_early_termination_after_last_actual_visit():
    visits = [
        SimpleNamespace(visit_code="筛选访视", planned_date=date(2026, 5, 3), actual_date=date(2026, 5, 3)),
        SimpleNamespace(visit_code="基线访视", planned_date=date(2026, 5, 3), actual_date=date(2026, 5, 3)),
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 10), actual_date=None),
        SimpleNamespace(visit_code="V2", planned_date=date(2026, 5, 17), actual_date=None),
        SimpleNamespace(visit_code="提前终止", planned_date=None, actual_date=date(2026, 5, 13)),
    ]
    visit_schedule = [
        {"visit_code": "筛选访视"},
        {"visit_code": "基线访视"},
        {"visit_code": "V1"},
        {"visit_code": "V2"},
    ]

    assert [visit.visit_code for visit in sort_visits_for_display(visits, visit_schedule)] == [
        "筛选访视",
        "基线访视",
        "提前终止",
        "V1",
        "V2",
    ]


def test_should_generate_visits_when_baseline_date_is_set_or_changed():
    assert should_generate_visits_after_subject_update(
        previous_baseline_date=None,
        next_baseline_date=date(2026, 5, 8),
    )
    assert should_generate_visits_after_subject_update(
        previous_baseline_date=date(2026, 5, 8),
        next_baseline_date=date(2026, 5, 9),
    )
    assert not should_generate_visits_after_subject_update(
        previous_baseline_date=None,
        next_baseline_date=None,
    )


def test_build_early_termination_visit_changes_adds_event_and_cancels_future_planned_visits():
    visits = [
        SimpleNamespace(visit_code="筛选访视", planned_date=date(2026, 5, 1), actual_date=date(2026, 5, 1), status="DONE"),
        SimpleNamespace(visit_code="基线访视", planned_date=date(2026, 5, 1), actual_date=date(2026, 5, 1), status="DONE"),
        SimpleNamespace(visit_code="V0", planned_date=date(2026, 5, 5), actual_date=None, status="LOST"),
        SimpleNamespace(
            visit_code="V1",
            planned_date=date(2026, 5, 6),
            window_start=date(2026, 5, 4),
            window_end=date(2026, 5, 8),
            actual_date=None,
            status="PLANNED",
        ),
        SimpleNamespace(
            visit_code="V2",
            planned_date=date(2026, 5, 15),
            window_start=date(2026, 5, 12),
            window_end=date(2026, 5, 18),
            actual_date=None,
            status="PLANNED",
        ),
    ]

    changes = build_early_termination_visit_changes(
        visits,
        termination_date=date(2026, 5, 6),
        reason="不良事件退出",
    )

    assert changes.event_visit_code == "提前终止"
    assert changes.event_actual_date == date(2026, 5, 6)
    assert changes.event_notes == "不良事件退出"
    assert [visit.visit_code for visit in changes.visits_to_cancel] == ["V1", "V2"]


def test_validate_early_termination_date_requires_date_before_last_visit_window_start():
    visits = [
        SimpleNamespace(visit_code="筛选访视", planned_date=date(2026, 5, 1), window_start=date(2026, 5, 1)),
        SimpleNamespace(visit_code="基线访视", planned_date=date(2026, 5, 1), window_start=date(2026, 5, 1)),
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 8), window_start=date(2026, 5, 6)),
        SimpleNamespace(visit_code="V2", planned_date=date(2026, 5, 15), window_start=date(2026, 5, 12)),
        SimpleNamespace(visit_code="提前终止", planned_date=None, window_start=None),
    ]

    assert get_last_planned_visit_window_start_date(visits) == date(2026, 5, 12)
    validate_early_termination_date(date(2026, 5, 11), visits)

    try:
        validate_early_termination_date(date(2026, 5, 12), visits)
    except ValueError as exc:
        assert "提前终止日期必须早于方案最后一个计划访视窗口开始日" in str(exc)
    else:
        raise AssertionError("same-day final visit window start should not be accepted as early termination")


def test_derive_subject_status_marks_dropped_when_early_termination_has_actual_date():
    subject = SimpleNamespace(screening_date=date(2026, 5, 1), enrollment_date=date(2026, 5, 3))
    visits = [
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 10), actual_date=date(2026, 5, 10), status="DONE", created_at=None),
        SimpleNamespace(visit_code="提前终止", planned_date=None, actual_date=date(2026, 5, 12), status="DONE", created_at=None),
    ]

    assert derive_subject_status(subject, visits, [{"visit_code": "V1"}]) == "DROPPED"


def test_derive_subject_status_marks_completed_when_last_standard_visit_has_actual_date():
    subject = SimpleNamespace(screening_date=date(2026, 5, 1), enrollment_date=date(2026, 5, 3))
    visits = [
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 10), actual_date=date(2026, 5, 10), status="DONE", created_at=None),
        SimpleNamespace(visit_code="V2", planned_date=date(2026, 5, 17), actual_date=date(2026, 5, 17), status="DONE", created_at=None),
    ]

    assert derive_subject_status(subject, visits, [{"visit_code": "V1"}, {"visit_code": "V2"}]) == "COMPLETED"


def test_derive_subject_status_rolls_back_to_enrolled_when_followup_after_standard_end_is_unfinished():
    subject = SimpleNamespace(screening_date=date(2026, 5, 1), enrollment_date=date(2026, 5, 3))
    visits = [
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 10), actual_date=date(2026, 5, 10), status="DONE", created_at=None),
        SimpleNamespace(visit_code="V2", planned_date=date(2026, 5, 17), actual_date=date(2026, 5, 17), status="DONE", created_at=None),
        SimpleNamespace(visit_code="安全性随访", planned_date=date(2026, 5, 24), actual_date=None, status="PLANNED", created_at=None),
    ]

    assert derive_subject_status(subject, visits, [{"visit_code": "V1"}, {"visit_code": "V2"}]) == "ENROLLED"


def test_derive_subject_status_uses_completed_standard_visit_when_extra_visit_is_before_standard_end():
    subject = SimpleNamespace(screening_date=date(2026, 5, 1), enrollment_date=date(2026, 5, 3))
    visits = [
        SimpleNamespace(visit_code="V1", planned_date=date(2026, 5, 10), actual_date=date(2026, 5, 10), status="DONE", created_at=None),
        SimpleNamespace(visit_code="安全性随访", planned_date=date(2026, 5, 12), actual_date=None, status="PLANNED", created_at=None),
        SimpleNamespace(visit_code="V2", planned_date=date(2026, 5, 17), actual_date=date(2026, 5, 17), status="DONE", created_at=None),
    ]

    assert derive_subject_status(subject, visits, [{"visit_code": "V1"}, {"visit_code": "V2"}]) == "COMPLETED"


def test_derive_subject_status_marks_screening_until_enrollment_date_is_filled():
    subject = SimpleNamespace(screening_date=date(2026, 5, 1), enrollment_date=None)

    assert derive_subject_status(subject, [], []) == "SCREENING"


def test_derive_subject_status_is_empty_before_screening_date_is_filled():
    subject = SimpleNamespace(screening_date=None, enrollment_date=None)

    assert derive_subject_status(subject, [], []) == ""