import pytest
from datetime import datetime, time, timedelta
from app.utils.time_utils import get_day_night_splits, minutes_after, day_start_pattern

class TestGetDayNightSplits:
    def test_zero_length_session(self):
        start = datetime(2024, 1, 15, 10, 0)
        end = datetime(2024, 1, 15, 10, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 0

    def test_session_entirely_in_day(self):
        start = datetime(2024, 1, 15, 10, 0)
        end = datetime(2024, 1, 15, 14, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 1
        assert segments[0]["type"] == "day"

    def test_session_entirely_in_night(self):
        start = datetime(2024, 1, 15, 22, 0)
        end = datetime(2024, 1, 16, 2, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 1
        assert segments[0]["type"] == "night"

    def test_session_spans_day_night_boundary(self):
        start = datetime(2024, 1, 15, 18, 0)
        end = datetime(2024, 1, 15, 22, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 2
        assert segments[0]["type"] == "day"
        assert segments[1]["type"] == "night"

    def test_session_spans_midnight(self):
        start = datetime(2024, 1, 15, 23, 0)
        end = datetime(2024, 1, 16, 2, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 1
        assert segments[0]["type"] == "night"

    def test_session_spans_two_days(self):
        # Start Day 1 at 23:00, End Day 2 at 01:00 (Night)
        # It should catch the transition if day_start/end logic is correct.
        # But here, no boundary (07:00 or 20:00) is in the session.
        # So it should just be one segment of type 'night'.
        start = datetime(2024, 1, 15, 23, 0)
        end = datetime(2024, 1, 16, 1, 0)
        day_start = time(7, 0)
        segments = get_day_night_splits(start, end, day_start, time(20, 0))
        assert len(segments) == 1
        assert segments[0]["type"] == "night"

    def test_session_boundary_at_start(self):
        # Session starts exactly at day_start
        start = datetime(2024, 1, 15, 7, 0)
        end = datetime(2024, 1, 15, 10, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        # The loop uses: if session_start < b1 < session_end
        # Since 7:00 is not > 7:00, b1 won't be added.
        # So it should result in 1 segment [start, end]
        assert len(segments) == 1
        assert segments[0]["type"] == "day"

    def test_session_boundary_at_end(self):
        # Session ends exactly at day_end
        start = datetime(2024, 1, 15, 18, 0)
        end = datetime(2024, 1, 15, 20, 0)
        day_start = time(7, 0)
        day_end = time(20, 0)
        segments = get_day_night_splits(start, end, day_start, day_end)
        assert len(segments) == 1
        assert segments[0]["type"] == "day"

class TestMinutesAfter:
    def test_minutes_at_reference(self):
        dt = datetime(2024, 1, 15, 4, 0)
        ref = time(4, 0)
        result = minutes_after(dt, ref)
        assert result == 0

    def test_minutes_after_reference(self):
        dt = datetime(2024, 1, 15, 7, 30)
        ref = time(4, 0)
        result = minutes_after(dt, ref)
        assert result == 210

    def test_before_reference(self):
        dt = datetime(2024, 1, 15, 3, 30)
        ref = time(4, 0)
        result = minutes_after(dt, ref)
        assert result == -30

class TestDayStartPattern:
    def test_within_day_range(self):
        assert day_start_pattern(time(12, 0), time(7, 0), time(20, 0)) is True

    def test_outside_day_range(self):
        assert day_start_pattern(time(3, 0), time(7, 0), time(20, 0)) is False

    def test_at_boundary(self):
        assert day_start_pattern(time(7, 0), time(7, 0), time(20, 0)) is True

    def test_just_after_boundary(self):
        # Test that the end boundary is exclusive
        assert day_start_pattern(time(20, 0), time(7, 0), time(20, 0)) is False

    def test_spans_midnight(self):
        assert day_start_pattern(time(22, 0), time(20, 0), time(7, 0)) is True
        assert day_start_pattern(time(3, 0), time(20, 0), time(7, 0)) is True