package timeutil

import (
	"testing"
	"time"
)

func TestPeriodOverlapUsesHalfOpenIntervals(t *testing.T) {
	start := time.Date(2026, 5, 29, 6, 0, 0, 0, time.UTC)
	left := Period{Start: start, End: start.Add(time.Hour)}
	touching := Period{Start: start.Add(time.Hour), End: start.Add(2 * time.Hour)}
	overlapping := Period{Start: start.Add(30 * time.Minute), End: start.Add(90 * time.Minute)}

	if left.Overlaps(touching) {
		t.Fatal("touching half-open periods overlap, want false")
	}
	if !left.Overlaps(overlapping) {
		t.Fatal("overlapping periods do not overlap, want true")
	}
}

func TestClockWindowHandlesOvernight(t *testing.T) {
	location := time.FixedZone("Test", -5*60*60)
	date := time.Date(2026, 5, 29, 12, 0, 0, 0, location)
	start, _ := ParseClock("22:00")
	end, _ := ParseClock("06:00")

	window := ClockWindow(date, location, start, end)
	if got := window.Start.Format("2006-01-02T15:04"); got != "2026-05-29T22:00" {
		t.Fatalf("Start = %s, want 2026-05-29T22:00", got)
	}
	if got := window.End.Format("2006-01-02T15:04"); got != "2026-05-30T06:00" {
		t.Fatalf("End = %s, want 2026-05-30T06:00", got)
	}
}