package callwindow

import (
	"strings"
	"testing"
	"time"
)

func TestAllowedBoundariesInShanghai(t *testing.T) {
	location := time.FixedZone("test", 8*60*60)
	tests := []struct {
		name string
		at   time.Time
		want bool
	}{
		{name: "before opening", at: time.Date(2026, 9, 20, 8, 59, 59, 0, location), want: false},
		{name: "opening", at: time.Date(2026, 9, 20, 9, 0, 0, 0, location), want: true},
		{name: "before closing", at: time.Date(2026, 9, 20, 19, 59, 59, 0, location), want: true},
		{name: "closing", at: time.Date(2026, 9, 20, 20, 0, 0, 0, location), want: false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := Allowed(tt.at); got != tt.want {
				t.Fatalf("Allowed(%s)=%v, want %v", tt.at, got, tt.want)
			}
		})
	}
}

func TestAllowedConvertsUTCToShanghai(t *testing.T) {
	if !Allowed(time.Date(2026, 9, 20, 1, 0, 0, 0, time.UTC)) {
		t.Fatal("01:00 UTC should be 09:00 Asia/Shanghai and allowed")
	}
	if Allowed(time.Date(2026, 9, 20, 12, 0, 0, 0, time.UTC)) {
		t.Fatal("12:00 UTC should be 20:00 Asia/Shanghai and rejected")
	}
}

func TestCheckExplainsClosedWindow(t *testing.T) {
	err := Check(time.Date(2026, 9, 20, 20, 0, 0, 0, time.FixedZone("test", 8*60*60)))
	if err == nil {
		t.Fatal("expected closed-window error")
	}
	for _, want := range []string{"09:00", "20:00", "Asia/Shanghai"} {
		if !strings.Contains(err.Error(), want) {
			t.Fatalf("error %q does not contain %q", err, want)
		}
	}
}