package cli

import (
	"testing"
	"time"
)

func TestDurationValueParses(t *testing.T) {
	cases := map[string]duration{
		"30d":     {days: 30},
		"7d":      {days: 7},
		"1y2m10d": {years: 1, months: 2, days: 10},
		"2m":      {months: 2},
		"1y":      {years: 1},
		"0d":      {days: 0},
	}
	for in, want := range cases {
		var v duration
		if err := v.Set(in); err != nil {
			t.Fatalf("Set(%q): %v", in, err)
		}
		if v != want {
			t.Fatalf("Set(%q) = %+v, want %+v", in, v, want)
		}
	}
}

func TestDurationValueRejectsBadInput(t *testing.T) {
	for _, in := range []string{"", "d", "5", "5x", "1h", "1m2m", "-3d", "y", "5 d", "99999999999999999999d"} {
		var v duration
		if err := v.Set(in); err == nil {
			t.Fatalf("Set(%q): expected error", in)
		}
	}
}

func TestDurationValueMonthIsCalendarMonth(t *testing.T) {
	var v duration
	if err := v.Set("1m"); err != nil {
		t.Fatal(err)
	}
	now := time.Date(2024, time.March, 31, 0, 0, 0, 0, time.UTC)
	// A calendar-aware month back from March 31 lands in February, not "31 days".
	got := v.cutoff(now)
	if got.Month() != time.February && got.Month() != time.March {
		t.Fatalf("cutoff month = %v, want calendar-aware", got.Month())
	}
	if got.Equal(now.AddDate(0, 0, -30)) {
		t.Fatalf("cutoff must not use a fixed 30-day month")
	}
}