package main

import (
	"testing"
	"time"
)

func TestParseCron(t *testing.T) {
	for _, spec := range []string{"*/5 * * * *", "0 9 * * 1-5", "30 8 1,15 * *", "* * * * *", "0 */2 * * *", "0 8-18/2 * * 1-5"} {
		if _, err := parseCron(spec); err != nil {
			t.Errorf("parseCron(%q) 应当成功，却得到: %v", spec, err)
		}
	}
	for _, spec := range []string{"* * * *", "61 * * * *", "* * * * 8", "a * * * *", "* * * * * *"} {
		if _, err := parseCron(spec); err == nil {
			t.Errorf("parseCron(%q) 应当失败", spec)
		}
	}
}

func TestCronNext(t *testing.T) {
	spec, _ := parseCron("30 9 * * *")
	next := cronNext(spec, time.Date(2026, 9, 8, 10, 0, 0, 0, time.Local))
	want := time.Date(2026, 9, 9, 9, 30, 0, 0, time.Local)
	if !next.Equal(want) {
		t.Fatalf("每日 09:30：期望 %v，得到 %v", want, next)
	}

	spec2, _ := parseCron("*/15 * * * *")
	next2 := cronNext(spec2, time.Date(2026, 9, 8, 10, 7, 0, 0, time.Local))
	want2 := time.Date(2026, 9, 8, 10, 15, 0, 0, time.Local)
	if !next2.Equal(want2) {
		t.Fatalf("*/15：期望 %v，得到 %v", want2, next2)
	}

	spec3, _ := parseCron("0 12 * * 5")
	next3 := cronNext(spec3, time.Date(2026, 9, 8, 12, 0, 0, 0, time.Local))
	want3 := time.Date(2026, 9, 11, 12, 0, 0, 0, time.Local)
	if !next3.Equal(want3) {
		t.Fatalf("仅周五：期望 %v，得到 %v", want3, next3)
	}

	spec4, _ := parseCron("0 0 * * 7")
	next4 := cronNext(spec4, time.Date(2026, 9, 12, 0, 0, 0, 0, time.Local)) // 周六
	want4 := time.Date(2026, 9, 13, 0, 0, 0, 0, time.Local)
	if !next4.Equal(want4) {
		t.Fatalf("7=周日：期望 %v，得到 %v", want4, next4)
	}
}