package timezone

import (
	"crypto/sha256"
	"fmt"
	"testing"
	"time"
)

func TestFrozenSnapshot(t *testing.T) {
	if got := fmt.Sprintf("%x", sha256.Sum256(data)); got != "b2d18a7c8fa8142097a48c99609fb3c92db5ee98bc740294e57eab8ae9f94779" {
		t.Fatal("snapshot changed without a new version")
	}
	t.Setenv("ZONEINFO", t.TempDir())
	for _, name := range []string{"UTC", "Asia/Shanghai", "America/New_York", "Australia/Lord_Howe", "Pacific/Apia"} {
		zone, err := Load(name, Version)
		if err != nil || zone == nil {
			t.Fatalf("load %s: %v", name, err)
		}
		again, err := Load(name, Version)
		if err != nil || again != zone {
			t.Fatal("cache changed")
		}
	}
	zone, _ := Load("Asia/Shanghai", Version)
	_, offset := time.Date(2026, 1, 1, 0, 0, 0, 0, zone).Zone()
	if offset != 8*3600 {
		t.Fatal("wrong frozen zone")
	}
	for _, name := range []string{"", "Local", "../UTC", "/etc/localtime"} {
		if _, err := Load(name, Version); err == nil {
			t.Fatal("accepted external timezone")
		}
	}
	if _, err := Load("UTC", "unavailable-version"); err == nil {
		t.Fatal("silently upgraded frozen version")
	}
}