package applog

import (
	"testing"
	"time"
)

func TestCursorRoundTripAndOrder(t *testing.T) {
	r := Record{TS: time.Date(2026, 8, 10, 12, 0, 30, 500, time.UTC), Box: "b1", Seq: 42, Msg: "m"}
	c, ok := DecodeCursor(EncodeCursor(r))
	if !ok || !c.TS.Equal(r.TS) || c.Box != "b1" || c.Seq != 42 {
		t.Fatalf("round trip: %+v %v", c, ok)
	}
	// Before mirrors MergeRecords' (ts, box, seq) order exactly.
	if c.Before(r) {
		t.Fatal("a cursor at r is not before r")
	}
	for _, after := range []Record{
		{TS: r.TS.Add(time.Nanosecond), Box: "a0", Seq: 1},
		{TS: r.TS, Box: "b2", Seq: 1},
		{TS: r.TS, Box: "b1", Seq: 43},
	} {
		if !c.Before(after) {
			t.Fatalf("cursor should be before %+v", after)
		}
	}
	if c.Before(Record{TS: r.TS, Box: "b1", Seq: 41}) {
		t.Fatal("cursor before an earlier seq")
	}
	for _, bad := range []string{"", "!!!", "bm90IGpzb24"} {
		if _, ok := DecodeCursor(bad); ok {
			t.Errorf("DecodeCursor(%q) ok", bad)
		}
	}
}