package storage

import (
	"testing"
)

// TestAwayWindowOnlyMovesOnANewVisit pins the session gap directly. Within the
// gap the window is held; past it, it advances to where the reader actually left
// off — never to now, or everything between their last load and this one would
// fall down the crack.
func TestAwayWindowOnlyMovesOnANewVisit(t *testing.T) {
	if err := Init(t.TempDir() + "/visit.db"); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { Close() })

	t0 := int64(1_000_000)
	if _, first, err := AdvVisitWindow("sub-1", t0); err != nil || !first {
		t.Fatalf("first call: first=%v err=%v", first, err)
	}
	// A minute later: same visit, window pinned to where it started.
	from, _, err := AdvVisitWindow("sub-1", t0+60)
	if err != nil || from != t0 {
		t.Fatalf("window = %d (err %v), want it held at %d inside the session", from, err, t0)
	}
	// Well past the gap: a new visit, reading from the last heartbeat (t0+60),
	// not from now.
	from, _, err = AdvVisitWindow("sub-1", t0+60+advVisitSessionGap+1)
	if err != nil {
		t.Fatal(err)
	}
	if from != t0+60 {
		t.Errorf("window = %d, want the previous heartbeat %d — anything else drops or replays events",
			from, t0+60)
	}
}