package controlapi

import (
	"bytes"
	"strings"
	"testing"
	"time"
)

func TestCursorIsScopedAndTamperEvident(t *testing.T) {
	codec := NewCursorCodec(bytes.Repeat([]byte{7}, 32))
	position := CursorPosition{CreatedAt: time.Date(2026, 8, 7, 1, 2, 3, 4, time.UTC), DeviceID: "dev_1"}
	value, err := codec.Encode("tenant-a", "site-a", "filters", position)
	if err != nil {
		t.Fatal(err)
	}
	decoded, err := codec.Decode(value, "tenant-a", "site-a", "filters")
	if err != nil || decoded.DeviceID != position.DeviceID || !decoded.CreatedAt.Equal(position.CreatedAt) {
		t.Fatalf("cursor did not round trip: %+v %v", decoded, err)
	}
	for name, candidate := range map[string]string{
		"tenant": "tenant-b", "site": "site-b", "filter": "other",
	} {
		tenant, site, filter := "tenant-a", "site-a", "filters"
		switch name {
		case "tenant":
			tenant = candidate
		case "site":
			site = candidate
		case "filter":
			filter = candidate
		}
		if _, err := codec.Decode(value, tenant, site, filter); err == nil {
			t.Fatalf("cursor was accepted across %s scope", name)
		}
	}
	tampered := value[:len(value)-1] + strings.ToUpper(value[len(value)-1:])
	if tampered == value {
		tampered = value[:len(value)-1] + "A"
	}
	if _, err := codec.Decode(tampered, "tenant-a", "site-a", "filters"); err == nil {
		t.Fatal("tampered cursor was accepted")
	}
}

func TestGeneratedIdentifiersMatchContractShape(t *testing.T) {
	value, err := newULID("op_", time.Now())
	if err != nil {
		t.Fatal(err)
	}
	if len(value) != 29 || !strings.HasPrefix(value, "op_") {
		t.Fatalf("invalid operation ID %q", value)
	}
	trace, err := newTraceID()
	if err != nil || len(trace) != 38 {
		t.Fatalf("invalid trace ID %q: %v", trace, err)
	}
}