package pfile

import (
	"bytes"
	crand "crypto/rand"
	"path/filepath"
	"testing"

	"git.crumpington.com/public/jldb/lib/wal"
	"git.crumpington.com/public/jldb/mdb/change"
)

func newForTesting(t *testing.T) (*File, *Index) {
	t.Helper()

	tmpDir := t.TempDir()
	filePath := filepath.Join(tmpDir, "pagefile")

	pf, err := Open(filePath)
	if err != nil {
		t.Fatal(err)
	}

	idx, err := NewIndex(pf)
	if err != nil {
		t.Fatal(err)
	}

	return pf, idx
}

func randBytes(size int) []byte {
	buf := make([]byte, size)
	if _, err := crand.Read(buf); err != nil {
		panic(err)
	}
	return buf
}

func changesToRec(changes []change.Change) wal.Record {
	buf := &bytes.Buffer{}
	if err := change.Write(changes, buf); err != nil {
		panic(err)
	}
	return wal.Record{
		DataSize: int64(buf.Len()),
		Reader:   buf,
	}
}

func TestChangesToRec(t *testing.T) {
	changes := []change.Change{
		{
			CollectionID: 2,
			ItemID:       3,
			Store:        true,
			Data:         []byte{2, 3, 4},
			WritePageIDs: []uint64{0, 1},
			ClearPageIDs: []uint64{2, 3},
		},
	}
	rec := changesToRec(changes)
	c2 := []change.Change{}
	c2, _ = change.Read(c2, rec.Reader)
}