package git

import (
	"fmt"
	"io/ioutil"
	"os"
	"path"
	"testing"
)

var (
	// This is a packfile with three objects. The second is a delta which
	// depends on the third, which is also a delta.
	outOfOrderPack = []byte{
		0x50, 0x41, 0x43, 0x4b, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x03,
		0x32, 0x78, 0x9c, 0x63, 0x67, 0x00, 0x00, 0x00, 0x10, 0x00, 0x08, 0x76,
		0xe6, 0x8f, 0xe8, 0x12, 0x9b, 0x54, 0x6b, 0x10, 0x1a, 0xee, 0x95, 0x10,
		0xc5, 0x32, 0x8e, 0x7f, 0x21, 0xca, 0x1d, 0x18, 0x78, 0x9c, 0x63, 0x62,
		0x66, 0x4e, 0xcb, 0xcf, 0x07, 0x00, 0x02, 0xac, 0x01, 0x4d, 0x75, 0x01,
		0xd7, 0x71, 0x36, 0x66, 0xf4, 0xde, 0x82, 0x27, 0x76, 0xc7, 0x62, 0x2c,
		0x10, 0xf1, 0xb0, 0x7d, 0xe2, 0x80, 0xdc, 0x78, 0x9c, 0x63, 0x62, 0x62,
		0x62, 0xb7, 0x03, 0x00, 0x00, 0x69, 0x00, 0x4c, 0xde, 0x7d, 0xaa, 0xe4,
		0x19, 0x87, 0x58, 0x80, 0x61, 0x09, 0x9a, 0x33, 0xca, 0x7a, 0x31, 0x92,
		0x6f, 0xae, 0x66, 0x75,
	}
)

func TestIndexerOutOfOrder(t *testing.T) {
	t.Parallel()

	tmpPath, err := ioutil.TempDir("", "git2go")
	checkFatal(t, err)
	defer os.RemoveAll(tmpPath)

	var finalStats TransferProgress
	idx, err := NewIndexer(tmpPath, nil, func(stats TransferProgress) ErrorCode {
		finalStats = stats
		return ErrorCodeOK
	})
	checkFatal(t, err)
	defer idx.Free()

	_, err = idx.Write(outOfOrderPack)
	checkFatal(t, err)
	oid, err := idx.Commit()
	checkFatal(t, err)

	// The packfile contains the hash as the last 20 bytes.
	expectedOid := NewOidFromBytes(outOfOrderPack[len(outOfOrderPack)-20:])
	if !expectedOid.Equal(oid) {
		t.Errorf("mismatched packfile hash, expected %v, got %v", expectedOid, oid)
	}
	if finalStats.TotalObjects != 3 {
		t.Errorf("mismatched transferred objects, expected 3, got %v", finalStats.TotalObjects)
	}
	if finalStats.ReceivedObjects != 3 {
		t.Errorf("mismatched received objects, expected 3, got %v", finalStats.ReceivedObjects)
	}
	if finalStats.IndexedObjects != 3 {
		t.Errorf("mismatched indexed objects, expected 3, got %v", finalStats.IndexedObjects)
	}

	odb, err := NewOdb()
	checkFatal(t, err)
	defer odb.Free()

	backend, err := NewOdbBackendOnePack(path.Join(tmpPath, fmt.Sprintf("pack-%s.idx", oid.String())))
	checkFatal(t, err)
	// Transfer the ownership of the backend to the odb, no freeing needed.
	err = odb.AddBackend(backend, 1)
	checkFatal(t, err)

	packfileObjects := 0
	err = odb.ForEach(func(id *Oid) error {
		packfileObjects += 1
		return nil
	})
	checkFatal(t, err)
	if packfileObjects != 3 {
		t.Errorf("mismatched packfile objects, expected 3, got %v", packfileObjects)
	}

	// Inspect one of the well-known objects in the packfile.
	obj, err := odb.Read(NewOidFromBytes([]byte{
		0x19, 0x10, 0x28, 0x15, 0x66, 0x3d, 0x23, 0xf8, 0xb7, 0x5a, 0x47, 0xe7,
		0xa0, 0x19, 0x65, 0xdc, 0xdc, 0x96, 0x46, 0x8c,
	}))
	checkFatal(t, err)
	defer obj.Free()
	if "foo" != string(obj.Data()) {
		t.Errorf("mismatched packfile object contents, expected foo, got %q", string(obj.Data()))
	}
}