"github.com/minio/minio/internal/logger"
)

// Erasure - erasure encoding details.
type Erasure struct {
	encoder                  func() reedsolomon.Encoder
	dataBlocks, parityBlocks int
	blockSize                int64
}

// NewErasure creates a new ErasureStorage.
func NewErasure(ctx context.Context, dataBlocks, parityBlocks int, blockSize int64) (e Erasure, err error) {
	// Check the parameters for sanity now.

// ShardSize - returns actual shared size from erasure blockSize.
func (e ErasureInfo) ShardSize() int64 {
	return ceilFrac(e.BlockSize, int64(e.DataBlocks))
}

// IsValid - tells if erasure info fields are valid.
func (fi FileInfo) IsValid() bool {
	if fi.Deleted {
		// Delete marker has no data, no need to check
		// for erasure coding information
		return true
	}
	dataBlocks := fi.Erasure.DataBlocks

	shardSize     int64
	shardFileSize int64
	buf           [][]byte
	readerToBuf   []int
	stashBuffer   []byte
}

// newParallelReader returns parallelReader.
func newParallelReader(readers []io.ReaderAt, e Erasure, offset, totalLength int64) *parallelReader {
	r2b := make([]int, len(readers))
	for i := range r2b {
		r2b[i] = i
	}
	bufs := make([][]byte, len(readers))
	shardSize := int(e.ShardSize())
	var b []byte

	_, err = xl.PutObject(ctx, "bucket", "dir/obj", mustGetPutObjReader(t, bytes.NewReader([]byte("abcd")), int64(len("abcd")), "", ""), ObjectOptions{})
	if err != nil {
		t.Fatalf("Erasure Object upload failed: <ERROR> %s", err)
	}
	for _, test := range testCases {
		t.Run("", func(t *testing.T) {
			_, err := xl.GetObjectInfo(ctx, "bucket", "dir/obj", ObjectOptions{})
			if err != nil {

		for i, disk := range disks {
			writers[i] = newBitrotWriter(disk, "", "testbucket", "object", erasure.ShardFileSize(test.data), writeAlgorithm, erasure.ShardSize())
		}
		n, err := erasure.Encode(t.Context(), bytes.NewReader(data), writers, buffer, erasure.dataBlocks+1)
		closeBitrotWriters(writers)
		if err != nil {
			t.Fatalf("Test %d: failed to create erasure test file: %v", i, err)
		}
		if n != test.data {

		writers := make([]io.Writer, len(disks))
		for i, disk := range disks {
			writers[i] = newBitrotWriter(disk, "", "testbucket", "testobject", erasure.ShardFileSize(test.size), test.algorithm, erasure.ShardSize())
		}
		_, err = erasure.Encode(t.Context(), bytes.NewReader(data), writers, buffer, erasure.dataBlocks+1)
		closeBitrotWriters(writers)
		if err != nil {
			t.Fatalf("Test %d: failed to create random test data: %v", i, err)
		}

	if err != errInvalidArgument {
		t.Fatalf("Expecting error, got %s", err)
	}

	// Initializes all erasure disks
	storageDisks, format, err := waitForFormatErasure(true, endpoints, 1, 1, 16, "")
	if err != nil {
		t.Fatalf("Unable to format drives for erasure, %s", err)
	}

	ep := PoolEndpoints{Endpoints: endpoints}

	parity, err := ecDrivesNoConfig(16)
	if err != nil {

	fi.DataDir = mustGetUUID()

	// Initialize erasure metadata.
	for index := range partsMetadata {
		partsMetadata[index] = fi
	}

	// Order disks according to erasure distribution
	var onlineDisks []StorageAPI
	onlineDisks, partsMetadata = shuffleDisksAndPartsMetadata(storageDisks, partsMetadata, fi)

	erasure, err := NewErasure(ctx, fi.Erasure.DataBlocks, fi.Erasure.ParityBlocks, fi.Erasure.BlockSize)
	if err != nil {

			if disk == OfflineDisk {
				continue
			}
			writers[i] = newBitrotWriter(disk, "", "testbucket", "object", erasure.ShardFileSize(int64(len(data[test.offset:]))), test.algorithm, erasure.ShardSize())
		}
		n, err := erasure.Encode(t.Context(), bytes.NewReader(data[test.offset:]), writers, buffer, erasure.dataBlocks+1)
		closeBitrotWriters(writers)
		if err != nil && !test.shouldFail {

		fi.Size = 1 << 20
		metaArr := make([]FileInfo, N)
		parities := make([]int, N)
		for i := range N {
			fi.Erasure.Index = i + 1
			metaArr[i] = fi
			parities[i] = parity
			if i < agree {
				continue
			}
			metaArr[i].Erasure.Index = 0 // creates invalid fi on remaining drives
			parities[i] = -1             // invalid fi are assigned parity -1
		}
		res.metaArr = metaArr