"compress/flate"
	"encoding/binary"
	"errors"
	"hash"
	"hash/adler32"
	"io"
)

const (
	zlibDeflate   = 8
	zlibMaxWindow = 7
)

var (
	// ErrChecksum is returned when reading ZLIB data that has an invalid checksum.
	ErrChecksum = errors.New("zlib: invalid checksum")
	// ErrDictionary is returned when reading ZLIB data that has an invalid dictionary.
	ErrDictionary = errors.New("zlib: invalid dictionary")

	gzipID2     = 0x8b
	gzipDeflate = 8
	flagText    = 1 << 0
	flagHdrCrc  = 1 << 1
	flagExtra   = 1 << 2
	flagName    = 1 << 3
	flagComment = 1 << 4
)

var (
	// ErrChecksum is returned when reading GZIP data that has an invalid checksum.
	ErrChecksum = errors.New("gzip: invalid checksum")
	// ErrHeader is returned when reading GZIP data that has an invalid header.
	ErrHeader = errors.New("gzip: invalid header")
)

	switch compType {
	case noneType:
		r = scannedReader
	case gzipType:
		gzr, err := gzip.NewReader(scannedReader)
		if err != nil {
			if errors.Is(err, gzip.ErrHeader) || errors.Is(err, gzip.ErrChecksum) {
				return nil, errInvalidCompression(err, compType)
			}
			return nil, errTruncatedInput(err)
		}
		r = gzr
		pr.closer = gzr
	case bzip2Type:

		"",
		[]byte{0x78, 0x9f, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01},
		nil,
		ErrHeader,
	},
	{
		"bad checksum",
		"",
		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0xff},
		nil,
		ErrChecksum,
	},
	{
		"not enough data",
		"",
		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00},
		nil,
		io.ErrUnexpectedEOF,
	},
	{
		"excess data is silently ignored",
		"",
		[]byte{

			0x74, 0x78, 0x74, 0x00, 0xcb, 0x48, 0xcd, 0xc9,
			0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
			0x02, 0x00, 0xff, 0xff, 0xff, 0xff, 0x0c, 0x00,
			0x00, 0x00,
		},
		ErrChecksum,
	},
	{ // has 1 non-empty fixed huffman block but corrupt size
		"hello.txt",
		"hello.txt + corrupt size",
		"hello world\n",
		[]byte{
			0x1f, 0x8b, 0x08, 0x08, 0xc8, 0x58, 0x13, 0x4a,

			if errors.As(err, &stErr) {
				return errInvalidCompression(err, s3Select.Input.CompressionType)
			}
			// Test these compressor errors
			errs := []error{
				gzip.ErrHeader, gzip.ErrChecksum,
				s2.ErrCorrupt, s2.ErrUnsupported, s2.ErrCRC,
				zstd.ErrBlockTooSmall, zstd.ErrMagicMismatch, zstd.ErrWindowSizeExceeded, zstd.ErrUnknownDictionary, zstd.ErrWindowSizeTooSmall,
				lz4.ErrInvalid, lz4.ErrBlockDependency,

		{"(*Writer).SetComment", Method, 10},
		{"(*Writer).SetOffset", Method, 5},
		{"Compressor", Type, 2},
		{"Decompressor", Type, 2},
		{"Deflate", Const, 0},
		{"ErrAlgorithm", Var, 0},
		{"ErrChecksum", Var, 0},
		{"ErrFormat", Var, 0},
		{"ErrInsecurePath", Var, 20},
		{"File", Type, 0},
		{"File.FileHeader", Field, 0},
		{"FileHeader", Type, 0},
		{"FileHeader.CRC32", Field, 0},

pkg archive/zip, type Reader struct, Comment string
pkg archive/zip, type Reader struct, File []*File
pkg archive/zip, type Writer struct
pkg archive/zip, var ErrAlgorithm error
pkg archive/zip, var ErrChecksum error
pkg archive/zip, var ErrFormat error
pkg bufio, func NewReadWriter(*Reader, *Writer) *ReadWriter
pkg bufio, func NewReader(io.Reader) *Reader
pkg bufio, func NewReaderSize(io.Reader, int) *Reader