//
// This package is supposed to be used by the net package of standard
// library. Therefore the package set used in the package must be the
// same as net package.

var (
	littleEndian binaryLittleEndian
	bigEndian    binaryBigEndian
)

type binaryByteOrder interface {
	Uint16([]byte) uint16
	Uint32([]byte) uint32
	PutUint16([]byte, uint16)
	PutUint32([]byte, uint32)
	Uint64([]byte) uint64
}

// readInt returns the size-bytes unsigned integer in native byte order at offset off.
func readInt(b []byte, off, size uintptr) (u uint64, ok bool) {
	if len(b) < int(off+size) {
		return 0, false
	}
	if goarch.BigEndian {
		return readIntBE(b[off:], size), true
	}
	return readIntLE(b[off:], size), true
}

func readIntBE(b []byte, size uintptr) uint64 {
	switch size {
	case 1:
		return uint64(b[0])
	case 2:

	var ident [4]byte
	if _, err := r.ReadAt(ident[0:], 0); err != nil {
		return nil, err
	}
	be := binary.BigEndian.Uint32(ident[0:])
	le := binary.LittleEndian.Uint32(ident[0:])
	switch Magic32 &^ 1 {
	case be &^ 1:
		f.ByteOrder = binary.BigEndian
		f.Magic = be
	case le &^ 1:
		f.ByteOrder = binary.LittleEndian
		f.Magic = le
	default:

				t.Errorf("error %q should contain math/rand", errStr)
			}
		}
	}
}

// Test the code to look up packages when given two args. First test case is
//
//	go doc binary BigEndian
//
// This needs to find encoding/binary.BigEndian, which means
// finding the package encoding/binary given only "binary".
// Second case is
//
//	go doc rand Float64
//

func keyHash(name string, key []byte) uint32 {
	h := sha256.New()
	h.Write([]byte(name))
	h.Write([]byte("\n"))
	h.Write(key)
	sum := h.Sum(nil)
	return binary.BigEndian.Uint32(sum)
}

var (
	errVerifierID   = errors.New("malformed verifier id")
	errVerifierAlg  = errors.New("unknown verifier algorithm")
	errVerifierHash = errors.New("invalid verifier hash")
)

//
// This package is supposed to be used by the net package of standard
// library. Therefore the package set used in the package must be the
// same as net package.

var (
	littleEndian binaryLittleEndian
	bigEndian    binaryBigEndian
)

type binaryByteOrder interface {
	Uint16([]byte) uint16
	Uint32([]byte) uint32
	Uint64([]byte) uint64
	PutUint16([]byte, uint16)
	PutUint32([]byte, uint32)
	PutUint64([]byte, uint64)

	}
	if d.tmp[12] != itNone && d.tmp[12] != itAdam7 {
		return FormatError("invalid interlace method")
	}
	d.interlace = int(d.tmp[12])

	w := int32(binary.BigEndian.Uint32(d.tmp[0:4]))
	h := int32(binary.BigEndian.Uint32(d.tmp[4:8]))
	if w <= 0 || h <= 0 {
		return FormatError("non-positive dimension")
	}
	nPixels64 := int64(w) * int64(h)
	nPixels := int(nPixels64)
	if nPixels64 != int64(nPixels) {

		if len(versions) > 0 {
			diskVersionsCount[binary.BigEndian.Uint64(versions)]++
		}
	}

	var commonVersions uint64
	max := 0
	for versions, count := range diskVersionsCount {
		if max < count {
			max = count
			commonVersions = versions
		}
	}

	if max >= writeQuorum {
		for _, versions := range diskVersions {
			if binary.BigEndian.Uint64(versions) == commonVersions {
				return versions
			}

}

func (m *mutator) rand(n int) int {
	return m.r.intn(n)
}

func (m *mutator) randByteOrder() binary.ByteOrder {
	if m.r.bool() {
		return binary.LittleEndian
	}
	return binary.BigEndian
}

// chooseLen chooses length of range mutation in range [1,n]. It gives
// preference to shorter ranges.
func (m *mutator) chooseLen(n int) int {
	switch x := m.rand(100); {
	case x < 90:

	buf = append(buf, input...)
	padlen := w - (len(buf) % w)
	return append(buf, make([]byte, padlen)...)
}

func leftEncode(value uint64) []byte {
	var b [9]byte
	binary.BigEndian.PutUint64(b[1:], value)
	// Trim all but last leading zero bytes
	i := byte(1)
	for i < 8 && b[i] == 0 {
		i++
	}
	// Prepend number of encoded bytes
	b[i-1] = 9 - i
	return b[i-1:]
}