package serial

import "encoding/hex"

// ByteToHexString converts a byte into hex string.
func ByteToHexString(value byte) string {
	return hex.EncodeToString([]byte{value})
}

// BytesToUint16 deserializes a byte array to a uint16 in big endian order. The byte array must have at least 2 elements.
func BytesToUint16(value []byte) uint16 {
	_ = value[1] // bounds check hint to compiler; see golang.org/issue/14808
	return uint16(value[0])<<8 | uint16(value[1])
}

// BytesToUint32 deserializes a byte array to a uint32 in big endian order. The byte array must have at least 4 elements.
func BytesToUint32(value []byte) uint32 {
	_ = value[3]
	return uint32(value[0])<<24 |
		uint32(value[1])<<16 |
		uint32(value[2])<<8 |
		uint32(value[3])
}

// BytesToInt deserializes a bytes array (of at leat 4 bytes) to an int in big endian order.
func BytesToInt(value []byte) int {
	_ = value[3]
	return int(value[0])<<24 |
		int(value[1])<<16 |
		int(value[2])<<8 |
		int(value[3])
}

// BytesToInt64 deserializes a byte array to an int64 in big endian order. The byte array must have at least 8 elements.
func BytesToInt64(value []byte) int64 {
	_ = value[7]
	return int64(value[0])<<56 |
		int64(value[1])<<48 |
		int64(value[2])<<40 |
		int64(value[3])<<32 |
		int64(value[4])<<24 |
		int64(value[5])<<16 |
		int64(value[6])<<8 |
		int64(value[7])
}

// BytesToHexString converts a byte array into hex string.
func BytesToHexString(value []byte) string {
	m := hex.EncodedLen(len(value))
	if m == 0 {
		return "[]"
	}
	n := 1 + m + m/2
	b := make([]byte, n)
	hex.Encode(b[1:], value)
	b[0] = '['
	for i, j := n-3, m-2+1; i > 0; i -= 3 {
		b[i+2] = ','
		b[i+1] = b[j+1]
		b[i] = b[j]
		j -= 2
	}
	b[n-1] = ']'
	return string(b)
}