package leb128

import (
	"bytes"
)

// Read unsigned leb128, no error
func ReadULEB(buf *bytes.Buffer) (uint, uint) {
	result := uint(0)
	shift := uint(0)
	bytes_read := uint(0)
	for {
		b, _ := buf.ReadByte()
		bytes_read += 1
		result |= uint(b&0b0111_1111) << shift
		shift += 7
		if (b & 0b1000_0000) == 0 {
			return result, bytes_read
		}
	}
}

// Read signed leb128, no error
func ReadSLEB(buf *bytes.Buffer) (int, uint) {
	result := int(0)
	shift := uint(0)
	bytes_read := uint(0)
	for {
		b, _ := buf.ReadByte()
		bytes_read += 1
		result |= int(b&0b0111_1111) << shift
		shift += 7
		if (b & 0b1000_0000) == 0 {
			if b&0x40 != 0 {
				return result | (-1 << shift), bytes_read
			}
			return result, bytes_read
		}
	}
}