#!/usr/bin/python -u
# -*- coding: utf-8 -*-


from struct import unpack


class AXMLReader():
    """Provide various read helpers."""

    def __init__(self, data):

        self._data = data

        self._position = 0
        self._length = len(self._data)


    def readInt(self):
        """Read a 4-bytes value."""

        self.skipInt()

        value = unpack('<L', self._data[self._position - 4 : self._position])[0]

        return value


    def skipInt(self):
        """Skip a 4-bytes value."""

        self._position += 4

        if self._position > self._length:
            raise Exception("Reader out of bound (%d > %d)!" % (self._position, self._length))


    def readIntArray(self, length):
        """Read an array composed of 4-bytes values."""

        return [ self.readInt() for i in range(0, length) ]