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


from defs import CHUNK_TYPE


class StringBlock():


    def __init__(self, reader):

        magic = reader.readInt()
        if magic != CHUNK_TYPE:
            raise Exception("Bad Magic Number (0x%08lx)!" % magic)

	chunk_size = reader.readInt()
        str_count = reader.readInt()
        style_offset_count = reader.readInt()
        reader.readInt() # ???
        str_offset = reader.readInt()
        styles_offset = reader.readInt()

        self._str_offsets = reader.readIntArray(str_count);
        self._style_offsets = reader.readIntArray(style_offset_count);

        if styles_offset == 0:
            size = chunk_size - str_offset
        else:
            size = styles_offset - str_offset

        if size % 4 != 0:
            raise Exception("String data size is not multiple of 4 (%d)!" % size)

        self._strings = reader.readIntArray(size / 4)

        if styles_offset > 0:

            size = chunk_size - styles_offset

            if size % 4 != 0:
                raise Exception("Style data size is not multiple of 4 (%d)!" % size)

            self._styles = reader.readIntArray(size / 4)

        self._str_data = [ self.getRaw(i) for i in range(self.count()) ]


    def count(self):
        """Count the number of strings in the current block."""

        return len(self._str_offsets)


    def getRaw(self, index):
        """Provide a raw string (without any styling information) at specified index."""

        if index < 0 or index >= len(self._str_offsets):
            raise Exception("Invalid Index (%d)!" % index)

        offset = self._str_offsets[index]
        length = self.getShort(self._strings, offset)

        data = ''

        for i in range(length):
            offset += 2
            data += unichr(self.getShort(self._strings, offset))

        return data


    def getShort(self, array, offset):

        value = array[offset / 4]

        if ((offset % 4) / 2) == 0:
            value &= 0xFFFF
        else:
            value >>= 16

        return value