# -*- coding: utf-8 -*-

# The MIT License (MIT)
#
# Copyright (c) 2015 Alex Headley <aheadley@waysaboutstuff.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

__all__ = ['decompress', 'compress', 'LZSS']

import struct
import logging

from naabal.util import StringIO
from naabal.util.bitio import BitReader, BitWriter

logger = logging.getLogger('naabal.util.lzss')

# MOD_WINDOW = lambda value: value & (LZSS.WINDOW_SIZE - 1)
MOD_WINDOW = lambda value: value % 4096

class LZSS(object):
    INDEX_BIT_COUNT         = 12
    LENGTH_BIT_COUNT        = 4
    WINDOW_SIZE             = 1 << INDEX_BIT_COUNT # 4096
    RAW_LOOK_AHEAD_SIZE     = 1 << LENGTH_BIT_COUNT # 16
    BREAK_EVEN              = (1 + INDEX_BIT_COUNT + LENGTH_BIT_COUNT) / 9 # 1
    LOOK_AHEAD_SIZE         = RAW_LOOK_AHEAD_SIZE + BREAK_EVEN
    TREE_ROOT               = WINDOW_SIZE
    END_OF_STREAM           = 0x000
    UNUSED                  = 0

    def compress_stream(self, input_buffer, output_buffer):
        current_position    = 1
        match_length        = 0
        match_position      = 0
        window = bytearray(self.WINDOW_SIZE)

        for i in xrange(self.LOOK_AHEAD_SIZE):