"""
Experimental script to convert Gothic BIN files to CSL files.

Source:
http://github.com/szapp/Ninja/wiki/Applications-and-Examples#translation-patch
"""
from __future__ import print_function
from datetime import datetime
import os
from struct import unpack
import sys


def convertOU(file, enc='utf-8'):
    """
    Convert output units bin to csl

    Parameters
    ----------
    file : str
        File path to the bin file

    Returns
    -------
    buffer : str
        String containing the ASCII converted content

    Raises
    ------
    ValueError :
        If file has incorrect header
    """
    type_names = {
        1: 'string',
        2: 'int',
        3: 'float',
        17: 'enum',
    }

    if not file.lower().endswith('.bin'):
        raise ValueError('File has incorrect extension')

    output = ''

    with open(file, 'rb') as f:
        if f.readline().rstrip().decode(enc) != 'ZenGin Archive':
            raise ValueError('Header: Not a ZenGin archive')
        if f.readline().rstrip().decode(enc) != 'ver 1':
            raise ValueError('Header: Incorrect version')
        if f.readline().rstrip().decode(enc) != 'zCArchiverBinSafe':
            raise ValueError('Header: Incorrect class')
        if f.readline().rstrip().decode(enc) != 'BIN_SAFE':
            raise ValueError('Header: Incorrect mode')
        if f.readline().rstrip().decode(enc) != 'saveGame 0':
            raise ValueError('Header: Expected savegame state')
        date = f.readline().rstrip().decode(enc)
        if not date.startswith('date '):
            raise ValueError('Header: Expected date')
        date = date[date.find(' ')+1:]
        user = f.readline().rstrip().decode(enc)
        if not user.startswith('user '):
            raise ValueError('Header: Expected user')
        user = user[user.find(' ')+1:]
        if f.readline().rstrip().decode(enc) != 'END':
            raise ValueError('Header: Expected END')

        # date = datetime.now().strftime('%d.%m.%Y %H:%M:%S')

        output += (
            'ZenGin Archive\r\n'
            'ver 1\r\n'
            'zCArchiverGeneric\r\n'
            'ASCII\r\n'
            'saveGame 0\r\n'
            'date ' + date + '\r\n'
            'user ' + user +'\r\n'
            'END\r\n'
        )

        if unpack('<i', f.read(4))[0] < 2:
            raise ValueError('Header: Invalid binary version')
        obj_count = unpack('<i', f.read(4))[0]
        chunk_pos = unpack('<i', f.read(4))[0]
        pos_seek = f.tell()
        f.seek(chunk_pos, 0)

        output += 'objects ' + str(obj_count) + '\r\n'
        output += 'END\r\n\r\n'

        n_count = unpack('<i', f.read(4))[0]

        var_names = [0] * n_count

        for i in range(n_count):
            str_len = unpack('<h', f.read(2))[0]
            ind_val = unpack('<h', f.read(2))[0]
            hash_val = unpack('<i', f.read(4))[0]

            textbuffer = f.read(str_len).decode(enc)
            textbuffer = textbuffer[:str_len]  # + chr(0)
            var_names[ind_val] = textbuffer
        f.seek(pos_seek, 0)

        idx = 0
        in_block = 0
        next_block = False

        byte = ord(f.read(1))
        while idx < obj_count and byte:
            if next_block:
                in_block += 1
                next_block = False

            if byte == 1:
                str_len, = unpack('<h', f.read(2))
                line = f.read(str_len).decode(enc)
                if line != '[]':
                    next_block = True
                    idx = int(line[line.rfind(' '):-1])
                else:
                    in_block -= 1

            elif byte == 18:
                var_n = var_names[unpack('<i', f.read(4))[0]]
                type_n = type_names[ord(f.read(1))]
                if type_n == 'string':
                    str_len, = unpack('<h', f.read(2))
                    line = var_n + '=' + type_n + ':' + f.read(str_len).decode(enc)
                else:
                    val, = unpack('<i', f.read(4))
                    line = var_n + '=' + type_n + ':' + str(val)

            output += '\t' * in_block + line + '\r\n'
            byte = ord(f.read(1))

        if output[-4:] == '[]\r\n':
            output = output[:-4]

        return output


if __name__ == '__main__':
    if len(sys.argv) <= 1:
        print('Usage: %s directory-containing-bin [encoding]'
              % os.path.basename(sys.argv[0]))
        exit(1)

    os.chdir(sys.argv[1])
    enc = sys.argv[2] if len(sys.argv) >= 3 else 'utf-8'

    out = convertOU('OU.BIN', enc)
    with open('OU.csl', 'wb') as f:
        f.write(bytes(out, enc))