#! /usr/bin/env python3

from random import randint
import binascii
import ctypes
import logging
import os
import subprocess

logging.getLogger(__name__)

class Sins:
    seed = bytes()

    def __init__(self, *, parent: str, seed: str=str(), run_dir: str=str()):
        self.parent = ctypes.CDLL(parent)
        self.parent.gen_fork.restype = ctypes.c_int
        self.parent.gen_fork.argtypes = [ctypes.c_void_p, ctypes.c_void_p]

        if seed:
            with open(seed, 'rb') as seed_file:
                self.seed = seed_file.read()

        try:
            os.mkdir(run_dir)
        except FileNotFoundError or PermissionError:
            run_dir = os.path.dirname(self.seed)
        except FileExistsError:
            pass

        self.run_dir = run_dir

        child = self.generation(
            parent=self.parent,
            scrap=self.seed,
            cwd=self.run_dir)

        if child:
            logging.info(child)

    def scrap_recent(self, *, run_dir: str)->str:
        scraps = sorted(os.listdir(run_dir))

        if scraps:
            return os.path.join(run_dir, scraps[-1])

        return None

    def generation(self, *, parent: ctypes.CDLL, scrap: bytes, cwd: str):
        offset = randint(0, len(scrap))
        flip = randint(0, 255)
        scrap_len = len(scrap)

        logging.info('scrap_length [{}]'.format(scrap_len))
        logging.info('scrap\n{}'.format(binascii.b2a_hex(scrap)))

        status = parent.gen_fork(scrap, scrap_len)

        logging.info('status {}'.format(status))
        logging.info('scrap_length [{}]'.format(scrap_len))
        logging.info('scrap\n{}'.format(binascii.b2a_hex(scrap)))



def hex_dumps(scrap_dir):
    scrap_dir = os.path.abspath(scrap_dir)
    dump_dir = os.path.join(scrap_dir, 'hex')

    if not os.path.isdir(dump_dir):
        os.mkdir(dump_dir)

    scraps = os.listdir(scrap_dir)

    for scrap in scraps:
        scrap_path = os.path.join(scrap_dir, scrap)
        hex_name = '{}.hex'.format(scrap)
        hex_path = os.path.join(dump_dir, hex_name)

        if os.path.isfile(scrap_path):
            with open(scrap_path, 'rb') as file_in:
                with open(hex_path, 'w') as file_out:
                    binary = bytes(file_in.read())
                    for each in binary:
                        file_out.writelines('\'\\x{:02X}\',\n'.format(each))


if __name__ == '__main__':
    import argparse
    import sys

    parser = argparse.ArgumentParser(
        description='position independent code (PIC) mutation experiment.')
    parser.add_argument('--verbose', '-v', action='count')
    parser.add_argument('-build', action='store_true',
                        help='build parent and seed PIC image, exit.')
    parser.add_argument('-provision', action='store_true',
                        help='provision ubuntu for run, exit.')
    parser.add_argument('-logfile', help='log to file.')
    parser.add_argument('-seed', default='build/seed.asm.2.o',
                        help='path to PIC image.')
    parser.add_argument('-parent', default='build/libgeneration.so',
                        help='path to generation lib.')
    parser.add_argument('-dir', default='sandbox',
                        help='path to execution directory.')
    parser.add_argument('-dumps', action='store_true',
                        help='dump hex values of scraps in directory, exit.')
    args = parser.parse_args()

    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG) if args.verbose else logger.setLevel(logging.INFO)
    formatter = logging.Formatter('# %(filename)s:%(lineno)s\n%(message)s')

    stream_handler = logging.StreamHandler()
    stream_handler.setFormatter(formatter)
    logger.addHandler(stream_handler)

    if args.logfile:
        file_handler = logging.FileHandler(args.logfile, 'a')
        file_handler.setFormatter(formatter)
        logger.addHandler(file_handler)

    logging.info(args)

    if args.provision:
        provision = ['sudo', 'sh', 'provision-ubuntu.sh']
        prov_proc = subprocess.run(provision)

        os.environ['CC'] = 'clang'
        waf = [sys.executable, 'waf.py', 'configure']
        waf_proc = subprocess.run(waf)

    elif args.build:
        waf = [sys.executable, 'waf.py', 'build']
        waf_proc = subprocess.run(waf)
        logging.info(waf_proc.stdout)

    elif args.dumps:
        hex_dumps(args.dir)

    else:
        sins = Sins(parent=args.parent, seed=args.seed, run_dir=args.dir)