#! /usr/bin/env python3
from argparse import ArgumentParser
from datetime import datetime
from multiprocessing import Process, Queue
from pathlib import Path
from queue import Empty
from sqlalchemy import exists, desc
from tempfile import TemporaryDirectory
import logging

from .mutation import generation, flip, seed_shell
from .orm import db_config, ScrapNode


def sins():
    now = '{0:%Y%m%dT%H%M%S}'.format(datetime.utcnow())
    parser = ArgumentParser(
        description='position independent code (PIC) mutation experiment.')
    parser.add_argument('-v', '--verbose', action='count')
    parser.add_argument('-s', '--seed', help='path to PIC image.')
    parser.add_argument('-o', '--output', help='path to results directory.')
    parser.add_argument('-l', '--lineage', default=10,
                        help='max count of unsuccessful generation.')
    args = parser.parse_args()

    log_level = logging.INFO
    log_format = logging.Formatter('%(message)s')

    if args.verbose:
        log_level = logging.DEBUG
        log_format = logging.Formatter(
            '%(levelname)s %(filename)s:%(lineno)d\n%(message)s\n')

    logger = logging.getLogger('sins')
    logger.setLevel(log_level)

    stream_handler = logging.StreamHandler()
    stream_handler.setLevel(log_level)
    stream_handler.setFormatter(log_format)
    logger.addHandler(stream_handler)

    if args.output:
        log_path = f'{args.output}/sins-{now}.log'
        file_handler = logging.FileHandler(log_path)
        file_handler.setLevel(log_level)
        file_handler.setFormatter(log_format)
        logger.addHandler(file_handler)

    logger.info(now)

    seed_data = seed_shell

    if args.seed:
        seed = Path(args.seed)

        with seed.open('rb') as seed_file:
            seed_data = seed_file.read()

    seed = ScrapNode(child=seed_data)

    logger.debug(f'seed:\n{seed}')

    if args.output:
        db_path = Path(f'{args.output}/sins.sqlite')
    else:
        temp_dir = TemporaryDirectory()
        db_path = Path(f'{temp_dir.name}/sins.sqlite')

    session = db_config(db_path)
    logger.info(f'db_path: {db_path}')

    if args.seed:
        exists = session.query(ScrapNode).filter(
            ScrapNode.checksum == seed.checksum)

        if exists:
            seed = exists[0]

        else:
            session.add(seed)
            session.commit()
    else:
        recent = session.query(ScrapNode).order_by(desc('ctime')).first()

        if recent:
            logger.debug(f'recent:\n{recent}')
            seed = recent

    parent = seed

    queue = Queue()

    while True:
        lineage = 0
        scrap = flip(parent.image)

        while lineage < args.lineage:
            logger.debug(f'lineage: {lineage}')
            result = None

            proc = Process(target=generation, args=(queue, scrap))
            proc.start()
            try:
                result = queue.get(timeout=1)
            except Empty:
                lineage += 1
                continue

            if not result:
                lineage += 1
                continue

            parent = ScrapNode(child=scrap, parent_id=parent.id)
            parent.length = result
            session.add(parent)
            session.commit()
            logger.info(f'scrap:\n{parent}')
            lineage = 0
            scrap = flip(parent.image)