import glob
import hashlib
import os
import sys
import time

import transaction
from pyramid.paster import (
    get_appsettings,
    setup_logging,
)
from pyramid.scripts.common import parse_vars
from ..models import (
    get_engine,
    get_session_factory,
    get_tm_session,
    Picture
)


def usage(argv):
    cmd = os.path.basename(argv[0])
    print('usage: %s <config_uri> [var=value]\n'
          '(example: "%s development.ini")' % (cmd, cmd))
    sys.exit(1)


def main(argv=sys.argv):
    if len(argv) < 2:
        usage(argv)
    config_uri = argv[1]
    options = parse_vars(argv[2:])
    setup_logging(config_uri)
    settings = get_appsettings(config_uri, options=options)

    engine = get_engine(settings)
    session_factory = get_session_factory(engine)
    with transaction.manager:
        dbsession = get_tm_session(session_factory, transaction.manager)
        scan(settings['directories'].splitlines(), dbsession)


def scan(directories, dbsession):
    for item in directories:
        name, path = item.split(':', 1)
        getFiles(name, path, dbsession)


def getFiles(name, path, dbsession):
    files = glob.glob(path + '**/*.jpg', recursive=True)
    for file in files:
        uri = name + ':' + file[len(path):]

        size = os.path.getsize(file)
        modified_time = time.gmtime(os.path.getmtime(file))
        old = dbsession.query(Picture).filter(Picture.uri == uri).first()
        # if old is not None and old.size == size and old.modified_time == modified_time:
        if old is not None:
            print('Old file with ' + old.file_hash + ' exists!')
            continue
        file_hash = getHash(file)
        # if old is not None:
        #     old.size = size
        #     old.modified_time = modified_time
        #     print('updated old', old.modified_time, 'with', modified_time)
        #     old.file_hash = file_hash
        #     print('Updated file with ' + file_hash)
        # else:
        picture = Picture(uri, 4096, file_hash, {}, {}, size, modified_time)
        dbsession.add(picture)
        print('Added file with ' + file_hash)


def getHash(file):
    # BUF_SIZE is totally arbitrary, change for your app!
    BUF_SIZE = 1 * 1024 * 1024  # lets read stuff in 64kb chunks!
    sha256 = hashlib.sha256()

    with open(file, 'rb') as f:
        while True:
            data = f.read(BUF_SIZE)
            if not data:
                break
            sha256.update(data)

    return "SHA256:{0}".format(sha256.hexdigest())