#!/usr/bin/env python3
from datetime import datetime
from sqlalchemy import Blob, Column, ForeignKey, Integer, String, DateTime, create_engine, exists, desc
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session, relationship, backref
from sqlalchemy.orm.collections import attribute_mapped_collection
import logging
from hashlib import sha1

logger = logging.getLogger('sins')
now = '{0:%Y%m%dT%H%M%S}'.format(datetime.utcnow())

Base = declarative_base()


class SeedNode(Base):
    ctime = Column(DateTime, default=datetime.utcnow)
    id = Column(Integer, primary_key=True)
    length = Column(Integer, default=0)
    mtime = Column(DateTime, onupdate=datetime.utcnow)
    parent_id = Column(Integer, ForeignKey(id))
    checksum = Column(String)
    stdout = Column(String)
    image = Column(Blob)

    children = relationship(
        "SeedNode",
        cascade="all, delete-orphan",
        backref=backref("parent", remote_side=id),
        collection_class=attribute_mapped_collection('name'))

    def __init__(self, *, child: bytes, parent: SeedNode = None):
        if parent:
            self.parent_id = parent.id

        self.image = child
        self.length = len(child)

    @property
    def sha1sum(self):
        if self.checksum:
            return self.checksum

        checksum = sha1()
        checksum.update(self.image)
        self.checksum = checksum.hexdigest()

        return self.checksum