import enum
from datetime import datetime

from sqlalchemy import (Column, DateTime, Enum, Integer, Unicode,
                        UniqueConstraint, create_engine)
from sqlalchemy.ext.declarative import declarative_base

from db import SqlDB, get_conn_str

Base = declarative_base()
engine = create_engine(get_conn_str())


class JobStatus(enum.Enum):
    UNKNOWN = 0
    SCHEDULED = 1
    RUNNING = 2
    STOPPED = 3
    ABORTED = 4
    ERROR = 5
    CLEARED = 6,
    DONE = 7


class Job(Base):
    __tablename__ = 'jobs'
    __table_args__ = (
        None,
        UniqueConstraint('id'),
    )

    id = Column(Integer, autoincrement=True, primary_key=True)
    starttime = Column(DateTime, nullable=False)
    stoptime = Column(DateTime, nullable=True)
    updated = Column(DateTime, nullable=True)
    status = Column(Enum(JobStatus), index=True, default=JobStatus.SCHEDULED,
                    nullable=True)
    comment = Column(Unicode(255), nullable=True)
    scanner = Column(Unicode(255), nullable=True)
    target = Column(Unicode(255), nullable=True)

    @classmethod
    def starter(cls, func, **kwargs):
        job_id = kwargs['job_id']
        retval = None

        del kwargs['job_id']

        with SqlDB.sql_session() as session:
            job = session.query(Job).filter(Job.id == job_id).one_or_none()
            job.status = JobStatus.RUNNING

            session.commit()

            try:
                retval = func(*kwargs)
            except Exception:
                job.status = JobStatus.ERROR
                job.stoptime = datetime.now()
                session.commit()
                print("Job raised an exception!")
            else:
                job.status = JobStatus.DONE
                job.stoptime = datetime.now()
                print("Job finished properly.")

        return retval

    def as_dict(self):
        """Return JSON serializable dict."""
        d = {}
        for col in self.__table__.columns:
            value = getattr(self, col.name)
            if issubclass(value.__class__, enum.Enum):
                value = value.value
            elif issubclass(value.__class__, Base):
                continue
            elif issubclass(value.__class__, datetime):
                value = str(value)
            d[col.name] = value
        return d


Base.metadata.create_all(engine)