"""Model for history table in label_copy_export database."""

from datetime import datetime

from oto import response
from oto import status as response_status

from sqlalchemy import Column
from sqlalchemy import DateTime
from sqlalchemy import Enum
from sqlalchemy import Integer
from sqlalchemy import String
from sqlalchemy.ext.hybrid import hybrid_property

from label_copy_export.connectors import mysql
from label_copy_export.constants import error
from label_copy_export.constants import lce_history
from label_copy_export.models import error_handlers


class Job(mysql.BaseModel):
    """Class representing the label copy export history's job."""

    __tablename__ = 'label_copy_export_history'
    job_id = Column('id', Integer, primary_key=True, autoincrement=True)
    user_id = Column(String(127))
    project_id = Column(Integer, nullable=False)
    status = Column(
        Enum(*lce_history.GENERATION_STATUSES),
        default=lce_history.REQUESTED)
    _last_change_date = Column(
        'last_change_date', DateTime, nullable=False,
        default=datetime.utcnow, onupdate=datetime.utcnow)

    @hybrid_property
    def last_change_date(self):
        """Getter for private attribute _last_change_date."""
        return self._last_change_date

    def to_dict(self):
        """Return object as dict.

        Returns:
            dict: Dictionary representation of object
        """
        job_dict = {
            'job_id': self.job_id,
            'user_id': self.user_id,
            'project_id': self.project_id,
            'status': self.status,
            'last_change_date': self.last_change_date
        }
        return job_dict


@error_handlers.sqlalchemy_error_handler
def change_status(job_id, status):
    """Change status of job.

    Args:
        job_id (int): job id.
        status (str): Job internal status,
            must be one of lce_history.GENERATION_STATUSES.
    Returns:
        response.Response: empty body on success, .errors on failure.
    """
    with mysql.label_copy_export_history_session_scope() as session:
        job = (session.query(Job).with_for_update()
               .filter_by(job_id=job_id).first())
        if not job:
            return response.create_not_found_response(
                error.JOB_DOES_NOT_EXIST)
        job.status = status
        session.add(job)
    return response.Response(status=response_status.NO_CONTENT)