"""InsertionPoint Model.

This model represents an InsertionPoint
"""


import sqlalchemy
from sqlalchemy import ForeignKey
from sqlalchemy.dialects.mysql import INTEGER

from podcast.connectors import mysql
from podcast.constants import error
from podcast.utils import api_utils
from podcast.utils import exc


class InsertionPoint(mysql.BaseModel):
    """InsertionPoint model."""

    __tablename__ = 'insertion_point'

    id = sqlalchemy.Column(INTEGER(unsigned=True), primary_key=True, autoincrement=True)  # noqa
    episode_id = sqlalchemy.Column(
        INTEGER(unsigned=True),
        ForeignKey('episode.id'),
        nullable=False
    )
    point_type = sqlalchemy.Column(sqlalchemy.Enum(*['pre', 'mid', 'post']))
    timecode = sqlalchemy.Column(sqlalchemy.DECIMAL(21, 15), nullable=False, default=0)
    count = sqlalchemy.Column(INTEGER(unsigned=True), nullable=False, default=1)
    created_by = sqlalchemy.Column(sqlalchemy.Integer)

    def to_dict(self):
        """Return the object as dictionary."""
        return dict(
            id=self.id,
            episode_id=self.episode_id,
            point_type=self.point_type,
            timecode=str(self.timecode),
            count=self.count,
            created_by=self.created_by
        )


def get_insertion_points(episode_id):
    """Return all the insertion points for an episode.

    Args:
        episode_id (int): the podcast unique identifier
        limit (int): how many podcasts to retrieve.
        offset (int): the offset (for pagination).

    Returns:
        dict: items' list of insertion points.
    """
    if not isinstance(episode_id, int):
        raise exc.OwsError.bad_request(error.ERROR_MESSAGE_BAD_PARAMS)

    with mysql.pod_db_session() as session:
        query = session.query(InsertionPoint).filter(
            InsertionPoint.episode_id == episode_id)
        rows = query.all()
        items = [row.to_dict() for row in rows]
        return {'items': items}


def create_insertion_points(episode_id, data, session=None, user_id=None):
    """Delete existing and insert new insertion points.

    Args:
        episode_id (int): The unique identifier of episode
        data (json): list of insertion points
        session (sqlalchemy.session.Session): live connection to database.

    Returns:
        dict: new insertion points' list
    """
    if not isinstance(episode_id, int):
        raise exc.OwsError.bad_request(error.ERROR_MESSAGE_BAD_PARAMS)

    user_id = user_id or api_utils.get_user_id()

    if session:
        return _create_insertion_points(episode_id, data, session, user_id)
    else:
        with mysql.pod_db_session() as session:
            return _create_insertion_points(episode_id, data, session, user_id)


def _create_insertion_points(episode_id, data, session, user_id):
    _delete_all(session, episode_id)
    for item in data:
        item['episode_id'] = episode_id
        item['created_by'] = user_id
        session.add(InsertionPoint(**item))
    return get_insertion_points(episode_id)


def delete_all(episode_id):
    """Delete existing insertion points.

    Args:
        episode_id (int): The unique identifier of episode
    Returns:
        None
    """
    if not isinstance(episode_id, int):
        raise exc.OwsError.bad_request(error.ERROR_MESSAGE_BAD_PARAMS)

    with mysql.pod_db_session() as session:
        _delete_all(session, episode_id)


def _delete_all(session, episode_id):
    session.query(InsertionPoint).filter(
        InsertionPoint.episode_id == episode_id
    ).delete()