"""Module containing scheduled operation related views."""

# vim: set tw=80 ts=4 sw=4 sts=4:

from flask_jwt_extended import jwt_required
from flask_restplus import Namespace, Resource, fields

from sqlalchemy import true

from ..models import db
from ..models.accounts import Account
from ..models.operations import Operation
from ..models.scheduled_operations import ScheduledOperation


# pylint: disable=invalid-name
ns = Namespace(
    'scheduled_operation',
    description='Scheduled operation management'
)

# Scheduled operation model.
scheduled_operation_model = ns.model('ScheduledOperation', {
    'id': fields.Integer(
        description='Id of the scheduled operation',
        readonly=True,
        default=None),
    'start_date': fields.Date(
        dt_format='iso8601',
        required=True,
        description='Start date of the scheduled operation'),
    'stop_date': fields.Date(
        dt_format='iso8601',
        required=True,
        description='End date of the scheduled operation'),
    'day': fields.Integer(
        required=True,
        description='Day of month for the scheduled operation'),
    'frequency': fields.Integer(
        required=True,
        description='Frequency of the scheduling in months'),
    'label': fields.String(
        required=True,
        description='Label of the generated operations'),
    'value': fields.Float(
        required=True,
        description='Value of the generated operations'),
    'category': fields.String(
        required=False,
        description='Category of the generated operations'),
    'account_id': fields.Integer(
        default=None,
        readonly=True,
        required=True,
        description='Account id of the scheduled operation'),
})

# Parser for an account id.
account_id_parser = ns.parser()
account_id_parser.add_argument(
    'account_id',
    type=int,
    required=True,
    location='args',
    help='Id of the account'
)
# pylint: enable=invalid-name


# pylint: disable=no-self-use
@ns.route('')
@ns.doc(
    security='apikey',
    responses={
        401: 'Unauthorized',
    })
class ScheduledOperationListResource(Resource):
    """Resource to handle scheduled operation lists."""

    @ns.expect(account_id_parser)
    @ns.response(200, 'OK', [scheduled_operation_model])
    @ns.marshal_list_with(scheduled_operation_model)
    @jwt_required
    def get(self):
        """Get all scheduled operation for an account."""

        data = account_id_parser.parse_args()

        return ScheduledOperation.query().filter_by(**data).all(), 200

    @ns.expect(scheduled_operation_model)
    @ns.response(200, 'OK', scheduled_operation_model)
    @ns.response(404, 'Account not found')
    @ns.response(406, 'Invalid operation data')
    @ns.marshal_with(scheduled_operation_model)
    @jwt_required
    def post(self):
        """Add a new scheduled operation."""

        data = self.api.payload

        account_id = data['account_id']
        account = Account.query().get(account_id)

        if not account:
            ns.abort(404, 'Account with id %d not found.' % account_id)

        # A new scheduled operation MUST NOT have an id;
        if data.get('id') is not None:
            ns.abort(406, 'Id must not be provided on creation.')

        scheduled_operation = ScheduledOperation(**data)

        db.session.add(scheduled_operation)  # pylint: disable=no-member

        scheduled_operation.reschedule()

        db.session.flush()  # pylint: disable=no-member

        return scheduled_operation, 201


@ns.route('/<int:scheduled_operation_id>')
@ns.doc(
    security='apikey',
    params={
        'scheduled_operation_id': 'Id of the scheduled operation to manage'
    },
    responses={
        401: 'Unauthorized',
        404: 'Scheduled operation not found'
    })
class ScheduledOperationResource(Resource):
    """Resource to handle scheduled operations."""

    @ns.response(200, 'OK', scheduled_operation_model)
    @ns.marshal_with(scheduled_operation_model)
    @jwt_required
    def get(self, scheduled_operation_id):
        """Get scheduled operation."""

        so_id = scheduled_operation_id

        scheduled_operation = ScheduledOperation.query().get(so_id)

        if not scheduled_operation:
            ns.abort(404, 'Scheduled operation with id %d not found.' % so_id)

        return scheduled_operation, 200

    @ns.response(200, 'OK', scheduled_operation_model)
    @ns.response(406, 'Invalid scheduled operation data')
    @ns.expect(scheduled_operation_model)
    @ns.marshal_with(scheduled_operation_model)
    @jwt_required
    def post(self, scheduled_operation_id):
        """Update a scheduled operation."""

        data = self.api.payload
        so_id = scheduled_operation_id

        # Check ID consistency.
        if data.get('id', so_id) != so_id:
            ns.abort(406, 'Id must not be provided or changed on update.')

        scheduled_operation = ScheduledOperation.query().get(so_id)

        if not scheduled_operation:
            ns.abort(404, 'Scheduled operation with id %d not found.' % so_id)

        # FIXME check account_id consistency.

        # SQLAlchemy objects ignore __dict__.update() with merge.
        for key, value in data.items():
            setattr(scheduled_operation, key, value)

        db.session.merge(scheduled_operation)  # pylint: disable=no-member

        scheduled_operation.reschedule()

        db.session.flush()  # pylint: disable=no-member

        return scheduled_operation, 200

    @ns.response(200, 'OK', scheduled_operation_model)
    @ns.response(409, 'Cannot be deleted')
    @ns.marshal_with(scheduled_operation_model)
    @jwt_required
    def delete(self, scheduled_operation_id):
        """Delete a scheduled operation."""

        so_id = scheduled_operation_id

        scheduled_operation = ScheduledOperation.query().get(so_id)

        if not scheduled_operation:
            ns.abort(404, 'Scheduled operation with id %d not found.' % so_id)

        operations = scheduled_operation.operations.filter(
            Operation.confirmed == true()
        ).count()

        if operations:
            ns.abort(409, 'There are still confirmed operations '
                     'associated to this scheduled operation.')

        # Delete unconfirmed operations
        scheduled_operation.operations.delete()

        db.session.delete(scheduled_operation)  # pylint: disable=no-member

        return None, 204