from app.extensions import db, ma
from flask_marshmallow import fields

class Shift(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    battery_changes = db.relationship('BatteryChange', 
                                      backref='battery_changes', 
                                      order_by='BatteryChange.order')

class ShiftSchema(ma.Schema):
    battery_changes = ma.Nested('BatteryChangeSchema', many=True)
    all_completed = fields.fields.Method('get_all_completed')
    class Meta:
        model=Shift
        include_fk=True
        fields = ("id", "battery_changes", "all_completed")

    def get_all_completed(self, obj):
        return all(change.completed == True for change in obj.battery_changes)