import sqlalchemy
from sqlalchemy.ext.declarative import declarative_base
from src.ORM_modules.Event import Event
from src.ORM_modules.Organisation import Organisation
from src.ORM_modules.Relationships import Organisation_Events
from src.ORM_modules.base import Base
from sqlalchemy import and_
 
# Define the MySQL engine using MySQL Connector/Python
engine = sqlalchemy.create_engine('mysql+mysqlconnector://admin:admin@localhost/wordpress',   echo=True)
 
 
Base.metadata.create_all(engine)
 
# Create a session
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
session = Session()

eventName = 'event2';
organisationName = 'Supger GMBH2';

# create these objects somwehre, check if their primary keys (names) exists
__event = Event(ETitle=eventName, Edate='20.07.2019', EUrl='www.hallo.de')
__organisation = Organisation(OName=organisationName, ODescription='Super Orga')

rcolumnAttribute = Event.ETitle
lcolumnAttribute = Organisation.OName

assocType = Organisation_Events

def commit_ltarget_rtarget(__linstance, __rinstance, rcolumnAttribute, lcolumnAttribute, assocType):

    attrKey  = rcolumnAttribute.__dict__['key']
    rcolumnAttributeValue = getattr(__rinstance,attrKey)
    rcolumnType = type(__rinstance)
    _rinstance =  session.query(rcolumnType).filter(rcolumnAttribute == rcolumnAttributeValue).first()

    attrKey  = lcolumnAttribute.__dict__['key']
    lcolumnAttributeValue = getattr(__linstance,attrKey)
    lcolumnType = type(__linstance)

    #check if already in DB
    _linstance =  session.query(lcolumnType).filter(lcolumnAttribute == lcolumnAttributeValue).first()
    _assoc = None

    # many to many:
    # if both exist dont create either, but check association. => it's possible that an event is there + organisations is there but the event is created by another organisation
    if ((_rinstance != None) and (_linstance != None)):
        lFK = assocType.getLeftFK()
        rFK = assocType.getRightFK()
        _assoc = session.query(assocType).filter(and_(rFK == _rinstance.getIndex(), lFK == _linstance.getIndex())).first()
        if (_assoc == None):
            # create only the new association
            _assoc = assocType(rrel = _rinstance, lrel = _linstance)
            session.add(_assoc)
            session.commit()

    else:
        if(_rinstance==None):
            #_event = Event(ETitle=eventName, Edate='20.07.2019', EUrl='www.hallo.de')
            _rinstance = __rinstance
        if(_linstance==None):
             #_organisation = Organisation(OName=organisationName, ODescription='Super Orga')
             _linstance = __organisation
        # create only the new association: missing events and/or organisations will be commited automatically
        _assoc = assocType(rrel = _rinstance, lrel = _linstance)
        session.add(_assoc)
        session.commit()

commit_ltarget_rtarget(__organisation, __event, rcolumnAttribute, lcolumnAttribute, assocType)