from sqlalchemy                 import create_engine, Column, Table, ForeignKey, Index, UniqueConstraint, MetaData, SmallInteger, Integer, String, Date, DateTime, Float, Boolean, Text, Numeric, DateTime
from sqlalchemy.orm             import relationship, sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.pool            import NullPool
from sqlalchemy.exc import OperationalError

Base = declarative_base()

# Funktion zur Herstellung einer Verbindung zur Datenbank
def db_connect():
    try:
        engine = create_engine("postgresql://example:example@localhost/geotrack", poolclass=NullPool)
        # Überprüfe die Verbindung
        with engine.connect() as connection:
            print("Verbindung zur Datenbank erfolgreich!")
        return engine
    except OperationalError as e:
        print(f"Fehler bei der Verbindung zur Datenbank: {e}")
        return None

# Funktion zur Erstellung der Tabellen
def create_table(engine):
    try:
        if engine is not None:
            Base.metadata.create_all(engine)
            print("Tabellen wurden erfolgreich erstellt!")
        else:
            print("Keine Verbindung zur Datenbank verfügbar.")
    except Exception as e:
        print(f"Fehler bei der Tabellenerstellung: {e}")
    
class Track(Base):
    __tablename__ = 'track'
    id = Column(Integer, primary_key=True, autoincrement=True)
    trackName = Column(String(200), nullable=True)
    vehicle_id = Column(Integer, ForeignKey('vehicle.id'), nullable=False, default=1)
    driver_id = Column(Integer, ForeignKey('driver.id'), nullable=False, default=1)
    date = Column(Date, nullable=True)
    distance = Column(Float, nullable=False, default=0)
    speed = Column(Float, nullable=False, default=0)
    start = Column(DateTime, nullable=False)
    end = Column(DateTime, nullable=False)
    
    # Beziehungen zu anderen Tabellen
    waypoints = relationship('Waypoint', backref='track', lazy=True)
    driver = relationship('Driver', back_populates='tracks')
    vehicle = relationship('Vehicle', back_populates='tracks')


class Waypoint(Base):
    __tablename__ = 'waypoint'
    id = Column(Integer, primary_key=True, autoincrement=True)
    lat = Column(Float, nullable=False)
    lon = Column(Float, nullable=False)
    ele = Column(Float, nullable=False)
    speed = Column(Float, nullable=True)
    time = Column(DateTime, nullable=True)
    track_id = Column(Integer, ForeignKey('track.id'), nullable=False)


class Driver(Base):
    __tablename__ = 'driver'
    id = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String, nullable=False)
    
    # Beziehung zu Track, zurück über 'tracks' auf Track-Seite
    tracks = relationship("Track", back_populates='driver')


class Vehicle(Base):
    __tablename__ = 'vehicle'
    id = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String, nullable=False)
    
    # Beziehung zu Track, zurück über 'tracks' auf Track-Seite
    tracks = relationship('Track', back_populates='vehicle')