from sqlalchemy import BigInteger, Column, MetaData, String, Float, Text, Index, Integer
from sqlalchemy.orm import DeclarativeBase
from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from src.config import settings

class Base(DeclarativeBase):
    metadata = MetaData()

class Drug(Base):
    __tablename__ = "drugs"
    
    id = Column(BigInteger, primary_key=True, index=True)
    name = Column(String, nullable=False, index=True)
    dosage = Column(Float, nullable=False)
    dosage_unit = Column(String, nullable=False)
    unit_price = Column(Float, nullable=False)
    description = Column(Text, nullable=True)

Index(
    "ix_drugs_name_dosage_dosage_unit",
    Drug.name,
    Drug.dosage,
    Drug.dosage_unit,
    unique=True
)


class Webpage(Base):
    __tablename__ = "webpage"

    id = Column(String, primary_key=True, index=True)
    n = Column(Integer, index=True)
    description = Column(String)


class UserSession(Base):
    __tablename__ = "user_session"

    id = Column(BigInteger, primary_key=True, index=True)
    user_id = Column(String, index=True)
    session_id = Column(String)


engine = create_engine(settings.DATABASE_URL)
Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)