from datetime import datetime
import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
import os

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'

    id = sa.Column(sa.Integer, primary_key=True)
    username = sa.Column(sa.String(50), unique=True, nullable=False)
    password = sa.Column(sa.String(255), nullable=False)
    full_name = sa.Column(sa.String(100))
    email = sa.Column(sa.String(100))
    school = sa.Column(sa.String(100))
    grade = sa.Column(sa.String(20))
    profile_photo = sa.Column(sa.Text)  # Store photo as base64
    created_at = sa.Column(sa.DateTime, default=datetime.utcnow)
    updated_at = sa.Column(sa.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

class History(Base):
    __tablename__ = 'history'

    id = sa.Column(sa.Integer, primary_key=True)
    user_id = sa.Column(sa.Integer, sa.ForeignKey('users.id'), nullable=False)
    equation = sa.Column(sa.String(255), nullable=False)
    solution = sa.Column(sa.Text, nullable=False)
    created_at = sa.Column(sa.DateTime, default=datetime.utcnow)

# Database setup
engine = create_engine(os.environ['DATABASE_URL'])
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

def init_db():
    Base.metadata.create_all(bind=engine)

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()