backend/app/db/models.py

from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, Text, func
from sqlalchemy.orm import relationship
from datetime import datetime
from .session import Base

class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True, index=True)
    email = Column(String(255), unique=True, index=True, nullable=False)
    username = Column(String(80), unique=True, index=True, nullable=False)
    password_hash = Column(String(255), nullable=False)
    created_at = Column(DateTime, default=datetime.utcnow)

    messages = relationship("Message", back_populates="user", cascade="all, delete-orphan")


class Message(Base):
    __tablename__ = "messages"
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True)
    role = Column(String(16), nullable=False)  # "user" | "bot"
    text = Column(Text, nullable=False)
    level = Column(String(8), nullable=True)
    topic = Column(String(64), nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow, index=True)

    user = relationship("User", back_populates="messages")

class Correction(Base):
    __tablename__ = "corrections"
    id = Column(Integer, primary_key=True, index=True)

    user_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True)  # ✅ مهم

    error = Column(String, nullable=False)
    suggestion = Column(String, default="")
    explanation = Column(Text, default="")

    created_at = Column(DateTime(timezone=True), server_default=func.now())

    user = relationship("User")