from datetime import datetime, timezone

from sqlalchemy import String, Boolean, DateTime, Integer
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


class User(Base):
    __tablename__ = "users"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    email: Mapped[str] = mapped_column(String(255), unique=True, index=True, nullable=False)
    username: Mapped[str] = mapped_column(String(100), unique=True, index=True, nullable=False)
    hashed_password: Mapped[str] = mapped_column(String(255), nullable=False)
    full_name: Mapped[str] = mapped_column(String(255), nullable=False)
    role: Mapped[str] = mapped_column(String(20), nullable=False, default="student")  # admin | instructor | student
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=lambda: datetime.now(timezone.utc))
    updated_at: Mapped[datetime] = mapped_column(
        DateTime,
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    # relationships
    courses_created = relationship("Course", back_populates="instructor", lazy="selectin")
    enrollments = relationship("CourseEnrollment", back_populates="student", lazy="selectin")
    submissions = relationship("ExamSubmission", back_populates="student", lazy="selectin")
    activity_logs = relationship("ActivityLog", back_populates="user", lazy="selectin")