app/models/class_.py

# app/models/class_.py
from datetime import datetime

from sqlalchemy import (
    Column,
    Integer,
    String,
    Boolean,
    Text,
    ForeignKey,
    DateTime,
)
from sqlalchemy.orm import relationship

from core.database import Base


class Class(Base):
    __tablename__ = "classes"

    id = Column(Integer, primary_key=True, index=True)

    # Basic info
    name = Column(String(255), nullable=False)
    description = Column(Text, nullable=True)

    # Schedule
    # Store time as a simple string "HH:MM" (or "HH:MM:SS") to avoid DB driver issues
    class_time = Column(String(8), nullable=False)
    # e.g. "Monday,Wednesday,Friday"
    days_of_week = Column(String(50), nullable=False)

    classes_per_week = Column(Integer, nullable=False, default=1)
    max_students = Column(Integer, nullable=False, default=20)
    
    # Coach assignment
    coach_email = Column(String(255), nullable=True, index=True)
    
    # Location - can be physical address or online meeting link
    location = Column(Text, nullable=True)

    # Status + timestamps
    is_active = Column(Boolean, default=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(
        DateTime,
        default=datetime.utcnow,
        onupdate=datetime.utcnow,
    )

    # Relationships
    # Keep this so ClassEnrollment.back_populates="class_" works
    enrollments = relationship(
        "ClassEnrollment",
        back_populates="class_",
        cascade="all, delete-orphan",
    )
    # Many-to-many relationship with membership plans
    membership_plans = relationship(
        "ClassMembershipPlan",
        back_populates="class_",
        cascade="all, delete-orphan",
    )


class ClassEnrollment(Base):
    __tablename__ = "class_enrollments"

    id = Column(Integer, primary_key=True, index=True)

    class_id = Column(
        Integer,
        ForeignKey("classes.id"),
        nullable=False,
    )

    # Link to student if available (for direct enrollment)
    student_id = Column(
        Integer,
        ForeignKey("students.id"),
        nullable=True,
    )

    student_email = Column(String(255), nullable=False)
    student_name = Column(String(255), nullable=True)

    status = Column(
        String(20),
        default="invited",  # invited | joined | removed
        nullable=False,
    )

    invited_at = Column(DateTime, default=datetime.utcnow)
    joined_at = Column(DateTime, nullable=True)
    # Optional, since your service sets removed_at when removing:
    removed_at = Column(DateTime, nullable=True)

    class_ = relationship("Class", back_populates="enrollments")


class ClassMembershipPlan(Base):
    """Many-to-many relationship between classes and membership plans."""
    __tablename__ = "class_membership_plans"

    id = Column(Integer, primary_key=True, index=True)
    
    class_id = Column(
        Integer,
        ForeignKey("classes.id"),
        nullable=False,
        index=True,
    )
    
    membership_plan_id = Column(
        Integer,
        ForeignKey("membership_plans.id"),
        nullable=False,
        index=True,
    )
    
    created_at = Column(DateTime, default=datetime.utcnow)
    
    # Relationships
    class_ = relationship("Class", back_populates="membership_plans")