from app import db
from datetime import datetime

class Subject(db.Model):
    __tablename__ = 'subjects'
    
    id = db.Column(db.Integer, primary_key=True)
    code = db.Column(db.String(20), unique=True, nullable=False, index=True)
    name = db.Column(db.String(200), nullable=False)
    description = db.Column(db.Text)
    department = db.Column(db.String(100), nullable=False)
    credits = db.Column(db.Integer, nullable=False)
    # duration_in_minutes = db.Column(db.Integer, nullable=False)
    is_active = db.Column(db.Boolean, default=True, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # Relationships
    commissions = db.relationship('Commission', backref='subject', lazy=True, cascade='all, delete-orphan')
    
    def to_dict(self):
        """Convert subject to dictionary"""
        return {
            'id': self.id,
            'code': self.code,
            'name': self.name,
            'description': self.description,
            'department': self.department,
            'credits': self.credits,
            # 'duration_minutes': self.duration_in_minutes,
            'is_active': self.is_active,
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'updated_at': self.updated_at.isoformat() if self.updated_at else None
        }
    
    def __repr__(self):
        return f'<Subject {self.code}>'

class Commission(db.Model):
    __tablename__ = 'commissions'
    
    id = db.Column(db.Integer, primary_key=True)
    subject_id = db.Column(db.Integer, db.ForeignKey('subjects.id'), nullable=False)
    code = db.Column(db.String(50), nullable=False)
    semester = db.Column(db.String(20), nullable=False)
    year = db.Column(db.Integer, nullable=False)
    teacher_id = db.Column(db.Integer, db.ForeignKey('users.id'))
    max_students = db.Column(db.Integer, nullable=False)
    current_students = db.Column(db.Integer, default=0)
    schedule = db.Column(db.String(255))
    active = db.Column(db.Boolean, default=True)  # Changed from is_active to active
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # Virtual property for compatibility
    @property
    def is_active(self):
        return self.active
    
    @is_active.setter
    def is_active(self, value):
        self.active = value
    
# Relationships
    pass  # Reservation already defines the relationship back to commission
    teacher = db.relationship('User', backref='teaching_commissions', foreign_keys=[teacher_id])
    
    # Virtual field for teacher_name
    @property
    def teacher_name(self):
        return f"{self.teacher.first_name} {self.teacher.last_name}" if self.teacher else "TBD"
    
    # Unique constraint
    __table_args__ = (db.UniqueConstraint('subject_id', 'code', 'semester', 'year'),)
    
    def to_dict(self):
        """Convert commission to dictionary"""
        return {
            'id': self.id,
            'subject_id': self.subject_id,
            'code': self.code,
            'semester': self.semester,
            'year': self.year,
            'teacher_name': self.teacher_name,
            'max_students': self.max_students,
            'current_students': self.current_students,
            'schedule': self.schedule,
            'active': self.active,
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'updated_at': self.updated_at.isoformat() if self.updated_at else None,
            'subject': self.subject.to_dict() if self.subject else None
        }
    
    def get_full_code(self):
        """Get full commission code"""
        return f"{self.subject.code if self.subject else 'N/A'}-{self.code}-{self.semester.upper()}{self.year if self.year else ''}"
    
    def __repr__(self):
        return f'<Commission {self.get_full_code()}>'