from extensions import db
from datetime import datetime

class Collaborator(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    notepad_id = db.Column(db.Integer, db.ForeignKey('notepad.id', ondelete='CASCADE'), nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id', ondelete='CASCADE'), nullable=False)
    permission = db.Column(db.String(20), default='read', nullable=False)  # 'read' or 'write'
    created_at = db.Column(db.DateTime, default=datetime.utcnow)

    user = db.relationship('User', backref=db.backref('collaborations', cascade='all, delete-orphan', lazy='dynamic'))
    notepad = db.relationship('Notepad', backref=db.backref('collaborators', cascade='all, delete-orphan', lazy='dynamic'))

    __table_args__ = (
        db.UniqueConstraint('notepad_id', 'user_id', name='unique_collaborator'),
    )

    def to_dict(self):
        return {
            'id': self.id,
            'notepad_id': self.notepad_id,
            'user_id': self.user_id,
            'user_email': self.user.email if self.user else None,
            'permission': self.permission
        }