"""Group model for organizing players and content."""
from datetime import datetime
from typing import List, Optional

from app.extensions import db


# Association table for many-to-many relationship between groups and content
group_content = db.Table('group_content',
    db.Column('group_id', db.Integer, db.ForeignKey('group.id'), primary_key=True),
    db.Column('content_id', db.Integer, db.ForeignKey('content.id'), primary_key=True)
)


class Group(db.Model):
    """Group model for organizing players with shared content.
    
    Attributes:
        id: Primary key
        name: Unique group name
        description: Optional group description
        created_at: Group creation timestamp
        updated_at: Last modification timestamp
    """
    __tablename__ = 'group'
    
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100), nullable=False, unique=True, index=True)
    description = db.Column(db.Text, nullable=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, 
                          onupdate=datetime.utcnow, nullable=False)
    
    # Relationships
    contents = db.relationship('Content', secondary=group_content, 
                              back_populates='groups', lazy='dynamic')
    
    def __repr__(self) -> str:
        """String representation of Group."""
        return f'<Group {self.name} (ID={self.id})>'
    

    
    @property
    def content_count(self) -> int:
        """Get number of content items in this group."""
        return self.contents.count()
    
    def add_player(self, player) -> None:
        """Add a player to this group.
        
        Args:
            player: Player instance to add
        """
        player.group_id = self.id
        self.updated_at = datetime.utcnow()
    
    def remove_player(self, player) -> None:
        """Remove a player from this group.
        
        Args:
            player: Player instance to remove
        """
        if player.group_id == self.id:
            player.group_id = None
            self.updated_at = datetime.utcnow()