"""Content model for media files."""
from datetime import datetime
from typing import Optional, List

from app.extensions import db
from app.models.group import group_content


class Content(db.Model):
    """Content model representing media files for display.
    
    Attributes:
        id: Primary key
        filename: Original filename
        content_type: Type of content (image, video, pdf, presentation, other)
        duration: Display duration in seconds
        file_size: File size in bytes
        description: Optional content description
        position: Display order position
        uploaded_at: Upload timestamp
    """
    __tablename__ = 'content'
    
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False, index=True)
    content_type = db.Column(db.String(50), nullable=False, index=True)
    duration = db.Column(db.Integer, default=10, nullable=True)
    file_size = db.Column(db.BigInteger, nullable=True)
    description = db.Column(db.Text, nullable=True)
    position = db.Column(db.Integer, default=0, index=True)
    uploaded_at = db.Column(db.DateTime, default=datetime.utcnow, 
                           nullable=False, index=True)
    
    # Relationships
    groups = db.relationship('Group', secondary=group_content, 
                            back_populates='contents', lazy='dynamic')
    
    def __repr__(self) -> str:
        """String representation of Content."""
        return f'<Content {self.filename} (Type={self.content_type})>'
    
    @property
    def file_size_mb(self) -> float:
        """Get file size in megabytes."""
        if self.file_size:
            return round(self.file_size / (1024 * 1024), 2)
        return 0.0
    
    @property
    def group_count(self) -> int:
        """Get number of groups containing this content."""
        return self.groups.count()
    
    def is_image(self) -> bool:
        """Check if content is an image."""
        return self.content_type == 'image'
    
    def is_video(self) -> bool:
        """Check if content is a video."""
        return self.content_type == 'video'
    
    def is_pdf(self) -> bool:
        """Check if content is a PDF."""
        return self.content_type == 'pdf'