"""
Note attachment model for storing uploaded files associated with notes.
"""

from datetime import datetime
from . import db


class NoteAttachment(db.Model):
    """Model for files attached to notes (images, documents, etc.)"""
    __tablename__ = 'note_attachment'
    
    id = db.Column(db.Integer, primary_key=True)
    note_id = db.Column(db.Integer, db.ForeignKey('note.id'), nullable=False)
    
    # File information
    filename = db.Column(db.String(255), nullable=False)  # Stored filename
    original_filename = db.Column(db.String(255), nullable=False)  # Original upload name
    file_path = db.Column(db.String(500), nullable=False)  # Relative path from uploads dir
    file_size = db.Column(db.Integer)  # Size in bytes
    mime_type = db.Column(db.String(100))
    
    # File type for easier filtering
    file_type = db.Column(db.String(20))  # 'image', 'document', 'archive', etc.
    
    # Metadata
    uploaded_at = db.Column(db.DateTime, default=datetime.now)
    uploaded_by_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)
    
    # For images: dimensions
    image_width = db.Column(db.Integer)
    image_height = db.Column(db.Integer)
    
    # Soft delete
    is_deleted = db.Column(db.Boolean, default=False)
    deleted_at = db.Column(db.DateTime)
    
    # Relationships
    note = db.relationship('Note', backref='attachments')
    uploaded_by = db.relationship('User', backref='uploaded_attachments')
    
    def __repr__(self):
        return f'<NoteAttachment {self.original_filename} for Note {self.note_id}>'
    
    @property
    def is_image(self):
        """Check if attachment is an image"""
        return self.file_type == 'image'
    
    @property
    def url(self):
        """Get the URL to access this attachment"""
        return f'/uploads/notes/{self.file_path}'
    
    def get_file_extension(self):
        """Get file extension"""
        return self.original_filename.rsplit('.', 1)[1].lower() if '.' in self.original_filename else ''
    
    @staticmethod
    def allowed_file(filename, file_type='any'):
        """Check if file extension is allowed"""
        ALLOWED_EXTENSIONS = {
            'image': {'png', 'jpg', 'jpeg', 'gif', 'webp', 'svg'},
            'document': {'pdf', 'doc', 'docx', 'txt', 'md', 'csv', 'xls', 'xlsx'},
            'archive': {'zip', 'tar', 'gz', '7z'},
            'any': {'png', 'jpg', 'jpeg', 'gif', 'webp', 'svg', 'pdf', 'doc', 
                   'docx', 'txt', 'md', 'csv', 'xls', 'xlsx', 'zip', 'tar', 'gz', '7z'}
        }
        
        if '.' not in filename:
            return False
            
        ext = filename.rsplit('.', 1)[1].lower()
        allowed = ALLOWED_EXTENSIONS.get(file_type, ALLOWED_EXTENSIONS['any'])
        return ext in allowed
    
    @staticmethod
    def get_file_type(filename):
        """Determine file type from extension"""
        if '.' not in filename:
            return 'unknown'
            
        ext = filename.rsplit('.', 1)[1].lower()
        
        if ext in {'png', 'jpg', 'jpeg', 'gif', 'webp', 'svg'}:
            return 'image'
        elif ext in {'pdf', 'doc', 'docx', 'txt', 'md', 'csv', 'xls', 'xlsx'}:
            return 'document'
        elif ext in {'zip', 'tar', 'gz', '7z'}:
            return 'archive'
        else:
            return 'other'