def get_ai_assessor():
    """
    Gets a singleton instance of the AIAssessment class.
    """
    from flask import current_app
    from app.services.ai_assessment import AIAssessment
    
    if not hasattr(current_app, 'ai_assessor'):
        current_app.ai_assessor = AIAssessment()
    
    return current_app.ai_assessor

def assess_submission(submission, feedback_text):
    """
    Process teacher's assessment of a student submission.
    
    Args:
        submission: The Submission object
        feedback_text: The teacher's feedback text
        
    Returns:
        dict: A dictionary with assessment results
    """
    assessor = get_ai_assessor()
    
    # Validate feedback text
    feedback = assessor.validate_word_count(feedback_text)
    
    # Simple structure with teacher feedback
    assessment = {
        'feedback': feedback,
        'score': submission.score,  # Use the score from the submission
        'timestamp': submission.reviewed_at.isoformat() if submission.reviewed_at else None
    }
    
    return assessment