from flask import Blueprint, render_template, redirect, url_for, flash, request
from models import db, Assessment, Student, Grade, GradingElement, Exercise

bp = Blueprint('grading', __name__)

@bp.route('/assessments/<int:assessment_id>/grading')
def assessment_grading(assessment_id):
    assessment = Assessment.query.get_or_404(assessment_id)
    students = Student.query.filter_by(class_group_id=assessment.class_group_id).order_by(Student.last_name, Student.first_name).all()
    
    # Get all grading elements for this assessment
    grading_elements = []
    for exercise in assessment.exercises:
        for element in exercise.grading_elements:
            grading_elements.append(element)
    
    # Get existing grades
    existing_grades = {}
    for grade in Grade.query.join(GradingElement).join(Exercise).filter_by(assessment_id=assessment_id).all():
        key = f"{grade.student_id}_{grade.grading_element_id}"
        existing_grades[key] = grade
    
    return render_template('assessment_grading.html', 
                         assessment=assessment, 
                         students=students, 
                         grading_elements=grading_elements,
                         existing_grades=existing_grades)

@bp.route('/assessments/<int:assessment_id>/grading/save', methods=['POST'])
def save_grades(assessment_id):
    assessment = Assessment.query.get_or_404(assessment_id)
    
    for key, value in request.form.items():
        if key.startswith('grade_'):
            # Parse key: grade_<student_id>_<element_id>
            parts = key.split('_')
            if len(parts) == 3:
                student_id = int(parts[1])
                element_id = int(parts[2])
                
                # Find or create grade
                grade = Grade.query.filter_by(
                    student_id=student_id,
                    grading_element_id=element_id
                ).first()
                
                if value.strip():  # If value is not empty
                    if not grade:
                        grade = Grade(
                            student_id=student_id,
                            grading_element_id=element_id,
                            value=value
                        )
                        db.session.add(grade)
                    else:
                        grade.value = value
                elif grade:  # If value is empty but grade exists, delete it
                    db.session.delete(grade)
    
    # Handle comments
    for key, value in request.form.items():
        if key.startswith('comment_'):
            parts = key.split('_')
            if len(parts) == 3:
                student_id = int(parts[1])
                element_id = int(parts[2])
                
                grade = Grade.query.filter_by(
                    student_id=student_id,
                    grading_element_id=element_id
                ).first()
                
                if grade:
                    grade.comment = value.strip() if value.strip() else None
    
    db.session.commit()
    flash('Notes sauvegardées avec succès !', 'success')
    return redirect(url_for('grading.assessment_grading', assessment_id=assessment_id))