from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
from sqlalchemy import Index, CheckConstraint
from decimal import Decimal

db = SQLAlchemy()

class ClassGroup(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100), nullable=False, unique=True)
    description = db.Column(db.Text)
    year = db.Column(db.String(20), nullable=False)
    students = db.relationship('Student', backref='class_group', lazy=True)
    assessments = db.relationship('Assessment', backref='class_group', lazy=True)
    

    def __repr__(self):
        return f'<ClassGroup {self.name}>'

class Student(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    last_name = db.Column(db.String(100), nullable=False)
    first_name = db.Column(db.String(100), nullable=False)
    email = db.Column(db.String(120), unique=True)
    class_group_id = db.Column(db.Integer, db.ForeignKey('class_group.id'), nullable=False)
    grades = db.relationship('Grade', backref='student', lazy=True)

    def __repr__(self):
        return f'<Student {self.first_name} {self.last_name}>'
    
    @property
    def full_name(self):
        return f"{self.first_name} {self.last_name}"

class Assessment(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), nullable=False)
    description = db.Column(db.Text)
    date = db.Column(db.Date, nullable=False, default=datetime.utcnow)
    class_group_id = db.Column(db.Integer, db.ForeignKey('class_group.id'), nullable=False)
    coefficient = db.Column(db.Float, default=1.0)  # Garder Float pour compatibilité
    exercises = db.relationship('Exercise', backref='assessment', lazy=True, cascade='all, delete-orphan')

    def __repr__(self):
        return f'<Assessment {self.title}>'

class Exercise(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    assessment_id = db.Column(db.Integer, db.ForeignKey('assessment.id'), nullable=False)
    title = db.Column(db.String(200), nullable=False)
    description = db.Column(db.Text)
    order = db.Column(db.Integer, default=1)
    grading_elements = db.relationship('GradingElement', backref='exercise', lazy=True, cascade='all, delete-orphan')

    def __repr__(self):
        return f'<Exercise {self.title}>'

class GradingElement(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    exercise_id = db.Column(db.Integer, db.ForeignKey('exercise.id'), nullable=False)
    label = db.Column(db.String(200), nullable=False)
    description = db.Column(db.Text)
    skill = db.Column(db.String(200))
    max_points = db.Column(db.Float, nullable=False)  # Garder Float pour compatibilité
    grading_type = db.Column(db.String(10), nullable=False, default='points')
    grades = db.relationship('Grade', backref='grading_element', lazy=True, cascade='all, delete-orphan')

    def __repr__(self):
        return f'<GradingElement {self.label}>'

class Grade(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    student_id = db.Column(db.Integer, db.ForeignKey('student.id'), nullable=False)
    grading_element_id = db.Column(db.Integer, db.ForeignKey('grading_element.id'), nullable=False)
    value = db.Column(db.String(10))  # Garder l'ancien format pour compatibilité
    comment = db.Column(db.Text)
    

    def __repr__(self):
        return f'<Grade {self.value} for {self.student.first_name if self.student else "Unknown"}>'