---

from datetime import datetime, date
from flask_sqlalchemy import SQLAlchemy
from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash

db = SQLAlchemy()

class User(UserMixin, db.Model):
    __tablename__ = "users"
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False, index=True)
    password_hash = db.Column(db.String(255), nullable=False)
    full_name = db.Column(db.String(150), nullable=False)
    role = db.Column(db.String(20), default="mentor", nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    interns = db.relationship("Intern", backref="mentor", lazy="dynamic")

    def set_password(self, password: str) -> None:
        self.password_hash = generate_password_hash(password)

    def check_password(self, password: str) -> bool:
        return check_password_hash(self.password_hash, password)

    @property
    def is_admin(self) -> bool:
        return self.role == "admin"

class Intern(db.Model):
    __tablename__ = "interns"
    id = db.Column(db.Integer, primary_key=True)
    full_name = db.Column(db.String(150), nullable=False)
    email = db.Column(db.String(120), unique=True)
    phone = db.Column(db.String(30))
    direction = db.Column(db.String(120))
    start_date = db.Column(db.Date, nullable=False, default=date.today)
    end_date = db.Column(db.Date)
    mentor_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    is_active = db.Column(db.Boolean, default=True, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    attendances = db.relationship("Attendance", backref="intern", lazy="dynamic", cascade="all, delete-orphan")

class Attendance(db.Model):
    __tablename__ = "attendances"
    id = db.Column(db.Integer, primary_key=True)
    intern_id = db.Column(db.Integer, db.ForeignKey("interns.id"), nullable=False)
    date = db.Column(db.Date, nullable=False, index=True)
    status = db.Column(db.String(20), nullable=False)
    note = db.Column(db.String(255))
    marked_by = db.Column(db.Integer, db.ForeignKey("users.id"))
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    
    __table_args__ = (
        db.UniqueConstraint("intern_id", "date", name="uq_intern_date"),
    )