from app import db
import sqlalchemy as sa
from flask_login import UserMixin
from datetime import datetime
from werkzeug.security import generate_password_hash, check_password_hash


class User(UserMixin, db.Model):
    id = sa.Column(sa.Integer, primary_key=True)
    username = sa.Column(sa.String(64), index=True, unique=True)
    role = sa.Column(sa.String(32), index=True)
    email = sa.Column(sa.String(120), index=True, unique=True)
    password_hash = sa.Column(sa.String(128))
    last_seen = sa.Column(sa.DateTime, default=datetime.utcnow)
    token = sa.Column(sa.String(32), index=True, unique=True)

    def __repr__(self):
        return f"<User {self.username}>"

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)

    def to_dict(self):
        return {
            "id": self.id,
            "username": self.username,
            "email": self.email,
        }

    def from_dict(self, data, new_user=False):
        for field in ["role", "username", "email"]:
            if field in data:
                setattr(self, field, data[field])
        if new_user and "password" in data:
            self.set_password(data["password"])

class Course(db.Model):
    id = sa.Column(sa.Integer, primary_key=True)
    name = sa.Column(sa.String(128), index=True)
    description = sa.Column(sa.Text, index=True)
    instructor = sa.Column(sa.ForeignKey(User.id), index=True)
    created_at = sa.Column(sa.DateTime, default=datetime.now())