from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.dialects.postgresql import JSONB
from werkzeug.security import generate_password_hash, check_password_hash

# Create a SQLAlchemy instance. This will be linked to the Flask app in main.py.
db = SQLAlchemy()

class User(db.Model):
    """Represents a user in the database."""
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password_hash = db.Column(db.String(256), nullable=False)
    is_admin = db.Column(db.Boolean, default=False, nullable=False)

    def set_password(self, password):
        """Creates a secure hash of the password."""
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        """Checks if the provided password matches the stored hash."""
        return check_password_hash(self.password_hash, password)

class Station(db.Model):
    """Represents a battery swap station in the database."""
    id = db.Column(db.Integer, primary_key=True)
    station_id = db.Column(db.String(120), unique=True, nullable=False)
    name = db.Column(db.String(120), nullable=True)
    location = db.Column(db.String(200), nullable=True)
    mqtt_broker = db.Column(db.String(255), nullable=False)
    mqtt_port = db.Column(db.Integer, nullable=False)
    mqtt_user = db.Column(db.String(120), nullable=True)
    mqtt_password = db.Column(db.String(120), nullable=True)

class MqttLog(db.Model):
    """Represents a single MQTT message payload for historical logging."""
    id = db.Column(db.Integer, primary_key=True)
    timestamp = db.Column(db.DateTime, server_default=db.func.now())
    station_id = db.Column(db.String(120), nullable=False, index=True)
    topic = db.Column(db.String(255), nullable=False)
    topic_type = db.Column(db.String(50), nullable=False, index=True)
    payload = db.Column(JSONB)