// In-memory user store for demonstration purposes
// In a real application, this would be a database model (e.g., Sequelize, Mongoose)

const users = [];
let nextId = 1;

/**
 * Finds a user by their SSO subject ID.
 * @param {string} ssoSub - The SSO subject ID.
 * @returns {Promise<object|null>} The user object or null if not found.
 */
async function findBySsoSub(ssoSub) {
    return users.find(user => user.sso_sub === ssoSub) || null;
}

/**
 * Finds a user by their internal ID.
 * @param {number} id - The user's internal ID.
 * @returns {Promise<object|null>} The user object or null if not found.
 */
async function findById(id) {
    return users.find(user => user.id === id) || null;
}

/**
 * Creates a new user.
 * @param {object} userData - The user data.
 * @param {string} userData.sso_sub - The SSO subject ID.
 * @returns {Promise<object>} The newly created user object.
 */
async function createUser({ sso_sub }) {
    const newUser = {
        id: nextId++,
        sso_sub: sso_sub,
        // In a real app, you might get a username/email from the JWT or prompt the user
        username: `user_${sso_sub.substring(0, 5)}` 
    };
    users.push(newUser);
    return newUser;
}

module.exports = {
    findBySsoSub,
    findById,
    createUser
};