const { Schema, model } = require("mongoose");

const user = new Schema({
    id: { type: String },
    username: { type: String },
    xp: { type: Number, default: 0 },
    level: { type: Number, default: 1 },
    message_count: { type: Number, default: 0 }
});

async function checkUser(user) {
    const userId = user.id;
    const username = user.username;

    // Find user by id
    const existingUser = await User.findOne({ id: userId });
    
    // If user doesn't exist, create new user
    if (!existingUser) {
        await User.create({
            id: userId,
            username: username,
            xp: 0,
            level: 1,
            message_count: 0
        });
    }
}

async function getUserXP(userId) {
    let userDoc = await User.findOne({ id: userId });
    
    // If user doesn't exist, create new user
    if (!userDoc) {
        userDoc = await User.create({
            id: userId,
            xp: 0,
            level: 1,
            message_count: 0
        });
    }
    
    return userDoc;
}

async function updateUserXP(user, xp) {
    const userId = user.id;
    const userDoc = await User.findOne({ id: userId });
    userDoc.xp = xp;
    await userDoc.save();
}

async function updateUserLevel(user, level) {
    const userId = user.id;
    const userDoc = await User.findOne({ id: userId });
    userDoc.level = level;
    await userDoc.save();
}

async function updateUserXPAndLevel(userId, xp, level, message_count) {
    const userDoc = await User.findOne({ id: userId });
    if (!userDoc) {
        return await User.create({
            id: userId,
            xp: xp,
            level: level,
            message_count: message_count
        });
    }
    userDoc.xp = xp;
    userDoc.level = level;
    userDoc.message_count = message_count;
    await userDoc.save();
}

async function updateUserMessageCount(userId, message_count) {
    const userDoc = await User.findOne({ id: userId });
    if (!userDoc) {
        return await User.create({
            id: userId,
            xp: 0,
            level: 1,
            message_count: message_count
        });
    }
    userDoc.message_count = message_count;
    await userDoc.save();
}
/**
 * Retrieves the top users sorted by XP
 * @param {number} limit - Maximum number of users to return (default: 10)
 * @returns {Promise<Array>} Array of user objects containing id, username, xp, and level
 */
async function getLeaderboard(limit = 10) {
    const users = await User.find()
        .sort({ xp: -1 })
        .limit(limit)
        .select('id username xp level');
    
    return users.map(user => ({
        user_id: user.id,
        username: user.username,
        xp: user.xp,
        level: user.level
    }));
}

const User = model("user", user);
module.exports = {
    checkUser,
    getUserXP,
    updateUserXP,
    updateUserLevel,
    updateUserXPAndLevel,
    getLeaderboard,
    updateUserMessageCount,
    User
};