auth.andert.me/src/lib/services/messages.js

import { writable } from 'svelte/store';

// Helper function to determine if we're running on the client side (browser) or server side.
function isClientSide() {
    return typeof window !== "undefined";
}

// Safely get item from localStorage
function getFromLocalStorage(key, defaultValue) {
    if (isClientSide()) {
        return localStorage.getItem(key)
            ? JSON.parse(localStorage.getItem(key))
            : defaultValue;
    }
    return defaultValue;
}

// Safely set item to localStorage
function setToLocalStorage(key, value) {
    if (isClientSide()) {
        localStorage.setItem(key, JSON.stringify(value));
    }
}

// Load messages from localStorage or set an empty array if not available
const initialMessages = getFromLocalStorage('chat-messages', []);

export const messages = writable(initialMessages);

// Subscribe to messages store to watch for changes and save them to localStorage
messages.subscribe(currentMessages => {
    setToLocalStorage('chat-messages', currentMessages);
});

// Dummy messages
const messagesList = [
    "Hello there!",
    "How are you?",
    "What's your favorite color?",
    "Nice weather today!",
    "Have a great day!",
    "I love Svelte!",
    "Svelte is awesome!",
    "Learning Svelte is fun!",
    "Greetings from Svelte!",
    "Keep coding and stay awesome!"
];

export function addRandomMessage() {
    const randomMessage = messagesList[Math.floor(Math.random() * messagesList.length)];
    const currentDate = new Date().toLocaleString();
    messages.update(oldMessages => [
        ...oldMessages,
        { text: randomMessage, timestamp: currentDate }
    ]);
}

export function createMessage(text) {
    const currentDate = new Date().toLocaleString();
    messages.update(oldMessages => [
        ...oldMessages,
        { text: text, timestamp: currentDate }
    ]);
}

export function clearMessages() {
    messages.set([]);
}