/**
 * clock.js - A modular clock component for displaying time and date
 * Specifically configured for Stockholm, Sweden timezone
 */

class Clock {
    constructor(options = {}) {
        // Default options
        this.options = {
            elementId: 'clock',
            timeFormat: 'HH:MM:SS',
            dateFormat: 'WEEKDAY, MONTH DAY, YEAR',
            timezone: 'Europe/Stockholm',
            updateInterval: 1000, // Update every second
            enableTimeSync: false, // Disable time sync by default to avoid CORS issues with local files
            ...options
        };
        
        this.element = document.getElementById(this.options.elementId);
        if (!this.element) {
            console.error(`Clock element with ID "${this.options.elementId}" not found`);
            return;
        }
        
        // Create DOM structure
        this.createClockElements();
        
        // Start the clock
        this.start();
        
        // Sync with time server once a day (if enabled)
        if (this.options.enableTimeSync) {
            this.setupTimeSync();
        }
    }
    
    /**
     * Create the DOM elements for the clock
     */
    createClockElements() {
        // Create container with appropriate styling
        this.element.classList.add('clock-container');
        
        // Create time element
        this.timeElement = document.createElement('div');
        this.timeElement.classList.add('clock-time');
        this.element.appendChild(this.timeElement);
        
        // Create a separate date element
        this.dateElement = document.createElement('div');
        this.dateElement.classList.add('clock-date');
        this.element.appendChild(this.dateElement);
    }
    
    /**
     * Start the clock with the specified update interval
     */
    start() {
        // Update immediately
        this.update();
        
        // Set interval for updates
        this.intervalId = setInterval(() => this.update(), this.options.updateInterval);
    }
    
    /**
     * Stop the clock
     */
    stop() {
        if (this.intervalId) {
            clearInterval(this.intervalId);
            this.intervalId = null;
        }
    }
    
    /**
     * Update the clock display
     */
    update() {
        const now = new Date();
        
        // Format and display the time
        this.timeElement.innerHTML = this.formatTime(now);
        
        // Format and display the date (with a separator)
        this.dateElement.textContent = " • " + this.formatDate(now);
        
        // Make sure the date element is visible and inline
        this.dateElement.style.display = 'inline-block';
    }
    
    /**
     * Format the time according to the specified format
     * @param {Date} date - The date object to format
     * @returns {string} - The formatted time string
     */
    formatTime(date) {
        const options = {
            hour: '2-digit',
            minute: '2-digit',
            second: '2-digit',
            hour12: false,
            timeZone: this.options.timezone
        };
        
        return date.toLocaleTimeString('sv-SE', options);
    }
    
    /**
     * Format the date according to the specified format
     * @param {Date} date - The date object to format
     * @returns {string} - The formatted date string
     */
    formatDate(date) {
        const options = {
            weekday: 'long',
            year: 'numeric',
            month: 'long',
            day: 'numeric',
            timeZone: this.options.timezone
        };
        
        return date.toLocaleDateString('sv-SE', options);
    }
    
    /**
     * Set up time synchronization with a time server
     * This will sync the time once a day to ensure accuracy
     */
    setupTimeSync() {
        // Function to sync time
        const syncTime = async () => {
            try {
                // Check if we're running from a local file (which would cause CORS issues)
                if (window.location.protocol === 'file:') {
                    console.log('Running from local file, skipping time sync to avoid CORS issues');
                    return;
                }
                
                // Use the WorldTimeAPI to get the current time for Stockholm
                const response = await fetch('https://worldtimeapi.org/api/timezone/Europe/Stockholm');
                if (!response.ok) {
                    throw new Error(`HTTP error! Status: ${response.status}`);
                }
                
                const data = await response.json();
                console.log('Time synced with WorldTimeAPI:', data);
                
                // The API already returns the time in the correct timezone
                // We just log it for verification purposes
            } catch (error) {
                console.log('Time sync skipped:', error.message);
            }
        };
        
        // Sync immediately on load
        syncTime();
        
        // Then sync once a day (86400000 ms = 24 hours)
        setInterval(syncTime, 86400000);
    }
}

// ES module export
export { Clock };

// Keep window reference for backward compatibility
window.Clock = Clock;