/**
 * Symbol Updater Module
 * Handles symbol cache checking and automatic updates for coin pages
 *
 * @package XPay
 * @since 1.0.0
 * @version 2.0.0
 */

(function() {
    'use strict';

    /**
     * Symbol Updater Object
     * Modular pattern for clean code organization
     */
    const SymbolUpdater = {
        /**
         * Configuration
         */
        config: {
            cacheExpirySeconds: 5, // Reduced from 60 to 5 for real-time updates
            elementId: 'symbol-data',
            cacheBasePath: '/wp-content/cache-api/symbols/',
            updateEndpoint: '/wp-json/xpay/v1/update-symbol'
        },

        /**
         * State management
         */
        state: {
            symbol: null,
            isChecking: false,
            checkUrl: null
        },

        /**
         * Initialize the updater
         */
        init() {
            // Get symbol from data attribute
            const element = document.getElementById(this.config.elementId);
            if (!element) return;

            this.state.symbol = element.dataset.symbol;
            if (!this.state.symbol) return;

            // Build check URL with cache-busting timestamp
            const timestamp = Date.now();
            this.state.checkUrl = `${this.config.cacheBasePath}${this.state.symbol}.json.gz?t=${timestamp}`;
            
            // Immediate check - no delays
            this.checkSymbol();
        },

        /**
         * Check if symbol cache needs update
         */
        checkSymbol() {
            if (this.state.isChecking) return;
            this.state.isChecking = true;

            fetch(this.state.checkUrl, {
                method: 'HEAD',
                cache: 'no-cache'
            })
            .then(response => {
                const lastModified = response.headers.get('Last-Modified');
                if (lastModified) {
                    const fileTime = new Date(lastModified).getTime();
                    const currentTime = Date.now();
                    const ageSeconds = (currentTime - fileTime) / 1000;

                    if (ageSeconds > this.config.cacheExpirySeconds) {
                        this.updateSymbol();
                    }
                }
            })
            .catch(error => {
                console.error('Error checking symbol cache:', error);
            })
            .finally(() => {
                this.state.isChecking = false;
            });
        },

        /**
         * Update symbol via API
         */
        updateSymbol() {
            fetch(this.config.updateEndpoint, {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify({
                    symbol: this.state.symbol
                })
            })
            .then(response => response.json())
            .then(data => {
                if (data.success) {
                    // Reload page to show updated data
                    window.location.reload();
                }
            })
            .catch(error => {
                console.error('Error updating symbol:', error);
            });
        }
    };

    // Auto-initialize when DOM is ready
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', () => SymbolUpdater.init());
    } else {
        SymbolUpdater.init();
    }

    // Expose to window for external access
    window.SymbolUpdater = SymbolUpdater;

})();

config: {
    cacheExpirySeconds: 5,           // Cache validity in seconds
    elementId: 'symbol-data',        // DOM element ID
    cacheBasePath: '/wp-content/cache-api/symbols/',
    updateEndpoint: '/wp-json/xpay/v1/update-symbol'
}

// Force update a specific symbol
fetch('/wp-json/xpay/v1/update-symbol', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
    },
    body: JSON.stringify({
        symbol: 'BTC'
    })
})
.then(response => response.json())
.then(data => console.log(data));

// Version 2.0.0 uses immediate execution
init() {
    // ...
    this.checkSymbol(); // No delay!
}