/**
 * IT-Hilfe Sofort - Main JavaScript
 * Cookie Consent, Mobile Navigation, Form Handling
 */

(function() {
    'use strict';

    // ========================================
    // Cookie Consent Management (DSGVO)
    // ========================================
    const CookieConsent = {
        storageKey: 'it-hilfe-cookie-consent',
        
        init() {
            const consent = this.getConsent();
            if (!consent) {
                this.showBanner();
            } else if (consent.analytics) {
                this.loadAnalytics();
            }
        },
        
        getConsent() {
            try {
                return JSON.parse(localStorage.getItem(this.storageKey));
            } catch {
                return null;
            }
        },
        
        saveConsent(consent) {
            localStorage.setItem(this.storageKey, JSON.stringify(consent));
        },
        
        showBanner() {
            const banner = document.getElementById('cookie-banner');
            if (banner) {
                banner.classList.remove('hidden');
                
                document.getElementById('cookie-accept')?.addEventListener('click', () => {
                    this.saveConsent({ essential: true, analytics: true, marketing: true });
                    this.loadAnalytics();
                    banner.classList.add('hidden');
                });
                
                document.getElementById('cookie-essential')?.addEventListener('click', () => {
                    this.saveConsent({ essential: true, analytics: false, marketing: false });
                    banner.classList.add('hidden');
                });
                
                document.getElementById('cookie-settings')?.addEventListener('click', () => {
                    // TODO: Open settings modal
                    alert('Cookie-Einstellungen werden in Kürze verfügbar sein.');
                });
            }
        },
        
        loadAnalytics() {
            // Placeholder for analytics loading (e.g., Matomo, Plausible)
            // Only loads after explicit consent
            console.log('Analytics geladen (nach Consent)');
        }
    };

    // ========================================
    // Mobile Navigation
    // ========================================
    const MobileNav = {
        init() {
            const toggle = document.querySelector('.nav-toggle');
            const menu = document.querySelector('.nav-menu');
            
            if (toggle && menu) {
                toggle.addEventListener('click', () => {
                    menu.classList.toggle('active');
                    toggle.setAttribute('aria-expanded', 
                        menu.classList.contains('active'));
                });
                
                // Close menu on link click
                menu.querySelectorAll('a').forEach(link => {
                    link.addEventListener('click', () => {
                        menu.classList.remove('active');
                    });
                });
            }
        }
    };

    // ========================================
    // Form Validation (Kontaktformular)
    // ========================================
    const FormHandler = {
        init() {
            const forms = document.querySelectorAll('form[data-validate]');
            forms.forEach(form => this.attachValidation(form));
        },
        
        attachValidation(form) {
            form.addEventListener('submit', (e) => {
                const errors = this.validateForm(form);
                if (errors.length > 0) {
                    e.preventDefault();
                    this.showErrors(form, errors);
                }
            });
        },
        
        validateForm(form) {
            const errors = [];
            const required = form.querySelectorAll('[required]');
            
            required.forEach(field => {
                if (!field.value.trim()) {
                    errors.push({
                        field: field.name,
                        message: 'Dieses Feld ist erforderlich'
                    });
                }
                
                if (field.type === 'email' && field.value) {
                    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
                    if (!emailRegex.test(field.value)) {
                        errors.push({
                            field: field.name,
                            message: 'Bitte geben Sie eine gültige E-Mail-Adresse ein'
                        });
                    }
                }
            });
            
            // Check consent checkbox
            const consent = form.querySelector('input[name="datenschutz"]');
            if (consent && !consent.checked) {
                errors.push({
                    field: 'datenschutz',
                    message: 'Sie müssen der Datenschutzerklärung zustimmen'
                });
            }
            
            return errors;
        },
        
        showErrors(form, errors) {
            // Remove existing errors
            form.querySelectorAll('.error-message').forEach(el => el.remove());
            form.querySelectorAll('.error').forEach(el => el.classList.remove('error'));
            
            errors.forEach(error => {
                const field = form.querySelector(`[name="${error.field}"]`);
                if (field) {
                    field.classList.add('error');
                    const errorEl = document.createElement('small');
                    errorEl.className = 'error-message';
                    errorEl.textContent = error.message;
                    errorEl.style.color = '#dc2626';
                    errorEl.style.fontSize = '0.875rem';
                    field.parentNode.insertBefore(errorEl, field.nextSibling);
                }
            });
        }
    };

    // ========================================
    // Lazy Loading Images
    // ========================================
    const LazyLoader = {
        init() {
            if ('IntersectionObserver' in window) {
                const observer = new IntersectionObserver((entries) => {
                    entries.forEach(entry => {
                        if (entry.isIntersecting) {
                            const img = entry.target;
                            img.src = img.dataset.src;
                            img.removeAttribute('data-src');
                            observer.unobserve(img);
                        }
                    });
                }, { rootMargin: '50px' });
                
                document.querySelectorAll('img[data-src]').forEach(img => {
                    observer.observe(img);
                });
            }
        }
    };

    // ========================================
    // Smooth Scroll for Anchor Links
    // ========================================
    const SmoothScroll = {
        init() {
            document.querySelectorAll('a[href^="#"]').forEach(anchor => {
                anchor.addEventListener('click', function(e) {
                    const targetId = this.getAttribute('href');
                    if (targetId === '#') return;
                    
                    const target = document.querySelector(targetId);
                    if (target) {
                        e.preventDefault();
                        target.scrollIntoView({
                            behavior: 'smooth',
                            block: 'start'
                        });
                    }
                });
            });
        }
    };

    // ========================================
    // Initialize All Modules
    // ========================================
    document.addEventListener('DOMContentLoaded', () => {
        CookieConsent.init();
        MobileNav.init();
        FormHandler.init();
        LazyLoader.init();
        SmoothScroll.init();
    });

})();