/**
 * BotKonzept - Main JavaScript
 * ============================
 * Handles all interactive functionality for the BotKonzept website
 */

// Configuration
const CONFIG = {
    // API Endpoints - Update these for production
    WEBHOOK_URL: 'https://n8n.userman.de/webhook/botkonzept-registration',
    API_BASE_URL: 'https://api.botkonzept.de',
    
    // Validation
    MIN_NAME_LENGTH: 2,
    MAX_NAME_LENGTH: 50,
    
    // Animation
    SCROLL_OFFSET: 100,
    ANIMATION_DELAY: 100,
};

// ============================================
// DOM Ready
// ============================================
document.addEventListener('DOMContentLoaded', () => {
    initNavigation();
    initMobileMenu();
    initSmoothScroll();
    initFAQ();
    initRegistrationForm();
    initScrollAnimations();
    initTypingAnimation();
});

// ============================================
// Navigation
// ============================================
function initNavigation() {
    const navbar = document.getElementById('navbar');
    let lastScroll = 0;
    
    window.addEventListener('scroll', () => {
        const currentScroll = window.pageYOffset;
        
        // Add shadow on scroll
        if (currentScroll > 50) {
            navbar.style.boxShadow = '0 4px 6px -1px rgb(0 0 0 / 0.1)';
        } else {
            navbar.style.boxShadow = 'none';
        }
        
        // Hide/show navbar on scroll (optional)
        // if (currentScroll > lastScroll && currentScroll > 200) {
        //     navbar.style.transform = 'translateY(-100%)';
        // } else {
        //     navbar.style.transform = 'translateY(0)';
        // }
        
        lastScroll = currentScroll;
    });
}

// ============================================
// Mobile Menu
// ============================================
function initMobileMenu() {
    const mobileMenuBtn = document.getElementById('mobileMenuBtn');
    const navLinks = document.getElementById('navLinks');
    
    if (!mobileMenuBtn || !navLinks) return;
    
    mobileMenuBtn.addEventListener('click', () => {
        navLinks.classList.toggle('active');
        
        // Toggle icon
        const icon = mobileMenuBtn.querySelector('i');
        if (navLinks.classList.contains('active')) {
            icon.classList.remove('fa-bars');
            icon.classList.add('fa-times');
        } else {
            icon.classList.remove('fa-times');
            icon.classList.add('fa-bars');
        }
    });
    
    // Close menu when clicking a link
    navLinks.querySelectorAll('a').forEach(link => {
        link.addEventListener('click', () => {
            navLinks.classList.remove('active');
            const icon = mobileMenuBtn.querySelector('i');
            icon.classList.remove('fa-times');
            icon.classList.add('fa-bars');
        });
    });
}

// ============================================
// Smooth Scroll
// ============================================
function initSmoothScroll() {
    document.querySelectorAll('a[href^="#"]').forEach(anchor => {
        anchor.addEventListener('click', function(e) {
            e.preventDefault();
            const targetId = this.getAttribute('href');
            
            if (targetId === '#') return;
            
            const targetElement = document.querySelector(targetId);
            if (targetElement) {
                const navbarHeight = document.getElementById('navbar').offsetHeight;
                const targetPosition = targetElement.offsetTop - navbarHeight - 20;
                
                window.scrollTo({
                    top: targetPosition,
                    behavior: 'smooth'
                });
            }
        });
    });
}

// ============================================
// FAQ Accordion
// ============================================
function initFAQ() {
    const faqItems = document.querySelectorAll('.faq-item');
    
    faqItems.forEach(item => {
        const question = item.querySelector('.faq-question');
        
        question.addEventListener('click', () => {
            // Close other items
            faqItems.forEach(otherItem => {
                if (otherItem !== item && otherItem.classList.contains('active')) {
                    otherItem.classList.remove('active');
                }
            });
            
            // Toggle current item
            item.classList.toggle('active');
        });
    });
}

// ============================================
// Registration Form
// ============================================
function initRegistrationForm() {
    const form = document.getElementById('registerForm');
    const submitBtn = document.getElementById('submitBtn');
    const formSuccess = document.getElementById('formSuccess');
    const formError = document.getElementById('formError');
    
    if (!form) return;
    
    form.addEventListener('submit', async (e) => {
        e.preventDefault();
        
        // Validate form
        if (!validateForm(form)) {
            return;
        }
        
        // Show loading state
        setLoadingState(submitBtn, true);
        
        // Collect form data
        const formData = {
            firstName: form.firstName.value.trim(),
            lastName: form.lastName.value.trim(),
            email: form.email.value.trim(),
            company: form.company.value.trim() || null,
            website: form.website.value.trim() || null,
            newsletter: form.newsletter.checked,
            timestamp: new Date().toISOString(),
            source: 'website',
            userAgent: navigator.userAgent,
            language: navigator.language,
        };
        
        try {
            // Send registration request
            const response = await fetch(CONFIG.WEBHOOK_URL, {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify(formData),
            });
            
            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }
            
            const result = await response.json();
            
            // Show success message
            form.style.display = 'none';
            formSuccess.style.display = 'block';
            
            // Track conversion (if analytics is set up)
            trackConversion('registration_complete', formData);
            
        } catch (error) {
            console.error('Registration error:', error);
            
            // Show error message
            form.style.display = 'none';
            formError.style.display = 'block';
            
            const errorMessage = document.getElementById('errorMessage');
            if (errorMessage) {
                errorMessage.textContent = getErrorMessage(error);
            }
        } finally {
            setLoadingState(submitBtn, false);
        }
    });
}

// Form validation
function validateForm(form) {
    let isValid = true;
    
    // Clear previous errors
    form.querySelectorAll('.error').forEach(el => el.classList.remove('error'));
    form.querySelectorAll('.error-message').forEach(el => el.remove());
    
    // Validate first name
    const firstName = form.firstName.value.trim();
    if (firstName.length < CONFIG.MIN_NAME_LENGTH) {
        showFieldError(form.firstName, 'Bitte geben Sie Ihren Vornamen ein');
        isValid = false;
    }
    
    // Validate last name
    const lastName = form.lastName.value.trim();
    if (lastName.length < CONFIG.MIN_NAME_LENGTH) {
        showFieldError(form.lastName, 'Bitte geben Sie Ihren Nachnamen ein');
        isValid = false;
    }
    
    // Validate email
    const email = form.email.value.trim();
    if (!isValidEmail(email)) {
        showFieldError(form.email, 'Bitte geben Sie eine gültige E-Mail-Adresse ein');
        isValid = false;
    }
    
    // Validate website (if provided)
    const website = form.website.value.trim();
    if (website && !isValidURL(website)) {
        showFieldError(form.website, 'Bitte geben Sie eine gültige URL ein (z.B. https://beispiel.de)');
        isValid = false;
    }
    
    // Validate privacy checkbox
    if (!form.privacy.checked) {
        showFieldError(form.privacy, 'Bitte akzeptieren Sie die Datenschutzerklärung');
        isValid = false;
    }
    
    return isValid;
}

// Show field error
function showFieldError(field, message) {
    field.classList.add('error');
    field.style.borderColor = '#ef4444';
    
    const errorDiv = document.createElement('div');
    errorDiv.className = 'error-message';
    errorDiv.style.color = '#ef4444';
    errorDiv.style.fontSize = '0.75rem';
    errorDiv.style.marginTop = '4px';
    errorDiv.textContent = message;
    
    field.parentNode.appendChild(errorDiv);
}

// Email validation
function isValidEmail(email) {
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    return emailRegex.test(email);
}

// URL validation
function isValidURL(url) {
    try {
        new URL(url);
        return true;
    } catch {
        return false;
    }
}

// Set loading state
function setLoadingState(button, isLoading) {
    const btnText = button.querySelector('.btn-text');
    const btnLoading = button.querySelector('.btn-loading');
    
    if (isLoading) {
        button.disabled = true;
        if (btnText) btnText.style.display = 'none';
        if (btnLoading) btnLoading.style.display = 'inline-flex';
    } else {
        button.disabled = false;
        if (btnText) btnText.style.display = 'inline';
        if (btnLoading) btnLoading.style.display = 'none';
    }
}

// Get user-friendly error message
function getErrorMessage(error) {
    if (error.message.includes('Failed to fetch')) {
        return 'Verbindungsfehler. Bitte überprüfen Sie Ihre Internetverbindung.';
    }
    if (error.message.includes('500')) {
        return 'Serverfehler. Bitte versuchen Sie es später erneut.';
    }
    if (error.message.includes('400')) {
        return 'Ungültige Eingabe. Bitte überprüfen Sie Ihre Daten.';
    }
    return 'Ein unerwarteter Fehler ist aufgetreten. Bitte versuchen Sie es später erneut.';
}

// Reset form
function resetForm() {
    const form = document.getElementById('registerForm');
    const formSuccess = document.getElementById('formSuccess');
    const formError = document.getElementById('formError');
    
    if (form) {
        form.reset();
        form.style.display = 'flex';
    }
    if (formSuccess) formSuccess.style.display = 'none';
    if (formError) formError.style.display = 'none';
}

// Make resetForm available globally
window.resetForm = resetForm;

// ============================================
// Scroll Animations
// ============================================
function initScrollAnimations() {
    const animatedElements = document.querySelectorAll('.feature-card, .step, .pricing-card, .faq-item');
    
    const observer = new IntersectionObserver((entries) => {
        entries.forEach((entry, index) => {
            if (entry.isIntersecting) {
                setTimeout(() => {
                    entry.target.classList.add('visible');
                    entry.target.style.opacity = '1';
                    entry.target.style.transform = 'translateY(0)';
                }, index * CONFIG.ANIMATION_DELAY);
                
                observer.unobserve(entry.target);
            }
        });
    }, {
        threshold: 0.1,
        rootMargin: '0px 0px -50px 0px'
    });
    
    animatedElements.forEach(el => {
        el.style.opacity = '0';
        el.style.transform = 'translateY(20px)';
        el.style.transition = 'opacity 0.5s ease, transform 0.5s ease';
        observer.observe(el);
    });
}

// ============================================
// Typing Animation (Chat Preview)
// ============================================
function initTypingAnimation() {
    const typingMessage = document.querySelector('.message.typing');
    if (!typingMessage) return;
    
    // Simulate typing response
    setTimeout(() => {
        typingMessage.innerHTML = '<p>Sie können Ihre Bestellung ganz einfach über unser Online-Formular aufgeben. Alternativ können Sie uns auch telefonisch unter 0800-123456 erreichen.</p>';
        typingMessage.classList.remove('typing');
    }, 3000);
}

// ============================================
// Analytics & Tracking
// ============================================
function trackConversion(eventName, data = {}) {
    // Google Analytics 4
    if (typeof gtag !== 'undefined') {
        gtag('event', eventName, {
            'event_category': 'conversion',
            'event_label': 'registration',
            ...data
        });
    }
    
    // Facebook Pixel
    if (typeof fbq !== 'undefined') {
        fbq('track', 'Lead', data);
    }
    
    // Console log for debugging
    console.log('Conversion tracked:', eventName, data);
}

// ============================================
// Utility Functions
// ============================================

// Debounce function
function debounce(func, wait) {
    let timeout;
    return function executedFunction(...args) {
        const later = () => {
            clearTimeout(timeout);
            func(...args);
        };
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
    };
}

// Throttle function
function throttle(func, limit) {
    let inThrottle;
    return function(...args) {
        if (!inThrottle) {
            func.apply(this, args);
            inThrottle = true;
            setTimeout(() => inThrottle = false, limit);
        }
    };
}

// Format currency
function formatCurrency(amount, currency = 'EUR') {
    return new Intl.NumberFormat('de-DE', {
        style: 'currency',
        currency: currency
    }).format(amount);
}

// Format date
function formatDate(date) {
    return new Intl.DateTimeFormat('de-DE', {
        year: 'numeric',
        month: 'long',
        day: 'numeric'
    }).format(new Date(date));
}

// ============================================
// Export for testing
// ============================================
if (typeof module !== 'undefined' && module.exports) {
    module.exports = {
        validateForm,
        isValidEmail,
        isValidURL,
        formatCurrency,
        formatDate
    };
}