// register.js

document.addEventListener("DOMContentLoaded", function() {
    const registerForm = document.getElementById('registerForm');
    const registerBtn = document.getElementById('registerSubmit');
    const successMessage = document.getElementById('successMessage');
    const errorMessage = document.getElementById('errorMessage');
    const errorText = document.getElementById('errorText');
    const passwordInput = document.getElementById('password');
    const confirmPasswordInput = document.getElementById('confirmPassword');
    const passwordStrength = document.getElementById('passwordStrength');

    // Check if user is already logged in
    checkExistingSession();

    // Password strength checker
    if (passwordInput && passwordStrength) {
        passwordInput.addEventListener('input', function() {
            const password = this.value;
            const strength = checkPasswordStrength(password);
            updatePasswordStrength(strength);
        });
    }

    // Password confirmation checker
    if (confirmPasswordInput && passwordInput) {
        confirmPasswordInput.addEventListener('input', function() {
            const password = passwordInput.value;
            const confirmPassword = this.value;
            
            if (confirmPassword && password !== confirmPassword) {
                this.setCustomValidity('Passwörter stimmen nicht überein');
            } else {
                this.setCustomValidity('');
            }
        });
    }

    // Registration form submission
    if (registerForm) {
        registerForm.addEventListener('submit', function(e) {
            e.preventDefault();
            
            // Get form data
            const formData = {
                firstName: document.getElementById('firstName').value,
                lastName: document.getElementById('lastName').value,
                email: document.getElementById('email').value,
                phone: document.getElementById('phone').value,
                company: document.getElementById('company').value,
                password: passwordInput.value,
                confirmPassword: confirmPasswordInput.value,
                terms: document.getElementById('terms').checked,
                newsletter: document.getElementById('newsletter').checked,
                registrationTime: new Date().toISOString()
            };
            
            // Validation
            const validation = validateRegistrationForm(formData);
            if (!validation.valid) {
                showError(validation.message);
                return;
            }
            
            // Show loading state
            setLoadingState(true);
            hideMessages();
            
            // Simulate registration (for demo purposes)
            setTimeout(() => {
                // Store user data (for demo purposes)
                const userData = {
                    firstName: formData.firstName,
                    lastName: formData.lastName,
                    email: formData.email,
                    phone: formData.phone,
                    company: formData.company,
                    registrationTime: formData.registrationTime,
                    newsletter: formData.newsletter
                };
                
                // Store in localStorage (for demo purposes)
                localStorage.setItem('userData', JSON.stringify(userData));
                localStorage.setItem('userRegistered', 'true');
                
                // Show success message
                showSuccess('Registrierung erfolgreich! Sie werden zum Login weitergeleitet...');
                
                // Redirect to login page after delay
                setTimeout(() => {
                    window.location.href = 'login.html';
                }, 3000);
                
                setLoadingState(false);
            }, 2000);
        });
    }

    // Password strength checker function
    function checkPasswordStrength(password) {
        let strength = 0;
        
        // Length check
        if (password.length >= 8) strength++;
        if (password.length >= 12) strength++;
        
        // Character variety checks
        if (/[a-z]/.test(password)) strength++; // lowercase
        if (/[A-Z]/.test(password)) strength++; // uppercase
        if (/[0-9]/.test(password)) strength++; // numbers
        if (/[^a-zA-Z0-9]/.test(password)) strength++; // special characters
        
        return strength;
    }

    // Update password strength indicator
    function updatePasswordStrength(strength) {
        const strengthBar = passwordStrength.querySelector('.strength-bar');
        const strengthText = passwordStrength.querySelector('.strength-text');
        
        // Remove all strength classes
        passwordStrength.classList.remove('strength-weak', 'strength-medium', 'strength-strong');
        
        if (strength <= 2) {
            passwordStrength.classList.add('strength-weak');
            strengthText.textContent = 'Schwach';
        } else if (strength <= 4) {
            passwordStrength.classList.add('strength-medium');
            strengthText.textContent = 'Mittel';
        } else {
            passwordStrength.classList.add('strength-strong');
            strengthText.textContent = 'Stark';
        }
    }

    // Form validation
    function validateRegistrationForm(data) {
        // Required fields check
        if (!data.firstName || !data.lastName || !data.email || !data.password) {
            return { valid: false, message: 'Bitte füllen Sie alle Pflichtfelder aus.' };
        }
        
        // Name validation
        if (data.firstName.length < 2 || data.lastName.length < 2) {
            return { valid: false, message: 'Vorname und Nachname müssen mindestens 2 Zeichen lang sein.' };
        }
        
        // Email validation
        const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
        if (!emailRegex.test(data.email)) {
            return { valid: false, message: 'Bitte geben Sie eine gültige E-Mail-Adresse ein.' };
        }
        
        // Password validation
        if (data.password.length < 8) {
            return { valid: false, message: 'Das Passwort muss mindestens 8 Zeichen lang sein.' };
        }
        
        // Password confirmation
        if (data.password !== data.confirmPassword) {
            return { valid: false, message: 'Die Passwörter stimmen nicht überein.' };
        }
        
        // Terms acceptance
        if (!data.terms) {
            return { valid: false, message: 'Sie müssen die Nutzungsbedingungen akzeptieren.' };
        }
        
        // Phone validation (if provided)
        if (data.phone) {
            const phoneRegex = /^[\d\s\-\+\(\)]+$/;
            if (!phoneRegex.test(data.phone)) {
                return { valid: false, message: 'Bitte geben Sie eine gültige Telefonnummer ein.' };
            }
        }
        
        return { valid: true, message: 'Validierung erfolgreich' };
    }

    // Loading state management
    function setLoadingState(loading) {
        if (registerBtn) {
            const btnText = registerBtn.querySelector('.btn-text');
            const btnLoading = registerBtn.querySelector('.btn-loading');
            
            if (loading) {
                registerBtn.disabled = true;
                if (btnText) btnText.style.display = 'none';
                if (btnLoading) btnLoading.style.display = 'inline-block';
            } else {
                registerBtn.disabled = false;
                if (btnText) btnText.style.display = 'inline-block';
                if (btnLoading) btnLoading.style.display = 'none';
            }
        }
    }

    // Message display functions
    function showSuccess(message) {
        if (successMessage) {
            const messageElement = successMessage.querySelector('p');
            if (messageElement) {
                messageElement.textContent = message;
            }
            successMessage.classList.add('show');
        }
    }

    function showError(message) {
        if (errorMessage && errorText) {
            errorText.textContent = message;
            errorMessage.classList.add('show');
            
            // Hide after 5 seconds
            setTimeout(() => {
                errorMessage.classList.remove('show');
            }, 5000);
        }
    }

    function hideMessages() {
        if (successMessage) successMessage.classList.remove('show');
        if (errorMessage) errorMessage.classList.remove('show');
    }
});

// Check existing session (same as login.js) - DISABLED auto-redirect
function checkExistingSession() {
    const sessionData = localStorage.getItem('userSession') || sessionStorage.getItem('userSession');
    
    if (sessionData) {
        try {
            const session = JSON.parse(sessionData);
            const loginTime = new Date(session.loginTime);
            const now = new Date();
            const sessionAge = (now - loginTime) / (1000 * 60 * 60); // hours
            
            // Auto-logout after 24 hours
            if (sessionAge < 24) {
                // User is still logged in - just log it, don't redirect
                console.log('User already logged in');
                // DISABLED: window.location.href = '../index.html';
            } else {
                // Session expired, remove it
                console.log('Session expired, removing...');
                localStorage.removeItem('userSession');
                sessionStorage.removeItem('userSession');
            }
        } catch (error) {
            console.error('Session parsing error:', error);
            localStorage.removeItem('userSession');
            sessionStorage.removeItem('userSession');
        }
    }
}