// Main application JavaScript for CodePress CMS
// Enhanced with PWA support and accessibility features

// Initialize application when DOM is ready
document.addEventListener('DOMContentLoaded', function() {
    console.log('CodePress CMS v1.5.0 initialized');

    // Register Service Worker for PWA
    if ('serviceWorker' in navigator) {
        navigator.serviceWorker.register('/sw.js')
            .then(function(registration) {
                console.log('Service Worker registered:', registration.scope);
            })
            .catch(function(error) {
                console.log('Service Worker registration failed:', error);
            });
    }

    // Handle nested dropdowns for touch devices
    initializeDropdowns();

    // Initialize accessibility features
    initializeAccessibility();

    // Initialize form validation
    initializeFormValidation();

    // Initialize PWA features
    initializePWA();

    // Initialize search enhancements
    initializeSearch();

    // Run accessibility tests in development
    if (window.location.hostname === 'localhost') {
        setTimeout(runAccessibilityTests, 1000);
    }
});

// Dropdown menu handling
function initializeDropdowns() {
    const dropdownSubmenus = document.querySelectorAll('.dropdown-submenu');

    dropdownSubmenus.forEach(function(submenu) {
        const toggle = submenu.querySelector('.dropdown-toggle');
        const dropdown = submenu.querySelector('.dropdown-menu');

        if (toggle && dropdown) {
            // Prevent default link behavior
            toggle.addEventListener('click', function(e) {
                e.preventDefault();
                e.stopPropagation();

                // Close other submenus at the same level
                const parent = submenu.parentElement;
                parent.querySelectorAll('.dropdown-submenu').forEach(function(sibling) {
                    if (sibling !== submenu) {
                        sibling.querySelector('.dropdown-menu').classList.remove('show');
                    }
                });

                // Toggle current submenu
                dropdown.classList.toggle('show');
            });

            // Close submenu when clicking outside
            document.addEventListener('click', function(e) {
                if (!submenu.contains(e.target)) {
                    dropdown.classList.remove('show');
                }
            });

            // Keyboard navigation for dropdowns
            toggle.addEventListener('keydown', function(e) {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    dropdown.classList.toggle('show');
                } else if (e.key === 'Escape') {
                    dropdown.classList.remove('show');
                    toggle.focus();
                }
            });
        }
    });
}

// Accessibility enhancements
function initializeAccessibility() {
    // High contrast mode detection
    if (window.matchMedia && window.matchMedia('(prefers-contrast: high)').matches) {
        document.documentElement.classList.add('high-contrast');
    }

    // Reduced motion preference
    if (window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches) {
        document.documentElement.classList.add('reduced-motion');
    }

    // Focus management
    document.addEventListener('keydown', function(e) {
        // Close modals with Escape
        if (e.key === 'Escape') {
            const openModals = document.querySelectorAll('.modal.show');
            openModals.forEach(modal => {
                const bsModal = bootstrap.Modal.getInstance(modal);
                if (bsModal) bsModal.hide();
            });

            // Close dropdowns
            const openDropdowns = document.querySelectorAll('.dropdown-menu.show');
            openDropdowns.forEach(dropdown => {
                dropdown.classList.remove('show');
            });
        }
    });

    // Announce dynamic content changes to screen readers
    const observer = new MutationObserver(function(mutations) {
        mutations.forEach(function(mutation) {
            if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
                // Announce new content
                announceToScreenReader('Content updated', 'polite');
            }
        });
    });

    observer.observe(document.body, {
        childList: true,
        subtree: true
    });

    // Focus trap for modals
    document.addEventListener('shown.bs.modal', function(e) {
        const modal = e.target;
        trapFocus(modal);
    });

    document.addEventListener('hidden.bs.modal', function(e) {
        const modal = e.target;
        releaseFocusTrap(modal);
    });

    // Enhanced keyboard navigation
    document.addEventListener('keydown', function(e) {
        // Skip to content with Ctrl+Home
        if (e.ctrlKey && e.key === 'Home') {
            e.preventDefault();
            const mainContent = document.getElementById('main-content');
            if (mainContent) {
                mainContent.focus();
                mainContent.scrollIntoView();
            }
        }
    });
}

// PWA functionality
function initializePWA() {
    // Install prompt handling
    let deferredPrompt;

    window.addEventListener('beforeinstallprompt', function(e) {
        e.preventDefault();
        deferredPrompt = e;

        // Show install button if desired
        const installButton = document.createElement('button');
        installButton.textContent = 'Install App';
        installButton.className = 'btn btn-primary position-fixed bottom-0 end-0 m-3 d-none d-md-block';
        installButton.style.zIndex = '1050';

        installButton.addEventListener('click', function() {
            deferredPrompt.prompt();
            deferredPrompt.userChoice.then(function(choiceResult) {
                if (choiceResult.outcome === 'accepted') {
                    console.log('User accepted the install prompt');
                }
                deferredPrompt = null;
                document.body.removeChild(installButton);
            });
        });

        document.body.appendChild(installButton);
    });

    // Online/offline status
    window.addEventListener('online', function() {
        console.log('Connection restored');
        showToast('Connection restored', 'success');
    });

    window.addEventListener('offline', function() {
        console.log('Connection lost');
        showToast('You are offline', 'warning');
    });
}

// Form validation and error handling
function initializeFormValidation() {
    const forms = document.querySelectorAll('form');

    forms.forEach(function(form) {
        form.addEventListener('submit', function(e) {
            if (!validateForm(form)) {
                e.preventDefault();
                // Focus first invalid field
                const firstInvalid = form.querySelector('[aria-invalid="true"]');
                if (firstInvalid) {
                    firstInvalid.focus();
                }
            }
        });

        // Real-time validation
        const inputs = form.querySelectorAll('input, select, textarea');
        inputs.forEach(function(input) {
            input.addEventListener('blur', function() {
                validateField(input);
            });

            input.addEventListener('input', function() {
                // Clear errors on input
                clearFieldError(input);
            });
        });
    });
}

// Validate entire form
function validateForm(form) {
    let isValid = true;
    const inputs = form.querySelectorAll('input, select, textarea');

    inputs.forEach(function(input) {
        if (!validateField(input)) {
            isValid = false;
        }
    });

    return isValid;
}

// Validate individual field
function validateField(field) {
    const value = field.value.trim();
    let isValid = true;
    let errorMessage = '';

    // Required field validation
    if (field.hasAttribute('required') && !value) {
        isValid = false;
        errorMessage = 'This field is required';
    }

    // Email validation
    if (field.type === 'email' && value) {
        const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
        if (!emailRegex.test(value)) {
            isValid = false;
            errorMessage = 'Please enter a valid email address';
        }
    }

    // Search field validation (minimum length)
    if (field.type === 'search' && value && value.length < 2) {
        isValid = false;
        errorMessage = 'Please enter at least 2 characters';
    }

    // Update field state
    field.setAttribute('aria-invalid', isValid ? 'false' : 'true');

    if (!isValid) {
        showFieldError(field, errorMessage);
    } else {
        clearFieldError(field);
    }

    return isValid;
}

// Show field error
function showFieldError(field, message) {
    // Remove existing error
    clearFieldError(field);

    // Create error message
    const errorDiv = document.createElement('div');
    errorDiv.className = 'invalid-feedback d-block';
    errorDiv.setAttribute('role', 'alert');
    errorDiv.setAttribute('aria-live', 'polite');
    errorDiv.textContent = message;

    // Add error class to field
    field.classList.add('is-invalid');

    // Insert error after field
    field.parentNode.insertBefore(errorDiv, field.nextSibling);
}

// Clear field error
function clearFieldError(field) {
    field.classList.remove('is-invalid');
    const errorDiv = field.parentNode.querySelector('.invalid-feedback');
    if (errorDiv) {
        errorDiv.remove();
    }
}

// Enhanced search functionality
function initializeSearch() {
    const searchInputs = document.querySelectorAll('input[type="search"]');

    searchInputs.forEach(function(input) {
        // Clear search on Escape
        input.addEventListener('keydown', function(e) {
            if (e.key === 'Escape') {
                input.value = '';
                input.blur();
                announceToScreenReader('Search cleared', 'polite');
            }
        });

        // Auto-focus search on '/' key
        document.addEventListener('keydown', function(e) {
            if (e.key === '/' && !['INPUT', 'TEXTAREA', 'SELECT'].includes(e.target.tagName)) {
                e.preventDefault();
                input.focus();
                announceToScreenReader('Search input focused', 'polite');
            }
        });

        // Announce search results
        input.addEventListener('input', debounce(function() {
            if (input.value.length > 0) {
                announceToScreenReader(`Searching for: ${input.value}`, 'polite');
            }
        }, 500));
    });
}

// Toast notification system
function showToast(message, type = 'info') {
    // Create toast container if it doesn't exist
    let toastContainer = document.querySelector('.toast-container');
    if (!toastContainer) {
        toastContainer = document.createElement('div');
        toastContainer.className = 'toast-container position-fixed top-0 end-0 p-3';
        toastContainer.style.zIndex = '1060';
        document.body.appendChild(toastContainer);
    }

    // Create toast
    const toast = document.createElement('div');
    toast.className = `toast align-items-center text-white bg-${type} border-0`;
    toast.setAttribute('role', 'alert');
    toast.setAttribute('aria-live', 'assertive');
    toast.setAttribute('aria-atomic', 'true');

    toast.innerHTML = `
        <div class="d-flex">
            <div class="toast-body">${message}</div>
            <button type="button" class="btn-close btn-close-white me-2 m-auto" data-bs-dismiss="toast" aria-label="Close"></button>
        </div>
    `;

    toastContainer.appendChild(toast);

    // Initialize and show toast
    const bsToast = new bootstrap.Toast(toast);
    bsToast.show();

    // Remove toast after it's hidden
    toast.addEventListener('hidden.bs.toast', function() {
        toast.remove();
    });
}

// Utility functions for accessibility
function announceToScreenReader(message, priority = 'polite') {
    // Remove existing announcements
    const existing = document.querySelectorAll('[aria-live]');
    existing.forEach(el => {
        if (el !== document.querySelector('.sr-only[aria-live]')) el.remove();
    });

    const announcement = document.createElement('div');
    announcement.setAttribute('aria-live', priority);
    announcement.setAttribute('aria-atomic', 'true');
    announcement.className = 'sr-only';
    announcement.textContent = message;

    document.body.appendChild(announcement);

    // Remove after announcement
    setTimeout(() => {
        if (announcement.parentNode) {
            document.body.removeChild(announcement);
        }
    }, 1000);
}

function trapFocus(element) {
    const focusableElements = element.querySelectorAll(
        'a[href], button, textarea, input[type="text"], input[type="search"], ' +
        'input[type="email"], select, [tabindex]:not([tabindex="-1"])'
    );

    if (focusableElements.length === 0) return null;

    const firstElement = focusableElements[0];
    const lastElement = focusableElements[focusableElements.length - 1];

    function handleTab(e) {
        if (e.key !== 'Tab') return;

        if (e.shiftKey) {
            if (document.activeElement === firstElement) {
                e.preventDefault();
                lastElement.focus();
            }
        } else {
            if (document.activeElement === lastElement) {
                e.preventDefault();
                firstElement.focus();
            }
        }
    }

    element.addEventListener('keydown', handleTab);

    // Focus first element
    firstElement.focus();

    // Return cleanup function
    return function() {
        element.removeEventListener('keydown', handleTab);
    };
}

function releaseFocusTrap(element) {
    // Focus trap is automatically released when event listener is removed
    // This function can be extended for additional cleanup
}

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

// Accessibility testing function
function runAccessibilityTests() {
    console.log('🧪 Running Accessibility Tests...');

    const results = {
        passed: 0,
        failed: 0,
        warnings: 0,
        total: 0
    };

    // Test 1: Check for alt text on images
    const images = document.querySelectorAll('img');
    images.forEach(img => {
        results.total++;
        if (!img.hasAttribute('alt') && !img.hasAttribute('role') && img.getAttribute('role') !== 'presentation') {
            console.warn('⚠️ Image missing alt text:', img.src);
            results.warnings++;
        } else {
            results.passed++;
        }
    });

    // Test 2: Check for form labels
    const inputs = document.querySelectorAll('input:not([type="hidden"]), select, textarea');
    inputs.forEach(input => {
        results.total++;
        const label = document.querySelector(`label[for="${input.id}"]`);
        const ariaLabel = input.getAttribute('aria-label');
        const ariaLabelledBy = input.getAttribute('aria-labelledby');

        if (!label && !ariaLabel && !ariaLabelledBy) {
            console.error('❌ Form control missing label:', input.name || input.id);
            results.failed++;
        } else {
            results.passed++;
        }
    });

    // Test 3: Check heading hierarchy
    const headings = document.querySelectorAll('h1, h2, h3, h4, h5, h6');
    let lastLevel = 0;

    headings.forEach(heading => {
        results.total++;
        const level = parseInt(heading.tagName.charAt(1));

        if (level - lastLevel > 1 && lastLevel !== 0) {
            console.warn('⚠️ Skipped heading level:', heading.textContent.trim().substring(0, 50));
            results.warnings++;
        } else {
            results.passed++;
        }

        lastLevel = level;
    });

    // Test 4: Check ARIA landmarks
    results.total++;
    const landmarks = document.querySelectorAll('[role="banner"], [role="main"], [role="complementary"], [role="contentinfo"], header, main, aside, footer');
    const uniqueRoles = new Set();

    landmarks.forEach(element => {
        const role = element.getAttribute('role') || element.tagName.toLowerCase();
        uniqueRoles.add(role);
    });

    const requiredRoles = ['banner', 'main', 'contentinfo'];
    let hasRequired = true;

    requiredRoles.forEach(role => {
        if (!uniqueRoles.has(role)) {
            console.error(`❌ Missing ARIA landmark: ${role}`);
            hasRequired = false;
        }
    });

    if (hasRequired) {
        results.passed++;
    } else {
        results.failed++;
    }

    // Test 5: Check focus indicators
    results.total++;
    const focusableElements = document.querySelectorAll('a, button, input, select, textarea, [tabindex]:not([tabindex="-1"])');

    if (focusableElements.length === 0) {
        results.passed++;
    } else {
        // Check if focus styles are defined in CSS
        const computedStyle = getComputedStyle(focusableElements[0]);
        const outline = computedStyle.outline;
        const boxShadow = computedStyle.boxShadow;

        if (outline !== 'none' && outline !== '' && outline !== '0px none rgb(0, 0, 0)') {
            results.passed++;
        } else if (boxShadow && boxShadow !== 'none') {
            results.passed++;
        } else {
            console.warn('⚠️ Focus indicators may not be visible');
            results.warnings++;
        }
    }

    // Summary
    console.log(`\n📊 Accessibility Test Results:`);
    console.log(`✅ Passed: ${results.passed}`);
    console.log(`❌ Failed: ${results.failed}`);
    console.log(`⚠️ Warnings: ${results.warnings}`);
    console.log(`📈 Success Rate: ${Math.round((results.passed / results.total) * 100)}%`);

    if (results.failed === 0 && results.warnings === 0) {
        console.log('🎉 All accessibility tests passed!');
    } else if (results.failed === 0) {
        console.log('👍 Accessibility compliant with minor warnings');
    } else {
        console.log('⚠️ Accessibility issues found - review and fix');
    }

    return results;
}

// Utility functions for accessibility
function announceToScreenReader(message, priority = 'polite') {
    // Remove existing announcements
    const existing = document.querySelectorAll('[aria-live]');
    existing.forEach(el => {
        if (el !== document.querySelector('.sr-only[aria-live]')) el.remove();
    });

    const announcement = document.createElement('div');
    announcement.setAttribute('aria-live', priority);
    announcement.setAttribute('aria-atomic', 'true');
    announcement.className = 'sr-only';
    announcement.textContent = message;

    document.body.appendChild(announcement);

    // Remove after announcement
    setTimeout(() => {
        if (announcement.parentNode) {
            document.body.removeChild(announcement);
        }
    }, 1000);
}

function releaseFocusTrap(element) {
    // Focus trap is automatically released when event listener is removed
    // This function can be extended for additional cleanup
}

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

// Accessibility testing function
function runAccessibilityTests() {
    console.log('🧪 Running Accessibility Tests...');

    const results = {
        passed: 0,
        failed: 0,
        warnings: 0,
        total: 0
    };

    // Test 1: Check for alt text on images
    const images = document.querySelectorAll('img');
    images.forEach(img => {
        results.total++;
        if (!img.hasAttribute('alt') && !img.hasAttribute('role') && img.getAttribute('role') !== 'presentation') {
            console.warn('⚠️ Image missing alt text:', img.src);
            results.warnings++;
        } else {
            results.passed++;
        }
    });

    // Test 2: Check for form labels
    const inputs = document.querySelectorAll('input:not([type="hidden"]), select, textarea');
    inputs.forEach(input => {
        results.total++;
        const label = document.querySelector(`label[for="${input.id}"]`);
        const ariaLabel = input.getAttribute('aria-label');
        const ariaLabelledBy = input.getAttribute('aria-labelledby');

        if (!label && !ariaLabel && !ariaLabelledBy) {
            console.error('❌ Form control missing label:', input.name || input.id);
            results.failed++;
        } else {
            results.passed++;
        }
    });

    // Test 3: Check heading hierarchy
    const headings = document.querySelectorAll('h1, h2, h3, h4, h5, h6');
    let lastLevel = 0;

    headings.forEach(heading => {
        results.total++;
        const level = parseInt(heading.tagName.charAt(1));

        if (level - lastLevel > 1 && lastLevel !== 0) {
            console.warn('⚠️ Skipped heading level:', heading.textContent.trim().substring(0, 50));
            results.warnings++;
        } else {
            results.passed++;
        }

        lastLevel = level;
    });

    // Test 4: Check ARIA landmarks
    results.total++;
    const landmarks = document.querySelectorAll('[role="banner"], [role="main"], [role="complementary"], [role="contentinfo"], header, main, aside, footer');
    const uniqueRoles = new Set();

    landmarks.forEach(element => {
        const role = element.getAttribute('role') || element.tagName.toLowerCase();
        uniqueRoles.add(role);
    });

    const requiredRoles = ['banner', 'main', 'contentinfo'];
    let hasRequired = true;

    requiredRoles.forEach(role => {
        if (!uniqueRoles.has(role)) {
            console.error(`❌ Missing ARIA landmark: ${role}`);
            hasRequired = false;
        }
    });

    if (hasRequired) {
        results.passed++;
    } else {
        results.failed++;
    }

    // Test 5: Check focus indicators
    results.total++;
    const focusableElements = document.querySelectorAll('a, button, input, select, textarea, [tabindex]:not([tabindex="-1"])');

    if (focusableElements.length === 0) {
        results.passed++;
    } else {
        // Check if focus styles are defined in CSS
        const computedStyle = getComputedStyle(focusableElements[0]);
        const outline = computedStyle.outline;
        const boxShadow = computedStyle.boxShadow;

        if (outline !== 'none' && outline !== '' && outline !== '0px none rgb(0, 0, 0)') {
            results.passed++;
        } else if (boxShadow && boxShadow !== 'none') {
            results.passed++;
        } else {
            console.warn('⚠️ Focus indicators may not be visible');
            results.warnings++;
        }
    }

    // Summary
    console.log(`\n📊 Accessibility Test Results:`);
    console.log(`✅ Passed: ${results.passed}`);
    console.log(`❌ Failed: ${results.failed}`);
    console.log(`⚠️ Warnings: ${results.warnings}`);
    console.log(`📈 Success Rate: ${Math.round((results.passed / results.total) * 100)}%`);

    if (results.failed === 0 && results.warnings === 0) {
        console.log('🎉 All accessibility tests passed!');
    } else if (results.failed === 0) {
        console.log('👍 Accessibility compliant with minor warnings');
    } else {
        console.log('⚠️ Accessibility issues found - review and fix');
    }

    return results;
}