// Validation Helpers
const ValidationRules = {
    date: {
        validate: (value, input) => {
            if (!value) return true;
            const date = new Date(value);
            const now = new Date();
            const min = new Date('1800-01-01');
            
            if (date > now) {
                return 'Date cannot be in the future';
            }
            if (date < min) {
                return 'Date cannot be before 1800';
            }
            return true;
        }
    },
    numeric: {
        validate: (value, input) => {
            if (!value) return true;
            const num = parseFloat(value);
            const min = parseFloat(input.getAttribute('min') || '-Infinity');
            const max = parseFloat(input.getAttribute('max') || 'Infinity');
            
            if (isNaN(num)) {
                return 'Please enter a valid number';
            }
            if (num < min) {
                return `Value must be at least ${min}`;
            }
            if (num > max) {
                return `Value must be no more than ${max}`;
            }
            return true;
        }
    }
};

// Form Validation and Error Handling
document.addEventListener('DOMContentLoaded', function() {
    // Form Validation
    document.querySelectorAll('form[hx-post]').forEach(form => {
        // Add validation on field change
        form.addEventListener('input', function(e) {
            const input = e.target;
            if (input.hasAttribute('data-validate')) {
                validateField(input);
            }
        });

        form.addEventListener('htmx:beforeRequest', function(event) {
            let isValid = true;

            // Validate all fields
            form.querySelectorAll('[data-validate]').forEach(input => {
                if (!validateField(input)) {
                    isValid = false;
                }
            });

            // Check required notes field
            const notesField = form.querySelector('textarea[name="notes"]');
            if (notesField && !notesField.value.trim()) {
                showError(notesField, 'Notes are required');
                isValid = false;
            }

            if (!isValid) {
                event.preventDefault();
                // Focus first invalid field
                form.querySelector('.border-red-500')?.focus();
            }
        });

        // Clear error states on input
        form.addEventListener('input', function(e) {
            if (e.target.classList.contains('border-red-500')) {
                e.target.classList.remove('border-red-500');
            }
        });
    });

    // Form State Management
    document.querySelectorAll('form[hx-post]').forEach(form => {
        const formId = form.getAttribute('id');
        if (!formId) return;

        // Save form state before submission
        form.addEventListener('htmx:beforeRequest', function() {
            const formData = new FormData(form);
            const state = {};
            formData.forEach((value, key) => {
                state[key] = value;
            });
            sessionStorage.setItem('formState-' + formId, JSON.stringify(state));
        });

        // Restore form state if available
        const savedState = sessionStorage.getItem('formState-' + formId);
        if (savedState) {
            const state = JSON.parse(savedState);
            Object.entries(state).forEach(([key, value]) => {
                const input = form.querySelector(`[name="${key}"]`);
                if (input) {
                    input.value = value;
                }
            });
        }
    });

    // Park Area Sync with Park Selection
    document.querySelectorAll('[id^="park-input-"]').forEach(parkInput => {
        const submissionId = parkInput.id.replace('park-input-', '');
        const areaSelect = document.querySelector(`#park-area-select-${submissionId}`);
        
        if (parkInput && areaSelect) {
            parkInput.addEventListener('change', function() {
                const parkId = this.value;
                if (!parkId) {
                    areaSelect.innerHTML = '<option value="">Select area</option>';
                    return;
                }

                htmx.ajax('GET', `/parks/${parkId}/areas/`, {
                    target: areaSelect,
                    swap: 'innerHTML'
                });
            });
        }
    });

    // Improved Error Handling
    document.body.addEventListener('htmx:responseError', function(evt) {
        const errorToast = document.createElement('div');
        errorToast.className = 'fixed bottom-4 right-4 bg-red-500 text-white px-6 py-3 rounded-lg shadow-lg z-50 flex items-center';
        errorToast.innerHTML = `
            <i class="fas fa-exclamation-circle mr-2"></i>
            <span>${evt.detail.error || 'An error occurred'}</span>
            <button class="ml-4 hover:text-red-200" onclick="this.parentElement.remove()">
                <i class="fas fa-times"></i>
            </button>
        `;
        document.body.appendChild(errorToast);
        setTimeout(() => {
            errorToast.remove();
        }, 5000);
    });

    // Accessibility Improvements
    document.addEventListener('htmx:afterSettle', function(evt) {
        // Focus management
        const target = evt.detail.target;
        const focusableElement = target.querySelector('button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])');
        if (focusableElement) {
            focusableElement.focus();
        }

        // Announce state changes
        if (target.hasAttribute('aria-live')) {
            const announcement = target.getAttribute('aria-label') || target.textContent;
            const announcer = document.getElementById('a11y-announcer') || createAnnouncer();
            announcer.textContent = announcement;
        }
    });
});

// Helper function to create accessibility announcer
function createAnnouncer() {
    const announcer = document.createElement('div');
    announcer.id = 'a11y-announcer';
    announcer.className = 'sr-only';
    announcer.setAttribute('aria-live', 'polite');
    document.body.appendChild(announcer);
    return announcer;
}

// Validation Helper Functions
function validateField(input) {
    const validationType = input.getAttribute('data-validate');
    if (!validationType || !ValidationRules[validationType]) return true;

    const result = ValidationRules[validationType].validate(input.value, input);
    if (result === true) {
        clearError(input);
        return true;
    } else {
        showError(input, result);
        return false;
    }
}

function showError(input, message) {
    const errorId = input.getAttribute('aria-describedby');
    const errorElement = document.getElementById(errorId);
    
    input.classList.add('border-red-500', 'error-shake');
    if (errorElement) {
        errorElement.textContent = message;
        errorElement.classList.remove('hidden');
    }

    // Announce error to screen readers
    const announcer = document.getElementById('a11y-announcer');
    if (announcer) {
        announcer.textContent = `Error: ${message}`;
    }

    setTimeout(() => {
        input.classList.remove('error-shake');
    }, 820);
}

function clearError(input) {
    const errorId = input.getAttribute('aria-describedby');
    const errorElement = document.getElementById(errorId);
    
    input.classList.remove('border-red-500');
    if (errorElement) {
        errorElement.classList.add('hidden');
        errorElement.textContent = '';
    }
}