jQuery(document).ready(function($) {
    const $countrySelect = $('#user_country');
    const $stateSelect = $('#user_state');
    const $stateOtherInput = $('#user_state_other');
    const $registrationForm = $('#hvac-registration-form');
    
    // Form validation helpers
    function showFieldError(fieldId, message) {
        const $field = $('#' + fieldId);
        const $existingError = $field.siblings('.error-message');
        
        if ($existingError.length) {
            $existingError.text(message);
        } else {
            $field.after('<p class="error-message" id="' + fieldId + '_error">' + message + '</p>');
        }
        
        $field.addClass('error');
    }
    
    function clearFieldError(fieldId) {
        const $field = $('#' + fieldId);
        $field.siblings('.error-message').remove();
        $field.removeClass('error');
    }
    
    // Real-time email validation
    $('#user_email').on('blur', function() {
        const email = $(this).val();
        if (email && !isValidEmail(email)) {
            showFieldError('user_email', 'Please enter a valid email address.');
        } else {
            clearFieldError('user_email');
        }
    });
    
    $('#business_email').on('blur', function() {
        const email = $(this).val();
        if (email && !isValidEmail(email)) {
            showFieldError('business_email', 'Please enter a valid business email address.');
        } else {
            clearFieldError('business_email');
        }
    });
    
    function isValidEmail(email) {
        const re = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
        return re.test(email);
    }
    
    // Real-time password validation
    $('#user_pass').on('input blur', function() {
        const password = $(this).val();
        if (password) {
            const errors = [];
            if (password.length < 8) {
                errors.push('at least 8 characters');
            }
            if (!/[A-Z]/.test(password)) {
                errors.push('one uppercase letter');
            }
            if (!/[a-z]/.test(password)) {
                errors.push('one lowercase letter');
            }
            if (!/[0-9]/.test(password)) {
                errors.push('one number');
            }
            
            if (errors.length > 0) {
                showFieldError('user_pass', 'Password must contain ' + errors.join(', ') + '.');
            } else {
                clearFieldError('user_pass');
                // Check confirm password if it has a value
                const confirmPass = $('#confirm_password').val();
                if (confirmPass) {
                    $('#confirm_password').trigger('blur');
                }
            }
        }
    });
    
    // Confirm password validation
    $('#confirm_password').on('blur', function() {
        const password = $('#user_pass').val();
        const confirmPassword = $(this).val();
        
        if (confirmPassword && password !== confirmPassword) {
            showFieldError('confirm_password', 'Passwords do not match.');
        } else {
            clearFieldError('confirm_password');
        }
    });
    
    // URL validation for optional fields
    function isValidURL(url) {
        try {
            new URL(url);
            return true;
        } catch (_) {
            return false;
        }
    }
    
    $('#user_url, #user_linkedin, #business_website').on('blur', function() {
        const url = $(this).val();
        const fieldId = $(this).attr('id');
        
        if (url && !isValidURL(url)) {
            const fieldName = fieldId === 'user_url' ? 'personal website' : 
                             fieldId === 'user_linkedin' ? 'LinkedIn profile' : 
                             'business website';
            showFieldError(fieldId, 'Please enter a valid URL for your ' + fieldName + '.');
        } else {
            clearFieldError(fieldId);
        }
    });
    
    // Form submission validation
    $registrationForm.on('submit', function(e) {
        let hasErrors = false;
        const errors = [];
        
        // Check required fields
        const requiredFields = [
            { id: 'user_email', name: 'Email' },
            { id: 'user_pass', name: 'Password' },
            { id: 'confirm_password', name: 'Confirm Password' },
            { id: 'first_name', name: 'First Name' },
            { id: 'last_name', name: 'Last Name' },
            { id: 'display_name', name: 'Display Name' },
            { id: 'description', name: 'Biographical Info' },
            { id: 'business_name', name: 'Business Name' },
            { id: 'business_phone', name: 'Business Phone' },
            { id: 'business_email', name: 'Business Email' },
            { id: 'business_description', name: 'Business Description' },
            { id: 'user_country', name: 'Country' },
            { id: 'user_city', name: 'City' },
            { id: 'user_zip', name: 'Zip/Postal Code' },
            { id: 'application_details', name: 'Application Details' }
        ];
        
        requiredFields.forEach(field => {
            const $field = $('#' + field.id);
            if (!$field.val() || $field.val().trim() === '') {
                hasErrors = true;
                errors.push(field.name + ' is required.');
                showFieldError(field.id, field.name + ' is required.');
            }
        });
        
        // Check state/province
        const country = $('#user_country').val();
        if (country) {
            if (country === 'United States' || country === 'Canada') {
                const state = $('#user_state').val();
                if (!state || state === '') {
                    hasErrors = true;
                    errors.push('State/Province is required.');
                    showFieldError('user_state', 'State/Province is required.');
                }
            } else {
                const otherState = $('#user_state_other').val();
                if (!otherState || otherState.trim() === '') {
                    hasErrors = true;
                    errors.push('State/Province is required.');
                    showFieldError('user_state_other', 'State/Province is required.');
                }
            }
        }
        
        // Check radio buttons
        if (!$('input[name="create_venue"]:checked').length) {
            hasErrors = true;
            errors.push('Please select whether to create a training venue profile.');
        }
        
        if (!$('input[name="business_type"]:checked').length) {
            hasErrors = true;
            errors.push('Business Type is required.');
        }
        
        // Check checkbox groups
        const checkboxGroups = [
            { name: 'training_audience[]', label: 'Training Audience' },
            { name: 'training_formats[]', label: 'Training Formats' },
            { name: 'training_locations[]', label: 'Training Locations' },
            { name: 'training_resources[]', label: 'Training Resources' }
        ];
        
        checkboxGroups.forEach(group => {
            if (!$('input[name="' + group.name + '"]:checked').length) {
                hasErrors = true;
                errors.push('Please select at least one option for ' + group.label + '.');
            }
        });
        
        if (hasErrors) {
            e.preventDefault();
            
            // Show error summary at the top
            let $errorSummary = $('.hvac-form-errors');
            if (!$errorSummary.length) {
                $errorSummary = $('<div class="hvac-form-errors" role="alert"><h3>Please correct the following errors:</h3><ul></ul></div>');
                $registrationForm.prepend($errorSummary);
            }
            
            const $errorList = $errorSummary.find('ul');
            $errorList.empty();
            errors.forEach(error => {
                $errorList.append('<li>' + error + '</li>');
            });
            
            // Scroll to top of form
            $('html, body').animate({
                scrollTop: $('.hvac-registration-form').offset().top - 100
            }, 500);
        }
    });

    // Function to populate states/provinces
    function loadStates(country) {
        console.log(`Loading states/provinces for ${country}`); // Keep log for debugging
        $stateSelect.find('option').not('[value=""],[value="Other"]').remove(); // Clear existing options except defaults

        let options = {};
        if (country === 'United States' && typeof hvacRegistrationData !== 'undefined' && hvacRegistrationData.states) {
            options = hvacRegistrationData.states;
        } else if (country === 'Canada' && typeof hvacRegistrationData !== 'undefined' && hvacRegistrationData.provinces) {
            options = hvacRegistrationData.provinces;
        } else {
            // If country is not US/CA or data is missing, ensure 'Other' is selected and input shown
             $stateSelect.val('Other').trigger('change'); // Trigger change to show 'Other' input if needed
             return;
        }

        // Append new options
        $.each(options, function(value, label) {
            // Append before the 'Other' option if it exists, otherwise just append
            const $otherOption = $stateSelect.find('option[value="Other"]');
            const $newOption = $('<option></option>').val(value).text(label);
            if ($otherOption.length > 0) {
                 $newOption.insertBefore($otherOption);
            } else {
                 $stateSelect.append($newOption);
            }
        });

         // Ensure the 'Other' input is hidden initially when states/provinces are loaded
         $stateOtherInput.hide().val('');
         // Reset state selection to default prompt
         $stateSelect.val('');
    }

    // Handle state/province field visibility based on 'Other' selection
    $stateSelect.change(function() {
        if ($(this).val() === 'Other') {
            $stateOtherInput.show().prop('required', true); // Make required if Other is selected
        } else {
            $stateOtherInput.hide().val('').prop('required', false); // Hide and make not required
        }
    }).trigger('change'); // Trigger on load to set initial visibility

    // Handle country change to show/hide/populate state field
    $countrySelect.change(function() {
        const country = $(this).val();

        if (country === 'United States' || country === 'Canada') {
            loadStates(country);
            $stateSelect.show().prop('required', true); // Show and require state select
            $stateOtherInput.prop('required', false); // Ensure 'Other' input is not required initially
        } else if (country) {
            // For other countries, hide state select, select 'Other', show/require 'Other' input
            $stateSelect.hide().val('Other').prop('required', false); // Hide and make not required
            $stateOtherInput.show().prop('required', true); // Show and require 'Other' input
        } else {
            // No country selected
            $stateSelect.hide().val('').prop('required', false); // Hide and make not required
            $stateOtherInput.hide().val('').prop('required', false); // Hide and make not required
        }
    }).trigger('change'); // Trigger on load to set initial state based on pre-selected country (if any)

});