feat: Implement Phase 2, Step 7 - WP Admin Interfaces

- Add AssessmentAjaxHandler class for AJAX requests.
- Add assessment.js for front-end logic.
- Implement pre-screening form submission via AJAX.
- Implement answer auto-save via AJAX.
- Implement final assessment submission via AJAX.
- Update assessment-shell.php template for dynamic rendering and JS hooks.
- Enqueue and localize assessment.js conditionally.

Refs: assessment_interaction_plan.md
Note: Includes TODOs for evaluation CPT handling, status updates, and sanitization.

public/js/assessment.js

@@ -0,0 +1,163 @@
+/**
+ * Quiztech Assessment Interaction Script
+ *
+ * Handles AJAX submissions for pre-screening, answer auto-save,
+ * and final assessment submission.
+ */
+(function($) {
+    'use strict';
+
+    $(function() {
+        console.log('Assessment script loaded.');
+
+        // Check if localized data is available
+        if (typeof quiztech_assessment_vars === 'undefined') {
+            console.error('Quiztech Assessment Error: Localized variables not found.');
+            return;
+        }
+
+        var $prescreeningForm = $('#quiztech-prescreening-form');
+        var $prescreeningSection = $('#quiztech-prescreening-section');
+        var $assessmentSection = $('#quiztech-assessment-section');
+        var $submitButton = $prescreeningForm.find('button[type="submit"]');
+        var $formMessages = $('<div class="form-messages"></div>').insertBefore($submitButton); // Area for messages
+
+        // --- Pre-Screening Form Handling ---
+        $prescreeningForm.on('submit', function(event) {
+            event.preventDefault(); // Stop traditional form submission
+
+            $formMessages.empty().removeClass('error success'); // Clear previous messages
+            $submitButton.prop('disabled', true).text('Submitting...'); // Disable button
+
+            var formData = $(this).serialize(); // Get form data
+
+            // Add required AJAX parameters
+            formData += '&action=quiztech_submit_prescreening';
+            formData += '&nonce=' + quiztech_assessment_vars.prescreening_nonce;
+            formData += '&invitation_id=' + quiztech_assessment_vars.invitation_id;
+
+            $.ajax({
+                type: 'POST',
+                url: quiztech_assessment_vars.ajax_url,
+                data: formData,
+                dataType: 'json', // Expect JSON response from server
+                success: function(response) {
+                    if (response.success) {
+                        // Success! Hide pre-screening, show assessment
+                        $formMessages.addClass('success').text(response.data.message || 'Success!'); // Show success message briefly
+                        $prescreeningSection.slideUp();
+                        $assessmentSection.slideDown();
+                        // No need to re-enable button as the form is gone
+                    } else {
+                        // Handle WP JSON error
+                        $formMessages.addClass('error').text(response.data.message || 'An error occurred.');
+                        $submitButton.prop('disabled', false).text('Submit Pre-Screening & Start Assessment'); // Re-enable button
+                    }
+                },
+                error: function(jqXHR, textStatus, errorThrown) {
+                    // Handle general AJAX error
+                    console.error("AJAX Error:", textStatus, errorThrown);
+                    $formMessages.addClass('error').text('A network error occurred. Please try again.');
+                    $submitButton.prop('disabled', false).text('Submit Pre-Screening & Start Assessment'); // Re-enable button
+                }
+            });
+        });
+
+        // --- Assessment Answer Auto-Save ---
+        var $assessmentForm = $('#quiztech-assessment-form');
+        var autoSaveTimeout; // To debounce requests
+
+        // Target input/textarea/select elements within the assessment form for auto-save
+        $assessmentForm.on('change blur', 'input, textarea, select', function() {
+            clearTimeout(autoSaveTimeout); // Clear previous timeout if exists
+
+            var $input = $(this);
+            var $questionGroup = $input.closest('.question-group');
+            var questionId = $questionGroup.data('question-id');
+            var answer = $input.val();
+
+            // Add a small visual indicator within the question group
+            var $indicator = $questionGroup.find('.save-indicator');
+            if ($indicator.length === 0) {
+                $indicator = $('<span class="save-indicator" style="margin-left: 10px; font-size: 0.8em; color: grey;"></span>').appendTo($questionGroup.find('label:first'));
+            }
+            $indicator.text('Saving...');
+
+            // Debounce the AJAX request slightly
+            autoSaveTimeout = setTimeout(function() {
+                $.ajax({
+                    type: 'POST',
+                    url: quiztech_assessment_vars.ajax_url,
+                    data: {
+                        action: 'quiztech_save_answer',
+                        nonce: quiztech_assessment_vars.assessment_nonce, // Use the correct nonce
+                        invitation_id: quiztech_assessment_vars.invitation_id,
+                        question_id: questionId,
+                        answer: answer
+                    },
+                    dataType: 'json',
+                    success: function(response) {
+                        if (response.success) {
+                            $indicator.text('Saved ✓').css('color', 'green');
+                            // Optionally fade out the indicator after a delay
+                            setTimeout(function() { $indicator.fadeOut().remove(); }, 2000);
+                        } else {
+                            $indicator.text('Error!').css('color', 'red');
+                            console.error("Auto-save error:", response.data.message);
+                            // Consider more prominent error display if needed
+                        }
+                    },
+                    error: function(jqXHR, textStatus, errorThrown) {
+                        $indicator.text('Network Error!').css('color', 'red');
+                        console.error("AJAX Error:", textStatus, errorThrown);
+                    }
+                });
+            }, 500); // Wait 500ms after the last change/blur before sending
+        });
+
+
+        // --- Final Assessment Submission ---
+        var $submitAssessmentButton = $('#quiztech-submit-assessment');
+        var $assessmentFormMessages = $('<div class="form-messages"></div>').insertAfter($submitAssessmentButton); // Area for messages
+
+        $submitAssessmentButton.on('click', function(event) {
+            event.preventDefault(); // Stop traditional form submission (though AJAX auto-save handles data)
+
+            if (!confirm('Are you sure you want to submit your assessment?')) {
+                return; // User cancelled
+            }
+
+            $assessmentFormMessages.empty().removeClass('error success');
+            $submitAssessmentButton.prop('disabled', true).text('Submitting...');
+
+            $.ajax({
+                type: 'POST',
+                url: quiztech_assessment_vars.ajax_url,
+                data: {
+                    action: 'quiztech_submit_assessment',
+                    nonce: quiztech_assessment_vars.assessment_nonce, // Reuse assessment nonce
+                    invitation_id: quiztech_assessment_vars.invitation_id
+                },
+                dataType: 'json',
+                success: function(response) {
+                    if (response.success) {
+                        // Success! Display message and potentially hide the form/button
+                        $assessmentFormMessages.addClass('success').text(response.data.message || 'Assessment Submitted Successfully!');
+                        $assessmentForm.hide(); // Hide the form after successful submission
+                        // Optionally redirect: window.location.href = response.data.redirect_url;
+                    } else {
+                        $assessmentFormMessages.addClass('error').text(response.data.message || 'An error occurred during submission.');
+                        $submitAssessmentButton.prop('disabled', false).text('Submit Assessment'); // Re-enable button
+                    }
+                },
+                error: function(jqXHR, textStatus, errorThrown) {
+                    console.error("AJAX Error:", textStatus, errorThrown);
+                    $assessmentFormMessages.addClass('error').text('A network error occurred. Please try again.');
+                    $submitAssessmentButton.prop('disabled', false).text('Submit Assessment'); // Re-enable button
+                }
+            });
+        });
+
+    }); // End document ready
+
+})(jQuery);

public/templates/assessment-shell.php

@@ -56,15 +56,17 @@ if ( ! $invitation_data || ! $current_step ) {
 		<h1><?php esc_html_e( 'Assessment Invitation', 'quiztech' ); ?></h1>
 
 		<?php if ( 'pre_screening' === $current_step ) : ?>
-
+		<div id="quiztech-prescreening-section"> <?php // Added ID for JS targeting ?>
 			<div class="step-info">
 				<h2><?php esc_html_e( 'Step 1: Pre-Screening Questions', 'quiztech' ); ?></h2>
 				<p><?php esc_html_e( 'Please answer the following questions before starting the assessment.', 'quiztech' ); ?></p>
 			</div>
 
-			<form method="post" action=""> <?php // TODO: Add action URL and nonce for processing submission ?>
-				<?php wp_nonce_field( 'quiztech_submit_prescreening_' . $invitation_data->token, 'quiztech_prescreening_nonce' ); ?>
-				<input type="hidden" name="quiztech_invitation_token" value="<?php echo esc_attr( $invitation_data->token ); ?>">
+			<form id="quiztech-prescreening-form" method="post" action=""> <?php // Action handled by AJAX ?>
+				<?php // Nonce is checked via AJAX, but good to have in form too for non-JS fallback (if implemented) ?>
+				<?php // wp_nonce_field( 'quiztech_submit_prescreening_' . $invitation_data->token, 'quiztech_prescreening_nonce' ); ?>
+				<?php // Token is passed via localized script vars ?>
+				<?php // <input type="hidden" name="quiztech_invitation_token" value="<?php echo esc_attr( $invitation_data->token ); ?>"> ?>
 				<input type="hidden" name="action" value="quiztech_submit_prescreening">
 
 				<?php if ( is_array( $pre_screening_questions ) && ! empty( $pre_screening_questions ) ) : ?>
@@ -90,9 +92,10 @@ if ( ! $invitation_data || ! $current_step ) {
 				<?php // Render questions here - Removed, handled above ?>
 				<button type="submit"><?php esc_html_e( 'Submit Pre-Screening & Start Assessment', 'quiztech' ); ?></button>
 			</form>
+		</div> <!-- #quiztech-prescreening-section -->
 
 		<?php elseif ( 'assessment' === $current_step ) : ?>
-
+		<div id="quiztech-assessment-section" style="display: none;"> <?php // Added ID and initially hidden ?>
 			<div class="step-info">
 				<h2><?php esc_html_e( 'Step 2: Assessment', 'quiztech' ); ?></h2>
 				<p><?php printf( esc_html__( 'You are about to begin Assessment ID: %d', 'quiztech' ), absint( $invitation_data->assessment_id ) ); ?></p>
@@ -132,10 +135,25 @@ if ( ! $invitation_data || ! $current_step ) {
 									<?php break; ?>
 
 								<?php case 'multiple-choice': ?>
-									<?php // TODO: Fetch actual choices from post meta ?>
-									<label><input type="radio" name="assessment_answer[<?php echo esc_attr( $question_id ); ?>]" value="opt1" required> Option 1</label><br>
-									<label><input type="radio" name="assessment_answer[<?php echo esc_attr( $question_id ); ?>]" value="opt2"> Option 2</label><br>
-									<label><input type="radio" name="assessment_answer[<?php echo esc_attr( $question_id ); ?>]" value="opt3"> Option 3</label>
+									<?php
+									$choices = get_post_meta( $question_id, 'question_choices', true );
+									if ( is_array( $choices ) && ! empty( $choices ) ) :
+										foreach ( $choices as $choice_index => $choice_text ) :
+											$choice_value = esc_attr( $choice_text ); // Use text as value for simplicity
+											$choice_id = 'choice_' . esc_attr( $question_id ) . '_' . esc_attr( $choice_index );
+											?>
+											<label for="<?php echo $choice_id; ?>">
+												<input type="radio"
+													   id="<?php echo $choice_id; ?>"
+													   name="assessment_answer[<?php echo esc_attr( $question_id ); ?>]"
+													   value="<?php echo $choice_value; ?>"
+													   required>
+												<?php echo esc_html( $choice_text ); ?>
+											</label><br>
+										<?php endforeach; ?>
+									<?php else : ?>
+										<p class="error"><?php esc_html_e( 'Error: Choices not found for this question.', 'quiztech' ); ?></p>
+									<?php endif; ?>
 									<?php break; ?>
 
 								<?php case 'true-false': ?>
@@ -160,6 +178,7 @@ if ( ! $invitation_data || ! $current_step ) {
 			endif;
 			?>
 			<?php // Removed the simple "Start Assessment" button, replaced by question rendering logic ?>
+		</div> <!-- #quiztech-assessment-section -->
 
 		<?php else : ?>
 			<p class="error"><?php esc_html_e( 'An unexpected error occurred. Invalid assessment step.', 'quiztech' ); ?></p>

quiztech-assessment-platform.php

@@ -116,8 +116,21 @@ function quiztech_init() {
 	$frontend_handler = new \Quiztech\AssessmentPlatform\Includes\FrontendHandler();
 	$frontend_handler->init_hooks();
 
+
+	// Initialize AJAX handler for assessment interactions
+	\Quiztech\AssessmentPlatform\Includes\Ajax\AssessmentAjaxHandler::init();
+
+	// Initialize Admin-specific features
+	if ( is_admin() ) {
+		$admin_list_tables = new \Quiztech\AssessmentPlatform\Admin\AdminListTables();
+		$admin_list_tables->register_hooks();
+
+		$settings_page = new \Quiztech\AssessmentPlatform\Admin\SettingsPage();
+		$settings_page->register_hooks();
+	}
+
 	// TODO: Instantiate other core classes and call their init methods here
-	// e.g., Admin menu handler, AJAX handlers, Shortcode handlers etc.
+	// e.g., Shortcode handlers etc.
 }
 add_action( 'plugins_loaded', 'quiztech_init' );
 

src/Admin/AdminListTables.php

@@ -0,0 +1,282 @@
+<?php
+
+namespace Quiztech\AssessmentPlatform\Admin;
+
+/**
+ * Customizes the WP Admin list tables for Quiztech CPTs.
+ */
+class AdminListTables {
+
+    /**
+     * Register hooks for customizing admin list tables.
+     */
+    public function register_hooks() {
+        // Question CPT Columns
+        add_filter( 'manage_question_posts_columns', [ $this, 'filter_question_columns' ] );
+        add_action( 'manage_question_posts_custom_column', [ $this, 'render_question_custom_columns' ], 10, 2 );
+
+        // Assessment CPT Columns
+        add_filter( 'manage_assessment_posts_columns', [ $this, 'filter_assessment_columns' ] );
+        add_action( 'manage_assessment_posts_custom_column', [ $this, 'render_assessment_custom_columns' ], 10, 2 );
+
+        // Job CPT Columns
+        add_filter( 'manage_job_posts_columns', [ $this, 'filter_job_columns' ] );
+        add_action( 'manage_job_posts_custom_column', [ $this, 'render_job_custom_columns' ], 10, 2 );
+
+        // User Evaluation CPT Columns
+        add_filter( 'manage_user_evaluation_posts_columns', [ $this, 'filter_user_evaluation_columns' ] );
+        add_action( 'manage_user_evaluation_posts_custom_column', [ $this, 'render_user_evaluation_custom_columns' ], 10, 2 );
+    }
+
+    // --- Question CPT ---
+
+    /**
+     * Filters the columns for the Question CPT list table.
+     *
+     * @param array $columns Existing columns.
+     * @return array Modified columns.
+     */
+    public function filter_question_columns( $columns ) {
+        // Add 'Question Type' column
+        // Keep 'Categories' (added by taxonomy registration)
+        // Example: Rearrange or add new columns
+        $new_columns = [];
+        foreach ($columns as $key => $title) {
+            $new_columns[$key] = $title;
+            if ($key === 'title') {
+                $new_columns['question_type'] = __( 'Question Type', 'quiztech' );
+            }
+        }
+         // If taxonomy column isn't added automatically, add it here:
+        // if (!isset($new_columns['taxonomy-quiztech_category'])) {
+        //     $new_columns['taxonomy-quiztech_category'] = __('Categories', 'quiztech');
+        // }
+        return $new_columns;
+    }
+
+    /**
+     * Renders the content for custom columns in the Question CPT list table.
+     *
+     * @param string $column_name The name of the column to render.
+     * @param int    $post_id     The ID of the current post.
+     */
+    public function render_question_custom_columns( $column_name, $post_id ) {
+        if ( 'question_type' === $column_name ) {
+            $question_type = get_post_meta( $post_id, '_quiztech_question_type', true );
+            echo esc_html( ucwords( str_replace( '-', ' ', $question_type ?: 'N/A' ) ) );
+        }
+    }
+
+    // --- Assessment CPT ---
+
+    /**
+     * Filters the columns for the Assessment CPT list table.
+     *
+     * @param array $columns Existing columns.
+     * @return array Modified columns.
+     */
+    public function filter_assessment_columns( $columns ) {
+        $new_columns = [];
+        foreach ($columns as $key => $title) {
+            $new_columns[$key] = $title;
+            if ($key === 'title') {
+                $new_columns['num_questions'] = __( 'No. Questions', 'quiztech' );
+                $new_columns['credit_cost'] = __( 'Credit Cost', 'quiztech' );
+            }
+        }
+        // Ensure Categories column exists
+        // if (!isset($new_columns['taxonomy-quiztech_category'])) {
+        //     $new_columns['taxonomy-quiztech_category'] = __('Categories', 'quiztech');
+        // }
+        return $new_columns;
+    }
+
+    /**
+     * Renders the content for custom columns in the Assessment CPT list table.
+     *
+     * @param string $column_name The name of the column to render.
+     * @param int    $post_id     The ID of the current post.
+     */
+    public function render_assessment_custom_columns( $column_name, $post_id ) {
+        switch ( $column_name ) {
+            case 'num_questions':
+                // TODO: Implement logic to get question count (e.g., from '_quiztech_question_ids' meta)
+                $question_ids = get_post_meta( $post_id, '_quiztech_question_ids', true );
+                echo is_array( $question_ids ) ? count( $question_ids ) : '0';
+                break;
+            case 'credit_cost':
+                // TODO: Implement logic to calculate credit cost based on associated questions
+                echo 'N/A'; // Placeholder
+                break;
+        }
+    }
+
+    // --- Job CPT ---
+
+    /**
+     * Filters the columns for the Job CPT list table.
+     *
+     * @param array $columns Existing columns.
+     * @return array Modified columns.
+     */
+    public function filter_job_columns( $columns ) {
+         $new_columns = [];
+        // Keep standard columns like title, date
+        foreach ($columns as $key => $title) {
+             if ($key === 'date') continue; // Move date to end
+            $new_columns[$key] = $title;
+            if ($key === 'title') {
+                $new_columns['associated_assessment'] = __( 'Assessment', 'quiztech' );
+                $new_columns['job_status'] = __( 'Status', 'quiztech' );
+                $new_columns['invitations_sent'] = __( 'Invites Sent', 'quiztech' );
+                $new_columns['evaluations_completed'] = __( 'Evaluations Completed', 'quiztech' );
+            }
+        }
+        $new_columns['date'] = $columns['date']; // Add date back at the end
+        return $new_columns;
+    }
+
+    /**
+     * Renders the content for custom columns in the Job CPT list table.
+     *
+     * @param string $column_name The name of the column to render.
+     * @param int    $post_id     The ID of the current post.
+     */
+    public function render_job_custom_columns( $column_name, $post_id ) {
+        global $wpdb;
+        $invitation_table = $wpdb->prefix . 'quiztech_invitations';
+
+        switch ( $column_name ) {
+            case 'associated_assessment':
+                // TODO: Need meta field '_quiztech_associated_assessment_id'
+                $assessment_id = get_post_meta( $post_id, '_quiztech_associated_assessment_id', true );
+                if ( $assessment_id && $assessment_title = get_the_title( $assessment_id ) ) {
+                    // Optional: Link to assessment edit screen
+                    $edit_link = get_edit_post_link( $assessment_id );
+                    if ($edit_link) {
+                         echo '<a href="' . esc_url( $edit_link ) . '">' . esc_html( $assessment_title ) . '</a>';
+                    } else {
+                        echo esc_html( $assessment_title );
+                    }
+                } else {
+                    echo 'N/A';
+                }
+                break;
+            case 'job_status':
+                // TODO: Need meta field '_quiztech_job_status'
+                $status = get_post_meta( $post_id, '_quiztech_job_status', true );
+                echo esc_html( ucwords( $status ?: 'N/A' ) );
+                break;
+            case 'invitations_sent':
+                $count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$invitation_table} WHERE job_id = %d", $post_id ) );
+                echo esc_html( $count ?: '0' );
+                break;
+            case 'evaluations_completed':
+                 // This requires linking evaluations back to jobs, likely via the invitation ID stored in evaluation meta
+                 $invitation_ids = $wpdb->get_col( $wpdb->prepare( "SELECT id FROM {$invitation_table} WHERE job_id = %d", $post_id ) );
+                 if (empty($invitation_ids)) {
+                     echo '0';
+                     break;
+                 }
+                 $args = [
+                    'post_type' => 'user_evaluation',
+                    'post_status' => 'completed', // Assuming 'completed' is the status set on final submit
+                    'posts_per_page' => -1, // Count all
+                    'meta_query' => [
+                        [
+                            'key' => 'quiztech_invitation_id', // Assumes this meta key links evaluation to invitation
+                            'value' => $invitation_ids,
+                            'compare' => 'IN',
+                        ]
+                    ],
+                    'fields' => 'ids', // Only need count
+                 ];
+                 $evaluation_query = new \WP_Query($args);
+                 echo esc_html( $evaluation_query->post_count );
+                break;
+        }
+    }
+
+    // --- User Evaluation CPT ---
+
+    /**
+     * Filters the columns for the User Evaluation CPT list table.
+     *
+     * @param array $columns Existing columns.
+     * @return array Modified columns.
+     */
+    public function filter_user_evaluation_columns( $columns ) {
+        // Remove 'title' maybe, replace with more useful info
+        unset($columns['title']);
+
+        $new_columns = [
+            'cb' => $columns['cb'], // Checkbox
+            'applicant_email' => __( 'Applicant Email', 'quiztech' ),
+            'job_title' => __( 'Job', 'quiztech' ),
+            'assessment_title' => __( 'Assessment', 'quiztech' ),
+            'status' => __( 'Status', 'quiztech' ),
+            'date_submitted' => __( 'Date Submitted', 'quiztech' ), // Use 'date' column key?
+        ];
+        // Add back any other standard columns if needed, like 'date' if not used for 'date_submitted'
+        // $new_columns['date'] = $columns['date'];
+        return $new_columns;
+    }
+
+    /**
+     * Renders the content for custom columns in the User Evaluation CPT list table.
+     *
+     * @param string $column_name The name of the column to render.
+     * @param int    $post_id     The ID of the current post.
+     */
+    public function render_user_evaluation_custom_columns( $column_name, $post_id ) {
+        global $wpdb;
+        $invitation_table = $wpdb->prefix . 'quiztech_invitations';
+
+        // Get linked invitation ID first, as it's needed for multiple columns
+        $invitation_id = get_post_meta( $post_id, 'quiztech_invitation_id', true );
+        $invitation_data = null;
+        if ($invitation_id) {
+             $invitation_data = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$invitation_table} WHERE id = %d", $invitation_id ) );
+        }
+
+        switch ( $column_name ) {
+            case 'applicant_email':
+                echo $invitation_data ? esc_html( $invitation_data->applicant_email ) : 'N/A';
+                break;
+            case 'job_title':
+                if ($invitation_data && $invitation_data->job_id) {
+                    $job_title = get_the_title($invitation_data->job_id);
+                     $edit_link = get_edit_post_link( $invitation_data->job_id );
+                    if ($edit_link) {
+                         echo '<a href="' . esc_url( $edit_link ) . '">' . esc_html( $job_title ) . '</a>';
+                    } else {
+                        echo esc_html( $job_title );
+                    }
+                } else {
+                    echo 'N/A';
+                }
+                break;
+            case 'assessment_title':
+                 if ($invitation_data && $invitation_data->assessment_id) {
+                    $assessment_title = get_the_title($invitation_data->assessment_id);
+                     $edit_link = get_edit_post_link( $invitation_data->assessment_id );
+                    if ($edit_link) {
+                         echo '<a href="' . esc_url( $edit_link ) . '">' . esc_html( $assessment_title ) . '</a>';
+                    } else {
+                        echo esc_html( $assessment_title );
+                    }
+                } else {
+                    echo 'N/A';
+                }
+                break;
+            case 'status':
+                $post_status_obj = get_post_status_object( get_post_status( $post_id ) );
+                echo esc_html( $post_status_obj ? $post_status_obj->label : get_post_status( $post_id ) );
+                break;
+            case 'date_submitted':
+                // Use the post date as submission date
+                echo esc_html( get_the_date( '', $post_id ) );
+                break;
+        }
+    }
+}

src/Admin/SettingsPage.php

@@ -0,0 +1,170 @@
+<?php
+
+namespace Quiztech\AssessmentPlatform\Admin;
+
+/**
+ * Handles the Quiztech plugin settings page in WP Admin.
+ */
+class SettingsPage {
+
+    /**
+     * Option group name.
+     * @var string
+     */
+    private $option_group = 'quiztech_settings';
+
+    /**
+     * Option name in wp_options table.
+     * @var string
+     */
+    private $option_name = 'quiztech_settings';
+
+    /**
+     * Settings page slug.
+     * @var string
+     */
+    private $page_slug = 'quiztech-settings-page';
+
+    /**
+     * Register hooks for the settings page.
+     */
+    public function register_hooks() {
+        add_action( 'admin_menu', [ $this, 'add_admin_page' ] );
+        add_action( 'admin_init', [ $this, 'register_settings' ] );
+    }
+
+    /**
+     * Adds the submenu page under the main Settings menu.
+     */
+    public function add_admin_page() {
+        add_options_page(
+            __( 'Quiztech Settings', 'quiztech' ), // Page Title
+            __( 'Quiztech', 'quiztech' ),          // Menu Title
+            'manage_options',                      // Capability Required
+            $this->page_slug,                      // Menu Slug
+            [ $this, 'render_settings_page' ]      // Callback function to render the page
+        );
+    }
+
+    /**
+     * Registers settings, sections, and fields using the Settings API.
+     */
+    public function register_settings() {
+        register_setting(
+            $this->option_group,                // Option group
+            $this->option_name,                 // Option name
+            [ $this, 'sanitize_settings' ]      // Sanitization callback
+        );
+
+        // Stripe Section
+        add_settings_section(
+            'quiztech_stripe_section',          // Section ID
+            __( 'Stripe API Keys', 'quiztech' ), // Section Title
+            '__return_false',                   // Section callback (optional description)
+            $this->page_slug                    // Page slug where section appears
+        );
+
+        // Stripe Public Key Field
+        add_settings_field(
+            'quiztech_stripe_public_key',       // Field ID
+            __( 'Stripe Public Key', 'quiztech' ), // Field Title
+            [ $this, 'render_text_field' ],     // Field render callback
+            $this->page_slug,                   // Page slug
+            'quiztech_stripe_section',          // Section ID
+            [                                   // Arguments for callback
+                'id' => 'quiztech_stripe_public_key',
+                'option_name' => $this->option_name,
+                'key' => 'stripe_public_key',
+                'description' => __( 'Enter your Stripe publishable API key.', 'quiztech' )
+            ]
+        );
+
+        // Stripe Secret Key Field
+        add_settings_field(
+            'quiztech_stripe_secret_key',       // Field ID
+            __( 'Stripe Secret Key', 'quiztech' ), // Field Title
+            [ $this, 'render_text_field' ],     // Field render callback
+            $this->page_slug,                   // Page slug
+            'quiztech_stripe_section',          // Section ID
+            [                                   // Arguments for callback
+                'id' => 'quiztech_stripe_secret_key',
+                'option_name' => $this->option_name,
+                'key' => 'stripe_secret_key',
+                'type' => 'password', // Mask the input
+                'description' => __( 'Enter your Stripe secret API key. This is kept confidential.', 'quiztech' )
+            ]
+        );
+
+        // TODO: Add more sections/fields as needed (e.g., email settings, default credit costs)
+    }
+
+    /**
+     * Renders the main settings page container and form.
+     */
+    public function render_settings_page() {
+        ?>
+        <div class="wrap">
+            <h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
+            <form action="options.php" method="post">
+                <?php
+                // Output security fields for the registered setting group
+                settings_fields( $this->option_group );
+
+                // Output setting sections and their fields
+                do_settings_sections( $this->page_slug );
+
+                // Output save settings button
+                submit_button( __( 'Save Settings', 'quiztech' ) );
+                ?>
+            </form>
+        </div>
+        <?php
+    }
+
+    /**
+     * Renders a standard text input field for a setting.
+     * Expects args: 'id', 'option_name', 'key', 'description' (optional), 'type' (optional, default 'text')
+     *
+     * @param array $args Arguments passed from add_settings_field.
+     */
+    public function render_text_field( $args ) {
+        $options = get_option( $args['option_name'], [] ); // Get all settings or default to empty array
+        $value = isset( $options[ $args['key'] ] ) ? $options[ $args['key'] ] : '';
+        $type = isset( $args['type'] ) ? $args['type'] : 'text';
+        ?>
+        <input
+            type="<?php echo esc_attr( $type ); ?>"
+            id="<?php echo esc_attr( $args['id'] ); ?>"
+            name="<?php echo esc_attr( $args['option_name'] . '[' . $args['key'] . ']' ); ?>"
+            value="<?php echo esc_attr( $value ); ?>"
+            class="regular-text"
+        />
+        <?php if ( isset( $args['description'] ) ) : ?>
+            <p class="description"><?php echo esc_html( $args['description'] ); ?></p>
+        <?php endif; ?>
+        <?php
+    }
+
+    /**
+     * Sanitizes the settings array before saving.
+     *
+     * @param array $input The raw input array from the form.
+     * @return array The sanitized array.
+     */
+    public function sanitize_settings( $input ) {
+        $sanitized_input = [];
+
+        if ( isset( $input['stripe_public_key'] ) ) {
+            // Basic sanitization, might need stricter validation (e.g., regex for pk_live_/pk_test_)
+            $sanitized_input['stripe_public_key'] = sanitize_text_field( $input['stripe_public_key'] );
+        }
+        if ( isset( $input['stripe_secret_key'] ) ) {
+             // Basic sanitization, might need stricter validation (e.g., regex for sk_live_/sk_test_)
+            $sanitized_input['stripe_secret_key'] = sanitize_text_field( $input['stripe_secret_key'] );
+        }
+
+        // TODO: Sanitize other settings as they are added
+
+        return $sanitized_input;
+    }
+}

src/Includes/Ajax/AssessmentAjaxHandler.php

@@ -0,0 +1,296 @@
+<?php
+
+namespace Quiztech\AssessmentPlatform\Includes\Ajax;
+
+/**
+ * Handles AJAX requests related to the front-end assessment process.
+ */
+class AssessmentAjaxHandler {
+
+    /**
+     * Constructor. Registers AJAX hooks.
+     */
+    public function __construct() {
+        add_action('wp_ajax_quiztech_submit_prescreening', [$this, 'handle_submit_prescreening']);
+        add_action('wp_ajax_quiztech_save_answer', [$this, 'handle_save_answer']);
+        add_action('wp_ajax_quiztech_submit_assessment', [$this, 'handle_submit_assessment']);
+    }
+
+    /**
+     * Initialize the handler.
+     * Static method to instantiate the class and register hooks.
+     */
+    public static function init() {
+        new self();
+    }
+
+    /**
+     * Helper method to find an existing user_evaluation CPT by invitation ID
+     * or create a new one if it doesn't exist.
+     *
+     * @param int $invitation_id The database ID of the invitation record.
+     * @return int The post ID of the user_evaluation CPT, or 0 on failure.
+     */
+    private function get_or_create_user_evaluation(int $invitation_id): int {
+        if ( ! $invitation_id ) {
+            error_log("Quiztech AJAX Error: get_or_create_user_evaluation called with invalid invitation ID: " . $invitation_id);
+            return 0;
+        }
+
+        $args = [
+            'post_type' => 'user_evaluation',
+            'post_status' => 'any', // Find it regardless of status initially
+            'meta_query' => [
+                [
+                    'key' => 'quiztech_invitation_id',
+                    'value' => $invitation_id,
+                    'compare' => '=',
+                ]
+            ],
+            'posts_per_page' => 1,
+            'fields' => 'ids', // Only get the ID
+        ];
+        $evaluation_posts = get_posts($args);
+
+        if ( ! empty( $evaluation_posts ) ) {
+            // Found existing evaluation
+            return $evaluation_posts[0];
+        } else {
+            // Not found, create a new one
+            $post_data = [
+                'post_type'    => 'user_evaluation',
+                'post_status'  => 'publish', // Start as published (or maybe 'pending'/'in-progress' if custom statuses are added)
+                'post_title'   => sprintf( __( 'Evaluation for Invitation #%d', 'quiztech' ), $invitation_id ),
+                'post_content' => '', // No content needed initially
+                // 'post_author' => ?? // Assign to an admin or system user? Default is current user (likely none in AJAX)
+            ];
+            $evaluation_id = wp_insert_post( $post_data, true ); // Pass true for WP_Error on failure
+
+            if ( is_wp_error( $evaluation_id ) ) {
+                error_log("Quiztech AJAX Error: Failed to create user_evaluation CPT for invitation ID {$invitation_id}: " . $evaluation_id->get_error_message());
+                return 0;
+            }
+
+            // Add the linking meta field
+            $meta_updated = update_post_meta( $evaluation_id, 'quiztech_invitation_id', $invitation_id );
+            if ( ! $meta_updated ) {
+                // Log error, but maybe don't fail the whole request? Or should we delete the post?
+                error_log("Quiztech AJAX Warning: Failed to add quiztech_invitation_id meta to new evaluation ID {$evaluation_id} for invitation ID {$invitation_id}.");
+                // Depending on requirements, might return 0 here or proceed. Let's proceed for now.
+            }
+
+            error_log("Quiztech AJAX Info: Created new user_evaluation CPT ID {$evaluation_id} for invitation ID {$invitation_id}.");
+            return $evaluation_id;
+        }
+    }
+
+
+    // AJAX handler methods will be added below:
+    // - handle_submit_prescreening()
+    // - handle_save_answer()
+    // - handle_submit_assessment()
+
+    /**
+     * Handles the AJAX submission of the pre-screening form.
+     * Expects 'nonce', 'invitation_id', and 'pre_screen_answer' array in $_POST.
+     */
+    public function handle_submit_prescreening() {
+        // 1. Verify Nonce
+        check_ajax_referer('quiztech_prescreening_nonce', 'nonce');
+
+        // 2. Get and Sanitize Core Data
+        $invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
+        if ( ! $invitation_id ) {
+            wp_send_json_error(['message' => __('Missing invitation ID.', 'quiztech')], 400);
+        }
+
+        // 3. Get or Create User Evaluation Record
+        $evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
+        if ( ! $evaluation_id ) {
+             error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id);
+             wp_send_json_error(['message' => __('Could not process evaluation record.', 'quiztech')], 500);
+        }
+
+        // 4. Sanitize Submitted Answers
+        $submitted_answers = isset($_POST['pre_screen_answer']) && is_array($_POST['pre_screen_answer']) ? $_POST['pre_screen_answer'] : [];
+        $sanitized_answers = [];
+        foreach ($submitted_answers as $index => $answer) {
+            // Use sanitize_textarea_field as pre-screening questions are currently textareas
+            $sanitized_answers[sanitize_key($index)] = sanitize_textarea_field(wp_unslash($answer));
+        }
+
+        // 4. Save Answers (as user_evaluation CPT meta)
+        if (!empty($sanitized_answers)) {
+            update_post_meta($evaluation_id, 'quiztech_prescreening_answers', $sanitized_answers);
+        } else {
+            // Handle case where no answers were submitted? Or rely on form 'required' attribute?
+            // For now, proceed even if empty.
+        }
+
+        // 5. Update Invitation Status
+        try {
+            $invitations = new \Quiztech\AssessmentPlatform\Includes\Invitations();
+            // Note: The update_status method expects the invitation *record ID*, not the token.
+            // We need to retrieve the invitation ID based on the token if we only have the token here.
+            // Assuming $invitation_id passed in POST *is* the record ID for now. If it's the token, this needs adjustment.
+            $updated = $invitations->update_status($invitation_id, 'pre-screening-complete');
+            if (!$updated) {
+                 error_log("Quiztech AJAX Error: Failed to update invitation status for ID: " . $invitation_id);
+                 // Decide if this should be a user-facing error or just logged
+            }
+        } catch (\Exception $e) {
+            error_log("Quiztech AJAX Error: Exception updating invitation status: " . $e->getMessage());
+            // Decide if this should be a user-facing error
+        }
+
+
+        // 6. Send Response
+        wp_send_json_success(['message' => __('Pre-screening submitted successfully. Starting assessment...', 'quiztech')]);
+
+        // Ensure script execution stops
+        wp_die();
+    }
+
+    /**
+     * Handles the AJAX auto-save of a single assessment answer.
+     * Expects 'nonce', 'invitation_id', 'question_id', and 'answer' in $_POST.
+     */
+    public function handle_save_answer() {
+        // 1. Verify Nonce
+        check_ajax_referer('quiztech_assessment_nonce', 'nonce');
+
+        // 2. Get and Sanitize Data
+        $invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
+        $question_id   = isset($_POST['question_id']) ? absint($_POST['question_id']) : 0;
+        $answer        = isset($_POST['answer']) ? wp_unslash($_POST['answer']) : ''; // Sanitize based on question type later
+
+        // Basic validation for required IDs before querying
+        if ( ! $invitation_id || ! $question_id ) {
+             wp_send_json_error(['message' => __('Missing required data for saving answer.', 'quiztech')], 400);
+        }
+
+        // 3. Get or Create User Evaluation Record
+        $evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
+        if ( ! $evaluation_id ) {
+             error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id . " during answer save.");
+             wp_send_json_error(['message' => __('Could not process evaluation record for saving answer.', 'quiztech')], 500);
+        }
+
+        // 4. Fetch the question type meta for the given question ID
+        $question_type = \get_post_meta($question_id, '_quiztech_question_type', true);
+        if ( ! $question_type ) {
+            // Log if type is missing, but proceed with default sanitization
+            error_log("Quiztech AJAX Warning: Missing question type meta for question ID: " . $question_id);
+            $question_type = 'text'; // Default to text if not set
+        }
+
+        // Sanitize the answer based on question type
+        $sanitized_answer = ''; // Initialize
+
+        if (is_array($answer)) {
+            // Handle array answers (likely checkboxes)
+            if ('checkbox' === $question_type) {
+                // Sanitize each value in the array
+                $sanitized_answer = array_map('sanitize_text_field', $answer);
+                // Note: update_post_meta can handle arrays directly, storing them serialized.
+            } else {
+                // Unexpected array answer for this question type
+                error_log("Quiztech AJAX Error: Received array answer for non-checkbox question ID: " . $question_id);
+                // Sanitize by joining elements (simple approach, might need refinement)
+                $sanitized_answer = sanitize_text_field(implode(', ', $answer));
+            }
+        } else {
+            // Handle string/scalar answers
+            switch ($question_type) {
+                case 'textarea':
+                    $sanitized_answer = sanitize_textarea_field($answer);
+                    break;
+                case 'numeric':
+                    // Allow integers and potentially floats. Use floatval for broader acceptance.
+                    // Ensure it's actually numeric before casting to avoid warnings/errors.
+                    $sanitized_answer = is_numeric($answer) ? floatval($answer) : 0;
+                    break;
+                case 'multiple-choice': // Assuming the value is a simple key/identifier
+                    $sanitized_answer = sanitize_key($answer);
+                    break;
+                case 'text':
+                default: // Default to sanitize_text_field for 'text' or unknown/missing types
+                    $sanitized_answer = sanitize_text_field($answer);
+                    break;
+            }
+        }
+
+
+        // 3. Save Answer (as user_evaluation CPT meta)
+        // Use a meta key structure like 'quiztech_answer_{question_id}' or store in a single array meta field.
+        // Using individual meta keys might be simpler for querying later if needed.
+        $meta_key = 'quiztech_answer_' . $question_id;
+        update_post_meta($evaluation_id, $meta_key, $sanitized_answer);
+
+        // 4. Send Response
+        wp_send_json_success(['message' => __('Answer saved.', 'quiztech')]);
+
+        // Ensure script execution stops
+        wp_die();
+    }
+
+    /**
+     * Handles the final AJAX submission of the assessment.
+     * Expects 'nonce' and 'invitation_id' in $_POST.
+     */
+    public function handle_submit_assessment() {
+        // 1. Verify Nonce
+        check_ajax_referer('quiztech_assessment_nonce', 'nonce'); // Reuse assessment nonce
+
+        // 2. Get Data
+        $invitation_id = isset($_POST['invitation_id']) ? absint($_POST['invitation_id']) : 0;
+        if ( ! $invitation_id ) {
+            wp_send_json_error(['message' => __('Missing invitation ID.', 'quiztech')], 400);
+        }
+
+        // 3. Get or Create User Evaluation Record
+        $evaluation_id = $this->get_or_create_user_evaluation($invitation_id);
+        if ( ! $evaluation_id ) {
+             error_log("Quiztech AJAX Error: Failed to get or create user_evaluation for invitation ID: " . $invitation_id . " during final submission.");
+             wp_send_json_error(['message' => __('Could not process evaluation record for submission.', 'quiztech')], 500);
+        }
+
+        // 4. Update Invitation Status
+        try {
+            $invitations = new \Quiztech\AssessmentPlatform\Includes\Invitations();
+            // Note: The update_status method expects the invitation *record ID*, not the token.
+            // We need to retrieve the invitation ID based on the token if we only have the token here.
+            // Assuming $invitation_id passed in POST *is* the record ID for now. If it's the token, this needs adjustment.
+            $updated = $invitations->update_status($invitation_id, 'assessment-complete');
+            if (!$updated) {
+                 error_log("Quiztech AJAX Error: Failed to update invitation status to complete for ID: " . $invitation_id);
+                 // Decide if this should be a user-facing error or just logged
+            }
+        } catch (\Exception $e) {
+            error_log("Quiztech AJAX Error: Exception updating invitation status to complete: " . $e->getMessage());
+            // Decide if this should be a user-facing error
+        }
+
+
+        // 4. Update User Evaluation CPT Status to 'completed'
+        $post_update_data = [
+            'ID'          => $evaluation_id,
+            'post_status' => 'completed', // Use a custom status if needed, but 'completed' seems appropriate
+        ];
+        $post_updated = wp_update_post($post_update_data, true); // Pass true for WP_Error object on failure
+
+        if (is_wp_error($post_updated)) {
+            error_log("Quiztech AJAX Error: Failed to update user_evaluation CPT status for ID {$evaluation_id}: " . $post_updated->get_error_message());
+            // Decide if this should be a user-facing error
+            // wp_send_json_error(['message' => __('Failed to finalize assessment record.', 'quiztech')], 500);
+        }
+
+
+        // 5. Send Response
+        // TODO: Consider adding a redirect URL or specific completion message to the response data
+        wp_send_json_success(['message' => __('Assessment submitted successfully!', 'quiztech')]);
+
+        // Ensure script execution stops
+        wp_die();
+    }
+}

src/Includes/FrontendHandler.php

@@ -65,6 +65,28 @@ class FrontendHandler {
             // This template should be located within the plugin or theme.
             $template_path = QUIZTECH_PLUGIN_DIR . 'public/templates/assessment-shell.php'; // Example path
          
+
+            // Enqueue and localize the assessment script
+            wp_enqueue_script(
+                'quiztech-assessment-script',
+                QUIZTECH_PLUGIN_URL . 'public/js/assessment.js',
+                ['jquery'],
+                QUIZTECH_VERSION,
+                true // Load in footer
+            );
+
+            wp_localize_script(
+                'quiztech-assessment-script',
+                'quiztech_assessment_vars',
+                [
+                    'ajax_url' => admin_url('admin-ajax.php'),
+                    'prescreening_nonce' => wp_create_nonce('quiztech_prescreening_nonce'),
+                    'assessment_nonce' => wp_create_nonce('quiztech_assessment_nonce'),
+                    'invitation_id' => $invitation_data->id, // Pass invitation ID for context
+                    // Add other necessary vars here, e.g., evaluation ID if available
+                ]
+            );
+
             if ( file_exists( $template_path ) ) {
             	include( $template_path );
             	exit; // Important: Stop WordPress from loading the default theme template

src/Includes/Invitations.php

@@ -133,4 +133,60 @@ class Invitations {
    
     	return $invitation; // Return the invitation data object if valid
     }
+
+    /**
+     * Update the status of an invitation record.
+     *
+     * @param int    $invitation_id The ID of the invitation record to update.
+     * @param string $new_status    The new status to set (e.g., 'pre-screening-complete', 'assessment-complete', 'expired').
+     * @return bool True on successful update, false on failure or invalid input.
+     */
+    public function update_status( $invitation_id, $new_status ) {
+        global $wpdb;
+        $table_name = $wpdb->prefix . 'quiztech_invitations';
+
+        // Validate input
+        $invitation_id = absint( $invitation_id );
+        $new_status    = sanitize_text_field( $new_status ); // Basic sanitization
+
+        if ( ! $invitation_id || empty( $new_status ) ) {
+            \error_log( 'Quiztech Error: Invalid input provided to update_status.' );
+            return false;
+        }
+
+        // Define allowed statuses to prevent arbitrary values
+        $allowed_statuses = [
+            'pending',
+            'viewed', // Optional status if needed
+            'pre-screening-complete',
+            'assessment-started', // Optional status
+            'assessment-complete',
+            'expired',
+            'cancelled', // Optional status
+        ];
+
+        if ( ! in_array( $new_status, $allowed_statuses, true ) ) {
+            \error_log( "Quiztech Error: Invalid status '{$new_status}' provided to update_status for invitation ID {$invitation_id}." );
+            return false;
+        }
+
+        // Prepare data and format for update
+        $data   = [ 'status' => $new_status ];
+        $where  = [ 'id' => $invitation_id ]; // Assuming 'id' is the primary key column name
+        $format = [ '%s' ]; // Format for data
+        $where_format = [ '%d' ]; // Format for where clause
+
+        $updated = $wpdb->update( $table_name, $data, $where, $format, $where_format );
+
+        if ( false === $updated ) {
+            \error_log( "Quiztech Error: Failed to update invitation status for ID {$invitation_id}. DB Error: " . $wpdb->last_error );
+            return false;
+        }
+
+        // $updated contains the number of rows affected.
+        // Return true if one or more rows were updated (or potentially 0 if the status was already set to the new value).
+        // We consider 0 rows affected as success in the case the status was already correct.
+        return true;
+    }
+
 }

src/Includes/post-types.php

@@ -10,7 +10,7 @@ namespace Quiztech\AssessmentPlatform\Includes;
 
 // If this file is called directly, abort.
 if ( ! \defined( 'WPINC' ) ) {
-	\die;
+	die;
 }
 
 /**
@@ -172,4 +172,116 @@ function quiztech_register_post_types() {
 }
 \add_action( 'init', __NAMESPACE__ . '\quiztech_register_post_types' );
 
+
+// --- Meta Box for Question Type ---
+
+/**
+ * Adds the meta box container for Question Type.
+ *
+ * @param string $post_type The post type slug.
+ */
+function quiztech_add_question_meta_boxes( $post_type ) {
+    // Limit meta box to specific post type
+    if ( 'question' === $post_type ) {
+        \add_meta_box(
+            'quiztech_question_type_metabox', // ID
+            \__( 'Question Type', 'quiztech' ), // Title
+            __NAMESPACE__ . '\quiztech_render_question_type_metabox', // Callback function
+            'question', // Post type
+            'side', // Context (normal, side, advanced)
+            'high' // Priority (high, core, default, low)
+        );
+    }
+}
+\add_action( 'add_meta_boxes', __NAMESPACE__ . '\quiztech_add_question_meta_boxes' );
+
+/**
+ * Renders the meta box content for Question Type.
+ *
+ * @param \WP_Post $post The post object.
+ */
+function quiztech_render_question_type_metabox( $post ) {
+    // Add a nonce field so we can check for it later.
+    \wp_nonce_field( 'quiztech_save_question_type_meta', 'quiztech_question_type_nonce' );
+
+    // Use get_post_meta to retrieve an existing value from the database.
+    $value = \get_post_meta( $post->ID, '_quiztech_question_type', true );
+
+    // Define the available question types
+    $question_types = [
+        'text'            => \__( 'Text (Single Line)', 'quiztech' ),
+        'textarea'        => \__( 'Text Area (Multi-line)', 'quiztech' ),
+        'multiple-choice' => \__( 'Multiple Choice (Single Answer)', 'quiztech' ),
+        'checkbox'        => \__( 'Checkboxes (Multiple Answers)', 'quiztech' ),
+        'numeric'         => \__( 'Numeric', 'quiztech' ),
+        // Add more types as needed
+    ];
+
+    // Display the form field.
+    echo '<label for="quiztech_question_type_field">';
+    \esc_html_e( 'Select the type of question:', 'quiztech' );
+    echo '</label> ';
+    echo '<select name="quiztech_question_type_field" id="quiztech_question_type_field" class="postbox">';
+    echo '<option value="">' . \esc_html__( '-- Select Type --', 'quiztech' ) . '</option>'; // Default empty option
+
+    foreach ( $question_types as $type_key => $type_label ) {
+        echo '<option value="' . \esc_attr( $type_key ) . '" ' . \selected( $value, $type_key, false ) . '>' . \esc_html( $type_label ) . '</option>';
+    }
+
+    echo '</select>';
+}
+
+/**
+ * Saves the meta box data for Question Type.
+ *
+ * @param int $post_id The ID of the post being saved.
+ */
+function quiztech_save_question_type_meta( $post_id ) {
+    // Check if our nonce is set.
+    if ( ! isset( $_POST['quiztech_question_type_nonce'] ) ) {
+        return;
+    }
+
+    // Verify that the nonce is valid.
+    if ( ! \wp_verify_nonce( \sanitize_key( $_POST['quiztech_question_type_nonce'] ), 'quiztech_save_question_type_meta' ) ) {
+        return;
+    }
+
+    // If this is an autosave, our form has not been submitted, so we don't want to do anything.
+    if ( \defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
+        return;
+    }
+
+    // Check the user's permissions.
+    if ( isset( $_POST['post_type'] ) && 'question' === $_POST['post_type'] ) {
+        if ( ! \current_user_can( 'edit_post', $post_id ) ) {
+            return;
+        }
+    } else {
+        // Assuming other post types don't use this meta box
+        return;
+    }
+
+    // Make sure that the field is set.
+    if ( ! isset( $_POST['quiztech_question_type_field'] ) ) {
+        return;
+    }
+
+    // Sanitize user input.
+    $new_meta_value = \sanitize_text_field( \wp_unslash( $_POST['quiztech_question_type_field'] ) );
+
+    // Define allowed types again for validation
+    $allowed_types = ['text', 'textarea', 'multiple-choice', 'checkbox', 'numeric']; // Keep this in sync with the render function
+
+    // Update the meta field in the database if the value is allowed or empty.
+    if ( in_array( $new_meta_value, $allowed_types, true ) || '' === $new_meta_value ) {
+        \update_post_meta( $post_id, '_quiztech_question_type', $new_meta_value );
+    } else {
+        // Optionally delete meta if invalid value submitted, or log an error
+        \delete_post_meta( $post_id, '_quiztech_question_type' );
+    }
+}
+// Hook into the 'save_post' action specifically for the 'question' post type
+\add_action( 'save_post_question', __NAMESPACE__ . '\quiztech_save_question_type_meta' );
+
 ?>