Initial commit: WordPress wp-content (themes, plugins, languages)

- Theme: momentry (custom theme with REST API routes)
- Plugins: code-snippets (contains all API proxies)
- Languages: zh_TW translations
- Excludes: cache, backups, uploads, logs

plugins/code-snippets/php/settings/class-setting-field.php

@@ -0,0 +1,271 @@
+<?php
+/**
+ * This file handles rendering the settings fields
+ *
+ * @since      2.0.0
+ * @package    Code_Snippets
+ * @subpackage Settings
+ */
+
+namespace Code_Snippets\Settings;
+
+/**
+ * Represents a single setting field
+ *
+ * @property-read string                $desc               Field description.
+ * @property-read string                $label              Field label.
+ * @property-read string                $type               Field type.
+ * @property-read string                $name               Setting name.
+ *
+ * @property-read int                   $min                Minimum value (for numerical inputs).
+ * @property-read int                   $max                Maximum value(for numerical inputs).
+ * @property-read array<string, string> $options            List of options for a select or checkboxes field.
+ * @property-read callable              $render_callback    Custom function to use when rendering a callback field.
+ * @property-read callable              $sanitize_callback  Custom function to use when sanitize the setting value.
+ * @property-read mixed                 $default            Default setting value.
+ *
+ * @property-read string                $input_name         Value of `name` HTML attribute on an input element.
+ * @property-read string                $element_id
+ */
+class Setting_Field {
+
+	/**
+	 * Input field identifier.
+	 *
+	 * @var string
+	 */
+	private string $field_id;
+
+	/**
+	 * Settings section identifier.
+	 *
+	 * @var string
+	 */
+	private string $section;
+
+	/**
+	 * List of possible arguments.
+	 *
+	 * @var array<string, mixed>
+	 */
+	private array $args = array(
+		'desc'    => '',
+		'label'   => '',
+		'min'     => null,
+		'max'     => null,
+		'options' => [],
+	);
+
+	/**
+	 * Class constructor.
+	 *
+	 * @param string               $section_id Settings section identifier.
+	 * @param string               $field_id   Setting field identifier.
+	 * @param array<string, mixed> $args       The setting field attributes.
+	 */
+	public function __construct( string $section_id, string $field_id, array $args ) {
+		$this->field_id = $field_id;
+		$this->section = $section_id;
+		$this->args = array_merge( $this->args, $args );
+	}
+
+	/**
+	 * Retrieve a single setting attribute.
+	 *
+	 * @param string $argument Attribute name.
+	 *
+	 * @return mixed Attribute value.
+	 */
+	public function __get( string $argument ) {
+
+		if ( 'input_name' === $argument ) {
+			return sprintf( '%s[%s][%s]', OPTION_NAME, $this->section, $this->field_id );
+		}
+
+		return $this->args[ $argument ];
+	}
+
+	/**
+	 * Retrieve the saved value for this setting.
+	 *
+	 * @return mixed
+	 */
+	private function get_saved_value() {
+		return get_setting( $this->section, $this->field_id );
+	}
+
+	/**
+	 * Render the setting field
+	 */
+	public function render() {
+		$method_name = 'render_' . $this->type . '_field';
+
+		if ( method_exists( $this, $method_name ) ) {
+			call_user_func( array( $this, $method_name ) );
+		} else {
+			// Error message, not necessary to translate.
+			printf( 'Cannot render a %s field.', esc_html( $this->type ) );
+			return;
+		}
+
+		if ( $this->desc ) {
+			echo '<p class="description">', wp_kses_post( $this->desc ), '</p>';
+		}
+	}
+
+	/**
+	 * Render a callback field.
+	 */
+	public function render_callback_field() {
+		if ( ! is_callable( $this->render_callback ) ) {
+			return;
+		}
+		
+		call_user_func( $this->render_callback, $this->args );
+	}
+
+	/**
+	 * Render a single checkbox field.
+	 *
+	 * @param string  $input_name Input name.
+	 * @param string  $label      Input label.
+	 * @param boolean $checked    Whether the checkbox should be checked.
+	 */
+	private static function render_checkbox( string $input_name, string $label, bool $checked ) {
+
+		$checkbox = sprintf(
+			'<input type="checkbox" name="%s"%s>',
+			esc_attr( $input_name ),
+			checked( $checked, true, false )
+		);
+
+		$kses = [
+			'input' => [
+				'type'    => [],
+				'name'    => [],
+				'checked' => [],
+			],
+		];
+
+		if ( $label ) {
+			printf(
+				'<label>%s %s</label>',
+				wp_kses( $checkbox, $kses ),
+				wp_kses_post( $label )
+			);
+		} else {
+			echo wp_kses( $checkbox, $kses );
+		}
+	}
+
+	/**
+	 * Render a checkbox field for a setting
+	 *
+	 * @return void
+	 * @since 2.0.0
+	 */
+	public function render_checkbox_field() {
+		$this->render_checkbox( $this->input_name, $this->label, $this->get_saved_value() ?? false );
+	}
+
+	/**
+	 * Render a checkbox field for a setting
+	 *
+	 * @return void
+	 * @since 2.0.0
+	 */
+	public function render_checkboxes_field() {
+		$saved_value = $this->get_saved_value();
+		$saved_value = is_array( $saved_value ) ? $saved_value : [];
+
+		echo '<fieldset>';
+		printf( '<legend class="screen-reader-text"><span>%s</span></legend>', esc_html( $this->name ) );
+
+		foreach ( $this->options as $option => $label ) {
+			$this->render_checkbox( $this->input_name . "[$option]", $label, in_array( $option, $saved_value, true ) );
+			echo '<br>';
+		}
+
+		echo '</fieldset>';
+	}
+
+	/**
+	 * Render a basic text field for an editor setting.
+	 *
+	 * @return void
+	 */
+	private function render_text_field() {
+		printf(
+			'<input id="%s" type="text" name="%s" value="%s" class="regular-text %s">',
+			esc_attr( $this->element_id ),
+			esc_attr( $this->input_name ),
+			esc_attr( $this->get_saved_value() ),
+			esc_attr( $this->element_id )
+		);
+
+		if ( $this->label ) {
+			echo ' ' . wp_kses_post( $this->label );
+		}
+	}
+
+	/**
+	 * Render a number select field for an editor setting
+	 *
+	 * @since 2.0.0
+	 */
+	private function render_number_field() {
+		printf(
+			'<input type="number" name="%s" value="%s"',
+			esc_attr( $this->input_name ),
+			esc_attr( $this->get_saved_value() )
+		);
+
+		if ( is_numeric( $this->min ) ) {
+			printf( ' min="%d"', intval( $this->min ) );
+		}
+
+		if ( is_numeric( $this->max ) ) {
+			printf( ' max="%d"', intval( $this->max ) );
+		}
+
+		echo '>';
+
+		if ( $this->label ) {
+			echo ' ' . wp_kses_post( $this->label );
+		}
+	}
+
+	/**
+	 * Render a number select field for an editor setting.
+	 *
+	 * @since 3.0.0
+	 */
+	private function render_select_field() {
+		$saved_value = $this->get_saved_value();
+		printf( '<select name="%s">', esc_attr( $this->input_name ) );
+
+		foreach ( $this->options as $option => $option_label ) {
+			printf(
+				'<option value="%s"%s>%s</option>',
+				esc_attr( $option ),
+				selected( $option, $saved_value, false ),
+				esc_html( $option_label )
+			);
+		}
+
+		echo '</select>';
+	}
+
+	/**
+	 * Render a button link.
+	 *
+	 * @since 3.5.1
+	 */
+	private function render_action_field() {
+		printf(
+			'<button type="submit" name="%s" class="button">%s</button>',
+			esc_attr( $this->input_name ),
+			esc_html( $this->label ? $this->label : $this->name )
+		);
+	}
+}

plugins/code-snippets/php/settings/class-version-switch.php

@@ -0,0 +1,362 @@
+<?php
+/**
+ * Class-based version switching functionality for the Code Snippets plugin.
+ *
+ * Converted from procedural `version-switch.php` to an OO class `Version_Switch`.
+ *
+ * @package    Code_Snippets
+ * @subpackage Settings
+ */
+
+namespace Code_Snippets\Settings;
+
+// Configuration constants for version switching
+const VERSION_CACHE_KEY = 'code_snippets_available_versions';
+const PROGRESS_KEY = 'code_snippets_version_switch_progress';
+const VERSION_CACHE_DURATION = HOUR_IN_SECONDS;
+const PROGRESS_TIMEOUT = 5 * MINUTE_IN_SECONDS;
+const WORDPRESS_API_ENDPOINT = 'https://api.wordpress.org/plugins/info/1.2/?action=plugin_information&slug=code-snippets';
+
+class Version_Switch {
+	/**
+	 * Initialize hook registrations.
+	 * Call this after the file is required.
+	 */
+	public static function init(): void {
+		add_action( 'wp_ajax_code_snippets_switch_version', [ __CLASS__, 'ajax_switch_version' ] );
+		add_action( 'wp_ajax_code_snippets_refresh_versions', [ __CLASS__, 'ajax_refresh_versions' ] );
+	}
+
+	public static function get_available_versions(): array {
+		$versions = get_transient( VERSION_CACHE_KEY );
+
+		if ( false === $versions ) {
+			$response = wp_remote_get( WORDPRESS_API_ENDPOINT );
+
+			if ( is_wp_error( $response ) ) {
+				return [];
+			}
+
+			$body = wp_remote_retrieve_body( $response );
+			$data = json_decode( $body, true );
+
+			if ( ! $data || ! isset( $data['versions'] ) ) {
+				return [];
+			}
+
+			// Filter out 'trunk' and sort versions
+			$versions = [];
+			foreach ( $data['versions'] as $version => $download_url ) {
+				if ( 'trunk' !== $version ) {
+					$versions[] = [
+						'version' => $version,
+						'url' => $download_url,
+					];
+				}
+			}
+
+			// Sort versions in descending order
+			usort( $versions, function( $a, $b ) {
+				return version_compare( $b['version'], $a['version'] );
+			});
+
+			// Cache for configured duration
+			set_transient( VERSION_CACHE_KEY, $versions, VERSION_CACHE_DURATION );
+		}
+
+		return $versions;
+	}
+
+	public static function get_current_version(): string {
+		return defined( 'CODE_SNIPPETS_VERSION' ) ? CODE_SNIPPETS_VERSION : '0.0.0';
+	}
+
+	public static function is_version_switch_in_progress(): bool {
+		return get_transient( PROGRESS_KEY ) !== false;
+	}
+
+	public static function clear_version_caches(): void {
+		delete_transient( VERSION_CACHE_KEY );
+		delete_transient( PROGRESS_KEY );
+	}
+
+	public static function validate_target_version( string $target_version, array $available_versions ): array {
+		if ( empty( $target_version ) ) {
+			return [
+				'success' => false,
+				'message' => __( 'No target version specified.', 'code-snippets' ),
+				'download_url' => '',
+			];
+		}
+
+		foreach ( $available_versions as $version_info ) {
+			if ( $version_info['version'] === $target_version ) {
+				return [
+					'success' => true,
+					'message' => '',
+					'download_url' => $version_info['url'],
+				];
+			}
+		}
+
+		return [
+			'success' => false,
+			'message' => __( 'Invalid version specified.', 'code-snippets' ),
+			'download_url' => '',
+		];
+	}
+
+	public static function create_error_response( string $message, string $technical_details = '' ): array {
+		if ( ! empty( $technical_details ) ) {
+			if ( function_exists( 'error_log' ) ) {
+				error_log( sprintf( 'Code Snippets version switch error: %s. Details: %s', $message, $technical_details ) );
+			}
+		}
+
+		return [
+			'success' => false,
+			'message' => $message,
+		];
+	}
+
+	public static function perform_version_install( string $download_url ) {
+		if ( ! function_exists( 'wp_update_plugins' ) ) {
+			require_once ABSPATH . 'wp-admin/includes/update.php';
+		}
+		if ( ! function_exists( 'show_message' ) ) {
+			require_once ABSPATH . 'wp-admin/includes/misc.php';
+		}
+		if ( ! class_exists( 'Plugin_Upgrader' ) ) {
+			require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
+		}
+
+		$update_handler = new \WP_Ajax_Upgrader_Skin();
+		$upgrader = new \Plugin_Upgrader( $update_handler );
+
+		global $code_snippets_last_update_handler, $code_snippets_last_upgrader;
+		$code_snippets_last_update_handler = $update_handler;
+		$code_snippets_last_upgrader = $upgrader;
+
+		return $upgrader->install( $download_url, [
+			'overwrite_package'   => true,
+			'clear_update_cache'  => true,
+		] );
+	}
+
+	public static function extract_handler_messages( $update_handler, $upgrader ): string {
+		$handler_messages = '';
+
+		if ( isset( $update_handler ) ) {
+			if ( method_exists( $update_handler, 'get_errors' ) ) {
+				$errs = $update_handler->get_errors();
+				if ( $errs instanceof \WP_Error && $errs->has_errors() ) {
+					$handler_messages .= implode( "\n", $errs->get_error_messages() );
+				}
+			}
+			if ( method_exists( $update_handler, 'get_error_messages' ) ) {
+				$em = $update_handler->get_error_messages();
+				if ( $em ) {
+					$handler_messages .= "\n" . $em;
+				}
+			}
+			if ( method_exists( $update_handler, 'get_upgrade_messages' ) ) {
+				$upgrade_msgs = $update_handler->get_upgrade_messages();
+				if ( is_array( $upgrade_msgs ) ) {
+					$handler_messages .= "\n" . implode( "\n", $upgrade_msgs );
+				} elseif ( $upgrade_msgs ) {
+					$handler_messages .= "\n" . (string) $upgrade_msgs;
+				}
+			}
+		}
+
+		if ( empty( $handler_messages ) && isset( $upgrader->result ) ) {
+			if ( is_wp_error( $upgrader->result ) ) {
+				$handler_messages = implode( "\n", $upgrader->result->get_error_messages() );
+			} else {
+				$handler_messages = is_scalar( $upgrader->result ) ? (string) $upgrader->result : print_r( $upgrader->result, true );
+			}
+		}
+
+		return trim( $handler_messages );
+	}
+
+	public static function log_version_switch_attempt( string $target_version, $result, string $details = '' ): void {
+		if ( function_exists( 'error_log' ) ) {
+			error_log( sprintf( 'Code Snippets version switch failed. target=%s, result=%s, details=%s', $target_version, var_export( $result, true ), $details ) );
+		}
+	}
+
+	public static function handle_installation_failure( string $target_version, string $download_url, $install_result ): array {
+		global $code_snippets_last_update_handler, $code_snippets_last_upgrader;
+
+		$handler_messages = self::extract_handler_messages( $code_snippets_last_update_handler, $code_snippets_last_upgrader );
+		self::log_version_switch_attempt( $target_version, $install_result, "URL: $download_url, Messages: $handler_messages" );
+
+		$fallback_message = __( 'Failed to switch versions. Please try again.', 'code-snippets' );
+		if ( ! empty( $handler_messages ) ) {
+			$short = wp_trim_words( wp_strip_all_tags( $handler_messages ), 40, '...' );
+			$fallback_message = sprintf( '%s %s', $fallback_message, $short );
+		}
+
+		return [
+			'success' => false,
+			'message' => $fallback_message,
+		];
+	}
+
+	public static function handle_version_switch( string $target_version ): array {
+		if ( ! current_user_can( 'update_plugins' ) ) {
+			return self::create_error_response( __( 'You do not have permission to update plugins.', 'code-snippets' ) );
+		}
+
+		$available_versions = self::get_available_versions();
+		$validation = self::validate_target_version( $target_version, $available_versions );
+
+		if ( ! $validation['success'] ) {
+			return self::create_error_response( $validation['message'] );
+		}
+
+		if ( self::get_current_version() === $target_version ) {
+			return self::create_error_response( __( 'Already on the specified version.', 'code-snippets' ) );
+		}
+
+		set_transient( PROGRESS_KEY, $target_version, PROGRESS_TIMEOUT );
+
+		$install_result = self::perform_version_install( $validation['download_url'] );
+
+		delete_transient( PROGRESS_KEY );
+
+		if ( is_wp_error( $install_result ) ) {
+			return self::create_error_response( $install_result->get_error_message() );
+		}
+
+		if ( $install_result ) {
+			delete_transient( VERSION_CACHE_KEY );
+
+			return [
+				'success' => true,
+				'message' => sprintf( __( 'Successfully switched to version %s. Please refresh the page to see changes.', 'code-snippets' ), $target_version ),
+			];
+		}
+
+		return self::handle_installation_failure( $target_version, $validation['download_url'], $install_result );
+	}
+
+	public static function render_version_switch_field( array $args ): void {
+		$current_version = self::get_current_version();
+		$available_versions = self::get_available_versions();
+		$is_switching = self::is_version_switch_in_progress();
+
+		?>
+		<div class="code-snippets-version-switch">
+			<p>
+				<strong><?php esc_html_e( 'Current Version:', 'code-snippets' ); ?></strong> 
+				<span class="current-version"><?php echo esc_html( $current_version ); ?></span>
+			</p>
+
+			<?php if ( $is_switching ) : ?>
+				<div class="notice notice-info inline">
+					<p><?php esc_html_e( 'Version switch in progress. Please wait...', 'code-snippets' ); ?></p>
+				</div>
+			<?php else : ?>
+				<p>
+					<label for="target_version">
+						<?php esc_html_e( 'Switch to Version:', 'code-snippets' ); ?>
+					</label>
+					<select id="target_version" name="target_version" <?php disabled( empty( $available_versions ) ); ?>>
+						<option value=""><?php esc_html_e( 'Select a version...', 'code-snippets' ); ?></option>
+						<?php foreach ( $available_versions as $version_info ) : ?>
+							<option value="<?php echo esc_attr( $version_info['version'] ); ?>" 
+								<?php selected( $version_info['version'], $current_version ); ?>>
+								<?php echo esc_html( $version_info['version'] ); ?>
+								<?php if ( $version_info['version'] === $current_version ) : ?>
+									<?php esc_html_e( ' (Current)', 'code-snippets' ); ?>
+								<?php endif; ?>
+							</option>
+						<?php endforeach; ?>
+					</select>
+				</p>
+
+				<p>
+					<button type="button" id="switch-version-btn" class="button button-secondary" disabled
+						<?php disabled( empty( $available_versions ) ); ?>>
+						<?php esc_html_e( 'Switch Version', 'code-snippets' ); ?>
+					</button>
+				</p>
+
+				<div id="version-switch-result" class="notice" style="display: none;"></div>
+			<?php endif; ?>
+		</div><?php
+	}
+
+	public static function ajax_switch_version(): void {
+		if ( ! wp_verify_nonce( $_POST['nonce'] ?? '', 'code_snippets_version_switch' ) ) {
+			wp_die( __( 'Security check failed.', 'code-snippets' ) );
+		}
+
+		if ( ! current_user_can( 'update_plugins' ) ) {
+			wp_send_json_error( [
+				'message' => __( 'You do not have permission to update plugins.', 'code-snippets' ),
+			] );
+		}
+
+		$target_version = sanitize_text_field( $_POST['target_version'] ?? '' );
+
+		if ( empty( $target_version ) ) {
+			wp_send_json_error( [
+				'message' => __( 'No target version specified.', 'code-snippets' ),
+			] );
+		}
+
+		$result = self::handle_version_switch( $target_version );
+
+		if ( $result['success'] ) {
+			wp_send_json_success( $result );
+		} else {
+			wp_send_json_error( $result );
+		}
+	}
+
+	public static function render_refresh_versions_field( array $args ): void {
+		?>
+		<button type="button" id="refresh-versions-btn" class="button button-secondary">
+			<?php esc_html_e( 'Refresh Available Versions', 'code-snippets' ); ?>
+		</button>
+		<p class="description">
+			<?php esc_html_e( 'Check for the latest available plugin versions from WordPress.org.', 'code-snippets' ); ?>
+		</p><?php
+	}
+
+	public static function ajax_refresh_versions(): void {
+		if ( ! wp_verify_nonce( $_POST['nonce'] ?? '', 'code_snippets_refresh_versions' ) ) {
+			wp_die( __( 'Security check failed.', 'code-snippets' ) );
+		}
+
+		if ( ! current_user_can( 'manage_options' ) ) {
+			wp_send_json_error( [
+				'message' => __( 'You do not have permission to manage options.', 'code-snippets' ),
+			] );
+		}
+
+		delete_transient( VERSION_CACHE_KEY );
+		self::get_available_versions();
+
+		wp_send_json_success( [
+			'message' => __( 'Available versions updated successfully.', 'code-snippets' ),
+		] );
+	}
+
+	public static function render_version_switch_warning(): void {
+		?>
+		<div id="version-switch-warning" class="notice notice-warning" style="display: none; margin-block-start: 20px;">
+			<p>
+				<strong><?php esc_html_e( 'Warning:', 'code-snippets' ); ?></strong>
+				<?php esc_html_e( 'Switching versions may cause compatibility issues. Always backup your site before switching versions.', 'code-snippets' ); ?>
+			</p>
+		</div>
+		<?php
+	}
+}
+
+// Initialize hooks when the file is loaded.
+Version_Switch::init();

plugins/code-snippets/php/settings/editor-preview.php

@@ -0,0 +1,132 @@
+<?php
+/**
+ * This file handles the editor preview setting
+ *
+ * @since   2.0.0
+ * @package Code_Snippets
+ */
+
+namespace Code_Snippets\Settings;
+
+use function Code_Snippets\code_snippets;
+use function Code_Snippets\enqueue_code_editor;
+use function Code_Snippets\get_editor_themes;
+
+/**
+ * Load the CSS and JavaScript for the editor preview field
+ */
+function enqueue_editor_preview_assets() {
+	$plugin = code_snippets();
+
+	enqueue_code_editor( 'php' );
+
+	// Enqueue all editor themes.
+	$themes = get_editor_themes();
+
+	foreach ( $themes as $theme ) {
+		wp_enqueue_style(
+			'code-snippets-editor-theme-' . $theme,
+			plugins_url( "dist/editor-themes/$theme.css", $plugin->file ),
+			[ 'code-editor' ],
+			$plugin->version
+		);
+	}
+
+	// Enqueue the menu scripts.
+	wp_enqueue_script(
+		'code-snippets-settings-menu',
+		plugins_url( 'dist/settings.js', $plugin->file ),
+		[ 'code-snippets-code-editor' ],
+		$plugin->version,
+		true
+	);
+
+	wp_set_script_translations( 'code-snippets-settings-menu', 'code-snippets' );
+
+	// Extract the CodeMirror-specific editor settings.
+	$setting_fields = get_settings_fields();
+	$editor_fields = array();
+
+	foreach ( $setting_fields['editor'] as $name => $field ) {
+		if ( empty( $field['codemirror'] ) ) {
+			continue;
+		}
+
+		$editor_fields[] = array(
+			'name'       => $name,
+			'type'       => $field['type'],
+			'codemirror' => addslashes( $field['codemirror'] ),
+		);
+	}
+
+	// Pass the saved options to the external JavaScript file.
+	$inline_script = 'var code_snippets_editor_settings = ' . wp_json_encode( $editor_fields ) . ';';
+
+	wp_add_inline_script( 'code-snippets-settings-menu', $inline_script, 'before' );
+
+	// Provide configuration and simple i18n for the version switch JS module.
+	$version_switch = array(
+		'ajaxurl' => admin_url( 'admin-ajax.php' ),
+		'nonce_switch' => wp_create_nonce( 'code_snippets_version_switch' ),
+		'nonce_refresh' => wp_create_nonce( 'code_snippets_refresh_versions' ),
+	);
+
+	$strings = array(
+		'selectDifferent' => esc_html__( 'Please select a different version to switch to.', 'code-snippets' ),
+		'switching' => esc_html__( 'Switching...', 'code-snippets' ),
+		'processing' => esc_html__( 'Processing version switch. Please wait...', 'code-snippets' ),
+		'error' => esc_html__( 'An error occurred.', 'code-snippets' ),
+		'errorSwitch' => esc_html__( 'An error occurred while switching versions. Please try again.', 'code-snippets' ),
+		'refreshing' => esc_html__( 'Refreshing...', 'code-snippets' ),
+		'refreshed' => esc_html__( 'Refreshed!', 'code-snippets' ),
+	);
+
+	wp_add_inline_script( 'code-snippets-settings-menu', 'var code_snippets_version_switch = ' . wp_json_encode( $version_switch ) . '; var __code_snippets_i18n = ' . wp_json_encode( $strings ) . ';', 'before' );
+}
+
+/**
+ * Retrieve the list of code editor themes.
+ *
+ * @return array<string, string> List of editor themes.
+ */
+function get_editor_theme_list(): array {
+	$themes = [
+		'default' => __( 'Default', 'code-snippets' ),
+	];
+
+	foreach ( get_editor_themes() as $theme ) {
+
+		// Skip mobile themes.
+		if ( '-mobile' === substr( $theme, -7 ) ) {
+			continue;
+		}
+
+		$themes[ $theme ] = ucwords( str_replace( '-', ' ', $theme ) );
+	}
+
+	return $themes;
+}
+
+/**
+ * Render the editor preview setting
+ */
+function render_editor_preview() {
+	$settings = get_settings_values();
+	$settings = $settings['editor'];
+
+	$indent_unit = absint( $settings['indent_unit'] );
+	$tab_size = absint( $settings['tab_size'] );
+
+	$n_tabs = $settings['indent_with_tabs'] ? floor( $indent_unit / $tab_size ) : 0;
+	$n_spaces = $settings['indent_with_tabs'] ? $indent_unit % $tab_size : $indent_unit;
+
+	$indent = str_repeat( "\t", $n_tabs ) . str_repeat( ' ', $n_spaces );
+
+	$code = "add_filter( 'admin_footer_text', function ( \$text ) {\n\n" .
+	        $indent . "\$site_name = get_bloginfo( 'name' );\n\n" .
+	        $indent . '$text = "Thank you for visiting $site_name.";' . "\n" .
+	        $indent . 'return $text;' . "\n" .
+	        "} );\n";
+
+	echo '<textarea id="code_snippets_editor_preview">', esc_textarea( $code ), '</textarea>';
+}

plugins/code-snippets/php/settings/settings-fields.php

@@ -0,0 +1,263 @@
+<?php
+/**
+ * Manages the settings field definitions.
+ *
+ * @package    Code_Snippets
+ * @subpackage Settings
+ */
+
+namespace Code_Snippets\Settings;
+
+use function Code_Snippets\code_snippets;
+
+/**
+ * Retrieve the default setting values
+ *
+ * @return array<string, array<string, mixed>>
+ */
+function get_default_settings(): array {
+	static $defaults;
+
+	if ( isset( $defaults ) ) {
+		return $defaults;
+	}
+
+	$defaults = [
+		'general' => [
+			'activate_by_default' => true,
+			'enable_tags'         => true,
+			'enable_description'  => true,
+			'visual_editor_rows'  => 5,
+			'list_order'          => 'priority-asc',
+			'disable_prism'       => false,
+			'hide_upgrade_menu'   => false,
+			'complete_uninstall'  => false,
+      'enable_flat_files'   => false,
+		],
+		'editor'  => [
+			'indent_with_tabs'            => true,
+			'tab_size'                    => 4,
+			'indent_unit'                 => 4,
+			'font_size'                   => 14,
+			'wrap_lines'                  => true,
+			'code_folding'                => true,
+			'line_numbers'                => true,
+			'auto_close_brackets'         => true,
+			'highlight_selection_matches' => true,
+			'highlight_active_line'       => true,
+			'keymap'                      => 'default',
+			'theme'                       => 'default',
+		],
+		'version-switch' => [
+			'selected_version'  => '',
+		],
+		'debug' => [
+			'enable_version_change' => false,
+		],
+	];
+
+	$defaults = apply_filters( 'code_snippets_settings_defaults', $defaults );
+
+	return $defaults;
+}
+
+/**
+ * Retrieve the settings fields
+ *
+ * @return array<string, array<string, array>>
+ */
+function get_settings_fields(): array {
+	static $fields;
+
+	if ( isset( $fields ) ) {
+		return $fields;
+	}
+
+	$fields = [];
+
+	$fields['debug'] = [
+		'database_update' => [
+			'name'  => __( 'Database Table Upgrade', 'code-snippets' ),
+			'type'  => 'action',
+			'label' => __( 'Upgrade Database Table', 'code-snippets' ),
+			'desc'  => __( 'Use this button to manually upgrade the Code Snippets database table. This action will only affect the snippets table and should be used only when necessary.', 'code-snippets' ),
+		],
+		'reset_caches'    => [
+			'name' => __( 'Reset Caches', 'code-snippets' ),
+			'type' => 'action',
+			'desc' => __( 'Use this button to manually clear snippets caches.', 'code-snippets' ),
+		],
+    'enable_version_change' => [
+			'name'  => __( 'Version Change', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'Enable the ability to switch or rollback versions of the Code Snippets core plugin.', 'code-snippets' ),
+		],
+	];
+
+	$fields['version-switch'] = [
+		'version_switcher'  => [
+			'name' => __( 'Switch Version', 'code-snippets' ),
+			'type' => 'callback',
+			'render_callback' => [ '\\Code_Snippets\\Settings\\Version_Switch', 'render_version_switch_field' ],
+		],
+		'refresh_versions'  => [
+			'name' => __( 'Refresh Versions', 'code-snippets' ),
+			'type' => 'callback',
+			'render_callback' => [ '\\Code_Snippets\\Settings\\Version_Switch', 'render_refresh_versions_field' ],
+		],
+		'version_warning'   => [
+			'name' => '',
+			'type' => 'callback',
+			'render_callback' => [ '\\Code_Snippets\\Settings\\Version_Switch', 'render_version_switch_warning' ],
+		],
+	];
+
+	$fields['general'] = [
+		'activate_by_default' => [
+			'name'  => __( 'Activate by Default', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( "Make the 'Save and Activate' button the default action when saving a snippet.", 'code-snippets' ),
+		],
+		'enable_tags'         => [
+			'name'  => __( 'Enable Snippet Tags', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'Show snippet tags on admin pages.', 'code-snippets' ),
+		],
+		'enable_description'  => [
+			'name'  => __( 'Enable Snippet Descriptions', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'Show snippet descriptions on admin pages.', 'code-snippets' ),
+		],
+		'visual_editor_rows'  => [
+			'name'  => __( 'Description Editor Height', 'code-snippets' ),
+			'type'  => 'number',
+			'label' => _x( 'rows', 'unit', 'code-snippets' ),
+			'min'   => 0,
+		],
+		'list_order'          => [
+			'name'    => __( 'Snippets List Order', 'code-snippets' ),
+			'type'    => 'select',
+			'desc'    => __( 'Default way to order snippets on the All Snippets admin menu.', 'code-snippets' ),
+			'options' => [
+				'priority-asc'  => __( 'Priority', 'code-snippets' ),
+				'name-asc'      => __( 'Name (A-Z)', 'code-snippets' ),
+				'name-desc'     => __( 'Name (Z-A)', 'code-snippets' ),
+				'modified-desc' => __( 'Modified (latest first)', 'code-snippets' ),
+				'modified-asc'  => __( 'Modified (oldest first)', 'code-snippets' ),
+			],
+		],
+		'disable_prism'       => [
+			'name'  => __( 'Disable Syntax Highlighter', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'Disable syntax highlighting when displaying snippet code on the front-end.', 'code-snippets' ),
+		],
+	];
+
+	if ( ! code_snippets()->licensing->is_licensed() ) {
+		$fields['general']['hide_upgrade_menu'] = [
+			'name'  => __( 'Hide Upgrade Notices', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'Hide notices inviting you to upgrade to Code Snippets Pro.', 'code-snippets' ),
+		];
+	}
+
+	if ( ! is_multisite() || is_main_site() ) {
+		$fields['general']['complete_uninstall'] = [
+			'name'  => __( 'Complete Uninstall', 'code-snippets' ),
+			'type'  => 'checkbox',
+			'label' => __( 'When the plugin is deleted from the Plugins menu, also delete all snippets and plugin settings.', 'code-snippets' ),
+		];
+	}
+
+	$fields['editor'] = [
+		'indent_with_tabs'            => [
+			'name'       => __( 'Indent With Tabs', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'label'      => __( 'Use hard tabs instead of spaces for indentation.', 'code-snippets' ),
+			'codemirror' => 'indentWithTabs',
+		],
+		'tab_size'                    => [
+			'name'       => __( 'Tab Size', 'code-snippets' ),
+			'type'       => 'number',
+			'desc'       => __( 'The width of a tab character.', 'code-snippets' ),
+			'label'      => _x( 'spaces', 'unit', 'code-snippets' ),
+			'codemirror' => 'tabSize',
+			'min'        => 0,
+		],
+		'indent_unit'                 => [
+			'name'       => __( 'Indent Unit', 'code-snippets' ),
+			'type'       => 'number',
+			'desc'       => __( 'The number of spaces to indent a block.', 'code-snippets' ),
+			'label'      => _x( 'spaces', 'unit', 'code-snippets' ),
+			'codemirror' => 'indentUnit',
+			'min'        => 0,
+		],
+		'font_size'                   => [
+			'name'       => __( 'Font Size', 'code-snippets' ),
+			'type'       => 'number',
+			'label'      => _x( 'px', 'unit', 'code-snippets' ),
+			'codemirror' => 'fontSize',
+			'min'        => 8,
+			'max'        => 28,
+		],
+		'wrap_lines'                  => [
+			'name'       => __( 'Wrap Lines', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'label'      => __( 'Soft-wrap long lines of code instead of horizontally scrolling.', 'code-snippets' ),
+			'codemirror' => 'lineWrapping',
+		],
+
+		'code_folding'                => [
+			'name'       => __( 'Code Folding', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'label'      => __( 'Allow folding functions or other blocks into a single line.', 'code-snippets' ),
+			'codemirror' => 'foldGutter',
+		],
+		'line_numbers'                => [
+			'name'       => __( 'Line Numbers', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'label'      => __( 'Show line numbers to the left of the editor.', 'code-snippets' ),
+			'codemirror' => 'lineNumbers',
+		],
+		'auto_close_brackets'         => [
+			'name'       => __( 'Auto Close Brackets', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'label'      => __( 'Auto-close brackets and quotes when typed.', 'code-snippets' ),
+			'codemirror' => 'autoCloseBrackets',
+		],
+		'highlight_selection_matches' => [
+			'name'       => __( 'Highlight Selection Matches', 'code-snippets' ),
+			'label'      => __( 'Highlight all instances of a currently selected word.', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'codemirror' => 'highlightSelectionMatches',
+		],
+		'highlight_active_line'       => [
+			'name'       => __( 'Highlight Active Line', 'code-snippets' ),
+			'label'      => __( 'Highlight the line that is currently being edited.', 'code-snippets' ),
+			'type'       => 'checkbox',
+			'codemirror' => 'styleActiveLine',
+		],
+		'keymap'                      => [
+			'name'       => __( 'Keymap', 'code-snippets' ),
+			'type'       => 'select',
+			'desc'       => __( 'The set of keyboard shortcuts to use in the code editor.', 'code-snippets' ),
+			'options'    => [
+				'default' => __( 'Default', 'code-snippets' ),
+				'vim'     => __( 'Vim', 'code-snippets' ),
+				'emacs'   => __( 'Emacs', 'code-snippets' ),
+				'sublime' => __( 'Sublime Text', 'code-snippets' ),
+			],
+			'codemirror' => 'keyMap',
+		],
+		'theme'                       => [
+			'name'       => __( 'Theme', 'code-snippets' ),
+			'type'       => 'select',
+			'options'    => get_editor_theme_list(),
+			'codemirror' => 'theme',
+		],
+	];
+
+	$fields = apply_filters( 'code_snippets_settings_fields', $fields );
+
+	return $fields;
+}

plugins/code-snippets/php/settings/settings.php

@@ -0,0 +1,351 @@
+<?php
+/**
+ * This file registers the settings
+ *
+ * @package    Code_Snippets
+ * @subpackage Settings
+ */
+
+namespace Code_Snippets\Settings;
+
+use Code_Snippets\Welcome_API;
+use function Code_Snippets\clean_snippets_cache;
+use function Code_Snippets\code_snippets;
+use const Code_Snippets\CACHE_GROUP;
+
+const CACHE_KEY = 'code_snippets_settings';
+const OPTION_GROUP = 'code-snippets';
+const OPTION_NAME = 'code_snippets_settings';
+
+/**
+ * Add a new option for either the current site or the current network
+ *
+ * @param bool   $network Whether to add a network-wide option.
+ * @param string $option  Name of option to add. Expected to not be SQL-escaped.
+ * @param mixed  $value   Option value, can be anything. Expected to not be SQL-escaped.
+ *
+ * @return bool False if the option was not added. True if the option was added.
+ */
+function add_self_option( bool $network, string $option, $value ): bool {
+	return $network ? add_site_option( $option, $value ) : add_option( $option, $value );
+}
+
+/**
+ * Retrieves an option value based on an option name from either the current site or the current network
+ *
+ * @param bool   $network       Whether to get a network-wide option.
+ * @param string $option        Name of option to retrieve. Expected to not be SQL-escaped.
+ * @param mixed  $default_value Optional value to return if option doesn't exist. Default false.
+ *
+ * @return mixed Value set for the option.
+ */
+function get_self_option( bool $network, string $option, $default_value = false ) {
+	return $network ? get_site_option( $option, $default_value ) : get_option( $option, $default_value );
+}
+
+/**
+ * Update the value of an option that was already added on the current site or the current network
+ *
+ * @param bool   $network Whether to update a network-wide option.
+ * @param string $option  Name of option. Expected to not be SQL-escaped.
+ * @param mixed  $value   Option value. Expected to not be SQL-escaped.
+ *
+ * @return bool False if value was not updated. True if value was updated.
+ */
+function update_self_option( bool $network, string $option, $value ): bool {
+	return $network ? update_site_option( $option, $value ) : update_option( $option, $value );
+}
+
+/**
+ * Returns 'true' if plugin settings are unified on a multisite installation
+ * under the Network Admin settings menu
+ *
+ * This option is controlled by the "Enable administration menus" setting on the Network Settings menu
+ *
+ * @return bool
+ */
+function are_settings_unified(): bool {
+	if ( ! is_multisite() ) {
+		return false;
+	}
+
+	$menu_perms = get_site_option( 'menu_items', array() );
+	return empty( $menu_perms['snippets_settings'] );
+}
+
+/**
+ * Retrieve the setting values from the database.
+ * If a setting does not exist in the database, the default value will be returned.
+ *
+ * @return array<string, array<string, mixed>>
+ */
+function get_settings_values(): array {
+	$settings = wp_cache_get( CACHE_KEY, CACHE_GROUP );
+	if ( $settings ) {
+		return $settings;
+	}
+
+	$settings = get_default_settings();
+	$saved = get_self_option( are_settings_unified(), OPTION_NAME, array() );
+
+	foreach ( $settings as $section => $fields ) {
+		if ( isset( $saved[ $section ] ) ) {
+			$settings[ $section ] = array_replace( $fields, $saved[ $section ] );
+		}
+	}
+
+	wp_cache_set( CACHE_KEY, $settings, CACHE_GROUP );
+	return $settings;
+}
+
+/**
+ * Retrieve an individual setting field value
+ *
+ * @param string $section ID of the section the setting belongs to.
+ * @param string $field   ID of the setting field.
+ *
+ * @return mixed
+ */
+function get_setting( string $section, string $field ) {
+	$settings = get_settings_values();
+
+	return $settings[ $section ][ $field ] ?? null;
+}
+
+/**
+ * Update a single setting to a new value.
+ *
+ * @param string $section   ID of the section the setting belongs to.
+ * @param string $field     ID of the setting field.
+ * @param mixed  $new_value Setting value. Expected to not be SQL-escaped.
+ *
+ * @return bool False if value was not updated. True if value was updated.
+ */
+function update_setting( string $section, string $field, $new_value ): bool {
+	$settings = get_settings_values();
+
+	$settings[ $section ][ $field ] = $new_value;
+
+	wp_cache_set( CACHE_KEY, $settings, CACHE_GROUP );
+	return update_self_option( are_settings_unified(), OPTION_NAME, $settings );
+}
+
+/**
+ * Retrieve the settings sections
+ *
+ * @return array<string, string> Settings sections.
+ */
+function get_settings_sections(): array {
+	$sections = array(
+		'general'        => __( 'General', 'code-snippets' ),
+		'editor'         => __( 'Code Editor', 'code-snippets' ),
+		'debug'          => __( 'Debug', 'code-snippets' ),
+	);
+
+	// Only show the Version section when the debug setting to enable version changes is enabled.
+	$enable_version = get_setting( 'debug', 'enable_version_change' );
+	if ( $enable_version ) {
+		$sections['version-switch'] = __( 'Version', 'code-snippets' );
+	}
+
+	return apply_filters( 'code_snippets_settings_sections', $sections );
+}
+
+/**
+ * Register settings sections, fields, etc
+ */
+function register_plugin_settings() {
+	if ( are_settings_unified() ) {
+		if ( ! get_site_option( OPTION_NAME ) ) {
+			add_site_option( OPTION_NAME, get_default_settings() );
+		}
+	} elseif ( ! get_option( OPTION_NAME ) ) {
+		add_option( OPTION_NAME, get_default_settings() );
+	}
+
+	// Register the setting.
+	register_setting(
+		OPTION_GROUP,
+		OPTION_NAME,
+		[ 'sanitize_callback' => __NAMESPACE__ . '\\sanitize_settings' ]
+	);
+
+	// Register settings sections.
+	foreach ( get_settings_sections() as $section_id => $section_name ) {
+		add_settings_section( $section_id, $section_name, '__return_empty_string', 'code-snippets' );
+	}
+
+	// Register settings fields. Only register fields for sections that exist (some sections may be gated by settings).
+	$registered_sections = get_settings_sections();
+	foreach ( get_settings_fields() as $section_id => $fields ) {
+		if ( ! isset( $registered_sections[ $section_id ] ) ) {
+			continue;
+		}
+
+		foreach ( $fields as $field_id => $field ) {
+			$field_object = new Setting_Field( $section_id, $field_id, $field );
+			add_settings_field( $field_id, $field['name'], [ $field_object, 'render' ], 'code-snippets', $section_id );
+		}
+	}
+
+	// Add editor preview as a field.
+	add_settings_field(
+		'editor_preview',
+		__( 'Editor Preview', 'code-snippets' ),
+		__NAMESPACE__ . '\\render_editor_preview',
+		'code-snippets',
+		'editor'
+	);
+}
+
+add_action( 'admin_init', __NAMESPACE__ . '\\register_plugin_settings' );
+
+/**
+ * Sanitize a single setting value.
+ *
+ * @param array<string, mixed> $field       Setting field information.
+ * @param mixed                $input_value User input setting value, or null if missing.
+ *
+ * @return mixed Sanitized setting value, or null if unset.
+ */
+function sanitize_setting_value( array $field, $input_value ) {
+	switch ( $field['type'] ) {
+
+		case 'checkbox':
+			return 'on' === $input_value;
+
+		case 'number':
+			return intval( $input_value );
+
+		case 'select':
+			$select_options = array_map( 'strval', array_keys( $field['options'] ) );
+			return in_array( strval( $input_value ), $select_options, true ) ? $input_value : null;
+
+		case 'checkboxes':
+			$results = [];
+
+			if ( ! empty( $input_value ) ) {
+				foreach ( $field['options'] as $option_id => $option_label ) {
+					if ( isset( $input_value[ $option_id ] ) && 'on' === $input_value[ $option_id ] ) {
+						$results[] = $option_id;
+					}
+				}
+			}
+
+			return $results;
+
+		case 'text':
+		case 'hidden':
+			return trim( sanitize_text_field( $input_value ) );
+
+		case 'callback':
+			return isset( $field['sanitize_callback'] ) && is_callable( $field['sanitize_callback'] ) ?
+				call_user_func( $field['sanitize_callback'], $input_value ) :
+				null;
+
+		default:
+			return null;
+	}
+}
+
+/**
+ * Process settings actions.
+ *
+ * @param array $input Provided settings input.
+ *
+ * @return array|null New $input value to return, or null to continue with settings update process.
+ */
+function process_settings_actions( array $input ): ?array {
+
+	if ( isset( $input['reset_settings'] ) ) {
+		add_settings_error(
+			OPTION_NAME,
+			'settings_reset',
+			__( 'All settings have been reset to their defaults.', 'code-snippets' ),
+			'updated'
+		);
+
+		delete_option( 'code_snippets_cloud_settings' );
+		return [];
+	}
+
+	if ( isset( $input['debug']['database_update'] ) ) {
+		code_snippets()->db->create_or_upgrade_tables();
+
+		add_settings_error(
+			OPTION_NAME,
+			'database_update_done',
+			__( 'Successfully performed database table upgrade.', 'code-snippets' ),
+			'updated'
+		);
+	}
+
+	if ( isset( $input['debug']['reset_caches'] ) ) {
+		Welcome_API::clear_cache();
+		clean_snippets_cache( code_snippets()->db->get_table_name( false ) );
+
+		if ( is_multisite() ) {
+			clean_snippets_cache( code_snippets()->db->get_table_name( true ) );
+		}
+
+		add_settings_error(
+			OPTION_NAME,
+			'snippet_caches_reset',
+			__( 'Successfully reset snippets caches.', 'code-snippets' ),
+			'updated'
+		);
+	}
+
+	return null;
+}
+
+/**
+ * Validate the settings
+ *
+ * @param array<string, array<string, mixed>> $input The received settings.
+ *
+ * @return array<string, array<string, mixed>> The validated settings.
+ */
+function sanitize_settings( array $input ): array {
+	wp_cache_delete( CACHE_KEY, CACHE_GROUP );
+	$result = process_settings_actions( $input );
+
+	if ( ! is_null( $result ) ) {
+		return $result;
+	}
+
+	$settings = get_settings_values();
+	$updated = false;
+
+	// Don't directly loop through $input as it does not include as deselected checkboxes.
+	foreach ( get_settings_fields() as $section_id => $fields ) {
+		foreach ( $fields as $field_id => $field ) {
+
+			// Fetch the corresponding input value from the posted data.
+			$input_value = $input[ $section_id ][ $field_id ] ?? null;
+
+			// Attempt to sanitize the setting value.
+			$sanitized_value = sanitize_setting_value( $field, $input_value );
+
+			$current_value = $settings[ $section_id ][ $field_id ] ?? null;
+			if ( ! is_null( $sanitized_value ) && $current_value !== $sanitized_value ) {
+				$settings[ $section_id ][ $field_id ] = $sanitized_value;
+				$updated = true;
+			}
+		}
+	}
+
+	// Add an updated message.
+	if ( $updated ) {
+		add_settings_error(
+			OPTION_NAME,
+			'settings-saved',
+			__( 'Settings saved.', 'code-snippets' ),
+			'updated'
+		);
+
+		do_action( 'code_snippets/settings_updated', $settings, $input );
+	}
+
+	return $settings;
+}