<?php
/**
 * Plugin functions
 *
 * @package WPVulnerability
 *
 * @version 2.0.0
 */

defined( 'ABSPATH' ) || die( 'No script kiddies please!' );

/**
 * Enqueues the admin JavaScript for plugin update interactions.
 *
 * @since 4.1.0
 *
 * @param string $hook Current admin page hook.
 *
 * @return void
 */
function wpvulnerability_plugins_admin_enqueue_scripts( $hook ) {
	if ( 'plugins.php' !== $hook && 'plugins-network' !== $hook ) {
		return;
	}

	wp_enqueue_script(
		'wpvulnerability-admin-js',
		WPVULNERABILITY_PLUGIN_URL . 'assets/admin.js',
		array( 'jquery' ),
		WPVULNERABILITY_PLUGIN_VERSION,
		true
	);
}
add_action( 'admin_enqueue_scripts', 'wpvulnerability_plugins_admin_enqueue_scripts' );

/**
 * Generate a deterministic signature for the installed plugins list.
 *
 * @since 4.1.2
 *
 * @param array<string,array<string,mixed>> $plugins List of plugins returned by get_plugins().
 * @return string Hash representing the installed plugins and their versions.
 */
function wpvulnerability_plugins_generate_signature( $plugins ) {
	$normalized = array();

	foreach ( $plugins as $file_path => $plugin_data ) {
		$plugin_file = sanitize_text_field( (string) $file_path );
		$version     = '';

		if ( isset( $plugin_data['Version'] ) ) {
			$v_raw   = $plugin_data['Version'];
			$version = sanitize_text_field( is_scalar( $v_raw ) ? (string) $v_raw : '' );
		}

		$normalized[ $plugin_file ] = $version;
	}

	ksort( $normalized );

	$encoded = wp_json_encode( $normalized );
	return md5( false !== $encoded ? $encoded : '' );
}

/**
 * Retrieve the signature of the currently installed plugins.
 *
 * @since 4.1.2
 *
 * @return string Hash representing the installed plugins and their versions.
 */
function wpvulnerability_plugins_get_current_signature() {
	if ( ! function_exists( 'get_plugins' ) ) {
		require_once ABSPATH . 'wp-admin/includes/plugin.php';
	}

	return wpvulnerability_plugins_generate_signature( get_plugins() );
}

/**
 * Adds a vulnerability notice under vulnerable plugins.
 *
 * This function retrieves the vulnerability data for the specified plugin from the WordPress options table
 * and displays a detailed notice below the plugin's row on the plugins management page in the WordPress admin area.
 * The notice includes information about the plugin's vulnerabilities, such as affected versions, severity, CVSS scores,
 * and links to sources.
 *
 * The function is applicable both in single-site and multisite installations. In a multisite setup, the notice
 * is displayed only in the network admin area or in the site admin area of individual sites.
 *
 * @since 2.0.0
 *
 * @param string               $plugin_file   Main plugin folder/file name.
 * @param array<string, mixed> $plugin_data   Plugin data array containing information about the plugin.
 *
 * @return void
 */
function wpvulnerability_plugin_info_after( $plugin_file, $plugin_data ) {

	// Retrieve the vulnerabilities for all plugins from the options table and decode the JSON.
	$raw_plugins            = is_multisite() ? get_site_option( 'wpvulnerability-plugins', '' ) : get_option( 'wpvulnerability-plugins', '' );
	$plugin_vulnerabilities = json_decode( is_string( $raw_plugins ) ? $raw_plugins : '', true );
	if ( ! is_array( $plugin_vulnerabilities ) ) {
		$plugin_vulnerabilities = array();
	}

	if ( ( is_multisite() && is_network_admin() ) || ! is_multisite() ) {

		// Determine whether the plugin is active and add an appropriate CSS class to the table row.
		$tr_class = is_plugin_active( $plugin_file ) ? 'active' : '';

		// Generate the vulnerability notice message with the plugin name.
		$message = sprintf(
		/* translators: 1: Plugin or theme name. */
			__( '%1$s has a known vulnerability that may be affecting your installed version.', 'wpvulnerability' ),
			wp_kses( is_scalar( $plugin_data['Name'] ) ? (string) $plugin_data['Name'] : '', 'strip' )
		);

		// Begin generating the table row HTML markup with appropriate CSS classes and the vulnerability notice message.
		$information  = '<tr class="wpvulnerability ' . esc_attr( $tr_class ) . '">';
		$information .= '<td colspan="4">';
		$information .= '<p class="text-red"><img src="' . esc_url( WPVULNERABILITY_PLUGIN_URL ) . 'assets/icon.svg" style="height: 16px; vertical-align: text-top; width: 16px;" alt="" title="WPVulnerability"> <strong>' . esc_html( $message ) . '</strong>';
		$information .= '</p>';
		$information .= '<table>';

		// Loop through all vulnerabilities for the current plugin and add their details to the table row HTML markup.
		$pf_entry        = isset( $plugin_vulnerabilities[ $plugin_file ] ) && is_array( $plugin_vulnerabilities[ $plugin_file ] ) ? $plugin_vulnerabilities[ $plugin_file ] : array();
		$vulnerabilities = isset( $pf_entry['vulnerabilities'] ) && is_array( $pf_entry['vulnerabilities'] ) ? $pf_entry['vulnerabilities'] : array();

		foreach ( $vulnerabilities as $vulnerability ) {
			if ( ! is_array( $vulnerability ) ) {
				continue;
			}

			$vuln_versions_raw = $vulnerability['versions'] ?? '';
			$vuln_versions     = is_scalar( $vuln_versions_raw ) ? (string) $vuln_versions_raw : '';
			$vuln_closed_raw   = $vulnerability['closed'] ?? 0;
			$vuln_closed       = is_scalar( $vuln_closed_raw ) ? intval( $vuln_closed_raw ) : 0;
			$vuln_unfixed_raw  = $vulnerability['unfixed'] ?? 0;
			$vuln_unfixed      = is_scalar( $vuln_unfixed_raw ) ? intval( $vuln_unfixed_raw ) : 0;
			$vuln_impact       = isset( $vulnerability['impact'] ) && is_array( $vulnerability['impact'] ) ? $vulnerability['impact'] : array();
			$vuln_cvss         = isset( $vuln_impact['cvss'] ) && is_array( $vuln_impact['cvss'] ) ? $vuln_impact['cvss'] : array();
			$vuln_cvss2        = isset( $vuln_impact['cvss2'] ) && is_array( $vuln_impact['cvss2'] ) ? $vuln_impact['cvss2'] : array();
			$vuln_cvss3        = isset( $vuln_impact['cvss3'] ) && is_array( $vuln_impact['cvss3'] ) ? $vuln_impact['cvss3'] : array();
			$vuln_cvss4        = isset( $vuln_impact['cvss4'] ) && is_array( $vuln_impact['cvss4'] ) ? $vuln_impact['cvss4'] : array();
			$vuln_ssvc         = isset( $vuln_impact['ssvc'] ) && is_array( $vuln_impact['ssvc'] ) ? $vuln_impact['ssvc'] : array();
			$vuln_cwe          = isset( $vuln_impact['cwe'] ) && is_array( $vuln_impact['cwe'] ) ? $vuln_impact['cwe'] : array();
			$vuln_sources      = isset( $vulnerability['source'] ) && is_array( $vulnerability['source'] ) ? $vulnerability['source'] : array();

			$kev          = ( isset( $vuln_ssvc['kev'] ) && true === $vuln_ssvc['kev'] );
			$exploitation = isset( $vuln_ssvc['exploitation'] ) && is_string( $vuln_ssvc['exploitation'] ) ? $vuln_ssvc['exploitation'] : '';
			$automatable  = isset( $vuln_ssvc['automatable'] ) && is_string( $vuln_ssvc['automatable'] ) ? $vuln_ssvc['automatable'] : '';
			$kev_date_raw = $vuln_ssvc['kev_date'] ?? null;
			$kev_date     = is_string( $kev_date_raw ) && '' !== $kev_date_raw ? $kev_date_raw : null;
			$epss_raw     = $vuln_impact['epss'] ?? null;
			$epss         = is_numeric( $epss_raw ) ? (float) $epss_raw : null;
			$description  = wpvulnerability_get_source_description( $vuln_sources );

			// Best available CVSS score and severity: cvss4 > cvss3 > cvss2 > legacy cvss.
			$score_raw = null;
			$sev_raw   = null;
			foreach ( array( $vuln_cvss4, $vuln_cvss3, $vuln_cvss2, $vuln_cvss ) as $cvss_c ) {
				if ( empty( $cvss_c ) ) {
					continue;
				}
				$s_raw = $cvss_c['score'] ?? null;
				$v_raw = $cvss_c['severity'] ?? null;
				$s     = is_numeric( $s_raw ) ? number_format( (float) $s_raw, 1, '.', '' ) : null;
				$v     = is_string( $v_raw ) && '' !== $v_raw ? $v_raw : null;
				if ( null !== $s || null !== $v ) {
					$score_raw = $s;
					$sev_raw   = $v;
					break;
				}
			}

			$what = array();
			foreach ( $vuln_cwe as $vulnerability_cwe ) {
				if ( ! is_array( $vulnerability_cwe ) ) {
					continue;
				}
				$cwe_name = $vulnerability_cwe['name'] ?? '';
				$cwe_desc = $vulnerability_cwe['description'] ?? '';
				$what[]   = '<div><b>' . wp_kses( is_scalar( $cwe_name ) ? (string) $cwe_name : '', 'strip' ) . '</b></div><div><i>' . esc_html( is_scalar( $cwe_desc ) ? (string) $cwe_desc : '' ) . '</i></div>';
			}

			$version_display = wpvulnerability_clean_version_range( $vuln_versions );
			$source_pills    = wpvulnerability_render_source_pills( $vuln_sources );
			$score_badge     = wpvulnerability_render_score_badge( $score_raw, $sev_raw, $epss );

			$information .= '<tr>';
			// Version range column.
			$information .= '<td style="max-width: 256px; min-width: 96px; vertical-align: top; padding-top: 6px;">';
			$information .= '' !== $version_display
				? '<span class="wpvuln-versions">' . $version_display . '</span>'
				: '&mdash;';
			$information .= '</td>';
			// Details column.
			$information .= '<td>';
			$show_active  = $kev || 'active' === $exploitation;
			$show_poc     = 'poc' === $exploitation;
			$show_auto    = 'yes' === $automatable;
			if ( $show_active || $show_poc || $show_auto || '' !== $score_badge ) {
				$information .= '<div style="display:flex; align-items:center; gap:6px; flex-wrap:wrap; margin-bottom:5px;">';
				if ( $show_active ) {
					$information .= '<span class="wpvuln-kev-label">&#9888; ' . esc_html__( 'Actively exploited', 'wpvulnerability' );
					if ( $kev && null !== $kev_date ) {
						$information .= ' &middot; ' . esc_html( $kev_date );
					}
					$information .= '</span>';
				}
				if ( $show_poc ) {
					$information .= '<span class="wpvuln-poc-label">&#9889; ' . esc_html__( 'Public exploit', 'wpvulnerability' ) . '</span>';
				}
				if ( $show_auto ) {
					$information .= '<span class="wpvuln-auto-label">&#9881; ' . esc_html__( 'Automatable', 'wpvulnerability' ) . '</span>';
				}
				if ( '' !== $score_badge ) {
					$information .= $score_badge;
				}
				$information .= '</div>';
			}
			if ( null !== $description ) {
				$information .= '<div style="padding-bottom: 5px;">' . esc_html( $description ) . '</div>';
			}
			if ( $vuln_closed || $vuln_unfixed ) {
				$information .= '<div style="padding-bottom: 5px;">';
				if ( $vuln_closed ) {
					$information .= '<div class="text-red">' . esc_html__( 'This plugin is closed. Please replace it with another.', 'wpvulnerability' ) . '</div>';
				}
				if ( $vuln_unfixed ) {
					$information .= '<div class="text-red">' . esc_html__( 'This vulnerability appears to be unpatched. Stay tuned for upcoming plugin updates.', 'wpvulnerability' ) . '</div>';
				}
				$information .= '</div>';
			}
			if ( ! empty( $what ) ) {
				$information .= '<div style="padding-bottom: 5px;">';
				foreach ( $what as $w ) {
					$information .= $w;
				}
				$information .= '</div>';
			}
			if ( '' !== $source_pills ) {
				$information .= '<div class="wpvuln-refs-row"><span class="wpvuln-refs-label">' . esc_html__( 'References:', 'wpvulnerability' ) . '</span>';
				$information .= $source_pills;
				$information .= '</div>';
			}
			$information .= '</td>';
			$information .= '</tr>';
		}

		$information .= '</table>';
		$information .= '</td>';
		$information .= '</tr>';

		echo $information; // phpcs:ignore
	}
}

/**
 * Retrieves vulnerabilities for a given plugin and updates its data.
 *
 * @since 2.0.0
 *
 * @param array<string, mixed> $plugin_data The plugin data array.
 * @param string               $file_path   The path to the plugin file.
 *
 * @return array<string, mixed> The updated plugin data array.
 */
function wpvulnerability_get_fresh_plugin_vulnerabilities( $plugin_data, $file_path ) {

	$plugin_slug = null;

	// Extract the folder name from the file path.
	$folder_name = explode( '/', $file_path );

	// Use the first folder segment as the plugin slug.
	$plugin_slug = wp_kses( trim( (string) $folder_name[0] ), 'strip' );
	unset( $folder_name );

	// If the plugin slug is empty, fall back to the TextDomain key.
	if ( empty( $plugin_slug ) && isset( $plugin_data['TextDomain'] ) ) {
		$td_raw      = $plugin_data['TextDomain'];
		$plugin_slug = wp_kses( is_scalar( $td_raw ) ? (string) $td_raw : '', 'strip' );
	}

	// Get the plugin version from the plugin data.
	$plugin_version_raw = $plugin_data['Version'] ?? '';
	$plugin_version     = wp_kses( is_scalar( $plugin_version_raw ) ? (string) $plugin_version_raw : '', 'strip' );

	// Initialize vulnerability-related fields.
	$plugin_data['vulnerabilities'] = null;
	$plugin_data['vulnerable']      = 0;

	// Retrieve vulnerabilities for the plugin using its slug and version.
	if ( ! empty( $plugin_slug ) ) {

		$plugin_api_response = wpvulnerability_get_plugin( $plugin_slug, $plugin_version, 0, 0 );

		// If vulnerabilities are found, update the plugin data accordingly.
		if ( ! empty( $plugin_api_response ) ) {

			$plugin_data['slug']            = $plugin_slug;
			$plugin_data['vulnerabilities'] = $plugin_api_response;
			$plugin_data['vulnerable']      = 1;

		}
	}

	return $plugin_data;
}

/**
 * Retrieves updated data for a specified plugin, potentially including vulnerability information.
 *
 * @since 3.1.0
 *
 * @param array<string, mixed> $plugin_data The original plugin data array, expected to contain keys like 'TextDomain' and 'Version'.
 * @param string               $file_path   The file path of the plugin, used to determine the plugin's slug if 'TextDomain' is not specified in `$plugin_data`.
 *
 * @return array<mixed>|null Updated plugin data array with fresh information or null if the plugin slug cannot be determined or no updated information is available.
 */
function wpvulnerability_get_fresh_plugin_data( $plugin_data, $file_path ) {

	$plugin_slug = '';

	// Extract the folder name from the file path.
	$folder_name = explode( '/', $file_path );

	// Use the first folder segment as the plugin slug.
	$plugin_slug = wp_kses( trim( (string) $folder_name[0] ), 'strip' );
	unset( $folder_name );

	// If the plugin slug is still empty, use the TextDomain key from the plugin data if it exists.
	if ( '' === $plugin_slug && isset( $plugin_data['TextDomain'] ) ) {
		$td_raw2     = $plugin_data['TextDomain'];
		$plugin_slug = wp_kses( is_scalar( $td_raw2 ) ? (string) $td_raw2 : '', 'strip' );
	}

	// Get the plugin version from the plugin data if it exists.
	$plugin_version_raw2 = $plugin_data['Version'] ?? '';
	$plugin_version      = wp_kses( is_scalar( $plugin_version_raw2 ) ? (string) $plugin_version_raw2 : '', 'strip' );

	// Retrieve vulnerabilities for the plugin using its slug and version.
	if ( ! empty( $plugin_slug ) ) {

		$plugin_api_response = wpvulnerability_get_plugin( $plugin_slug, $plugin_version, 1, 1 );

		// If vulnerabilities are found, return the updated plugin data.
		if ( ! empty( $plugin_api_response ) ) {
			return $plugin_api_response;
		}
	}

	return null; // Return null if no valid data is found.
}

/**
 * Get Installed Plugins
 * Retrieves the list of installed plugins, checks for vulnerabilities in each of them, caches the data, and sends an email notification if vulnerabilities are detected.
 *
 * @since 2.0.0
 * @since 4.1.2 Stores a signature of the installed plugins to detect inventory changes.
 *
 * @return string JSON-encoded array of plugin data with vulnerabilities and vulnerable status, or '[]' on encoding error.
 */
function wpvulnerability_plugin_get_installed() {

	$wpvulnerability_plugins_vulnerable = 0;

	// Ensure the get_plugins() function is available.
	if ( ! function_exists( 'get_plugins' ) ) {
		require_once ABSPATH . 'wp-admin/includes/plugin.php';
	}

	// Retrieve the list of installed plugins.
	$plugins   = get_plugins();
	$signature = wpvulnerability_plugins_generate_signature( $plugins );

	// Iterate through each plugin and check for vulnerabilities.
	foreach ( $plugins as $file_path => $plugin_data ) {

		$plugins[ $file_path ] = wpvulnerability_get_fresh_plugin_vulnerabilities( $plugin_data, $file_path );

		// Increment the vulnerable plugin counter if vulnerabilities are found.
		$vuln_flag = $plugins[ $file_path ]['vulnerable'] ?? null;
		if ( is_scalar( $vuln_flag ) && (int) $vuln_flag ) {
			++$wpvulnerability_plugins_vulnerable;
		}
	}

	// Update site options for multisite installations.
	if ( is_multisite() ) {
		update_site_option( 'wpvulnerability-plugins', wp_json_encode( $plugins ) );
		update_site_option( 'wpvulnerability-plugins-vulnerable', wp_json_encode( number_format( $wpvulnerability_plugins_vulnerable, 0, '.', '' ) ) );
		update_site_option( 'wpvulnerability-plugins-cache', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ) );
		update_site_option( 'wpvulnerability-plugins-signature', wp_json_encode( $signature ) );
	} else {
		// Update options for single site installations.
		update_option( 'wpvulnerability-plugins', wp_json_encode( $plugins ), false );
		update_option( 'wpvulnerability-plugins-vulnerable', wp_json_encode( number_format( $wpvulnerability_plugins_vulnerable, 0, '.', '' ) ), false );
		update_option( 'wpvulnerability-plugins-cache', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ), false );
		update_option( 'wpvulnerability-plugins-signature', wp_json_encode( $signature ), false );
	}

	// Return the JSON-encoded array of plugin data.
	$encoded = wp_json_encode( $plugins );
	return false !== $encoded ? $encoded : '[]';
}

/**
 * Retrieves cached data for installed plugins, optionally refreshing when forced.
 *
 * @since 3.1.0
 * @since 4.1.2 Refreshes automatically when the installed plugins signature changes.
 *
 * @param bool $clean Optional. Whether to force a refresh of the plugin data cache. Default false.
 *
 * @return string JSON-encoded array of plugin data, or '[]' on encoding error.
 */
function wpvulnerability_plugin_get_data( $clean = false ) {
	if ( true === $clean ) {
		// Ensure the get_plugins() function is available.
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		// Retrieve the list of installed plugins.
		$plugins     = get_plugins();
		$pluginsdata = array();
		$signature   = wpvulnerability_plugins_generate_signature( $plugins );

		// Iterate through each plugin and get fresh data.
		foreach ( $plugins as $file_path => $plugin_data ) {
			$pluginsdata[ $file_path ] = wpvulnerability_get_fresh_plugin_data( $plugin_data, $file_path );
		}

		// Update site options for multisite installations.
		if ( is_multisite() ) {
			update_site_option( 'wpvulnerability-plugins-data', wp_json_encode( $pluginsdata ) );
			update_site_option( 'wpvulnerability-plugins-cache-data', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ) );
			update_site_option( 'wpvulnerability-plugins-cache', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ) );
			update_site_option( 'wpvulnerability-plugins-signature', wp_json_encode( $signature ) );
		} else {
			// Update options for single site installations.
			update_option( 'wpvulnerability-plugins-data', wp_json_encode( $pluginsdata ), false );
			update_option( 'wpvulnerability-plugins-cache-data', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ), false );
			update_option( 'wpvulnerability-plugins-cache', wp_json_encode( number_format( time() + ( 3600 * wpvulnerability_cache_hours() ), 0, '.', '' ) ), false );
			update_option( 'wpvulnerability-plugins-signature', wp_json_encode( $signature ), false );
		}

		$encoded_data = wp_json_encode( $pluginsdata );
		return false !== $encoded_data ? $encoded_data : '[]';
	}

	$raw_pd      = is_multisite() ? get_site_option( 'wpvulnerability-plugins-data', '' ) : get_option( 'wpvulnerability-plugins-data', '' );
	$plugin_data = json_decode( is_string( $raw_pd ) ? $raw_pd : '', true );

	if ( ! is_array( $plugin_data ) ) {
		$plugin_data = array();
	}

	$encoded = wp_json_encode( $plugin_data );
	return false !== $encoded ? $encoded : '[]';
}

/**
 * Get cached plugin vulnerabilities without contacting the API. Data is refreshed by scheduled or manual updates.
 *
 * @since 2.0.0
 * @since 4.1.2 Refreshes when the installed plugins signature changes.
 *
 * @return array<string, mixed> Array of installed plugins with their vulnerabilities.
 */
function wpvulnerability_plugin_get_vulnerabilities() {

	$raw_data    = is_multisite() ? get_site_option( 'wpvulnerability-plugins', '' ) : get_option( 'wpvulnerability-plugins', '' );
	$plugin_data = json_decode( is_string( $raw_data ) ? $raw_data : '', true );

	return is_array( $plugin_data ) ? $plugin_data : array();
}

/**
 * Update the installed plugins cache and remove any old cache data.
 *
 * @since 2.0.0
 *
 * @return void
 */
function wpvulnerability_plugin_get_vulnerabilities_clean() {
	wpvulnerability_clear_cache( 'plugins' );
	wpvulnerability_plugin_get_installed();
	wpvulnerability_plugin_get_data( true );
}

/**
 * Displays information in the 'Last Updated' column for each plugin in the plugins list table.
 *
 * This function is triggered for each row in the plugins list table when the 'Last Updated' column is rendered.
 * It retrieves the last update date from stored plugin data, compares it against the current date to highlight
 * plugins not updated in over a year or those marked as closed, and displays this information.
 *
 * @since 3.1.0 Introduced.
 *
 * @param string               $column_name The name of the current column being rendered.
 * @param string               $plugin_file Path to the plugin file, relative to the plugins directory.
 * @param array<string, mixed> $plugin_data Array of plugin data, such as the plugin's name, version, and description.
 *
 * @return void Outputs the last updated information directly to the browser, including any warnings for plugins
 *              not updated in over a year or marked as closed.
 */
function wpvulnerability_plugin_show_lastupdated( $column_name, $plugin_file, $plugin_data ) {

	$now  = time();
	$year = strtotime( '-1 year', $now );

	if ( 'last_updated' === $column_name && $plugin_file ) {

		$plugin_slug = '';

		// Extract the plugin slug from the file path.
		$folder_name = explode( '/', $plugin_file );

		// Use the first folder segment as the plugin slug.
		$plugin_slug = wp_kses( trim( (string) $folder_name[0] ), 'strip' );
		unset( $folder_name );

		// If the plugin slug is empty, extract it from the plugin data.
		if ( '' === $plugin_slug && isset( $plugin_data['TextDomain'] ) ) {
			$td_raw3     = $plugin_data['TextDomain'];
			$plugin_slug = wp_kses( is_scalar( $td_raw3 ) ? (string) $td_raw3 : '', 'strip' );
		}

		if ( '' !== $plugin_slug ) {

			// Retrieve the vulnerabilities for all plugins from the options table and decode the JSON.
			$raw_plugins_data = is_multisite() ? get_site_option( 'wpvulnerability-plugins-data', '' ) : get_option( 'wpvulnerability-plugins-data', '' );
			$plugins_data     = json_decode( is_string( $raw_plugins_data ) ? $raw_plugins_data : '', true );
			if ( ! is_array( $plugins_data ) ) {
				$plugins_data = array();
			}

			// Get the plugin data from the stored data.
			if ( isset( $plugins_data[ $plugin_file ] ) && is_array( $plugins_data[ $plugin_file ] ) ) {
				$pd = $plugins_data[ $plugin_file ];

				$pd_latest_raw = $pd['latest'] ?? 0;
				$pd_latest     = is_scalar( $pd_latest_raw ) ? intval( $pd_latest_raw ) : 0;
				if ( $pd_latest > 0 ) {

					$timestamp   = $pd_latest;
					$df_raw      = get_option( 'date_format', 'Y-m-d' );
					$date_format = is_scalar( $df_raw ) ? (string) $df_raw : 'Y-m-d';
					if ( function_exists( 'wp_date' ) ) {
						$plugin_data_updated = (string) wp_date( $date_format, $timestamp );
					} else {
						$plugin_data_updated = gmdate( $date_format, $timestamp );
					}
					$plugin_data_ago = human_time_diff( $timestamp );

					$warning_date   = $pd_latest < $year;
					$pd_closed_raw  = $pd['closed'] ?? 0;
					$warning_closed = isset( $pd['closed'] ) && ( is_scalar( $pd_closed_raw ) ? intval( $pd_closed_raw ) : 0 );

					echo '<p>' . wp_kses( $plugin_data_updated, 'strip' ) . ' (' . wp_kses( (string) $plugin_data_ago, 'strip' ) . ')</p>';

					if ( $warning_date ) {
						echo '<p><strong>⚠️ ';
						esc_html_e( 'It hasn\'t been updated in over a year.', 'wpvulnerability' );
						echo '</strong></p>';
					}

					if ( $warning_closed ) {
						echo '<p><strong>⚠️ ';
						esc_html_e( 'It may no longer be available (closed?).', 'wpvulnerability' );
						echo '</strong></p>';
					}
				} else {
					echo '<p></p>';
				}
			}
		}
	}
}

/**
 * Adds a 'Last Updated' column to the plugins table list in the WordPress admin area.
 *
 * This function iterates over the existing columns in the plugins table and inserts a new column titled 'Last Updated'
 * just before the 'auto-updates' column if it exists. If the 'auto-updates' column is not found, the 'Last Updated'
 * column is appended at the end. The function is typically hooked to the 'manage_plugins_columns' filter in WordPress
 * to modify the columns of the plugins table.
 *
 * @since 3.1.0 Introduced.
 *
 * @param array<string, string> $columns An associative array of column names and titles for the plugins table.
 *
 * @return array<string, string> An associative array containing the modified list of columns, including the new 'Last Updated' column.
 */
function wpvulnerability_plugin_add_lastupdated_column( $columns ) {

	$toadd       = true;
	$new_columns = array();

	// Loop through each existing column and add it to the new columns array.
	foreach ( $columns as $key => $title ) {

		// Add the existing column to the new columns array.
		$new_columns[ $key ] = $title;

		// Insert your custom column before the 'auto-updates' column.
		if ( 'description' === $key && $toadd ) {
			$new_columns['last_updated'] = __( 'Last updated on', 'wpvulnerability' );
			$toadd                       = false;
		}
	}

	// If 'auto-updates' column is not found, add 'last_updated' column at the end.
	if ( $toadd ) {
		$new_columns['last_updated'] = __( 'Last updated on', 'wpvulnerability' );
	}

	// Return the modified columns array.
	return $new_columns;
}

/**
 * Admin Head
 * Adds vulnerability information after the plugin row and notices on the plugin page based on the installed plugins cache.
 *
 * @since 2.0.0
 *
 * @return void
 */
function wpvulnerability_plugin_page() {

	// Check if the current page is the plugins page.
	global $pagenow;

	if ( wpvulnerability_analyze_filter( 'plugins' ) && 'plugins.php' === $pagenow && wpvulnerability_capabilities() ) {

		// Get the vulnerabilities for the installed plugins.
		$plugins = wpvulnerability_plugin_get_vulnerabilities();

		// Loop through the plugins and add vulnerability information after the plugin row for vulnerable plugins.
		foreach ( $plugins as $file_path => $plugin_data ) {

			if ( is_array( $plugin_data ) && isset( $plugin_data['vulnerable'] ) ) {
				$vulnerable_raw = $plugin_data['vulnerable'];
				if ( 1 === ( is_scalar( $vulnerable_raw ) ? intval( $vulnerable_raw ) : 0 ) ) {
					add_action( 'after_plugin_row_' . $file_path, 'wpvulnerability_plugin_info_after', 10, 2 );
				}
			}
		}

		// Add 'Last Updated' column to the plugins table based on user capabilities.
		if ( is_multisite() ) {

			add_filter( 'manage_plugins-network_columns', 'wpvulnerability_plugin_add_lastupdated_column' );

		} else {

			add_filter( 'manage_plugins_columns', 'wpvulnerability_plugin_add_lastupdated_column' );

		}

		add_action( 'manage_plugins_custom_column', 'wpvulnerability_plugin_show_lastupdated', 10, 3 );

	}
}
// Add notices for vulnerable plugins on the plugin page.
add_action( 'admin_head', 'wpvulnerability_plugin_page' );

/**
 * Filters the plugins list to show only vulnerable plugins when the "Vulnerable" tab is selected.
 *
 * This function hooks into the WordPress plugins listing to filter the displayed plugins based on their
 * vulnerability status. When the "Vulnerable" tab is selected (identified by the `plugin_status=vulnerable`
 * query parameter), it filters the plugins list to include only those plugins with known vulnerabilities.
 *
 * The function retrieves the vulnerabilities for all plugins from the WordPress options table and compares
 * them against the active list of plugins. Plugins without vulnerabilities are removed from the list, leaving
 * only those that are considered vulnerable.
 *
 * @since 3.3.5
 *
 * @return void
 */
function wpvulnerability_plugins_filter() {
	if ( isset( $_GET['plugin_status'] ) && 'vulnerable' === $_GET['plugin_status'] ) { // phpcs:ignore

		// Verify nonce for CSRF protection.
		$nonce_raw = isset( $_GET['wpv_nonce'] ) && is_string( $_GET['wpv_nonce'] ) ? $_GET['wpv_nonce'] : ''; // phpcs:ignore
		$nonce     = sanitize_text_field( wp_unslash( $nonce_raw ) );

		if ( ! wp_verify_nonce( $nonce, 'wpvulnerability_filter_plugins' ) ) {
			// If nonce verification fails, silently return without filtering.
			// This provides graceful degradation - users simply see all plugins instead of an error.
			return;
		}

		global $wp_list_table;

		// Retrieve the vulnerabilities for all plugins from the options table and decode the JSON.
		$raw_pv                 = is_multisite() ? get_site_option( 'wpvulnerability-plugins', '' ) : get_option( 'wpvulnerability-plugins', '' );
		$plugin_vulnerabilities = json_decode( is_string( $raw_pv ) ? $raw_pv : '', true );
		if ( ! is_array( $plugin_vulnerabilities ) ) {
			$plugin_vulnerabilities = array();
		}

		foreach ( $wp_list_table->items as $plugin_file => $plugin_data ) {
			$pf_data  = isset( $plugin_vulnerabilities[ $plugin_file ] ) && is_array( $plugin_vulnerabilities[ $plugin_file ] ) ? $plugin_vulnerabilities[ $plugin_file ] : array();
			$pf_vulns = isset( $pf_data['vulnerabilities'] ) && is_array( $pf_data['vulnerabilities'] ) ? $pf_data['vulnerabilities'] : array();
			if ( empty( $pf_vulns ) ) {
				unset( $wp_list_table->items[ $plugin_file ] );
			}
		}
	}
}
add_action( 'pre_current_active_plugins', 'wpvulnerability_plugins_filter' );

/**
 * Adds a "Vulnerable" tab to the WordPress plugins page that displays the count of vulnerable plugins.
 *
 * This function checks the cache for the number of vulnerable plugins and adds a new tab to the plugins
 * management page in the WordPress admin area. The tab displays the count of vulnerable plugins and highlights it
 * if it is currently active.
 *
 * @since 3.3.5
 *
 * @param array<string, string> $views An array of existing plugin views (tabs) in the WordPress admin plugins page.
 *
 * @return array<string, string> The modified array of views including the "Vulnerable" tab.
 */
function wpvulnerability_plugins_view( $views ) {

	if ( ! wpvulnerability_analyze_filter( 'plugins' ) ) {
		return $views;
	}

	// Retrieve the number of plugins vulnerabilities from cache.
	$raw_count = is_multisite()
		? get_site_option( 'wpvulnerability-plugins-vulnerable', '0' )
		: get_option( 'wpvulnerability-plugins-vulnerable', '0' );

	$decoded_count                 = json_decode( is_string( $raw_count ) ? $raw_count : '0', true );
	$wpvulnerability_plugins_total = is_scalar( $decoded_count ) ? intval( $decoded_count ) : 0;

	$current_class = ( isset( $_GET['plugin_status'] ) && 'vulnerable' === $_GET['plugin_status'] ) ? ' class="current"' : ''; // phpcs:ignore

	$url = is_multisite()
		? network_admin_url( 'plugins.php?plugin_status=vulnerable' )
		: admin_url( 'plugins.php?plugin_status=vulnerable' );

	// Add nonce for CSRF protection.
	$url = esc_url( wp_nonce_url( $url, 'wpvulnerability_filter_plugins', 'wpv_nonce' ) );

	$views['vulnerable'] = sprintf(
		'<a href="%s"%s>%s</a>',
		$url,
		$current_class,
		// translators: the number of vulnerabilities.
		sprintf( __( 'Vulnerabilities (%d)', 'wpvulnerability' ), $wpvulnerability_plugins_total )
	);

	return $views;
}

/**
 * Adds a custom filter to the plugins page in the WordPress admin to display a tab for vulnerable plugins.
 *
 * This function hooks into the 'views_plugins' filter to add a custom tab or view for displaying vulnerable plugins
 * on the plugins management page in the WordPress admin area. The tab is added in both single-site and multisite
 * installations, but in a multisite setup, it is only added to the network admin area.
 *
 * @since 3.3.5
 *
 * @return void
 */
function wpvulnerability_plugins_add_tab() {

	if ( is_multisite() ) {
		if ( is_network_admin() ) {
			add_filter( 'views_plugins-network', 'wpvulnerability_plugins_view' );
		}
	} else {
		add_filter( 'views_plugins', 'wpvulnerability_plugins_view' );
	}
}
add_action( 'admin_head', 'wpvulnerability_plugins_add_tab' );