<?php
/**
 * Plugin Name: Admin Bar Server Info
 * Description: Displays essential server and environment information directly in the WordPress admin bar for administrators.
 * Version: 1.1.0
 * Author: Raúl Fernández
 * Author URI: https://clink.es
 * License: GPLv2 or later
 * License URI: https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain: admin-bar-server-info
 * Domain Path: /languages
 * Requires at least: 5.0
 * Requires PHP: 7.4
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Main plugin class.
 *
 * @since 1.0.0
 */
class Admin_Bar_Server_Info {

	/**
	 * Plugin version.
	 *
	 * @since 1.0.0
	 * @var string
	 */
	const VERSION = '1.1.0';

	/**
	 * Initialize the plugin.
	 *
	 * @since 1.0.0
	 */
	public function __construct() {
		// Hook into admin bar menu with high priority to appear on the right side.
		add_action( 'admin_bar_menu', array( $this, 'add_server_info_to_admin_bar' ), 999 );
		
		// Enqueue styles.
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_styles' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_styles' ) );
	}

	/**
	 * Add server information to the admin bar.
	 *
	 * @since 1.0.0
	 * @param WP_Admin_Bar $wp_admin_bar The admin bar object.
	 */
	public function add_server_info_to_admin_bar( $wp_admin_bar ) {
		// Only show for administrators.
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		// Get server information.
		$server_info = $this->get_server_info();

		// Build the title with server information.
		// Grouped logically: PHP info, Memory info, Server info, WordPress info.
		$title = sprintf(
			/* translators: 1: PHP version, 2: SAPI, 3: OS, 4: Max exec time, 5: Max upload, 6: Memory usage, 7: WP Memory limit, 8: Server software, 9: Database version, 10: Server IP, 11: WordPress version */
			esc_html__( '* PHP %1$s | %2$s | %3$s | %4$s | Upload %5$s | Mem %6$s | WP Limit %7$s | %8$s | %9$s | %10$s | WP %11$s *', 'admin-bar-server-info' ),
			esc_html( $server_info['php_version'] ),
			esc_html( $server_info['sapi'] ),
			esc_html( $server_info['os'] ),
			esc_html( $server_info['max_execution_time'] ),
			esc_html( $server_info['max_upload_size'] ),
			esc_html( $server_info['memory_usage'] ),
			esc_html( $server_info['wp_memory_limit'] ),
			esc_html( $server_info['server_software'] ),
			esc_html( $server_info['db_version'] ),
			esc_html( $server_info['server_ip'] ),
			esc_html( $server_info['wp_version'] )
		);

		// Add menu item to admin bar (right side).
		// Using 'top-secondary' as parent ensures it appears on the right side.
		$wp_admin_bar->add_node(
			array(
				'id'     => 'abs_server_info',
				'title'  => $title,
				'parent' => 'top-secondary',
				'meta'   => array(
					'title' => '',
					'class' => 'abs-server-info',
				),
			)
		);
	}

	/**
	 * Enqueue styles for admin bar.
	 *
	 * @since 1.0.3
	 */
	public function enqueue_styles() {
		// Only enqueue styles for administrators.
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		$css_file = plugin_dir_url( __FILE__ ) . 'assets/css/admin-bar-server-info.css';
		wp_enqueue_style(
			'admin-bar-server-info',
			$css_file,
			array(),
			self::VERSION
		);
	}

	/**
	 * Get server and environment information.
	 *
	 * @since 1.0.0
	 * @return array Array containing server information.
	 */
	private function get_server_info() {
		global $wpdb;

		$info = array();

		// Get PHP version.
		$info['php_version'] = $this->get_php_version();

		// Get database version.
		$info['db_version'] = $this->get_database_version( $wpdb );

		// Get server software.
		$info['server_software'] = $this->get_server_software();

		// Get WordPress version.
		$info['wp_version'] = get_bloginfo( 'version' );

		// Get server IP address.
		$info['server_ip'] = $this->get_server_ip();

		// Get memory usage.
		$info['memory_usage'] = $this->get_memory_usage();

		// Get WordPress memory limit.
		$info['wp_memory_limit'] = $this->get_wp_memory_limit();

		// Get operating system.
		$info['os'] = $this->get_operating_system();

		// Get PHP SAPI.
		$info['sapi'] = $this->get_php_sapi();

		// Get max execution time.
		$info['max_execution_time'] = $this->get_max_execution_time();

		// Get max upload size.
		$info['max_upload_size'] = $this->get_max_upload_size();

		return $info;
	}

	/**
	 * Get PHP version.
	 *
	 * @since 1.0.0
	 * @return string PHP version with architecture info.
	 */
	private function get_php_version() {
		$php_version = PHP_VERSION;
		
		// Get architecture (32 or 64 bit).
		$php_bits = PHP_INT_SIZE * 8;
		
		// Format: "8.3.29 @64BitOS" (matching the original plugin format).
		return $php_version . ' @' . $php_bits . 'BitOS';
	}

	/**
	 * Get database version.
	 *
	 * @since 1.0.0
	 * @param wpdb $wpdb WordPress database object.
	 * @return string Database version.
	 */
	private function get_database_version( $wpdb ) {
		// Get full database version using SQL query for better detection.
		$db_version_full = $wpdb->get_var( 'SELECT VERSION()' );

		if ( empty( $db_version_full ) ) {
			// Fallback to WordPress db_version() method.
			$db_version_full = $wpdb->db_version();
		}

		if ( empty( $db_version_full ) ) {
			return esc_html__( 'Unknown', 'admin-bar-server-info' );
		}

		// Check if it's MariaDB (case-insensitive search).
		$is_mariadb = ( stripos( $db_version_full, 'mariadb' ) !== false );

		// Extract version numbers (major.minor).
		// MariaDB version format: "10.11.2-MariaDB" or similar.
		// MySQL version format: "8.0.35" or similar.
		preg_match( '/(\d+)\.(\d+)/', $db_version_full, $matches );
		
		if ( ! empty( $matches ) && count( $matches ) >= 3 ) {
			$major = $matches[1];
			$minor = $matches[2];
			$db_type = $is_mariadb ? 'MariaDB' : 'MySQL';
			return $db_type . ' ' . $major . '.' . $minor;
		}

		// Fallback: return as-is with detected type.
		$db_type = $is_mariadb ? 'MariaDB' : 'MySQL';
		return $db_type . ' ' . $db_version_full;
	}

	/**
	 * Get server software name.
	 *
	 * @since 1.0.0
	 * @return string Server software name.
	 */
	private function get_server_software() {
		// Check if SERVER_SOFTWARE is available.
		if ( ! isset( $_SERVER['SERVER_SOFTWARE'] ) || empty( $_SERVER['SERVER_SOFTWARE'] ) ) {
			return esc_html__( 'Unknown', 'admin-bar-server-info' );
		}

		$server_software = sanitize_text_field( wp_unslash( $_SERVER['SERVER_SOFTWARE'] ) );

		// Detect common server software.
		if ( stripos( $server_software, 'apache' ) !== false ) {
			return 'Apache';
		} elseif ( stripos( $server_software, 'nginx' ) !== false ) {
			return 'Nginx';
		} elseif ( stripos( $server_software, 'litespeed' ) !== false ) {
			return 'LiteSpeed';
		} elseif ( stripos( $server_software, 'iis' ) !== false ) {
			return 'IIS';
		} elseif ( stripos( $server_software, 'caddy' ) !== false ) {
			return 'Caddy';
		}

		// If no known server detected, return first part of SERVER_SOFTWARE.
		$parts = explode( '/', $server_software );
		if ( ! empty( $parts[0] ) ) {
			return esc_html( trim( $parts[0] ) );
		}

		return esc_html__( 'Unknown', 'admin-bar-server-info' );
	}

	/**
	 * Get server IP address with hostname.
	 *
	 * @since 1.0.3
	 * @return string Server IP address with hostname in parentheses.
	 */
	private function get_server_ip() {
		// Try SERVER_ADDR first (standard for most servers).
		$server_ip = ! empty( $_SERVER['SERVER_ADDR'] ) ? sanitize_text_field( wp_unslash( $_SERVER['SERVER_ADDR'] ) ) : '';

		// Fallback to LOCAL_ADDR for IIS servers.
		if ( empty( $server_ip ) && ! empty( $_SERVER['LOCAL_ADDR'] ) ) {
			$server_ip = sanitize_text_field( wp_unslash( $_SERVER['LOCAL_ADDR'] ) );
		}

		// If still empty, try to get from hostname.
		if ( empty( $server_ip ) && function_exists( 'gethostname' ) ) {
			$hostname = gethostname();
			if ( $hostname ) {
				$ip = gethostbyname( $hostname );
				if ( $ip !== $hostname ) {
					$server_ip = $ip;
				}
			}
		}

		// Get hostname for display (matching the original plugin format).
		$hostname = '';
		if ( function_exists( 'gethostname' ) ) {
			$hostname = gethostname();
		}

		// Format: "IP 172.23.0.3 (hostname)" or just "IP 172.23.0.3" if no hostname.
		if ( empty( $server_ip ) ) {
			return esc_html__( 'N/A', 'admin-bar-server-info' );
		}

		$ip_display = esc_html( $server_ip );
		if ( ! empty( $hostname ) ) {
			$ip_display .= ' (' . esc_html( $hostname ) . ')';
		}

		return $ip_display;
	}

	/**
	 * Get memory usage information.
	 *
	 * @since 1.0.3
	 * @return string Memory usage formatted string.
	 */
	private function get_memory_usage() {
		// Get memory limit (current PHP limit, which WordPress may have adjusted).
		$memory_limit = ini_get( 'memory_limit' );
		
		// Convert memory limit to bytes using our own converter for maximum compatibility.
		$memory_limit_bytes = $this->convert_to_bytes( $memory_limit );

		// Get peak memory usage.
		$memory_usage_bytes = function_exists( 'memory_get_peak_usage' ) ? memory_get_peak_usage( true ) : 0;

		// Handle unlimited memory (-1).
		if ( -1 === $memory_limit_bytes ) {
			// Unlimited memory - show usage only.
			if ( empty( $memory_usage_bytes ) ) {
				return esc_html__( 'N/A', 'admin-bar-server-info' );
			}
			$memory_usage_mb = round( $memory_usage_bytes / 1024 / 1024, 2 );
			return sprintf(
				'%s MB (%s)',
				number_format_i18n( $memory_usage_mb, 2 ),
				esc_html__( 'Unlimited', 'admin-bar-server-info' )
			);
		}

		// Handle invalid values.
		if ( empty( $memory_usage_bytes ) || empty( $memory_limit_bytes ) || $memory_limit_bytes <= 0 ) {
			return esc_html__( 'N/A', 'admin-bar-server-info' );
		}

		// Convert to MB for display.
		$memory_usage_mb = round( $memory_usage_bytes / 1024 / 1024, 2 );
		$memory_limit_mb = round( $memory_limit_bytes / 1024 / 1024, 2 );

		// Calculate percentage.
		$memory_percent = round( ( $memory_usage_bytes / $memory_limit_bytes ) * 100, 0 );

		// Format: "used/total MB (XX%)" - matching the original plugin format more closely.
		return sprintf(
			'%s/%s MB (%d%%)',
			number_format_i18n( $memory_usage_mb, 2 ),
			number_format_i18n( $memory_limit_mb, 2 ),
			$memory_percent
		);
	}

	/**
	 * Convert memory size string to bytes.
	 *
	 * @since 1.0.3
	 * @param string $size Memory size string (e.g., "128M", "256K", "-1" for unlimited).
	 * @return int Size in bytes, or -1 for unlimited.
	 */
	private function convert_to_bytes( $size ) {
		$size = trim( $size );
		
		// Handle empty or invalid values.
		if ( empty( $size ) ) {
			return 0;
		}
		
		// Handle unlimited memory (-1).
		if ( '-1' === $size ) {
			return -1;
		}
		
		// Get the last character to determine unit.
		$last = strtolower( substr( $size, -1 ) );
		$value = (int) $size;

		// Convert based on unit (G, M, K).
		switch ( $last ) {
			case 'g':
				$value *= 1024;
				// Fall through.
			case 'm':
				$value *= 1024;
				// Fall through.
			case 'k':
				$value *= 1024;
		}

		return $value;
	}

	/**
	 * Get WordPress memory limit.
	 *
	 * @since 1.0.3
	 * @return string WordPress memory limit formatted string.
	 */
	private function get_wp_memory_limit() {
		// Check if WP_MEMORY_LIMIT constant is defined.
		if ( ! defined( 'WP_MEMORY_LIMIT' ) ) {
			return esc_html__( 'N/A', 'admin-bar-server-info' );
		}

		$wp_limit = WP_MEMORY_LIMIT;
		
		// Convert to bytes for formatting.
		$wp_limit_bytes = $this->convert_to_bytes( $wp_limit );
		
		if ( empty( $wp_limit_bytes ) || $wp_limit_bytes <= 0 ) {
			return esc_html__( 'N/A', 'admin-bar-server-info' );
		}

		// Use WordPress size_format function if available, otherwise format manually.
		if ( function_exists( 'size_format' ) ) {
			return size_format( $wp_limit_bytes );
		}

		// Manual formatting if size_format is not available.
		$wp_limit_mb = round( $wp_limit_bytes / 1024 / 1024, 0 );
		return number_format_i18n( $wp_limit_mb ) . ' MB';
	}

	/**
	 * Get operating system name.
	 *
	 * @since 1.0.3
	 * @return string Operating system name.
	 */
	private function get_operating_system() {
		// Try php_uname first (more detailed).
		if ( function_exists( 'php_uname' ) ) {
			$os = php_uname( 's' );
			if ( ! empty( $os ) ) {
				return esc_html( $os );
			}
		}

		// Fallback to PHP_OS constant.
		if ( defined( 'PHP_OS' ) ) {
			return esc_html( PHP_OS );
		}

		return esc_html__( 'Unknown', 'admin-bar-server-info' );
	}

	/**
	 * Get PHP SAPI (Server API).
	 *
	 * @since 1.0.3
	 * @return string PHP SAPI name (shortened for common values).
	 */
	private function get_php_sapi() {
		if ( function_exists( 'php_sapi_name' ) ) {
			$sapi = php_sapi_name();
			if ( ! empty( $sapi ) ) {
				// Shorten common SAPIs to avoid redundancy.
				switch ( $sapi ) {
					case 'apache2handler':
						return 'mod_php';
					case 'fpm-fcgi':
						return 'fpm';
					case 'cgi-fcgi':
						return 'cgi';
					default:
						return esc_html( $sapi );
				}
			}
		}

		return esc_html__( 'Unknown', 'admin-bar-server-info' );
	}

	/**
	 * Get max execution time.
	 *
	 * @since 1.0.3
	 * @return string Max execution time in seconds.
	 */
	private function get_max_execution_time() {
		$max_exec_time = ini_get( 'max_execution_time' );
		
		// Handle unlimited (0 or -1).
		if ( empty( $max_exec_time ) || $max_exec_time < 0 ) {
			return esc_html__( 'Unlimited', 'admin-bar-server-info' );
		}

		return esc_html( $max_exec_time ) . 's';
	}

	/**
	 * Get max upload size.
	 *
	 * @since 1.0.3
	 * @return string Max upload size formatted.
	 */
	private function get_max_upload_size() {
		$upload_max = ini_get( 'upload_max_filesize' );
		
		if ( empty( $upload_max ) ) {
			return esc_html__( 'N/A', 'admin-bar-server-info' );
		}

		// Return as-is (already formatted like "64M", "2M", etc.).
		return esc_html( $upload_max );
	}
}

/**
 * Initialize the plugin.
 *
 * @since 1.0.0
 */
function abs_init() {
	new Admin_Bar_Server_Info();
}
add_action( 'init', 'abs_init' );