<?php
/**
 * Responsible for enabling or disabling the file editor in WordPress.
 *
 * @package WP_Defender\Component\Security_Tweaks
 */

namespace WP_Defender\Component\Security_Tweaks;

use WP_Error;
use Calotes\Base\Component;
use WP_Defender\Component\Security_Tweaks\Servers\Server;
use WP_Defender\Component\Security_Tweak as Security_Tweak_Component;

/**
 * Handles the implementation of the disable-file-editor security tweak.
 */
class Disable_File_Editor extends Component {

	/**
	 * Slug identifier for the component.
	 *
	 * @var string
	 */
	public $slug = 'disable-file-editor';

	/**
	 * Check whether the issue has been resolved or not.
	 *
	 * @return bool
	 */
	public function check() {
		if ( defined( 'DISALLOW_FILE_EDIT' ) && true === constant( 'DISALLOW_FILE_EDIT' ) ) {
			return true;
		}

		return false;
	}

	/**
	 * Get pattern for DISALLOW_FILE_EDIT.
	 *
	 * @return string
	 */
	private function get_file_edit_pattern() {
		return "/^define\(\s*['|\"]DISALLOW_FILE_EDIT['|\"],(.*)\)/";
	}

	/**
	 * Set data in wp-config.php.
	 *
	 * @param  bool $value  The value to set for DISALLOW_FILE_EDIT.
	 *
	 * @return bool|WP_Error
	 */
	private function set_file_edit_data( $value ) {
		$sec_tweak_component = new Security_Tweak_Component();
		$obj_file            = 'flywheel' === Server::get_current_server()
			? $sec_tweak_component->advanced_check_file()
			: $sec_tweak_component->file();
		if ( false === $obj_file ) {
			return new WP_Error(
				'defender_file_not_writable',
				esc_html__( 'The file wp-config.php is not writable', 'defender-security' )
			);
		} elseif ( is_numeric( $obj_file ) ) {
			return new WP_Error(
				'defender_file_not_writable',
				$sec_tweak_component->show_hosting_notice( 'DISALLOW_FILE_EDIT' )
			);
		}

		$file_edit         = 'DISALLOW_FILE_EDIT';
		$value             = $value ? 'true' : 'false';
		$pattern           = $this->get_file_edit_pattern();
		$hook_line_pattern = $sec_tweak_component->get_hook_line_pattern();
		$file_edit_line    = "define( '{$file_edit}', {$value} ); // Added by Defender";
		$lines             = array();
		$line_found        = false;
		$hook_line_no      = null;

		foreach ( $obj_file as $line ) {
			if ( ! $line_found && preg_match( $pattern, $line ) ) {
				// If this is revert request and the changes is not made by us throw error.
				if ( 'true' === $value && ! preg_match(
					"/^define\(\s*['|\"]{$file_edit}['|\"],(.*)\);\s*\/\/\s*Added\s*by\s*Defender.?.*/i",
					$line
				) ) {
					return new WP_Error(
						'defender_file_not_writable',
						$sec_tweak_component->show_hosting_notice_with_code( $file_edit, $file_edit_line )
					);
				}

				$lines[]    = $file_edit_line;
				$line_found = true;
				continue;
			}

			// If there is no match, keep reference of `hook_line_no` so that we can insert data there as needed.
			if ( ! $line_found && preg_match( $hook_line_pattern, $line ) ) {
				$hook_line_no               = $obj_file->key();
				$lines[ $hook_line_no + 1 ] = trim( $line );
				continue;
			}

			$lines[] = trim( $line );
		}

		// There is no match, so set DISALLOW_FILE_EDIT data just before the hook line ei: `$table_prefix`.
		if ( ! $line_found && ! is_null( $hook_line_no ) ) {
			$line_found             = true;
			$lines[ $hook_line_no ] = $file_edit_line;
			ksort( $lines );
		}

		return $line_found
			? $sec_tweak_component->write( $lines )
			: new WP_Error(
				'defender_line_not_found',
				esc_html__( 'Error writing to file.', 'defender-security' ),
				404
			);
	}

	/**
	 * Allow file editor.
	 *
	 * @return bool|WP_Error
	 */
	private function allow_file_editor() {
		return $this->set_file_edit_data( false );
	}

	/**
	 * Prevent file editor.
	 *
	 * @return bool|WP_Error
	 */
	private function prevent_file_editor() {
		return $this->set_file_edit_data( true );
	}

	/**
	 * Here is the code for processing, if the return is true, we add it to resolve list, WP_Error if any error.
	 *
	 * @return bool|WP_Error
	 */
	public function process() {
		return $this->prevent_file_editor();
	}

	/**
	 * This is for un-do stuff that has be done in @process.
	 *
	 * @return bool|WP_Error
	 */
	public function revert() {
		return $this->allow_file_editor();
	}

	/**
	 * Define the DISALLOW_FILE_EDIT constant, so we can hide the editor page.
	 *
	 * @return bool Always returns true.
	 */
	public function shield_up() {
		return true;
	}

	/**
	 * Return a summary data of this tweak.
	 *
	 * @return array
	 */
	public function to_array() {
		return array(
			'slug'             => $this->slug,
			'title'            => esc_html__( 'Disable the file editor', 'defender-security' ),
			'errorReason'      => esc_html__( 'The file editor is currently enabled.', 'defender-security' ),
			'successReason'    => esc_html__( 'You\'ve disabled the file editor, winning.', 'defender-security' ),
			'misc'             => array(),
			'bulk_description' => esc_html__(
				'The file editor is currently active, this means anyone with access to your login information can further edit your plugin and theme files and inject malicious code. We will disable file editor for you.',
				'defender-security'
			),
			'bulk_title'       => esc_html__( 'File Editor', 'defender-security' ),
		);
	}
}