<?php
/**
 * File-manager copy-file ability (Feature 089).
 *
 * @license    GPL-2.0-or-later
 * @package    AcrossAI_Abilities_Manager
 * @subpackage Includes\Abilities\FileManager
 * @since      0.1.0
 */

namespace AcrossAI_Abilities_Manager\Includes\Abilities\FileManager;

use AcrossAI_Abilities_Manager\Includes\Modules\Library\Ability_Definition;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\Fs_Roots;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\File_Mods_Guard;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\Audit_Trail;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\Hardening_Enforcer;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\Path_Allowlist_Guard;
use AcrossAI_Abilities_Manager\Includes\Abilities\Utilities\Wp_Filesystem_Init;

defined( 'ABSPATH' ) || exit;

/**
 * Copy_File ability class.
 *
 * Copy a file between two paths under ABSPATH. Refuses when the destination
 * exists (unless overwrite:true). Refuses when the destination resolves to
 * wp-config.php or .htaccess at ABSPATH root even with overwrite:true.
 */
class Copy_File extends Ability_Definition {

	/**
	 * Filenames refused as destinations even when overwrite:true is set.
	 * Same list as Read_File::PROTECTED_FILES and Delete_File::PROTECTED_FILES.
	 *
	 * @var array<int,string>
	 */
	private const PROTECTED_FILES = array(
		'wp-config.php',
		'.htaccess',
	);

	/**
	 * Full ability spec for wp_register_ability().
	 *
	 * @return array
	 */
	protected function ability(): array {
		return array(
			'name' => 'file-manager/copy-file',
			'args' => array(
				'label'               => __( 'Copy File', 'acrossai-abilities-manager' ),
				'description'         => __( 'Copy a file from a source path to a destination path within the WordPress installation. Both paths must remain inside a WordPress directory (the content directory, plugins, mu-plugins, a theme root, uploads, or ABSPATH). Default refuses when the destination exists; pass overwrite:true to replace it. Refuses when the destination resolves to wp-config.php or .htaccess even with overwrite:true.', 'acrossai-abilities-manager' ),
				'category'            => 'acrossai-file-manager',
				'execute_callback'    => array( $this, 'execute' ),
				'permission_callback' => static function (): bool {
					return current_user_can( 'manage_options' );
				},
				'input_schema'        => array(
					'type'                 => 'object',
					'properties'           => array(
						'source'      => array(
							'type'        => 'string',
							'description' => __( 'Source file path relative to a WordPress directory.', 'acrossai-abilities-manager' ),
						),
						'destination' => array(
							'type'        => 'string',
							'description' => __( 'Destination file path relative to a WordPress directory.', 'acrossai-abilities-manager' ),
						),
						'overwrite'   => array(
							'type'        => 'boolean',
							'default'     => false,
							'description' => __( 'When true, an existing destination file is replaced. wp-config.php and .htaccess are still refused.', 'acrossai-abilities-manager' ),
						),
						'context'     => array(
							'type'        => 'string',
							'maxLength'   => 2000,
							'description' => __( 'Optional caller-supplied reason for this copy. Captured in the audit log. Truncated to 500 chars in the persisted entry.', 'acrossai-abilities-manager' ),
						),
					),
					'required'             => array( 'source', 'destination' ),
					'additionalProperties' => false,
				),
				'output_schema'       => array(
					'type'                 => 'object',
					'properties'           => array(
						'success'        => array( 'type' => 'boolean' ),
						'source'         => array( 'type' => 'string' ),
						'destination'    => array( 'type' => 'string' ),
						'overwritten'    => array( 'type' => 'boolean' ),
						'message'        => array( 'type' => 'string' ),
						'blocked_reason' => array( 'type' => 'string' ),
						'allowed_roots'  => array( 'type' => 'array' ),
						'path'           => array( 'type' => 'string' ),
						// Feature 093 context fields.
						'extension'      => array( 'type' => 'string' ),
						'basename'       => array( 'type' => 'string' ),
						'directive'      => array( 'type' => 'string' ),
						'input'          => array( 'type' => 'string' ),
						'sanitized'      => array( 'type' => 'string' ),
						'size'           => array( 'type' => 'integer' ),
						'max_bytes'      => array( 'type' => 'integer' ),
						'marker'         => array( 'type' => 'string' ),
						// Feature 094 audit-trail addition.
						'backup_path'    => array( 'type' => array( 'string', 'null' ) ),
					),
					'required'             => array( 'success', 'message' ),
					'additionalProperties' => false,
				),
				'meta'                => array(
					'acrossai'     => array(
						'tab_group'       => 'files',
						'sub_group'       => 'files',
						'sub_group_label' => __( 'Files', 'acrossai-abilities-manager' ),
					),
					'show_in_rest' => true,
					'mcp'          => array(
						'public' => false,
						'type'   => 'tool',
					),
					'annotations'  => array(
						'readonly'    => false,
						'destructive' => false,
						'idempotent'  => false,
					),
				),
			),
		);
	}

	/**
	 * Execute the ability.
	 *
	 * @param array $input Ability input payload.
	 * @return array
	 */
	public function execute( array $input = array() ): array {
		$blocked = File_Mods_Guard::blocked_response();
		if ( null !== $blocked ) {
			return $blocked;
		}
		$blocked = Wp_Filesystem_Init::blocked_response();
		if ( null !== $blocked ) {
			return $blocked;
		}
		$fs = Wp_Filesystem_Init::get();

		$rel_source = sanitize_text_field( $input['source'] ?? '' );
		$rel_dest   = sanitize_text_field( $input['destination'] ?? '' );
		$overwrite  = ! empty( $input['overwrite'] );

		// Feature 135: both paths resolve against every WordPress root. $base stays ABSPATH for the
		// protected-file guards below, which are about wp-config.php at the install root.
		$base = rtrim( realpath( ABSPATH ) ?: ABSPATH, '/' );

		$src_resolved = Fs_Roots::resolve( $rel_source, true );

		if ( is_wp_error( $src_resolved ) ) {
			return Fs_Roots::blocked_response( $src_resolved );
		}

		$src_real = $src_resolved['path'];

		$dest_resolved = Fs_Roots::resolve( $rel_dest );

		if ( is_wp_error( $dest_resolved ) ) {
			return Fs_Roots::blocked_response( $dest_resolved );
		}

		$dest_abs    = $dest_resolved['path'];
		$dest_parent = dirname( $dest_abs );

		if ( ! $fs->is_file( $src_real ) ) {
			return array(
				'success'        => false,
				'blocked_reason' => 'source_not_found',
				'message'        => __( 'Source file does not exist or is not a regular file.', 'acrossai-abilities-manager' ),
			);
		}

		$dest_basename = basename( $dest_abs );
		if ( in_array( $dest_basename, self::PROTECTED_FILES, true ) && $dest_parent === $base ) {
			return array(
				'success'        => false,
				'blocked_reason' => 'protected_write',
				/* translators: %s: filename */
				'message'        => sprintf( __( 'File "%s" is protected and cannot be written.', 'acrossai-abilities-manager' ), $dest_basename ),
			);
		}

		$overwritten = false;
		if ( $fs->exists( $dest_abs ) ) {
			if ( ! $overwrite ) {
				return array(
					'success'        => false,
					'blocked_reason' => 'destination_exists',
					'message'        => __( 'Destination already exists. Pass overwrite:true to replace it.', 'acrossai-abilities-manager' ),
				);
			}
			$overwritten = true;
		}

		// Feature 092: admin-controlled write allowlist gate — both endpoints.
		$blocked = Path_Allowlist_Guard::blocked_write_response( $src_real );
		if ( null !== $blocked ) {
			return $blocked;
		}
		$blocked = Path_Allowlist_Guard::blocked_write_response( $dest_abs );
		if ( null !== $blocked ) {
			return $blocked;
		}

		// Feature 093: content-filter enforcement — apply checks to the
		// DESTINATION basename (spec User Story 4). Pass a lazy content reader
		// so the htaccess-directive scanner only reads the source file when
		// the target is actually .htaccess; source_size backs the write cap.
		$blocked = Hardening_Enforcer::check_write(
			$src_real,
			'',
			array(
				'mode'                     => 'copy',
				'target_basename_override' => basename( $dest_abs ),
				'source_size'              => (int) $fs->size( $src_real ),
				'source_content_reader'    => static function () use ( $fs, $src_real ) {
					$bytes = $fs->get_contents( $src_real );
					return is_string( $bytes ) ? $bytes : '';
				},
			)
		);
		if ( null !== $blocked ) {
			return $blocked;
		}

		// Feature 094: pre-image backup captures the destination's PRIOR
		// content (only when overwriting an existing file); source is not
		// touched by copy.
		$dest_existed  = $fs->exists( $dest_abs );
		$size_before   = $dest_existed ? (int) $fs->size( $dest_abs ) : null;
		$backup_result = $dest_existed ? Audit_Trail::write_backup( $dest_abs ) : null;
		$backup_path   = is_string( $backup_result ) ? $backup_result : null;
		$backup_status = is_string( $backup_result )
			? 'written'
			: ( false === $backup_result ? 'failed' : ( $dest_existed ? 'disabled' : 'skipped' ) );

		if ( ! $fs->copy( $src_real, $dest_abs, $overwrite, FS_CHMOD_FILE ) ) {
			Audit_Trail::write_log(
				'COPY',
				$src_real,
				array(
					'ability_slug'  => 'file-manager/copy-file',
					'size_before'   => $size_before,
					'size_after'    => null,
					'destination'   => $dest_abs,
					'backup_status' => $backup_status,
					'backup_path'   => $backup_path,
					'backup_reason' => 'primary copy failed',
					'context'       => (string) ( $input['context'] ?? '' ),
				)
			);
			return array(
				'success'     => false,
				'message'     => __( 'Could not copy file.', 'acrossai-abilities-manager' ),
				'backup_path' => $backup_path,
			);
		}

		$dest_final = realpath( $dest_abs ) ?: $dest_abs;

		Audit_Trail::write_log(
			'COPY',
			$src_real,
			array(
				'ability_slug'  => 'file-manager/copy-file',
				'size_before'   => $size_before,
				'size_after'    => (int) $fs->size( $dest_final ),
				'destination'   => $dest_final,
				'backup_status' => $backup_status,
				'backup_path'   => $backup_path,
				'backup_reason' => ( 'skipped' === $backup_status ) ? 'destination did not exist' : '',
				'context'       => (string) ( $input['context'] ?? '' ),
			)
		);

		return array(
			'success'     => true,
			'source'      => $src_real,
			'destination' => $dest_final,
			'overwritten' => $overwritten,
			'message'     => $overwritten
				? __( 'File copied (destination replaced).', 'acrossai-abilities-manager' )
				: __( 'File copied.', 'acrossai-abilities-manager' ),
			'backup_path' => $backup_path,
		);
	}
}