<?php
/**
 * OpenStation — upload REST intake.
 *
 * One route:
 *
 *   POST /desktop-mode/v1/files/uploads
 *       multipart/form-data with ONE file part (`file`) plus:
 *       `parentId`     target folder id (0 = desktop root)
 *       `relativePath` optional `a/b/c.txt`-style path from a
 *                      folder-tree upload; the server resolves the
 *                      directory segments to folder rows mkdir-p
 *                      style (deduped by parent + name)
 *       `x`, `y`       optional tile coordinates (root drops)
 *
 * One file per request on purpose: per-file retry, per-file
 * progress, and no interaction with `max_file_uploads` /
 * `post_max_size` aggregates. Internally the handler is split into
 * receive (bytes → disk) and register (row + placement) so a future
 * resumable-upload layer can feed the same register step.
 *
 * @package OpenStation
 */

defined( 'ABSPATH' ) || exit;

/**
 * Extensions that must never be accepted regardless of the MIME
 * policy — server- or config-executable files. Matched against
 * EVERY dot-segment of the client filename (`shell.php.gif` is
 * rejected even though its final extension is fine), per the
 * OWASP double-extension guidance. Belt and suspenders: the WP
 * MIME policy would reject most of these anyway, and the stored
 * disk name is an extensionless UUID that no handler dispatches.
 *
 * @return string[]
 */
function openstation_stored_files_denied_extensions() {
	$denied = array(
		'php',
		'php3',
		'php4',
		'php5',
		'php7',
		'php8',
		'phtml',
		'phar',
		'pht',
		'phps',
		'cgi',
		'pl',
		'asp',
		'aspx',
		'jsp',
		'shtml',
	);
	/**
	 * Filters the hard-denied extension list. Narrowing this below
	 * the shipped set is strongly discouraged.
	 *
	 * @param string[] $denied Lowercase extensions.
	 */
	return (array) apply_filters( 'openstation_stored_files_denied_extensions', $denied );
}

/**
 * Whole-filename denylist (dotfiles / server config).
 *
 * @param string $name Client filename.
 * @return bool True when the name is forbidden.
 */
function openstation_stored_files_is_denied_filename( $name ) {
	$name = strtolower( trim( (string) $name ) );
	if ( in_array( $name, array( '.htaccess', '.user.ini', 'web.config' ), true ) ) {
		return true;
	}
	$segments = explode( '.', $name );
	array_shift( $segments ); // Everything after the first dot is an "extension" segment.
	$denied = openstation_stored_files_denied_extensions();
	foreach ( $segments as $segment ) {
		if ( in_array( $segment, $denied, true ) ) {
			return true;
		}
	}
	return false;
}

/**
 * Effective per-file size cap in bytes.
 *
 * @param int $user_id User.
 * @return int
 */
function openstation_stored_files_max_upload_bytes( $user_id ) {
	$max = (int) wp_max_upload_size();
	/**
	 * Filters the per-file upload cap for desktop storage. May only
	 * effectively lower it below the server limits — PHP discards
	 * larger bodies before WordPress runs.
	 *
	 * @param int $max     Cap in bytes. Default `wp_max_upload_size()`.
	 * @param int $user_id User.
	 */
	return max( 0, (int) apply_filters( 'openstation_stored_files_max_upload_bytes', $max, (int) $user_id ) );
}

/**
 * Permission: base files gate + the upload capability.
 */
function openstation_files_rest_uploads_permission() {
	$base = openstation_files_rest_permission();
	if ( is_wp_error( $base ) ) {
		return $base;
	}
	if ( ! current_user_can( openstation_stored_files_upload_capability() ) ) {
		return new WP_Error(
			'openstation_stored_files_cannot_upload',
			__( 'You are not allowed to upload files.', 'desktop-mode' ),
			array( 'status' => 403 )
		);
	}
	return true;
}

/**
 * Register the upload route.
 */
function openstation_files_register_upload_rest_routes() {
	register_rest_route(
		'desktop-mode/v1',
		'/files/uploads',
		array(
			// POST only — PHP parses multipart into $_FILES for real
			// POST requests exclusively.
			'methods'             => WP_REST_Server::CREATABLE,
			'permission_callback' => 'openstation_files_rest_uploads_permission',
			'callback'            => 'openstation_files_rest_upload',
			'args'                => array(
				'parentId'     => array(
					'type'              => 'integer',
					'default'           => 0,
					'sanitize_callback' => 'absint',
				),
				'relativePath' => array(
					'type'    => 'string',
					'default' => '',
				),
				// No defaults on x/y on purpose: absent coords mean
				// "server picks the next free grid slot".
				'x'            => array(
					'type'     => 'integer',
					'required' => false,
				),
				'y'            => array(
					'type'     => 'integer',
					'required' => false,
				),
			),
		)
	);

	register_rest_route(
		'desktop-mode/v1',
		'/files/uploads/paths',
		array(
			'methods'             => WP_REST_Server::CREATABLE,
			'permission_callback' => 'openstation_files_rest_uploads_permission',
			'callback'            => 'openstation_files_rest_ensure_upload_path',
			'args'                => array(
				'parentId'     => array(
					'type'              => 'integer',
					'default'           => 0,
					'sanitize_callback' => 'absint',
				),
				'relativePath' => array(
					'type'     => 'string',
					'required' => true,
				),
			),
		)
	);

	register_rest_route(
		'desktop-mode/v1',
		'/files/uploads/(?P<id>\d+)',
		array(
			'methods'             => WP_REST_Server::EDITABLE,
			'permission_callback' => 'openstation_files_rest_permission',
			'callback'            => 'openstation_files_rest_rename_upload',
			'args'                => array(
				'name' => array(
					'type'     => 'string',
					'required' => true,
				),
			),
		)
	);
}

/**
 * POST /files/uploads/paths — mkdir-p a directory path with no
 * file attached. Used by folder-tree drops to preserve EMPTY
 * directories (the drag-drop Entries API sees them; files-only
 * transports lose them).
 *
 * @param WP_REST_Request $req Request.
 * @return WP_REST_Response|WP_Error
 */
function openstation_files_rest_ensure_upload_path( WP_REST_Request $req ) {
	$rel = (string) $req->get_param( 'relativePath' );
	if ( '' === trim( $rel, " \t/" ) ) {
		return new WP_Error( 'openstation_stored_files_bad_path', __( 'Invalid path.', 'desktop-mode' ), array( 'status' => 400 ) );
	}
	if ( '/' !== substr( $rel, -1 ) ) {
		$rel .= '/'; // Whole string is a directory path.
	}
	$folder_id = openstation_files_resolve_relative_path(
		get_current_user_id(),
		(int) $req->get_param( 'parentId' ),
		$rel
	);
	if ( is_wp_error( $folder_id ) ) {
		return $folder_id;
	}
	return rest_ensure_response( array( 'folderId' => (int) $folder_id ) );
}

/**
 * PATCH /files/uploads/<id> — rename (owner only). Not-found and
 * not-owner are both 404 (existence masking, same as downloads).
 *
 * @param WP_REST_Request $req Request.
 * @return WP_REST_Response|WP_Error
 */
function openstation_files_rest_rename_upload( WP_REST_Request $req ) {
	$file_id = (int) $req['id'];
	$user_id = get_current_user_id();
	$row     = openstation_stored_files_get( $file_id );
	if ( ! $row || (int) $row['owner_id'] !== $user_id ) {
		return openstation_files_download_not_found();
	}
	$ok = openstation_stored_files_rename( $file_id, (string) $req->get_param( 'name' ) );
	if ( is_wp_error( $ok ) ) {
		return $ok;
	}
	$row = openstation_stored_files_get( $file_id );
	return rest_ensure_response(
		array(
			'id'        => (int) $row['id'],
			'name'      => (string) $row['display_name'],
			'sizeBytes' => (int) $row['size_bytes'],
			'mime'      => (string) $row['mime'],
		)
	);
}
add_action( 'rest_api_init', 'openstation_files_register_upload_rest_routes' );

/**
 * POST /files/uploads
 *
 * @param WP_REST_Request $req Request.
 * @return WP_REST_Response|WP_Error
 */
function openstation_files_rest_upload( WP_REST_Request $req ) {
	$user_id = get_current_user_id();
	$files   = $req->get_file_params();

	// A body larger than `post_max_size` reaches PHP as a paramless
	// request: $_POST and $_FILES both empty while CONTENT_LENGTH
	// says bytes were sent. Answer a clear 413 instead of the
	// baffling "missing parameter" default.
	if ( empty( $files ) ) {
		$content_length = isset( $_SERVER['CONTENT_LENGTH'] ) ? (int) $_SERVER['CONTENT_LENGTH'] : 0;
		if ( $content_length > 0 ) {
			return new WP_Error(
				'openstation_stored_files_too_large',
				__( 'That file is larger than this server accepts.', 'desktop-mode' ),
				array( 'status' => 413 )
			);
		}
		return new WP_Error(
			'openstation_stored_files_no_file',
			__( 'No file was uploaded.', 'desktop-mode' ),
			array( 'status' => 400 )
		);
	}
	if ( empty( $files['file'] ) || ! is_array( $files['file'] ) ) {
		return new WP_Error(
			'openstation_stored_files_no_file',
			__( 'No file was uploaded.', 'desktop-mode' ),
			array( 'status' => 400 )
		);
	}

	$received = openstation_files_upload_receive( $files['file'], $user_id );
	if ( is_wp_error( $received ) ) {
		return $received;
	}

	$x      = $req->get_param( 'x' );
	$y      = $req->get_param( 'y' );
	$coords = ( null !== $x && null !== $y )
		? array(
			'x' => (int) $x,
			'y' => (int) $y,
		)
		: null;

	$registered = openstation_files_upload_register(
		$user_id,
		$received,
		(int) $req->get_param( 'parentId' ),
		(string) $req->get_param( 'relativePath' ),
		$coords
	);
	if ( is_wp_error( $registered ) ) {
		// Bytes are already on disk; don't leak them.
		if ( ! empty( $received['path'] ) && file_exists( $received['path'] ) ) {
			wp_delete_file( $received['path'] );
		}
		return $registered;
	}

	$row = openstation_files_get_placement( $registered['placement_id'] );
	return rest_ensure_response(
		array(
			'placement'    => openstation_files_shape_placement( $row ),
			'storedFileId' => (int) $registered['file_id'],
		)
	);
}

/**
 * Receive step: validate and move the bytes into the owner's
 * storage dir under a fresh UUID disk name. Returns
 * `{ path, disk_name, display_name, size_bytes, mime }` or an
 * error. No DB writes happen here.
 *
 * @internal
 *
 * @param array $file    Single `$_FILES`-shaped entry.
 * @param int   $user_id Uploader.
 * @return array|WP_Error
 */
function openstation_files_upload_receive( $file, $user_id ) {
	$user_id     = (int) $user_id;
	$client_name = isset( $file['name'] ) ? (string) $file['name'] : '';

	if ( openstation_stored_files_is_denied_filename( $client_name ) ) {
		return new WP_Error(
			'openstation_stored_files_forbidden_type',
			__( 'This file type is not allowed.', 'desktop-mode' ),
			array( 'status' => 400 )
		);
	}

	$size = isset( $file['size'] ) ? (int) $file['size'] : 0;
	$max  = openstation_stored_files_max_upload_bytes( $user_id );
	if ( $max > 0 && $size > $max ) {
		return new WP_Error(
			'openstation_stored_files_too_large',
			sprintf(
				/* translators: %s: formatted maximum file size. */
				__( 'That file is larger than the allowed maximum of %s.', 'desktop-mode' ),
				size_format( $max )
			),
			array( 'status' => 413 )
		);
	}

	$quota = openstation_stored_files_user_quota_bytes( $user_id );
	if ( $quota > 0 && ( openstation_stored_files_total_bytes( $user_id ) + $size ) > $quota ) {
		return new WP_Error(
			'openstation_stored_files_quota_exceeded',
			__( 'Your desktop storage is full.', 'desktop-mode' ),
			array( 'status' => 403 )
		);
	}

	$dir = openstation_stored_files_ensure_dir( $user_id );
	if ( is_wp_error( $dir ) ) {
		return $dir;
	}

	require_once ABSPATH . 'wp-admin/includes/file.php';

	/**
	 * Filters the `ext => mime` allowlist for desktop-storage
	 * uploads. Defaults to the user-scoped WordPress policy.
	 * Additions here genuinely widen the policy (the scoped
	 * `upload_mimes` hook below keeps core's re-check in
	 * `wp_check_filetype_and_ext()` in agreement).
	 *
	 * @param array<string,string> $mimes   Allowed map.
	 * @param int                  $user_id Uploader.
	 */
	$mimes = (array) apply_filters(
		'openstation_stored_files_allowed_mimes',
		get_allowed_mime_types( $user_id ),
		$user_id
	);

	$disk_name   = wp_generate_uuid4();
	$scoped_mime = static function () use ( $mimes ) {
		return $mimes;
	};
	$name_cb     = static function ( $dir_unused, $name_unused, $ext_unused ) use ( $disk_name ) {
		return $disk_name;
	};
	// Resolve the target paths BEFORE hooking `upload_dir` and close
	// over plain strings — `openstation_stored_files_dir()` calls
	// `wp_get_upload_dir()`, which applies the `upload_dir` filter,
	// so calling it from inside the closure would recurse infinitely.
	$target_base = openstation_stored_files_dir();
	$target_dir  = openstation_stored_files_dir( $user_id );
	$redirect    = static function ( $dirs ) use ( $user_id, $target_base, $target_dir ) {
		$dirs['subdir']  = '/' . $user_id;
		$dirs['path']    = $target_dir;
		$dirs['url']     = $dirs['baseurl'] . '/desktop-mode-files/' . $user_id;
		$dirs['basedir'] = $target_base;
		$dirs['baseurl'] = $dirs['baseurl'] . '/desktop-mode-files';
		return $dirs;
	};

	/**
	 * Filters the `wp_handle_upload()` overrides for desktop-storage
	 * uploads. Exists mainly so tests (and future resumable layers
	 * feeding pre-staged files) can switch `action` to the sideload
	 * variant — never remove `test_form => false`.
	 *
	 * @param array $overrides Overrides array.
	 * @param int   $user_id   Uploader.
	 */
	$overrides = (array) apply_filters(
		'openstation_stored_files_upload_overrides',
		array(
			'test_form'                => false,
			'mimes'                    => $mimes,
			'unique_filename_callback' => $name_cb,
		),
		$user_id
	);

	add_filter( 'upload_dir', $redirect );
	add_filter( 'upload_mimes', $scoped_mime );
	$result = wp_handle_upload( $file, $overrides );
	remove_filter( 'upload_mimes', $scoped_mime );
	remove_filter( 'upload_dir', $redirect );

	if ( isset( $result['error'] ) ) {
		return new WP_Error(
			'openstation_stored_files_upload_failed',
			(string) $result['error'],
			array( 'status' => 400 )
		);
	}

	$path = (string) $result['file'];
	return array(
		'path'         => $path,
		'disk_name'    => $disk_name,
		'display_name' => sanitize_file_name( $client_name ),
		'size_bytes'   => (int) @filesize( $path ),
		'mime'         => (string) $result['type'],
	);
}

/**
 * Register step: stored-file row + folder resolution + placement.
 *
 * @internal
 *
 * @param int        $user_id       Uploader.
 * @param array      $received      Return value of the receive step.
 * @param int        $parent_id     Base target folder (0 = root).
 * @param string     $relative_path Optional `a/b/c.ext` path; directory
 *                                  segments are resolved under `$parent_id`.
 * @param array|null $coords        `x`, `y` for the placement, or null
 *                                  to auto-place at the next free slot.
 * @return array|WP_Error `{ file_id, placement_id }`.
 */
function openstation_files_upload_register( $user_id, $received, $parent_id, $relative_path = '', $coords = null ) {
	$parent_id = max( 0, (int) $parent_id );

	if ( '' !== (string) $relative_path ) {
		$resolved = openstation_files_resolve_relative_path( (int) $user_id, $parent_id, (string) $relative_path );
		if ( is_wp_error( $resolved ) ) {
			return $resolved;
		}
		$parent_id = $resolved;
	}

	$file_id = openstation_stored_files_create(
		(int) $user_id,
		array(
			'display_name' => $received['display_name'],
			'disk_name'    => $received['disk_name'],
			'size_bytes'   => $received['size_bytes'],
			'mime'         => $received['mime'],
		)
	);
	if ( is_wp_error( $file_id ) ) {
		return $file_id;
	}

	if ( is_array( $coords ) && isset( $coords['x'], $coords['y'] ) ) {
		$placement_id = openstation_files_place(
			(int) $user_id,
			$parent_id,
			'upload',
			(string) $file_id,
			array(
				'x' => (int) $coords['x'],
				'y' => (int) $coords['y'],
			)
		);
	} else {
		// No coords sent (folder-tree members, batch files after
		// the first) — the server picks the next free grid slot so
		// tiles never stack at the origin.
		$placement_id = openstation_files_place_at_next_free_slot(
			(int) $user_id,
			$parent_id,
			'upload',
			(string) $file_id
		);
	}
	if ( is_wp_error( $placement_id ) ) {
		// Roll back through the store primitive so the documented
		// `openstation_stored_file_created` / `_deleted` action pair
		// stays balanced for subscribers (and the bytes go with the
		// row — the caller's outer cleanup guard becomes a no-op).
		openstation_stored_files_delete( (int) $file_id );
		return $placement_id;
	}

	/**
	 * Fires after an upload lands (bytes, row, and placement all
	 * exist).
	 *
	 * @param int $file_id      Stored-file id.
	 * @param int $placement_id Placement id.
	 * @param int $user_id      Uploader.
	 */
	do_action( 'openstation_stored_file_uploaded', (int) $file_id, (int) $placement_id, (int) $user_id );

	return array(
		'file_id'      => (int) $file_id,
		'placement_id' => (int) $placement_id,
	);
}

/**
 * Resolve the DIRECTORY part of `a/b/c.ext` to a folder id under
 * `$base_parent_id`, creating folder rows + placements mkdir-p
 * style. Existing folders are reused when the acting user already
 * has a live folder of that name in that parent (dedupe — parallel
 * uploads of one tree share segments instead of racing).
 *
 * The final path segment is the FILE name and is ignored here.
 *
 * @param int    $user_id        Acting user.
 * @param int    $base_parent_id Folder to resolve under (0 = root).
 * @param string $relative_path  `a/b/c.ext` or `a/b/` (trailing
 *                               slash = pure directory path, e.g.
 *                               an empty folder from a drag).
 * @return int|WP_Error Folder id to place the file in.
 */
function openstation_files_resolve_relative_path( $user_id, $base_parent_id, $relative_path ) {
	global $wpdb;
	$user_id   = (int) $user_id;
	$parent_id = max( 0, (int) $base_parent_id );
	$path      = str_replace( '\\', '/', (string) $relative_path );

	if ( false !== strpos( $path, "\0" ) ) {
		return new WP_Error( 'openstation_stored_files_bad_path', __( 'Invalid path.', 'desktop-mode' ), array( 'status' => 400 ) );
	}

	$is_dir_path = '/' === substr( $path, -1 );
	$segments    = array_values( array_filter( explode( '/', $path ), 'strlen' ) );
	if ( ! $is_dir_path ) {
		array_pop( $segments ); // Last segment is the file name.
	}
	if ( empty( $segments ) ) {
		return $parent_id;
	}
	if ( count( $segments ) > 32 ) {
		return new WP_Error( 'openstation_stored_files_path_too_deep', __( 'That folder tree is nested too deeply.', 'desktop-mode' ), array( 'status' => 400 ) );
	}

	$tables = openstation_files_table_names();
	foreach ( $segments as $segment ) {
		if ( '.' === $segment || '..' === $segment ) {
			return new WP_Error( 'openstation_stored_files_bad_path', __( 'Invalid path.', 'desktop-mode' ), array( 'status' => 400 ) );
		}
		$name = sanitize_file_name( wp_strip_all_tags( $segment ) );
		if ( '' === $name ) {
			return new WP_Error( 'openstation_stored_files_bad_path', __( 'Invalid path.', 'desktop-mode' ), array( 'status' => 400 ) );
		}

		// Dedupe: a live folder of this name, placed in this parent,
		// owned by the acting user.
		$existing = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT f.id FROM {$tables['folders']} f
				INNER JOIN {$tables['placements']} p
					ON p.file_type = 'folder'
					AND p.file_ref = CAST( f.id AS CHAR )
					AND p.trashed_at_ms IS NULL
				WHERE p.parent_id = %d
					AND p.owner_id = %d
					AND f.owner_id = %d
					AND f.trashed_at_ms IS NULL
					AND f.name = %s
				LIMIT 1",
				$parent_id,
				$user_id,
				$user_id,
				$name
			)
		);
		if ( $existing ) {
			$parent_id = (int) $existing;
			continue;
		}

		$folder_id = openstation_files_create_folder( $user_id, array( 'name' => $name ) );
		if ( is_wp_error( $folder_id ) ) {
			return $folder_id;
		}
		$placement = openstation_files_place( $user_id, $parent_id, 'folder', (string) $folder_id );
		if ( is_wp_error( $placement ) ) {
			return $placement;
		}
		$parent_id = (int) $folder_id;
	}
	return $parent_id;
}

/**
 * Shell-config injection: what the client upload/download UX needs
 * to know up front.
 *
 * @param array $config Shell config.
 * @return array
 */
function openstation_stored_files_inject_shell_config( $config ) {
	$user_id                  = get_current_user_id();
	$config['desktopStorage'] = array(
		'canUpload'    => $user_id > 0 && current_user_can( openstation_stored_files_upload_capability() ),
		'maxBytes'     => openstation_stored_files_max_upload_bytes( $user_id ),
		'quotaBytes'   => openstation_stored_files_user_quota_bytes( $user_id ),
		'zipAvailable' => class_exists( 'ZipArchive' ),
	);
	return $config;
}
add_filter( 'openstation_shell_config', 'openstation_stored_files_inject_shell_config', 20 );