<?php
namespace CustomFields;
defined( 'ABSPATH' ) || exit;

/** Download/CLI portability and bounded read-only local imports. */
final class Portability {
    public static function boot() {
        if ( defined( 'WP_CLI' ) && WP_CLI ) { \WP_CLI::add_command( 'customfields schema', array( __CLASS__, 'cli' ) ); }
    }

    /** Compatibility callback: schema saves no longer write to configured directories. */
    public static function export_local( $groups ) {}

    /** Resolve an existing absolute local path without following any symlink component. */
    public static function local_path( $path, $directory = false ) {
        if ( ! is_string( $path ) || strpos( $path, "\0" ) !== false || ! preg_match( '~^(?:/|[A-Za-z]:[\\\\/])~', $path ) ) {
            return new \WP_Error( 'customfields_local_path', __( 'Choose an existing absolute local path without links.', 'customfields-com' ) );
        }
        $normalized = rtrim( wp_normalize_path( $path ), '/' );
        if ( $normalized === '' ) { $normalized = '/'; }
        if ( preg_match( '~(?:^|/)\.\.?(?:/|$)~', $normalized ) || strpos( $normalized, '//' ) !== false ) {
            return new \WP_Error( 'customfields_local_path', __( 'Local paths cannot contain traversal or network paths.', 'customfields-com' ) );
        }
        $component = $normalized;
        do {
            clearstatcache( true, $component );
            if ( is_link( $component ) ) { return new \WP_Error( 'customfields_local_path', __( 'Local paths cannot contain symbolic links.', 'customfields-com' ) ); }
            $parent = wp_normalize_path( dirname( $component ) );
            if ( $parent === $component ) { break; }
            $component = $parent;
        } while ( $component !== '.' );
        $real = realpath( $normalized );
        if ( ! $real || wp_normalize_path( $real ) !== $normalized || ! is_readable( $real ) || ( $directory ? ! is_dir( $real ) : ! is_file( $real ) ) ) {
            return new \WP_Error( 'customfields_local_path', __( 'The local path is unavailable or is not a readable regular file or directory.', 'customfields-com' ) );
        }
        return $real;
    }

    /** Read one bounded snapshot; never open a write stream or create a sidecar file. */
    public static function read_local( $path ) {
        $real = self::local_path( $path );
        if ( is_wp_error( $real ) ) { return $real; }
        $before = @lstat( $real );
        $stream = @fopen( $real, 'rb' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen -- Read-only, symlink-resistant local import; native stream identity and byte bounds protect the reviewed snapshot.
        if ( ! $stream ) { return new \WP_Error( 'customfields_local_read', __( 'Cannot read the local schema file.', 'customfields-com' ) ); }
        try {
            $opened = fstat( $stream );
            if ( ! $before || ! $opened || ( $opened['mode'] & 0170000 ) !== 0100000 || $before['dev'] !== $opened['dev'] || $before['ino'] !== $opened['ino'] || $opened['size'] > Schema::MAX_BYTES ) {
                return new \WP_Error( 'customfields_local_read', __( 'The schema must be an unchanged regular file of at most 1 MB.', 'customfields-com' ) );
            }
            $json = stream_get_contents( $stream, Schema::MAX_BYTES + 1 );
            clearstatcache( true, $real );
            $resolved = self::local_path( $path );
            $after = is_wp_error( $resolved ) ? false : @lstat( $resolved );
            if ( ! is_string( $json ) || strlen( $json ) > Schema::MAX_BYTES || ! $after || $resolved !== $real || $opened['dev'] !== $after['dev'] || $opened['ino'] !== $after['ino'] || $opened['size'] !== $after['size'] || $opened['mtime'] !== $after['mtime'] || $opened['ctime'] !== $after['ctime'] ) {
                return new \WP_Error( 'customfields_local_read', __( 'The schema file changed while reading or exceeds the 1 MB limit. Read it again.', 'customfields-com' ) );
            }
            return $json;
        } finally {
            fclose( $stream ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Close the bounded read-only local import stream.
        }
    }
    /**
     * Export, check or import a complete schema snapshot.
     *
     * ## OPTIONS
     * <operation>
     * : export, check, or import.
     * [<file>]
     * : Local JSON path, required for check/import.
     * [--apply]
     * : Apply a validated import; otherwise only inspect.
     * [--expected-hash=<hash>]
     * : Require the current schema SHA-256 when applying.
     */
    public static function cli( $args, $assoc ) {
        $operation = $args[0] ?? ''; $groups = customfields_get_groups();
        $hash = hash( 'sha256', Schema::encode( $groups ) );
        if ( 'export' === $operation ) { \WP_CLI::line( Schema::encode( $groups ) ); return; }
        if ( ! in_array( $operation, array( 'check', 'import' ), true ) || empty( $args[1] ) ) { \WP_CLI::error( 'Use export, check <local-file>, or import <local-file>. Files must be readable JSON under 1 MB.' ); }
        // CLI paths may be relative to the operator's working directory; the reader still rejects links.
        $path = preg_match( '~^(?:/|[A-Za-z]:[\\\\/])~', $args[1] ) ? $args[1] : getcwd() . '/' . $args[1];
        $json = self::read_local( $path );
        if ( is_wp_error( $json ) ) { \WP_CLI::error( $json->get_error_message() ); }
        $incoming = Schema::decode( $json );
        if ( is_wp_error( $incoming ) ) { \WP_CLI::error( $incoming->get_error_message() ); }
        \WP_CLI::line( 'Current schema hash: ' . $hash );
        \WP_CLI::line( 'Validated groups: ' . count( $incoming ) . '. Import replaces definitions only; content is unchanged.' );
        if ( 'import' !== $operation || ! isset( $assoc['apply'] ) ) { return; }
        if ( ! current_user_can( 'manage_options' ) ) { \WP_CLI::error( 'Use --user=<administrator> to apply schema changes.' ); }
        if ( empty( $assoc['expected-hash'] ) || ! hash_equals( $hash, (string) $assoc['expected-hash'] ) ) { \WP_CLI::error( 'Review the schema and pass the matching --expected-hash before applying.' ); }
        update_option( 'customfields_groups', $incoming, false );
        do_action( 'customfields_schema_saved', $incoming, $groups );
        \WP_CLI::success( 'Schema imported. Existing values were preserved.' );
    }
}