<?php

/**
 * Asset Loader Trait.
 *
 * Provides shared utility methods for loading Webpack assets and handling
 * merged JSON translations for React-based scripts.
 *
 * @package    Primeplaced_Logless_Analytics
 * @author     Dobrzepostawieni <contact@dobrzepostawieni.pl>
 * @copyright  2026 Dobrzepostawieni.pl
 * @license    GPL-3.0-or-later
 */
namespace Primeplaced_Logless_Analytics\Engine\Traits;

// Prevent direct file access.
if ( !defined( 'ABSPATH' ) ) {
    exit;
}
/**
 * Trait AssetLoader
 */
trait AssetLoader
{
    /**
     * Reads the .asset.php file dynamically generated by Webpack and appends cache buster.
     *
     * @param string             $asset_file_path Absolute path to the .asset.php file.
     * @param array<int, string> $default_deps    Fallback dependencies.
     * @return array{dependencies: array<int, string>, version: string} Asset configuration.
     */
    protected function get_webpack_asset_config( string $asset_file_path, array $default_deps = array('wp-element', 'wp-components', 'wp-i18n') ) : array {
        $config = array(
            'dependencies' => $default_deps,
            'version'      => ( \defined( 'PPLA_VERSION' ) ? \PPLA_VERSION : '1.0.0' ),
        );
        if ( \file_exists( $asset_file_path ) ) {
            $file_data = (require $asset_file_path);
            if ( \is_array( $file_data ) ) {
                $config['dependencies'] = $file_data['dependencies'] ?? $config['dependencies'];
                $config['version'] = (string) ($file_data['version'] ?? $config['version']);
            }
        }
        $config['version'] = $this->append_build_revision( $config['version'], $asset_file_path );
        $config['version'] = $this->append_cache_buster_suffix( $config['version'] );
        return $config;
    }

    /**
     * Appends one build-wide revision so entry assets and dynamic chunks refresh together.
     *
     * @param string $version         Original asset version.
     * @param string $asset_file_path Absolute entry asset metadata path.
     * @return string Version including the trusted build revision when present.
     */
    private function append_build_revision( string $version, string $asset_file_path ) : string {
        $asset_directory = \dirname( $asset_file_path );
        $revision_files = array($asset_directory . '/ppla-build-revision.php', \dirname( $asset_directory ) . '/ppla-build-revision.php');
        foreach ( $revision_files as $revision_file ) {
            if ( !\file_exists( $revision_file ) ) {
                continue;
            }
            $revision = (require $revision_file);
            if ( \is_string( $revision ) && 1 === \preg_match( '/^[a-f0-9]{8,64}$/', $revision ) ) {
                return $version . '-' . \substr( $revision, 0, 20 );
            }
        }
        return $version;
    }

    /**
     * Appends the package edition so a plan change also refreshes cached assets.
     *
     * @param string $version The original version string from Webpack.
     * @return string The modified version string.
     */
    private function append_cache_buster_suffix( string $version ) : string {
        $suffix = 'free';
        return $version . '-' . $suffix;
    }

    /**
     * Configures script translations and JSON merging for provided handles.
     *
     * @param string|string[] $handles Single handle or array of script handles.
     */
    protected function setup_translations( $handles ) : void {
        $handles = (array) $handles;
        $action = ( \is_admin() ? 'admin_enqueue_scripts' : 'wp_enqueue_scripts' );
        \add_action( $action, function () use($handles) : void {
            foreach ( $handles as $handle ) {
                $this->set_script_translations_for_handle( $handle );
            }
        }, 99 );
        \add_filter(
            'pre_load_script_translations',
            function (
                $translations,
                $file,
                $handle,
                $domain
            ) use($handles) {
                if ( !\in_array( $handle, $handles, true ) || \PPLA_TEXTDOMAIN !== $domain ) {
                    return $translations;
                }
                return $this->merge_json_translations_logic( $translations, $handle, $domain );
            },
            10,
            4
        );
    }

    /**
     * Binds translations to a specific script handle.
     *
     * @param string $handle The script handle.
     */
    protected function set_script_translations_for_handle( string $handle ) : void {
        \wp_set_script_translations( $handle, \PPLA_TEXTDOMAIN, \plugin_dir_path( \PPLA_PLUGIN_ABSOLUTE ) . 'languages' );
    }

    /**
     * Merges split JSON translation files generated by WP-CLI into a single translation object.
     *
     * @param string|false|null $translations The existing translations JSON string.
     * @param string            $handle       The current script handle.
     * @param string            $domain       The current text domain.
     * @return string|false|null Merged JSON string or original value on failure.
     */
    protected function merge_json_translations_logic( $translations, string $handle, string $domain ) {
        $locale = \determine_locale();
        $dir = \plugin_dir_path( \PPLA_PLUGIN_ABSOLUTE ) . 'languages';
        $files = \glob( $dir . '/' . $domain . '-' . $locale . '-*.json' );
        if ( !\is_array( $files ) || empty( $files ) ) {
            return $translations;
        }
        if ( !\class_exists( '\\WP_Filesystem_Direct' ) ) {
            require_once ABSPATH . 'wp-admin/includes/class-wp-filesystem-base.php';
            require_once ABSPATH . 'wp-admin/includes/class-wp-filesystem-direct.php';
        }
        $file_system = new \WP_Filesystem_Direct(null);
        $merged_messages = array();
        $base_data = array();
        foreach ( $files as $json_file ) {
            $data = $this->read_json_translation_file( $json_file, $file_system );
            if ( empty( $data ) ) {
                continue;
            }
            if ( empty( $base_data ) ) {
                $base_data = $data;
            }
            $merged_messages = \array_merge( $merged_messages, $data['locale_data']['messages'] );
        }
        if ( empty( $merged_messages ) ) {
            return $translations;
        }
        $base_data['locale_data']['messages'] = $merged_messages;
        $encoded = \wp_json_encode( $base_data );
        return ( false !== $encoded ? $encoded : $translations );
    }

    /**
     * Reads and decodes a local JSON translation file via WordPress Filesystem.
     *
     * @param string                $file_path   Absolute path to the JSON file.
     * @param \WP_Filesystem_Direct $file_system The filesystem instance.
     * @return array<string, mixed> Decoded JSON data or empty array on failure.
     */
    private function read_json_translation_file( string $file_path, \WP_Filesystem_Direct $file_system ) : array {
        $content = $file_system->get_contents( $file_path );
        if ( empty( $content ) || !\is_string( $content ) ) {
            return array();
        }
        $data = \json_decode( $content, true );
        if ( !\is_array( $data ) || empty( $data['locale_data']['messages'] ) ) {
            return array();
        }
        return $data;
    }

}