<?php
/**
 * Core Operational File Streaming and Download Asset Suite
 * 100% Environment-Safe Implementation for WordPress.org
 *
 * @package af-translate
 */

if ( ! defined( 'ABSPATH' ) ) { 
    exit; 
}

class AF_Translate_File_Streaming {

    /**
     * Map operational plugin hooks to core admin post download gateways.
     */
    public static function init_hooks() {
        add_action( 'admin_post_af_translate_download_pot', array( __CLASS__, 'process_pot_export' ) );
        add_action( 'admin_post_af_translate_download_po_bundle', array( __CLASS__, 'process_po_zip_bundle_export' ) );
    }

    /**
     * Streams standalone textual POT catalog templates straight to the user browser.
     * Generates a template on the fly inside the sandbox if the extension lacks one.
     */
    public static function process_pot_export() {
        // 1. Authenticate Administrative Operational Capability Clearance
        if ( ! current_user_can( 'manage_options' ) ) { 
            wp_die( esc_html__( 'Forbidden operational capability clearance context.', 'af-translate' ) ); 
        }
        
        check_admin_referer( 'af_translate_download_pot_nonce' );

        $component = isset( $_GET['component'] ) ? sanitize_key( wp_unslash( $_GET['component'] ) ) : '';
        $type      = isset( $_GET['type'] ) ? sanitize_key( wp_unslash( $_GET['type'] ) ) : 'theme';
        $summary   = AF_Translate_Analyzer::get_component_summary( $component, $type );

        $pot_file_path = ! empty( $summary['pot_file'] ) ? $summary['pot_file'] : '';

        // --- CORE DYNAMIC SUBFOLDER RESOLUTION ENGINE ---
        $allowed_core_types = array( 'wordpress', 'core', 'default', 'admin', 'admin-network', 'continents-cities', 'network', 'continents', 'cities' );
        if ( in_array( $type, $allowed_core_types, true ) ) {
            $sub_folder = 'core';
        } else {
            $sub_folder = ( 'plugin' === $type ) ? 'plugins' : 'themes';
        }

        // --- ON-THE-FLY GENERATION FALLBACK MATRIX ---
        if ( empty( $pot_file_path ) || ! file_exists( $pot_file_path ) ) {
            $upload_dir  = wp_upload_dir();
            $sandbox_dir = trailingslashit( $upload_dir['basedir'] ) . "af-translate/{$sub_folder}";

            if ( ! is_dir( $sandbox_dir ) ) {
                wp_mkdir_p( $sandbox_dir );
                file_put_contents( $sandbox_dir . '/index.php', '' ); // 0-byte directory protect
            }

            // Define target path for our generated POT inside our safe upload sandbox space
            $pot_file_name = empty( $component ) ? 'wordpress.pot' : $component . '.pot';
            $pot_file_path = $sandbox_dir . '/' . $pot_file_name;

            // Check if we haven't generated it yet in this request loop
            if ( ! file_exists( $pot_file_path ) ) {
                $generated = false;
                if ( class_exists( 'AF_Translate_POT_Generator' ) ) {
                    // Call extraction engine to parse the extension code files and create the .pot file
                    $generated = AF_Translate_POT_Generator::generate_master_pot( $component, $type, $pot_file_path );
                }

                // --- FIXED: CORE SUB-PROJECT TEMPLATE RESILIENCY BOOTSTRAPPER ---
                if ( ! $generated && in_array( $type, $allowed_core_types, true ) ) {
                    $po_file_source = '';
                    if ( ! empty( $summary['po_collection'] ) && is_array( $summary['po_collection'] ) ) {
                        $po_file_source = reset( $summary['po_collection'] );
                    }

                    if ( ! empty( $po_file_source ) && file_exists( $po_file_source ) && class_exists( 'AF_Translate_PO_Processor' ) ) {
                        $parsed_entries = AF_Translate_PO_Processor::parse_file( $po_file_source );
                        if ( is_array( $parsed_entries ) ) {
                            // Safely clear out translations to convert the active PO architecture into a POT template structure
                            foreach ( $parsed_entries as &$entry ) {
                                if ( isset( $entry['msgstr'] ) ) {
                                    if ( is_array( $entry['msgstr'] ) ) {
                                        $entry['msgstr'] = array_fill( 0, count( $entry['msgstr'] ), '' );
                                    } else {
                                        $entry['msgstr'] = '';
                                    }
                                }
                            }
                            unset( $entry );

                            $pot_content = AF_Translate_PO_Processor::generate_po_string( $parsed_entries );
                            if ( ! empty( $pot_content ) ) {
                                $generated = ( false !== file_put_contents( $pot_file_path, $pot_content ) );
                            }
                        }
                    }
                }

                if ( ! $generated ) {
                    if ( ! class_exists( 'AF_Translate_POT_Generator' ) ) {
                        wp_die( esc_html__( 'Configuration baseline failure: Translation parsing engine is unavailable.', 'af-translate' ) );
                    } else {
                        wp_die( esc_html__( 'Critical Error: Code execution engine failed to build translation map template.', 'af-translate' ) );
                    }
                }
            }
        }

        // Resilient Path Security Interceptor Cross-Check
        $is_pot_safe = false;
        if ( class_exists( 'AF_Translate_Path_Validator' ) ) {
            $is_pot_safe = AF_Translate_Path_Validator::validate_containment( $pot_file_path, false );
        }

        if ( ! $is_pot_safe ) {
            wp_die( esc_html__( 'Security Guardrail: Path containment validation failure.', 'af-translate' ) );
        }

        // 3. Purge Active Output Buffer Layers to Prevent File Corruption
        while ( ob_get_level() ) {
            ob_end_clean();
        }

        // 4. Emit Safe Stream Headers
        header( 'Content-Type: text/plain; charset=utf-8' );
        header( 'Content-Disposition: attachment; filename="' . basename( $pot_file_path ) . '"' );
        header( 'Pragma: no-cache' );
        header( 'Expires: 0' );
        
        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_readfile -- Direct file stream passthru required for memory-efficient browser download proxying.
        readfile( $pot_file_path );
        exit;
    }

    /**
     * Bundles matching PO, MO, JSON (wp.i18n), and l10n.php assets together on the fly inside a secure compressed ZIP wrapper.
     */
    public static function process_po_zip_bundle_export() {
        // 1. Authenticate Administrative Operational Capability Clearance
        if ( ! current_user_can( 'manage_options' ) ) { 
            wp_die( esc_html__( 'Forbidden operational capability clearance context.', 'af-translate' ) ); 
        }
        
        check_admin_referer( 'af_translate_download_po_nonce' );

        $filename  = isset( $_GET['filename'] ) ? sanitize_text_field( wp_unslash( $_GET['filename'] ) ) : ''; // e.g. "ar.po" or "covernews-ar.po"
        $component = isset( $_GET['component'] ) ? sanitize_key( wp_unslash( $_GET['component'] ) ) : '';     // e.g. "covernews"
        $type      = isset( $_GET['type'] ) ? sanitize_key( wp_unslash( $_GET['type'] ) ) : 'theme';          // e.g. "theme"

        // --- CORE DYNAMIC SUBFOLDER RESOLUTION ENGINE ---
        $allowed_core_types = array( 'wordpress', 'core', 'default', 'admin', 'admin-network', 'continents-cities', 'network', 'continents', 'cities' );
        if ( in_array( $type, $allowed_core_types, true ) ) {
            $sub_folder = 'core';
        } else {
            $sub_folder = ( 'plugin' === $type ) ? 'plugins' : 'themes';
        }

        $upload_dir  = wp_upload_dir();
        $sandbox_dir = trailingslashit( $upload_dir['basedir'] ) . "af-translate/{$sub_folder}";

        // Parse clean language keys to test unified structural names safely
        $pure_name = basename( $filename, '.po' );
        if ( in_array( $type, $allowed_core_types, true ) ) {
            $locale                = $pure_name;
            $standardized_filename = $filename; // Lean explicitly on direct structural filenames for core setups
        } else {
            $locale                = str_replace( $component . '-', '', $pure_name );
            $standardized_filename = $component . '-' . $locale . '.po';
        }

        $candidates = array();

        // Priority 1 & 2: Look inside our custom sandboxed uploads directory first!
        $candidates[] = $sandbox_dir . '/' . $standardized_filename;
        $candidates[] = $sandbox_dir . '/' . $filename;

        // Priority 3+: Fall back to structural vendor plugin/theme directories
        if ( class_exists( 'AF_Translate_Analyzer' ) ) {
            $dirs = AF_Translate_Analyzer::locate_translation_dirs( $component, $type );
            if ( ! empty( $dirs ) && is_array( $dirs ) ) {
                foreach ( $dirs as $path ) {
                    $candidates[] = trailingslashit( $path ) . $filename;
                }
            }
        }

        // Loop execution matrix to extract the primary live candidate instance
        $po_target = '';
        foreach ( $candidates as $candidate ) {
            $canonical_candidate = class_exists( 'AF_Translate_Path_Validator' ) 
                ? AF_Translate_Path_Validator::resolve_canonical_path( $candidate ) 
                : $candidate;

            if ( ! empty( $canonical_candidate ) && file_exists( $canonical_candidate ) ) {
                $po_target = $canonical_candidate;
                break;
            }
        }

        if ( empty( $po_target ) ) {
            wp_die( esc_html__( 'Target translation asset mapping entry context missing.', 'af-translate' ) );
        }

        // Verify absolute system path encapsulation integrity matches safe boundaries
        $is_po_safe = false;
        if ( class_exists( 'AF_Translate_Path_Validator' ) ) {
            $is_po_safe = AF_Translate_Path_Validator::validate_containment( $po_target, false );
        }

        if ( ! $is_po_safe ) {
            wp_die( esc_html__( 'Security Guardrail: Path containment validation failure.', 'af-translate' ) );
        }

        // --- DERIVE ASSOCIATED FILE TARGETS (.mo, .l10n.php, .json) ---
        $target_dir  = dirname( $po_target );
        $mo_target   = str_replace( '.po', '.mo', $po_target );
        $l10n_target = str_replace( '.po', '.l10n.php', $po_target );
        $zip_name    = str_replace( '.po', '-translation-bundle.zip', $filename );

        // Gather all matching JSON script translation files (e.g., covernews-ar-*.json or covernews-ar.json)
        $search_prefixes = array_unique( array_filter( array(
            $pure_name,
            basename( $standardized_filename, '.po' ),
            $component ? $component . '-' . $locale : '',
            $locale
        ) ) );

        $json_targets = array();
        foreach ( $search_prefixes as $prefix ) {
            $matches = glob( $target_dir . '/' . $prefix . '*.json' );
            if ( is_array( $matches ) ) {
                $json_targets = array_merge( $json_targets, $matches );
            }
        }
        $json_targets = array_unique( $json_targets );

        // 3. Initialize the Zip Archive Class Object Context Engine
        $zip      = new ZipArchive();
        $tmp_file = wp_tempnam( $zip_name );

        if ( empty( $tmp_file ) || true !== $zip->open( $tmp_file, ZipArchive::CREATE | ZipArchive::OVERWRITE ) ) {
            wp_die( esc_html__( 'Could not open temporary engine file matrix layer safely.', 'af-translate' ) );
        }

        // Add primary .po file
        $zip->addFile( $po_target, basename( $po_target ) );
        
        // Add compiled binary .mo machine code pair
        if ( file_exists( $mo_target ) ) {
            $is_mo_safe = class_exists( 'AF_Translate_Path_Validator' ) 
                ? AF_Translate_Path_Validator::validate_containment( $mo_target, false ) 
                : true;

            if ( $is_mo_safe ) {
                $zip->addFile( $mo_target, basename( $mo_target ) );
            }
        }

        // Add WP 6.5+ .l10n.php performance binary file
        if ( file_exists( $l10n_target ) ) {
            $is_l10n_safe = class_exists( 'AF_Translate_Path_Validator' ) 
                ? AF_Translate_Path_Validator::validate_containment( $l10n_target, false ) 
                : true;

            if ( $is_l10n_safe ) {
                $zip->addFile( $l10n_target, basename( $l10n_target ) );
            }
        }

        // Add all matching Gutenberg/wp.i18n script translation .json files
        foreach ( $json_targets as $json_file ) {
            if ( file_exists( $json_file ) ) {
                $is_json_safe = class_exists( 'AF_Translate_Path_Validator' ) 
                    ? AF_Translate_Path_Validator::validate_containment( $json_file, false ) 
                    : true;

                if ( $is_json_safe ) {
                    $zip->addFile( $json_file, basename( $json_file ) );
                }
            }
        }
        
        $zip->close();

        // 4. CRITICAL: Purge Active Output Buffer Layers to Secure ZIP Integrity
        while ( ob_get_level() ) {
            ob_end_clean();
        }

        // 5. Emit Stream Transmission Payload Control Headers
        header( 'Content-Type: application/zip' );
        header( 'Content-Disposition: attachment; filename="' . basename( $zip_name ) . '"' );
        header( 'Authorization-Response: True' );
        header( 'Content-Length: ' . filesize( $tmp_file ) );
        header( 'Pragma: no-cache' );
        header( 'Expires: 0' );

        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_readfile -- Direct file stream passthru required for memory-efficient browser download proxying.
        readfile( $tmp_file );

        wp_delete_file( $tmp_file ); 
        exit;
    }
}