<?php
/**
 * Core Binary File Compiler and Translation Synchronization Engine
 * Pure PHP Workspace Processor
 *
 * @package af-translate
 */

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

class AF_Translate_Compiler_Engine {

    /**
     * Resolves all structural path segments to produce a clean canonical absolute path.
     */
    public static function resolve_canonical_path( $path ) {
        if ( empty( $path ) ) {
            return '';
        }
        
        $path = wp_normalize_path( $path );
        
        $drive = '';
        if ( preg_match( '/^([a-zA-Z]:)/', $path, $matches ) ) {
            $drive = $matches[1];
            $path  = substr( $path, 2 );
        }
        
        $segments = explode( '/', $path );
        $canonical_segments = array();
        
        foreach ( $segments as $segment ) {
            if ( '' === $segment || '.' === $segment ) {
                continue;
            }
            if ( '..' === $segment ) {
                array_pop( $canonical_segments );
            } else {
                $canonical_segments[] = $segment;
            }
        }
        
        $leading_slash = ( 0 === strpos( $path, '/' ) || ! empty( $drive ) ) ? '/' : '';
        return $drive . $leading_slash . implode( '/', $canonical_segments );
    }

    /**
     * Absolute Post-Processing Guardrail: Ensures absolute uniqueness on text level.
     */
    private static function deduplicate_raw_po_string( $po_string ) {
        $po_string = str_replace( "\r\n", "\n", $po_string );
        $blocks    = explode( "\n\n", $po_string );
        
        $unique_blocks = array();
        $seen_keys     = array();
        
        foreach ( $blocks as $block ) {
            $block_trimmed = trim( $block );
            if ( empty( $block_trimmed ) ) {
                continue;
            }
            
            if ( 0 === strpos( $block_trimmed, '#' ) && false === strpos( $block_trimmed, 'msgid' ) ) {
                $unique_blocks[] = $block;
                continue;
            }
            
            $context = '';
            if ( preg_match( '/^msgctxt\s+"(.*)"/m', $block_trimmed, $context_matches ) ) {
                $context = trim( $context_matches[1] );
            }
            
            $msgid = '';
            if ( preg_match( '/^msgid\s+"(.*)"/m', $block_trimmed, $id_matches ) ) {
                $msgid = trim( $id_matches[1] );
            }
            
            if ( '' === $msgid && '' === $context && ( false !== strpos( $block_trimmed, 'Content-Type' ) || false !== strpos( $block_trimmed, 'Project-Id-Version' ) ) ) {
                $unique_blocks[] = $block;
                continue;
            }
            
            $compound_key = $context . '|||' . $msgid;
            
            if ( isset( $seen_keys[ $compound_key ] ) ) {
                continue; 
            }
            
            $seen_keys[ $compound_key ] = true;
            $unique_blocks[] = $block;
        }
        
        return implode( "\n\n", $unique_blocks ) . "\n";
    }

    /**
     * Synchronizes a target PO file from scratch using a POT template blueprint in pure PHP.
     * Computes real-time additions and removals for user tracking.
     */
    public static function sync_pot_into_po( $po_path, $pot_path ) {
        $po_path  = self::resolve_canonical_path( $po_path );
        $pot_path = self::resolve_canonical_path( $pot_path );

        if ( ! file_exists( $pot_path ) || ! class_exists( 'AF_Translate_PO_Processor' ) ) {
            return false; 
        }

        $pot_entries = AF_Translate_PO_Processor::parse_file( $pot_path );
        if ( empty( $pot_entries ) ) {
            return false;
        }

        $translation_map    = array();
        $fallback_msgid_map = array();
        $existing_po_keys   = array();

        if ( file_exists( $po_path ) ) {
            $po_entries = AF_Translate_PO_Processor::parse_file( $po_path );
            
            foreach ( $po_entries as $entry ) {
                $context = isset( $entry['msgctxt'] ) ? trim( (string) $entry['msgctxt'] ) : '';
                $msgid   = isset( $entry['msgid'] ) ? trim( (string) $entry['msgid'] ) : '';
                
                if ( '' === $msgid ) {
                    continue; 
                }

                $exact_key = $context . '|||' . $msgid;
                $existing_po_keys[ $exact_key ] = true;

                if ( ! isset( $translation_map[ $exact_key ] ) || empty( $translation_map[ $exact_key ] ) ) {
                    $translation_map[ $exact_key ] = $entry['msgstr'];
                }

                if ( ! empty( $entry['msgstr'] ) ) {
                    $fallback_msgid_map[ $msgid ] = $entry['msgstr'];
                }
            }
        }

        $unique_compiled_output = array();
        $new_strings_count      = 0;
        $matched_pot_keys       = array();
        
        foreach ( $pot_entries as $pot_node ) {
            $pot_context = isset( $pot_node['msgctxt'] ) ? trim( (string) $pot_node['msgctxt'] ) : '';
            $pot_msgid   = isset( $pot_node['msgid'] ) ? trim( (string) $pot_node['msgid'] ) : '';

            if ( '' === $pot_msgid && '' === $pot_context ) {
                continue;
            }

            $compound_key = $pot_context . '|||' . $pot_msgid;
            $matched_pot_keys[ $compound_key ] = true;

            if ( isset( $unique_compiled_output[ $compound_key ] ) ) {
                continue;
            }

            if ( ! isset( $existing_po_keys[ $compound_key ] ) ) {
                $new_strings_count++;
            }

            if ( isset( $translation_map[ $compound_key ] ) ) {
                $pot_node['msgstr'] = $translation_map[ $compound_key ];
            } elseif ( isset( $fallback_msgid_map[ $pot_msgid ] ) ) {
                $pot_node['msgstr'] = $fallback_msgid_map[ $pot_msgid ];
            }

            $unique_compiled_output[ $compound_key ] = $pot_node;
        }

        $obsolete_strings_count = 0;
        foreach ( $existing_po_keys as $old_key => $void ) {
            if ( ! isset( $matched_pot_keys[ $old_key ] ) ) {
                $obsolete_strings_count++;
            }
        }

        $raw_po_text       = AF_Translate_PO_Processor::generate_po_string( array_values( $unique_compiled_output ) );
        $sanitized_po_text = self::deduplicate_raw_po_string( $raw_po_text );

        if ( false === file_put_contents( $po_path, $sanitized_po_text ) ) {
            return false;
        }

        return array(
            'new'      => $new_strings_count,
            'obsolete' => $obsolete_strings_count,
        );
    }

    /**
     * Compiles clean standard plain-text raw .po files into machine-readable .mo formats.
     */
    public static function compile_po_to_mo( $po_path, $mo_path ) {
        $po_path = self::resolve_canonical_path( $po_path );
        $mo_path = self::resolve_canonical_path( $mo_path );

        if ( ! file_exists( $po_path ) || ! class_exists( 'AF_Translate_PO_Processor' ) ) { 
            return false; 
        }

        $entries_parsed = AF_Translate_PO_Processor::parse_file( $po_path );
        $entries = array();

        foreach ( $entries_parsed as $entry ) {
            $id = isset( $entry['msgid'] ) ? (string) $entry['msgid'] : '';
            if ( empty( $id ) ) {
                continue;
            }
            
            if ( ! empty( $entry['msgid_plural'] ) ) {
                $id .= "\x00" . $entry['msgid_plural'];
            }

            if ( ! empty( $entry['msgctxt'] ) ) {
                $id = $entry['msgctxt'] . "\x04" . $id;
            }

            $str_val = '';
            if ( ! empty( $entry['msgstr'] ) ) {
                $str_val = implode( "\x00", $entry['msgstr'] );
            }

            $entries[ $id ] = $str_val;
        }

        ksort( $entries );
        $count = count( $entries );
        if ( 0 === $count ) {
            return false;
        }

        $ids          = '';
        $strs         = '';
        $ids_offsets  = array();
        $strs_offsets = array();

        foreach ( $entries as $id => $str ) {
            $ids_offsets[] = array( 'len' => strlen( $id ), 'pos' => strlen( $ids ) );
            $ids          .= $id . "\x00";
            
            $strs_offsets[] = array( 'len' => strlen( $str ), 'pos' => strlen( $strs ) );
            $strs          .= $str . "\x00";
        }

        $key_start  = 28;
        $val_start  = $key_start + ( $count * 8 );
        $size_start = $val_start + ( $count * 8 );

        $offsets_key = '';
        foreach ( $ids_offsets as $offset ) {
            $offsets_key .= pack( 'VV', $offset['len'], $offset['pos'] + $size_start );
        }

        $offsets_val = '';
        foreach ( $strs_offsets as $offset ) {
            $offsets_val .= pack( 'VV', $offset['len'], $offset['pos'] + $size_start + strlen( $ids ) );
        }

        $mo_header      = pack( 'VvvIIIII', 0x950412de, 0, 0, $count, $key_start, $val_start, 0, 0 );
        $mo_binary_data = $mo_header . $offsets_key . $offsets_val . $ids . $strs;

        return ( false !== file_put_contents( $mo_path, $mo_binary_data ) );
    }
}