<?php
/**
 * Trait AIJE_Meta
 * Meta-Description Generator, KI-Themen-Analyse, Interner Link-Handler
 */
if ( ! defined( 'ABSPATH' ) ) { exit; }

trait AIJE_Meta {

    public function aije_generate_meta_handler() {
        check_ajax_referer( 'aije_meta_nonce', 'nonce' );
        if ( ! current_user_can( 'edit_posts' ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        $post_id = intval( $_POST['post_id'] ?? 0 );
        $post    = get_post( $post_id );
        if ( ! $post ) { wp_send_json_error( array( 'msg' => 'Beitrag nicht gefunden.' ) ); }
        // SICHERHEIT: Rechte für GENAU diesen Beitrag prüfen, nicht nur "edit_posts" —
        // sonst kann ein Mitarbeiter fremde Entwürfe/private Beiträge auslesen lassen.
        if ( ! current_user_can( 'edit_post', $post_id ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }

        $result = $this->ai_generate_meta_variants( $post );
        if ( ! empty( $result['error'] ) ) {
            $err_data = array( 'msg' => $result['error'] );
            if ( ! empty( $result['limit'] ) ) {
                $err_data['limit']       = true;
                $err_data['upgrade_url'] = $result['upgrade_url'] ?? 'https://wprankify.de/#pricing';
            }
            wp_send_json_error( $err_data );
        }
        $variants = $result['variants'] ?? array();
        if ( empty( $variants ) ) { wp_send_json_error( array( 'msg' => 'Nicht genug Inhalt.' ) ); }

        $existing = get_post_meta( $post_id, '_yoast_wpseo_metadesc', true );
        if ( empty( $existing ) ) { $existing = get_post_meta( $post_id, 'rank_math_description', true ); }
        if ( empty( $existing ) ) { $existing = get_post_meta( $post_id, '_aioseo_description', true ); }
        $seo = $this->get_active_seo_plugin();
        $target = $seo === 'rankmath' ? 'rankmath' : ( $seo === 'aioseo' ? 'aioseo' : ( $seo === 'yoast' ? 'yoast' : 'none' ) );
        wp_send_json_success( array( 'variants' => $variants, 'existing_meta' => $existing ?: '', 'target' => $target, 'post_id' => $post_id, 'quota' => $result['quota'] ?? array() ) );
    }

    /**
     * Ersetzt die frühere rein PHP-template-basierte Generierung (immer Deutsch,
     * feste Textbausteine) durch einen KI-Aufruf am Proxy — analog zur
     * Themen-Analyse. Sprache folgt der Einstellung content_language:
     * 'auto' = Proxy erkennt Sprache am Artikelinhalt selbst; sonst wird die
     * gewählte Sprache erzwungen, damit KI-Ausgaben einheitlich bleiben.
     */
    private function ai_generate_meta_variants( $post ) {
        $title   = wp_strip_all_tags( get_the_title( $post ) );
        $content = apply_filters( 'the_content', $post->post_content );
        $content = preg_replace( '/<p[^>]*>\s*(SEO\s*·|Lesedauer|Reading time)[^<]*<\/p>/iu', '', $content );
        $content = wp_strip_all_tags( $content );
        $content = preg_replace( '/\s+/', ' ', trim( $content ) );
        if ( mb_strlen( $content ) < 100 ) { return array( 'variants' => array() ); }

        $o        = $this->get_opts();
        $language = $o['content_language'] ?? 'auto';

        $payload  = array(
            'secret'   => self::stats_secret(),
            'site_key' => self::site_key(),
            'site_url' => home_url(),
            'title'    => $title,
            'content'  => $content,
            'action'   => 'meta',
            'language' => $language,
        );
        $response = wp_remote_post( self::AI_PROXY_URL, array( 'timeout' => 35, 'headers' => array( 'Content-Type' => 'application/json' ), 'body' => wp_json_encode( $payload ), 'sslverify' => true ) );
        if ( is_wp_error( $response ) ) { return array( 'error' => 'Verbindungsfehler: ' . $response->get_error_message() ); }
        $http_code = wp_remote_retrieve_response_code( $response );
        $body      = json_decode( wp_remote_retrieve_body( $response ), true );
        if ( empty( $body['success'] ) ) {
            $err = $body['error'] ?? 'Fehler';
            if ( $http_code === 429 ) { return array( 'error' => $err, 'limit' => true, 'upgrade_url' => $body['upgrade_url'] ?? 'https://wprankify.de/#pricing' ); }
            return array( 'error' => $err );
        }
        $variants = array();
        foreach ( (array) ( $body['data']['variants'] ?? array() ) as $v ) {
            $text = trim( (string) ( $v['text'] ?? '' ) );
            if ( $text === '' ) { continue; }
            $variants[] = array(
                'strategy' => sanitize_text_field( (string) ( $v['strategy'] ?? '' ) ),
                'text'     => $text,
                'chars'    => mb_strlen( $text ),
                'score'    => max( 0, min( 100, (int) ( $v['score'] ?? 0 ) ) ),
            );
        }
        return array( 'variants' => $variants, 'quota' => $body['quota'] ?? array() );
    }

    public function aije_save_meta_handler() {
        // SICHERHEIT: Nonce fehlte komplett (CSRF) — das JS sendet sie bereits mit.
        check_ajax_referer( 'aije_meta_nonce', 'nonce' );
        if ( ! current_user_can( 'edit_posts' ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        $post_id = intval( $_POST['post_id'] ?? 0 );
        // SICHERHEIT: Nur Beiträge, die der Nutzer selbst bearbeiten darf (vorher konnte
        // jeder Mitarbeiter die Meta-Description JEDES Beitrags überschreiben).
        if ( ! $post_id || ! get_post( $post_id ) || ! current_user_can( 'edit_post', $post_id ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        $meta    = sanitize_text_field( wp_unslash( $_POST['meta_text'] ?? '' ) );
        $target  = sanitize_key( wp_unslash( $_POST['target'] ?? 'none' ) );
        if ( ! $post_id || empty( $meta ) ) { wp_send_json_error( array( 'msg' => 'Ungültige Parameter.' ) ); }
        switch ( $target ) {
            case 'rankmath': update_post_meta( $post_id, 'rank_math_description', $meta ); break;
            case 'aioseo':   update_post_meta( $post_id, '_aioseo_description',   $meta ); break;
            case 'none':     update_post_meta( $post_id, '_aije_metadesc',         $meta ); break;
            default:         update_post_meta( $post_id, '_yoast_wpseo_metadesc', $meta ); break;
        }
        update_post_meta( $post_id, '_aije_metadesc', $meta );
        clean_post_cache( $post_id );
        wp_send_json_success( array( 'msg' => 'Gespeichert.', 'chars' => mb_strlen( $meta ), 'meta' => $meta ) );
    }

    private function render_meta_generator_box( $post ) {
        $nonce  = wp_create_nonce( 'aije_meta_nonce' );
        $seo    = $this->get_active_seo_plugin();
        $target = array( 'rankmath' => 'rankmath', 'aioseo' => 'aioseo', 'yoast' => 'yoast' )[ $seo ] ?? 'none';
        $tl     = array( 'rankmath' => 'RankMath', 'aioseo' => 'AIOSEO', 'yoast' => 'Yoast', 'none' => 'WP Rankify' )[ $target ] ?? 'WP Rankify';
        $ex = get_post_meta( $post->ID, '_yoast_wpseo_metadesc', true ) ?: get_post_meta( $post->ID, 'rank_math_description', true ) ?: get_post_meta( $post->ID, '_aioseo_description', true ) ?: get_post_meta( $post->ID, '_aije_metadesc', true );
        $el = mb_strlen( $ex ); $ec = ( $el >= 140 && $el <= 160 ) ? '#22c55e' : ( $el > 0 ? '#f59e0b' : '#ef4444' );
        echo '<div id="aije-meta-box" style="margin-top:16px;padding-top:14px;border-top:1px solid #eee;">';
        echo '<div style="font-size:11px;font-weight:600;color:#555;text-transform:uppercase;letter-spacing:.04em;margin-bottom:8px;">Meta-Description Generator</div>';
        if ( ! empty( $ex ) ) { echo '<div id="aije-meta-status-box" style="background:#f8f8f8;border:1px solid #eee;border-radius:5px;padding:8px 10px;margin-bottom:10px;"><div style="display:flex;justify-content:space-between;font-size:11px;color:#888;margin-bottom:4px;"><span>Aktuelle Meta (' . esc_html( $tl ) . ')</span><span id="aije-current-meta-len" style="color:' . esc_attr( $ec ) . ';font-weight:600;">' . $el . ' Zeichen</span></div><div id="aije-current-meta-display" style="font-size:11px;color:#333;line-height:1.5;">' . esc_html( mb_substr( $ex, 0, 120 ) ) . ( $el > 120 ? '...' : '' ) . '</div></div>'; }
        else { echo '<div id="aije-meta-empty-hint" style="background:#fff8f0;border:1px solid #fed7aa;border-radius:5px;padding:8px 10px;margin-bottom:10px;font-size:11px;color:#92400e;">Noch keine Meta-Description vorhanden.</div>'; }
        echo '<button type="button" id="aije-meta-gen-btn" data-post-id="' . esc_attr( $post->ID ) . '" data-nonce="' . esc_attr( $nonce ) . '" data-target="' . esc_attr( $target ) . '" style="width:100%;padding:8px;background:#f29400;color:#fff;border:none;border-radius:5px;font-size:12px;font-weight:600;cursor:pointer;margin-bottom:8px;">Meta-Descriptions vorschlagen</button>';
        echo '<div id="aije-meta-loading" style="display:none;text-align:center;padding:10px;font-size:12px;color:#888;">Analysiere Beitrag...</div>';
        echo '<div id="aije-meta-results" style="display:none;"></div></div>';
        // JS aus separater Datei laden
        require plugin_dir_path( AIJE_PLUGIN_FILE ) . 'admin/metabox-meta-js.php';
    }

    public function aije_topic_analysis_handler() {
        check_ajax_referer( 'aije_topic_nonce', 'nonce' );
        if ( ! current_user_can( 'edit_posts' ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        $post_id = intval( $_POST['post_id'] ?? 0 );
        $post    = get_post( $post_id );
        if ( ! $post ) { wp_send_json_error( array( 'msg' => 'Beitrag nicht gefunden.' ) ); }
        if ( ! current_user_can( 'edit_post', $post_id ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        if ( ! in_array( $post->post_status, array( 'publish','draft','pending','private','future' ), true ) ) { wp_send_json_error( array( 'msg' => 'Ungültiger Status.' ) ); }
        $lock_key = 'aije_analysis_lock_' . $post_id . '_' . get_current_user_id();
        if ( get_transient( $lock_key ) ) { wp_send_json_error( array( 'msg' => 'Bitte kurz warten.' ) ); }
        set_transient( $lock_key, 1, 15 );
        $title   = get_the_title( $post ) ?: '(Kein Titel)';
        $content = // Aufbereitung: HTML-Tags entfernen, Entities dekodieren, Whitespace normalisieren
        $plain = html_entity_decode( wp_strip_all_tags( $post->post_content ), ENT_QUOTES, 'UTF-8' );
        $plain = preg_replace( '/[ \t]+/', ' ', $plain );
        $plain = preg_replace( '/\n{3,}/', "\n\n", $plain );
        $plain = trim( $plain );

        // H2-Überschriften als Inhaltsübersicht extrahieren
        // Das Modell sieht damit die Struktur des gesamten Artikels – auch was nach dem Textlimit steht
        preg_match_all( '/<h2[^>]*>(.*?)<\/h2>/is', $post->post_content, $h2_matches );
        $h2_list = array();
        foreach ( $h2_matches[1] as $h2 ) {
            $h2_list[] = '- ' . trim( wp_strip_all_tags( $h2 ) );
        }
        $structure_note = ! empty( $h2_list )
            ? "Artikelstruktur (alle Abschnitte):\n" . implode( "\n", $h2_list ) . "\n\n"
            : '';

        // Volltext auf 15.000 Zeichen begrenzen (reicht für ~3.000 Wörter)
        $char_limit    = 15000;
        $is_truncated  = mb_strlen( $plain ) > $char_limit;
        $content       = $structure_note . ( $is_truncated ? mb_substr( $plain, 0, $char_limit ) : $plain );
        $force   = ! empty( $_POST['force'] );
        if ( ! $force ) { $cached = get_transient( 'aije_topic_' . $post_id ); if ( $cached ) { wp_send_json_success( array( 'data' => $cached, 'quota' => array(), 'cached' => true ) ); } }
        $o        = $this->get_opts();
        $payload  = array( 'secret' => self::stats_secret(), 'site_key' => self::site_key(), 'site_url' => home_url(), 'title' => $title, 'content' => $content, 'action' => 'analyze', 'language' => $o['content_language'] ?? 'auto' );
        $response = wp_remote_post( self::AI_PROXY_URL, array( 'timeout' => 35, 'headers' => array( 'Content-Type' => 'application/json' ), 'body' => wp_json_encode( $payload ), 'sslverify' => true ) );
        if ( is_wp_error( $response ) ) { wp_send_json_error( array( 'msg' => 'Verbindungsfehler: ' . $response->get_error_message() ) ); }
        $http_code = wp_remote_retrieve_response_code( $response );
        $body      = json_decode( wp_remote_retrieve_body( $response ), true );
        if ( empty( $body['success'] ) ) { $err = $body['error'] ?? 'Fehler'; if ( $http_code === 429 ) { wp_send_json_error( array( 'msg' => $err, 'limit' => true, 'upgrade_url' => $body['upgrade_url'] ?? 'https://wprankify.de/#pricing' ) ); } wp_send_json_error( array( 'msg' => $err ) ); }
        delete_transient( 'aije_topic_' . $post_id );
        set_transient( 'aije_topic_' . $post_id, $body['data'], DAY_IN_SECONDS );
        wp_send_json_success( array( 'data' => $body['data'], 'quota' => $body['quota'] ?? array() ) );
    }

    private function render_topic_analysis_box( $post ) {
        $nonce      = wp_create_nonce( 'aije_topic_nonce' );
        $cached     = get_transient( 'aije_topic_' . $post->ID );
        $pro_status = $this->get_pro_status();
        $tier       = $pro_status['tier'] ?? 'free';
        $remaining  = $pro_status['remaining'] ?? 3;
        $is_pro     = ! empty( $pro_status['is_pro'] );
        $tc = array( 'free' => '#888', 'starter' => '#22c55e', 'pro' => '#f29400', 'agency' => '#3b82f6' )[ $tier ] ?? '#888';
        echo '<div id="aije-topic-box" style="margin-top:14px;padding-top:14px;border-top:1px solid #eee;">';
        echo '<div style="display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;"><div style="font-size:11px;font-weight:600;color:#555;text-transform:uppercase;letter-spacing:.04em;">🧠 KI-Themen-Analyse</div>';
        echo '<div style="display:flex;align-items:center;gap:6px;"><span id="aije-tier-badge" style="font-size:10px;font-weight:700;padding:2px 7px;border-radius:4px;background:' . esc_attr( $tc ) . '22;color:' . esc_attr( $tc ) . ';">' . esc_html( strtoupper( $tier ) ) . '</span>';
        if ( ! $is_pro ) { echo '<span style="font-size:10px;color:#aaa;">' . (int) $remaining . ' verbleibend</span><button type="button" id="aije-refresh-status" data-nonce="' . esc_attr( $nonce ) . '" style="font-size:10px;background:none;border:none;color:#f29400;cursor:pointer;padding:0;">↻</button>'; }
        echo '</div></div>';
        echo '<button type="button" id="aije-topic-btn" data-post-id="' . esc_attr( $post->ID ) . '" data-nonce="' . esc_attr( $nonce ) . '" style="width:100%;padding:8px;background:#111;color:#fff;border:none;border-radius:5px;font-size:12px;font-weight:600;cursor:pointer;margin-bottom:8px;">🧠 Themen analysieren</button>';
        echo '<div id="aije-topic-loading" style="display:none;text-align:center;padding:10px;font-size:12px;color:#888;">KI analysiert… (ca. 5–10 Sek.)</div>';
        echo '<div id="aije-topic-results" style="display:none;"></div>';
        if ( $cached ) { echo '<div id="aije-topic-cached" style="font-size:11px;color:#aaa;margin-bottom:4px;padding:5px 8px;background:#f8f8f8;border-radius:4px;">💾 Letzte Analyse verfügbar.</div>'; }
        echo '</div>';
        require plugin_dir_path( AIJE_PLUGIN_FILE ) . 'admin/metabox-topic-js.php';
    }

    public function aije_insert_link_handler() {
        check_ajax_referer( 'aije_insert_link', 'nonce' );
        if ( ! current_user_can( 'edit_posts' ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        $post_id   = intval( $_POST['post_id']   ?? 0 );
        $target_id = intval( $_POST['target_id'] ?? 0 );
        if ( ! $post_id || ! $target_id || $post_id === $target_id ) { wp_send_json_error( array( 'msg' => 'Ungültige Parameter.' ) ); }
        $post = get_post( $post_id ); $target = get_post( $target_id );
        if ( ! $post || ! $target ) { wp_send_json_error( array( 'msg' => 'Beitrag nicht gefunden.' ) ); }
        // SICHERHEIT: Bearbeitungsrecht für den Quellbeitrag; Linkziel muss öffentlich sein.
        if ( ! current_user_can( 'edit_post', $post_id ) ) { wp_send_json_error( array( 'msg' => 'Keine Berechtigung.' ) ); }
        if ( 'publish' !== get_post_status( $target ) || ! is_post_type_viewable( $target->post_type ) ) { wp_send_json_error( array( 'msg' => 'Linkziel ist nicht öffentlich.' ) ); }

        $content      = $post->post_content;
        $target_url   = get_permalink( $target_id );
        $target_title = wp_strip_all_tags( get_the_title( $target_id ) );
        $method       = '';
        $anchor       = '';
        $ai_info      = array();
        // mode=backlink: Link wird aus einem ANDEREN Beitrag gesetzt ("Backlink
        // setzen") → ausschließlich über den KI-Dienst (Kontingent je Tarif).
        // Ohne mode (Vorschlags-Fenster, Link im eigenen Beitrag): wie bisher
        // inkl. Stichwort-Methode.
        $is_backlink  = ( 'backlink' === sanitize_key( wp_unslash( $_POST['mode'] ?? '' ) ) );

        // ── 1) KI-Verlinkung (Dienst über den Proxy, Kontingent pro Zielbeitrag) ──
        $ai = $this->ai_suggest_link( $post, $target, $content );
        $ai_info = $ai['links'] ?? array();
        if ( isset( $ai['paragraph_offset'], $ai['paragraph_length'], $ai['anchor'] ) ) {
            $para_html = substr( $content, $ai['paragraph_offset'], $ai['paragraph_length'] );
            $new_para  = self::link_phrase_in_html( $para_html, $ai['anchor'], $target_url, $target_title );
            if ( $new_para !== null ) {
                $content = substr( $content, 0, $ai['paragraph_offset'] ) . $new_para . substr( $content, $ai['paragraph_offset'] + $ai['paragraph_length'] );
                $method  = 'ai';
                $anchor  = $ai['anchor'];
            }
        }

        if ( $is_backlink && $method === '' ) {
            $note = $ai['note'] ?? 'error';
            $err  = array(
                'limit'          => 'KI-Kontingent für diesen Beitrag aufgebraucht.',
                'no_match'       => 'Die KI hat in diesem Beitrag keine passende Stelle gefunden.',
                'already_linked' => 'Dieser Beitrag verlinkt bereits hierher.',
                'no_paragraphs'  => 'Der Beitrag hat keine geeigneten Absätze.',
            );
            wp_send_json_error( array(
                'msg'         => $err[ $note ] ?? 'KI-Dienst gerade nicht erreichbar. Bitte später erneut versuchen.',
                'reason'      => $note,
                'limit'       => ( 'limit' === $note ),
                'ai_links'    => $ai_info,
                'upgrade_url' => 'https://wprankify.de/#pricing',
            ) );
        }

        // ── 2) Stichwort-Methode (nur für Links im eigenen Beitrag) ──
        if ( $method === '' ) {
            foreach ( self::link_keyword_candidates( $target_title ) as $kw ) {
                $new = self::link_phrase_in_html( $content, $kw, $target_url, $target_title, true );
                if ( $new !== null ) { $content = $new; $method = 'keyword'; $anchor = $kw; break; }
            }
        }

        // ── 3) Fallback: Lese-auch-Absatz am Ende ──
        if ( $method === '' ) {
            $content .= "\n\n" . '<p style="background:#f0f7ff;border-left:4px solid #3498db;padding:12px 16px;border-radius:4px;margin:24px 0;font-size:15px;">&#128214; Wenn dich dieses Thema interessiert, lies auch unseren Artikel: <a href="' . esc_url( $target_url ) . '"><strong>' . esc_html( $target_title ) . '</strong></a></p>';
            $method   = 'paragraph';
        }

        // Vorher-Stand als Revision sichern → Änderung über "Revisionen" rückgängig machbar.
        if ( function_exists( 'wp_save_post_revision' ) && post_type_supports( $post->post_type, 'revisions' ) ) {
            wp_save_post_revision( $post_id );
        }
        global $wpdb;
        $updated = $wpdb->update( $wpdb->posts, array( 'post_content' => $content, 'post_modified' => current_time( 'mysql' ), 'post_modified_gmt' => current_time( 'mysql', 1 ) ), array( 'ID' => $post_id ), array( '%s', '%s', '%s' ), array( '%d' ) );
        clean_post_cache( $post_id );
        if ( $updated === false ) { wp_send_json_error( array( 'msg' => 'Datenbankfehler.' ) ); }

        if ( $method === 'ai' && ! empty( $ai_info ) ) {
            update_post_meta( $target_id, '_aije_ai_links_used', array( 'used' => (int) ( $ai_info['used'] ?? 0 ), 'limit' => (int) ( $ai_info['limit'] ?? 0 ) ) );
        }
        update_option( 'aije_internal_link_uses', (int) get_option( 'aije_internal_link_uses', 0 ) + 1, false );

        $msgs = array(
            'ai'        => '✓ KI-Link „' . $anchor . '" gesetzt.',
            'keyword'   => '✓ „' . $anchor . '" verlinkt.',
            'paragraph' => '✓ Lese-auch-Absatz eingefügt.',
        );
        wp_send_json_success( array(
            'method'      => $method,
            'keyword'     => $anchor,
            'msg'         => $msgs[ $method ],
            'ai_links'    => $ai_info,
            'ai_note'     => $ai['note'] ?? '',
            'new_content' => $content,
        ) );
    }

    /**
     * Fragt den Proxy (action "link"), welcher Absatz des Quellbeitrags am besten
     * auf den Zielbeitrag verlinkt und mit welchem Ankertext. Das Kontingent
     * (KI-Links pro Zielbeitrag je nach Tarif) verwaltet der Proxy.
     * Rückgabe: paragraph_offset/paragraph_length/anchor bei Erfolg, sonst nur
     * 'links' (Kontingent) und ggf. 'note' (Grund, warum keine KI genutzt wurde).
     */
    private function ai_suggest_link( $post, $target, $content ) {
        // Absätze des Quellbeitrags sammeln (ohne den ersten/Intro-Absatz).
        $segments   = self::link_text_segments( $content );
        if ( empty( $segments ) ) { return array( 'note' => 'no_paragraphs' ); }
        $target_url = get_permalink( $target->ID );
        $paras = array(); $map = array();
        foreach ( $segments as $i => $pm ) {
            if ( $i === 0 ) { continue; }
            if ( stripos( $pm[0], $target_url ) !== false ) { return array( 'note' => 'already_linked' ); }
            $text = trim( preg_replace( '/\s+/', ' ', html_entity_decode( wp_strip_all_tags( $pm[0] ), ENT_QUOTES, 'UTF-8' ) ) );
            if ( mb_strlen( $text ) < 40 ) { continue; }
            $idx = count( $paras );
            $paras[] = array( 'i' => $idx, 'text' => mb_substr( $text, 0, 700 ) );
            $map[ $idx ] = array( $pm[1], strlen( $pm[0] ) );
            if ( count( $paras ) >= 40 ) { break; }
        }
        if ( empty( $paras ) ) { return array( 'note' => 'no_paragraphs' ); }

        $t_text  = trim( preg_replace( '/\s+/', ' ', html_entity_decode( wp_strip_all_tags( $target->post_content ), ENT_QUOTES, 'UTF-8' ) ) );
        $o       = $this->get_opts();
        $payload = array(
            'secret'         => self::stats_secret(),
            'site_key'       => self::site_key(),
            'site_url'       => home_url(),
            'action'         => 'link',
            'language'       => $o['content_language'] ?? 'auto',
            'title'          => wp_strip_all_tags( get_the_title( $target ) ),
            'content'        => mb_substr( $t_text, 0, 600 ),
            'paragraphs'     => $paras,
            'target_post_id' => (int) $target->ID,
            'source_post_id' => (int) $post->ID,
            'plugin_version' => AIJE_PLUGIN_VERSION,
        );
        $response = wp_remote_post( self::AI_PROXY_URL, array( 'timeout' => 35, 'headers' => array( 'Content-Type' => 'application/json' ), 'body' => wp_json_encode( $payload ), 'sslverify' => true ) );
        if ( is_wp_error( $response ) ) { return array( 'note' => 'connection' ); }
        $body = json_decode( wp_remote_retrieve_body( $response ), true );
        if ( ! is_array( $body ) ) { return array( 'note' => 'invalid_response' ); }
        $links = isset( $body['links'] ) && is_array( $body['links'] ) ? $body['links'] : array();
        if ( empty( $body['success'] ) ) {
            return array( 'note' => ! empty( $body['link_limit'] ) ? 'limit' : 'error', 'links' => $links );
        }
        $pi     = (int) ( $body['data']['paragraph'] ?? -1 );
        $anchor = trim( (string) ( $body['data']['anchor'] ?? '' ) );
        if ( $pi < 0 || $anchor === '' || ! isset( $map[ $pi ] ) ) { return array( 'note' => 'no_match', 'links' => $links ); }
        return array( 'paragraph_offset' => $map[ $pi ][0], 'paragraph_length' => $map[ $pi ][1], 'anchor' => $anchor, 'links' => $links );
    }

    /**
     * Verlinkt das erste Vorkommen von $phrase in $html — aber NUR in sichtbarem
     * Text: nicht in Tags/Attributen, HTML-Kommentaren (Block-Editor), bestehenden
     * Links, Überschriften, Code/Script/Style. Achtet auf Wortgrenzen.
     * $skip_first_p: ersten Absatz (Einleitung) auslassen.
     * Gibt das geänderte HTML zurück oder null, wenn nichts gefunden wurde.
     */
    private static function link_phrase_in_html( $html, $phrase, $url, $title, $skip_first_p = false ) {
        $phrase = trim( (string) $phrase );
        if ( $phrase === '' ) { return null; }
        $parts = preg_split( '/(<!--.*?-->|<[^>]*>)/s', $html, -1, PREG_SPLIT_DELIM_CAPTURE );
        if ( ! is_array( $parts ) ) { return null; }
        $words   = preg_split( '/\s+/u', $phrase );
        $pattern = '/(?<![\p{L}\p{N}])(' . implode( '\s+', array_map( function ( $w ) { return preg_quote( $w, '/' ); }, $words ) ) . ')(?![\p{L}\p{N}])/iu';
        $block = 0; $p_count = 0; $in_first_p = false;
        foreach ( $parts as $k => $part ) {
            if ( $part === '' ) { continue; }
            if ( $part[0] === '<' ) {
                if ( strpos( $part, '<!--' ) === 0 ) { continue; }
                if ( preg_match( '/^<(\/?)(a|h[1-6]|script|style|code|pre|button|figcaption|textarea)\b/i', $part, $t ) ) {
                    $block += ( $t[1] === '/' ) ? -1 : 1;
                    if ( $block < 0 ) { $block = 0; }
                } elseif ( preg_match( '/^<p\b/i', $part ) ) {
                    $p_count++; $in_first_p = ( $p_count === 1 );
                } elseif ( preg_match( '/^<\/p>/i', $part ) ) {
                    $in_first_p = false;
                }
                continue;
            }
            if ( $block > 0 || ( $skip_first_p && $in_first_p ) ) { continue; }
            if ( preg_match( $pattern, $part, $mm, PREG_OFFSET_CAPTURE ) ) {
                $found = $mm[1][0]; $off = $mm[1][1];
                $parts[ $k ] = substr( $part, 0, $off ) . '<a href="' . esc_url( $url ) . '" title="' . esc_attr( $title ) . '">' . $found . '</a>' . substr( $part, $off + strlen( $found ) );
                return implode( '', $parts );
            }
        }
        return null;
    }

    /**
     * Zerlegt den gespeicherten Beitragsinhalt in Textabschnitte samt Byte-Offset
     * ([html, offset]), in die ein Link eingefügt werden kann:
     *  - Block-Editor / HTML: <p>…</p> und <li>…</li>
     *  - Klassischer Editor: dort stehen KEINE <p>-Tags in der Datenbank (die
     *    setzt WordPress erst bei der Ausgabe per wpautop) – Absätze sind nur
     *    durch Leerzeilen getrennt. Diese Abschnitte werden zusätzlich erkannt.
     */
    private static function link_text_segments( $content ) {
        $segs = array();
        if ( preg_match_all( '/<(p|li)\b[^>]*>.*?<\/\1>/is', $content, $m, PREG_OFFSET_CAPTURE ) ) {
            foreach ( $m[0] as $pm ) { $segs[ $pm[1] ] = $pm; }
        }
        if ( count( $segs ) < 2 ) {
            // Klassischer Editor: Leerzeilen-Absätze (nur Text-Abschnitte, keine
            // Überschriften/Listen/Shortcodes/Block-Kommentare am Anfang)
            $parts = preg_split( '/\r?\n\s*\r?\n/', $content, -1, PREG_SPLIT_OFFSET_CAPTURE | PREG_SPLIT_NO_EMPTY );
            foreach ( (array) $parts as $pm ) {
                $txt = ltrim( $pm[0] );
                if ( $txt === '' ) { continue; }
                if ( preg_match( '/^(<(h[1-6]|ul|ol|table|figure|div|img|iframe|blockquote|pre|script|style)\b|<!--|\[)/i', $txt ) ) { continue; }
                $lead = strlen( $pm[0] ) - strlen( $txt );
                $off  = $pm[1] + $lead;
                $overlap = false;
                foreach ( $segs as $so => $sm ) { if ( $off < $so + strlen( $sm[0] ) && $so < $off + strlen( $txt ) ) { $overlap = true; break; } }
                if ( ! $overlap ) { $segs[ $off ] = array( rtrim( $txt ), $off ); }
            }
        }
        ksort( $segs );
        return array_values( $segs );
    }

    /** Stichwort-Kandidaten aus dem Zieltitel: erst Wortpaare, dann lange Einzelwörter. */
    private static function link_keyword_candidates( $title ) {
        $stop = array( 'der','die','das','den','dem','des','ein','eine','einer','eines','und','oder','aber','wenn','weil','dass','dann','ist','sind','hat','haben','wird','werden','kann','muss','soll','sein','nicht','auch','noch','nur','sehr','mehr','alle','hier','dort','jetzt','mit','von','zu','bei','in','an','auf','aus','nach','für','über','unter','wie','was','wann','warum','the','and','for','with','this','that','are','was','have','not','how','what','why','when','your','artikel','beitrag','tipps','hilfe','guide','alles','wissen','ratgeber','worauf','achten','sollte','man' );
        $words = array_values( array_filter( preg_split( '/[^\p{L}\p{N}\-]+/u', mb_strtolower( $title ), -1, PREG_SPLIT_NO_EMPTY ) ) );
        $cands = array();
        for ( $i = 0; $i < count( $words ) - 1; $i++ ) {
            if ( in_array( $words[ $i ], $stop, true ) || in_array( $words[ $i + 1 ], $stop, true ) ) { continue; }
            $cands[] = $words[ $i ] . ' ' . $words[ $i + 1 ];
        }
        $single = array_filter( $words, function ( $w ) use ( $stop ) { return mb_strlen( $w ) >= 5 && ! in_array( $w, $stop, true ); } );
        usort( $single, function ( $a, $b ) { return mb_strlen( $b ) - mb_strlen( $a ); } );
        return array_values( array_unique( array_merge( $cands, $single ) ) );
    }
}