<?php
/**
 * Aiforya_Faq_Generator_Ajax — handlers AJAX de l'administration (version gratuite).
 *
 * Endpoints (wp_ajax_*) :
 *   - aiforya_fg_save_settings     : sauvegarde des réglages d'affichage
 *   - aiforya_fg_save_faq          : enregistre la FAQ (éditeur manuel) d'un article
 *   - aiforya_fg_delete_faq        : supprime la FAQ d'un article
 *   - aiforya_fg_get_post_content  : charge la FAQ existante d'un article
 *   - aiforya_fg_detect_faq        : détecte automatiquement les Q&A d'un article
 *                                    par analyse de la structure (sans IA, 0 réseau)
 *
 * Tous les handlers : capability check `manage_options` + nonce + réponse JSON.
 *
 * @package aiforya-faq-generator
 */

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

if ( class_exists( 'Aiforya_Faq_Generator_Ajax', false ) ) {
    return;
}

class Aiforya_Faq_Generator_Ajax {

    /** @var self|null Singleton instance (pattern AIFORYA canonical). */
    private static ?self $instance = null;

    const NONCE_ACTION = 'aiforya_fg_nonce';

    public static function get_instance(): self {
        if ( self::$instance === null ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    public function __construct() {
        add_action( 'wp_ajax_aiforya_fg_save_settings',    [ $this, 'handle_save_settings' ] );
        add_action( 'wp_ajax_aiforya_fg_save_faq',         [ $this, 'handle_save_faq' ] );
        add_action( 'wp_ajax_aiforya_fg_delete_faq',       [ $this, 'handle_delete_faq' ] );
        add_action( 'wp_ajax_aiforya_fg_get_post_content', [ $this, 'handle_get_post_content' ] );
        add_action( 'wp_ajax_aiforya_fg_detect_faq',       [ $this, 'handle_detect_faq' ] );
    }

    private function db(): Aiforya_Faq_Generator_Db {
        return Aiforya_Faq_Generator_Db::get_instance();
    }

    private function guard(): void {
        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error( [ 'message' => __( 'Permission denied.', 'aiforya-faq-generator' ) ], 403 );
        }
        check_ajax_referer( self::NONCE_ACTION, 'nonce' );
    }

    /**
     * Nettoie une liste de paires question/réponse en entrée AJAX.
     *
     * @param mixed $raw Tableau brut [ [ 'question' => ..., 'answer' => ... ], ... ].
     * @return array Items schema.org valides.
     */
    private function sanitize_qa_items( $raw ): array {
        if ( ! is_array( $raw ) ) {
            return [];
        }
        $items = [];
        foreach ( $raw as $pair ) {
            if ( ! is_array( $pair ) ) {
                continue;
            }
            $q = isset( $pair['question'] ) ? sanitize_text_field( (string) $pair['question'] ) : '';
            $a = isset( $pair['answer'] ) ? wp_kses_post( (string) $pair['answer'] ) : '';
            $q = trim( $q );
            $a = trim( $a );
            if ( '' === $q || '' === $a ) {
                continue;
            }
            $items[] = [
                '@type'          => 'Question',
                'name'           => $q,
                'acceptedAnswer' => [
                    '@type' => 'Answer',
                    'text'  => $a,
                ],
            ];
        }
        return $items;
    }

    // =========================================================================
    // Réglages d'affichage.
    // =========================================================================

    public function handle_save_settings(): void {
        $this->guard();

        $db   = $this->db();
        $cur  = $db->get_settings();
        $post = wp_unslash( $_POST );

        $position = sanitize_key( (string) ( $post['position'] ?? $cur['position'] ) );
        $cur['position'] = in_array( $position, [ 'manual', 'after', 'before' ], true ) ? $position : 'manual';

        $layout = sanitize_key( (string) ( $post['layout'] ?? $cur['layout'] ) );
        $cur['layout'] = in_array( $layout, [ 'accordion', 'cards', 'list', 'numbered', 'minimal' ], true ) ? $layout : 'accordion';

        $cur['default_title'] = sanitize_text_field( (string) ( $post['default_title'] ?? $cur['default_title'] ) );

        foreach ( [ 'color_primary', 'color_bg', 'color_text', 'color_question' ] as $ck ) {
            $val = sanitize_hex_color( (string) ( $post[ $ck ] ?? '' ) );
            if ( $val ) {
                $cur[ $ck ] = $val;
            }
        }

        $db->save_settings( $cur );

        wp_send_json_success( [
            'message'  => __( 'Settings saved.', 'aiforya-faq-generator' ),
            'settings' => $cur,
        ] );
    }

    // =========================================================================
    // Éditeur manuel de FAQ.
    // =========================================================================

    public function handle_save_faq(): void {
        $this->guard();

        $post_id = absint( wp_unslash( $_POST['post_id'] ?? 0 ) );
        if ( $post_id <= 0 || ! get_post( $post_id ) ) {
            wp_send_json_error( [ 'message' => __( 'Invalid post.', 'aiforya-faq-generator' ) ], 400 );
        }

        $items = $this->sanitize_qa_items( map_deep( wp_unslash( $_POST['items'] ?? [] ), 'wp_kses_post' ) );

        // Aucune question valide → suppression de la FAQ existante.
        if ( empty( $items ) ) {
            $this->db()->delete_faq_by_post_id( $post_id );
            wp_send_json_success( [
                'message' => __( 'FAQ emptied (no questions).', 'aiforya-faq-generator' ),
                'count'   => 0,
            ] );
        }

        $schema = [
            '@context'   => 'https://schema.org',
            '@type'      => 'FAQPage',
            'mainEntity' => $items,
        ];

        $post         = get_post( $post_id );
        $source_hash  = md5( $post->post_title . "\n\n" . wp_strip_all_tags( $post->post_content ) );
        $result       = $this->db()->save_faq( $post_id, wp_json_encode( $schema ), $source_hash );

        if ( is_wp_error( $result ) ) {
            wp_send_json_error( [ 'message' => $result->get_error_message() ], 400 );
        }

        wp_send_json_success( [
            'message' => __( 'FAQ saved.', 'aiforya-faq-generator' ),
            'count'   => count( $items ),
        ] );
    }

    public function handle_delete_faq(): void {
        $this->guard();

        $post_id = absint( wp_unslash( $_POST['post_id'] ?? 0 ) );
        if ( $post_id <= 0 ) {
            wp_send_json_error( [ 'message' => __( 'Invalid post.', 'aiforya-faq-generator' ) ], 400 );
        }

        $this->db()->delete_faq_by_post_id( $post_id );
        wp_send_json_success( [ 'message' => __( 'FAQ deleted.', 'aiforya-faq-generator' ) ] );
    }

    public function handle_get_post_content(): void {
        $this->guard();

        $post_id = absint( wp_unslash( $_POST['post_id'] ?? 0 ) );
        $post    = $post_id > 0 ? get_post( $post_id ) : null;
        if ( ! $post ) {
            wp_send_json_error( [ 'message' => __( 'Post not found.', 'aiforya-faq-generator' ) ], 400 );
        }

        $existing = $this->db()->get_faq_by_post_id( $post_id );
        $items    = [];
        if ( $existing && ! empty( $existing->content_json ) ) {
            $data = json_decode( (string) $existing->content_json, true );
            if ( ! empty( $data['mainEntity'] ) && is_array( $data['mainEntity'] ) ) {
                foreach ( $data['mainEntity'] as $it ) {
                    if ( ! empty( $it['name'] ) && ! empty( $it['acceptedAnswer']['text'] ) ) {
                        $items[] = [
                            'question' => (string) $it['name'],
                            'answer'   => (string) $it['acceptedAnswer']['text'],
                        ];
                    }
                }
            }
        }

        wp_send_json_success( [
            'post_title' => $post->post_title,
            'items'      => $items,
            'has_faq'    => ! empty( $items ),
        ] );
    }

    // =========================================================================
    // Détection automatique (parser règle-based, sans IA, 0 réseau).
    // =========================================================================

    public function handle_detect_faq(): void {
        $this->guard();

        $post_id = absint( wp_unslash( $_POST['post_id'] ?? 0 ) );
        $post    = $post_id > 0 ? get_post( $post_id ) : null;
        if ( ! $post ) {
            wp_send_json_error( [ 'message' => __( 'Post not found.', 'aiforya-faq-generator' ) ], 400 );
        }

        $parser = new Aiforya_Fg_Parser();
        $items  = $parser->extract_from_content( (string) $post->post_content );

        if ( empty( $items ) ) {
            wp_send_json_error( [
                'message' => __( 'No question detected. Add headings (H2/H3) ending with a question mark followed by an answer paragraph, or enter your questions by hand.', 'aiforya-faq-generator' ),
            ] );
        }

        wp_send_json_success( [
            'items'   => $items,
            'count'   => count( $items ),
            'message' => sprintf(
                /* translators: %d: nombre de questions détectées */
                _n( '%d question detected.', '%d questions detected.', count( $items ), 'aiforya-faq-generator' ),
                count( $items )
            ),
        ] );
    }
}