<?php
/**
 * The logic to process the Bulk Add Documents form submissions.
 */

// SECURITY: Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class TTDVR_Bulk_Upload {

    public function __construct() {
        // Listens for the exact action name in your hidden form field.
        add_action( 'admin_post_ttdvr_bulk_add_documents', array( $this, 'process_bulk_form' ) );
    }

    /**
     * Catch the form data, prevent duplicates, save to the database, and redirect.
     */
    public function process_bulk_form() {
        global $wpdb; // Call the WordPress database object
        
        // 1. SECURITY CHECKS
        if ( ! isset( $_POST['ttdvr_bulk_add_documents_nonce_field'] ) || ! wp_verify_nonce( $_POST['ttdvr_bulk_add_documents_nonce_field'], 'ttdvr_bulk_add_documents_nonce' ) ) {
            wp_die( esc_html__( 'Security check failed. Please refresh the page and try again.', '24tt-document-verifier' ) );
        }

        if ( ! current_user_can( 'manage_ttdvr_documents' ) ) {
            wp_die( esc_html__( 'You do not have permission to perform this action.', '24tt-document-verifier' ) );
        }

        // 2. PROCESS THE DATA
        $documents       = isset( $_POST['documents'] ) ? $_POST['documents'] : array();
        $success_count   = 0;
        $duplicate_count = 0;

        if ( ! empty( $documents ) && is_array( $documents ) ) {
            
            foreach ( $documents as $doc ) {
                $title  = isset( $doc['title'] ) ? sanitize_text_field( $doc['title'] ) : '';
                $doc_id = isset( $doc['verification_id'] ) ? sanitize_text_field( $doc['verification_id'] ) : '';

                if ( empty( $title ) || empty( $doc_id ) ) {
                    continue; 
                }

                // --- NEW UNIQUE KEY CHECK ---
                // Query the database directly to see if this Document ID already exists
                $existing_id = $wpdb->get_var( $wpdb->prepare( 
                    "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_ttdvr_verification_id' AND meta_value = %s LIMIT 1", 
                    $doc_id 
                ) );

                // If it exists, count it as a duplicate and skip to the next row!
                if ( $existing_id ) {
                    $duplicate_count++;
                    continue;
                }
                // ----------------------------

                $doc_type = isset( $doc['document_type'] ) ? sanitize_text_field( $doc['document_type'] ) : '';
                if ( $doc_type === 'Other' && ! empty( $doc['document_type_other'] ) ) {
                    $doc_type = sanitize_text_field( $doc['document_type_other'] );
                }

                $post_id = wp_insert_post( array(
                    'post_title'  => $title,
                    'post_type'   => 'ttdvr_document',
                    'post_status' => 'publish'
                ) );

                if ( ! is_wp_error( $post_id ) ) {
                    update_post_meta( $post_id, '_ttdvr_verification_id', $doc_id );
                    
                    if ( ! empty( $doc['recipient_name'] ) ) update_post_meta( $post_id, '_ttdvr_recipient_name', sanitize_text_field( $doc['recipient_name'] ) );
                    if ( ! empty( $doc_type ) ) update_post_meta( $post_id, '_ttdvr_document_type', $doc_type );
                    if ( ! empty( $doc['course_subject'] ) ) update_post_meta( $post_id, '_ttdvr_course_subject', sanitize_text_field( $doc['course_subject'] ) );
                    if ( ! empty( $doc['issued_date'] ) ) update_post_meta( $post_id, '_ttdvr_issued_date', sanitize_text_field( $doc['issued_date'] ) );

                    if ( ! empty( $doc['category_id'] ) ) {
                        wp_set_object_terms( $post_id, intval( $doc['category_id'] ), 'ttdvr_doc_category' );
                    }

                    $success_count++;
                }
            }
        }

        // 3. SET DYNAMIC FEEDBACK MESSAGES
        if ( $success_count > 0 ) {
            $message = sprintf( esc_html__( 'Success! %d documents were added to your database.', '24tt-document-verifier' ), $success_count );
            
            // Append a warning if duplicates were caught
            if ( $duplicate_count > 0 ) {
                $message .= ' ' . sprintf( esc_html__( 'However, %d documents were skipped because their Document IDs already exist.', '24tt-document-verifier' ), $duplicate_count );
                set_transient( 'ttdvr_bulk_upload_message_type', 'warning', 45 ); // Yellow warning banner
            } else {
                set_transient( 'ttdvr_bulk_upload_message_type', 'success', 45 ); // Green success banner
            }
            
            set_transient( 'ttdvr_bulk_upload_message', $message, 45 );

        } elseif ( $duplicate_count > 0 ) {
            // They submitted only duplicates
            set_transient( 'ttdvr_bulk_upload_message', sprintf( esc_html__( 'Failed: All %d documents were skipped because those Document IDs already exist.', '24tt-document-verifier' ), $duplicate_count ), 45 );
            set_transient( 'ttdvr_bulk_upload_message_type', 'error', 45 );
        } else {
            set_transient( 'ttdvr_bulk_upload_message', esc_html__( 'No documents were added. Please ensure the Title and Doc ID fields are filled out.', '24tt-document-verifier' ), 45 );
            set_transient( 'ttdvr_bulk_upload_message_type', 'error', 45 );
        }

        // 4. REDIRECT
        wp_safe_redirect( admin_url( 'admin.php?page=ttdvr-tools' ) );
        exit;
    }
}

new TTDVR_Bulk_Upload();