<?php
if (!defined('ABSPATH')) exit;

// -------------------- REST API: FAQ Generator (Client) --------------------
add_action('rest_api_init', function() {
    register_rest_route('aicont/v1', '/generate_faq', [
        'methods' => 'POST',
        'callback' => 'aicont_generate_faq_api',
        'permission_callback' => function() {
            return current_user_can('edit_posts');
        },
        'args' => [
            'keyword'       => ['required' => true,  'type' => 'string',  'sanitize_callback' => 'sanitize_text_field'],
            'post_id'       => ['required' => true,  'type' => 'integer', 'sanitize_callback' => 'absint'],
            'post_title'    => ['required' => true,  'type' => 'string',  'sanitize_callback' => 'sanitize_text_field'],
            'api_key'       => ['required' => false, 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field'],
            'site_language' => ['required' => false, 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field'],
            'site_title'    => ['required' => false, 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field'],
            'prompt'        => ['required' => false, 'type' => 'string',  'sanitize_callback' => 'sanitize_textarea_field'],
        ]
    ]);
});

function aicont_generate_faq_api($request) {
    global $aicont_api_key, $aicont_site_language, $aicont_site_title;

    $keyword       = $request->get_param('keyword');
    $post_id       = $request->get_param('post_id');
    $post_title    = $request->get_param('post_title');
    $api_key       = $request->get_param('api_key') ?: $aicont_api_key;
    $site_language = $request->get_param('site_language') ?: $aicont_site_language;
    $site_title    = $request->get_param('site_title') ?: $aicont_site_title;
    $prompt        = $request->get_param('prompt');

    // Validation
    if (empty($keyword)) return new WP_REST_Response(['success' => false, 'error_code' => 'err_keyword_empty'], 400);
    if (empty($post_id)) return new WP_REST_Response(['success' => false, 'error_code' => 'err_post_id_invalid'], 400);
    if (empty($post_title)) return new WP_REST_Response(['success' => false, 'error_code' => 'err_post_title_missing'], 400);

    $post = get_post($post_id);
    if (!$post) return new WP_REST_Response(['success' => false, 'error_code' => 'err_post_not_found'], 404);

    $client_site_url = home_url('', 'https');
    if (empty($client_site_url)) return new WP_REST_Response(['success' => false, 'error_code' => 'err_site_url'], 500);

    $server_url = 'https://webtinus.com/wp-json/aicont/v1/generate_faq';
    $body = wp_json_encode([
        'keyword'         => $keyword,
        'post_id'         => $post_id,
        'post_title'      => $post_title,
        'prompt'          => $prompt,
        'api_key'         => $api_key,
        'client_site_url' => $client_site_url,
        'site_title'      => $site_title,
        'site_language'   => $site_language
    ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

    $response = wp_remote_post($server_url, [
        'headers' => ['Content-Type' => 'application/json', 'X-Client-Site' => $client_site_url],
        'body' => $body,
        'timeout' => 120,
        'sslverify' => true
    ]);

    if (is_wp_error($response)) {
        return new WP_REST_Response(['success' => false, 'error_code' => 'err_connection_failed'], 500);
    }

    $status_code = wp_remote_retrieve_response_code($response);
    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);

    if ($status_code !== 200 || !isset($data['success'])) {
        $code = $data['error_code'] ?? 'err_server_error';
        return new WP_REST_Response(['success' => false, 'error_code' => $code], $status_code);
    }

    if (!$data['success'] || empty($data['faq_content'])) {
        return new WP_REST_Response(['success' => false, 'error_code' => $data['error_code'] ?? 'err_faq_empty'], 500);
    }

    $faq_content = trim($data['faq_content']);
    $lines = array_filter(preg_split('/\r\n|\r|\n/', $faq_content), 'trim');

    $template_type = get_option('aicont_plugin_template_type', 'ready');
    $faq_html = '';

    if ($template_type === 'custom') {
        $article_class  = sanitize_html_class(get_option('aicont_plugin_faq_article_id', 'faq-article'));
        $question_class = sanitize_html_class(get_option('aicont_plugin_faq_question_id', 'faq-question'));
        $answer_class   = sanitize_html_class(get_option('aicont_plugin_faq_answer_id', 'faq-answer'));

        $faq_html .= "<article class='" . esc_attr($article_class) . "'>";
        $faq_html .= "<h2>" . esc_html__('Frequently Asked Questions', 'aicontify') . "</h2>";
        for ($i = 0; $i < count($lines); $i += 2) {
            $question = trim($lines[$i] ?? '');
            $answer   = trim($lines[$i + 1] ?? '');
            if ($question && $answer) {
                $faq_html .= "<h3 class='" . esc_attr($question_class) . "'>" . esc_html($question) . "</h3>";
                $faq_html .= "<p class='" . esc_attr($answer_class) . "'>" . wp_kses_post($answer) . "</p>";
            }
        }
        $faq_html .= "</article>";
    } else {
        $faq_html .= "<div class='aicont-faq-section'>";
        $faq_html .= "<h2>" . esc_html__('Frequently Asked Questions', 'aicontify') . "</h2>";
        for ($i = 0; $i < count($lines); $i += 2) {
            $question = trim($lines[$i] ?? '');
            $answer   = trim($lines[$i + 1] ?? '');
            if ($question && $answer) {
                $faq_html .= "<h3>" . esc_html($question) . "</h3>";
                $faq_html .= "<p>" . wp_kses_post($answer) . "</p>";
            }
        }
        $faq_html .= "</div>";
    }

    $saved = 0;
    if ($template_type === 'custom') {
        $acf_repeater_field = get_option('aicont_plugin_faq_article_id', 'faq_post_single');
        $acf_question_field = get_option('aicont_plugin_faq_question_id', 'tit_faq_post_single');
        $acf_answer_field   = get_option('aicont_plugin_faq_answer_id', 'desc_faq_post_single');

        if (!function_exists('delete_field') || !function_exists('add_row')) {
            return new WP_REST_Response(['success' => false, 'error_code' => 'err_acf_missing'], 400);
        }

        delete_field($acf_repeater_field, $post_id);
        for ($i = 0; $i < count($lines); $i += 2) {
            $question = trim($lines[$i] ?? '');
            $answer   = trim($lines[$i + 1] ?? '');
            if ($question && $answer) {
                $added = add_row($acf_repeater_field, [
                    $acf_question_field => $question,
                    $acf_answer_field   => $answer,
                ], $post_id);
                if ($added) $saved++;
            }
        }

        if ($saved === 0) {
            return new WP_REST_Response(['success' => false, 'error_code' => 'err_save_failed'], 500);
        }

    } else {
        $current_content = $post->post_content;
        $post_data = [
            'ID' => $post_id,
            'post_content' => $current_content . "\n" . wp_kses_post($faq_html),
            'post_modified' => current_time('mysql'),
            'post_modified_gmt' => current_time('mysql', 1),
        ];
        $post_updated = wp_update_post($post_data, true);
        if (is_wp_error($post_updated)) {
            return new WP_REST_Response(['success' => false, 'error_code' => 'err_save_failed'], 500);
        }
    }

    return new WP_REST_Response([
        'success' => true,
        'message_code' => 'success_faq_generated',
        'faq_content' => $faq_content,
        'faq_html' => $faq_html
    ], 200);
}