<?php
/**
 * AKSRT Search Push Service
 *
 * 提供搜索引擎主动推送能力。当前支持百度推送。
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Search_Push {

    private static $instance = null;

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

    /**
     * 绑定运行时钩子：发布/更新主动推送 + 前台自动推送 JS。
     */
    public function init(): void {
        add_action('transition_post_status', [$this, 'on_transition_post_status'], 10, 3);
        add_action('wp_footer', [$this, 'output_auto_push_script'], 99);
    }

    /**
     * 文章发布/更新时主动推送链接到百度。
     *
     * @param string  $new_status 新状态。
     * @param string  $old_status 旧状态。
     * @param WP_Post $post       文章对象。
     */
    public function on_transition_post_status(string $new_status, string $old_status, $post): void {
        if (!($post instanceof WP_Post)) {
            return;
        }
        if ($new_status !== 'publish') {
            return;
        }
        if (wp_is_post_revision($post->ID) || wp_is_post_autosave($post->ID)) {
            return;
        }
        // 仅推送公开可索引的内容类型。
        $allowed = function_exists('aksrt_searchable_post_types')
            ? aksrt_searchable_post_types()
            : ['post'];
        if (!in_array($post->post_type, $allowed, true)) {
            return;
        }

        $config = $this->get_config();
        if (empty($config['baidu_push_enabled'])) {
            return;
        }

        $is_new = $old_status !== 'publish';
        if ($is_new && empty($config['baidu_push_on_publish'])) {
            return;
        }
        if (!$is_new && empty($config['baidu_push_on_update'])) {
            return;
        }

        $this->push_url((string) get_permalink($post));
    }

    /**
     * 前台输出百度自动推送 JS（由 wp_footer 调用）。
     */
    public function output_auto_push_script(): void {
        if (is_admin()) {
            return;
        }
        $script = $this->get_auto_push_script();
        if ($script !== '') {
            echo $script; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped — 固定常量脚本，无用户输入
        }
    }

    /**
     * 推送单条 URL 到百度
     *
     * @param string $url 待推送的完整 URL
     * @return array{success: bool, message: string, result: array}
     */
    public function push_url(string $url): array {
        $config = $this->get_config();

        if (empty($config['baidu_push_enabled'])) {
            return ['success' => false, 'message' => __('百度推送未启用', 'aksrt'), 'result' => []];
        }

        $token = (string) ($config['baidu_push_token'] ?? '');
        if ($token === '') {
            return ['success' => false, 'message' => __('推送 Token 未配置', 'aksrt'), 'result' => []];
        }

        $api_url = "http://data.zz.baidu.com/urls?site=" . rawurlencode(home_url('/')) . "&token={$token}";

        $response = wp_remote_post($api_url, [
            'timeout' => 10,
            'headers' => ['Content-Type' => 'text/plain'],
            'body'    => $url,
        ]);

        if (is_wp_error($response)) {
            $this->log('error', $url, $response->get_error_message());
            return ['success' => false, 'message' => $response->get_error_message(), 'result' => []];
        }

        $body   = json_decode(wp_remote_retrieve_body($response), true);
        $status = wp_remote_retrieve_response_code($response);

        if ($status === 200 && isset($body['success'])) {
            $this->log('success', $url, wp_json_encode($body));
            return ['success' => true, 'message' => __('推送成功', 'aksrt'), 'result' => $body];
        }

        $err_msg = $body['message'] ?? ($body['error'] ?? sprintf('HTTP %d', $status));
        $this->log('error', $url, $err_msg);
        return ['success' => false, 'message' => $err_msg, 'result' => $body ?? []];
    }

    /**
     * 批量推送 URL
     *
     * @param string[] $urls
     * @return array{success: int, failed: int, results: array}
     */
    public function push_batch(array $urls): array {
        $config     = $this->get_config();
        $batch_size = max(1, min(500, (int) ($config['baidu_push_batch_size'] ?? 50)));
        $success    = 0;
        $failed     = 0;
        $results    = [];

        $chunks = array_chunk($urls, $batch_size);
        foreach ($chunks as $chunk) {
            $token    = (string) ($config['baidu_push_token'] ?? '');
            $api_url  = "http://data.zz.baidu.com/urls?site=" . rawurlencode(home_url('/')) . "&token={$token}";
            $body_str = implode("\n", $chunk);

            $response = wp_remote_post($api_url, [
                'timeout' => 15,
                'headers' => ['Content-Type' => 'text/plain'],
                'body'    => $body_str,
            ]);

            if (is_wp_error($response)) {
                $failed += count($chunk);
                $results[] = ['error' => $response->get_error_message()];
                continue;
            }

            $body = json_decode(wp_remote_retrieve_body($response), true);
            if (isset($body['success'])) {
                $success += (int) ($body['success'] ?? 0);
                $failed  += (int) ($body['not_same_site'] ?? 0) + (int) ($body['not_valid'] ?? 0);
            } else {
                $failed += count($chunk);
            }
            $results[] = $body ?? [];
        }

        return ['success' => $success, 'failed' => $failed, 'results' => $results];
    }

    /**
     * 获取自动推送 JS 代码
     */
    public function get_auto_push_script(): string {
        $config = $this->get_config();
        if (empty($config['baidu_push_enabled']) || empty($config['baidu_push_auto'])) {
            return '';
        }

        $site_url = home_url('/');
        return <<<SCRIPT
<script>
(function(){
    var bp = document.createElement('script');
    var curProtocol = window.location.protocol.split(':')[0];
    if (curProtocol === 'https') {
        bp.src = 'https://zz.bdstatic.com/linksubmit/push.js';
    } else {
        bp.src = 'http://push.zhanzhang.baidu.com/push.js';
    }
    var s = document.getElementsByTagName("script")[0];
    s.parentNode.insertBefore(bp, s);
})();
</script>
SCRIPT;
    }

    /**
     * 获取服务运行时状态
     */
    public function get_status(): array {
        $config  = $this->get_config();
        $enabled = !empty($config['baidu_push_enabled']);
        $token   = (string) ($config['baidu_push_token'] ?? '');

        $missing = [];
        if ($enabled && $token === '') {
            $missing[] = 'baidu_push_token';
        }

        return [
            'enabled'        => $enabled,
            'provider'       => 'baidu',
            'configured'     => $enabled && $token !== '',
            'available'      => $enabled && $token !== '',
            'verified'       => !empty($config['baidu_push_verified']),
            'transport'      => 'http_api',
            'missing_fields' => $missing,
            'auto_push'      => !empty($config['baidu_push_auto']),
            'on_publish'     => !empty($config['baidu_push_on_publish']),
            'on_update'      => !empty($config['baidu_push_on_update']),
            'batch_size'     => max(1, (int) ($config['baidu_push_batch_size'] ?? 50)),
        ];
    }

    private function get_config(): array {
        if (class_exists('AKSRT_Settings')) {
            return AKSRT_Settings::get_search_push_settings();
        }
        return ['baidu_push_enabled' => false];
    }

    private function log(string $level, string $url, string $message): void {
        if (!defined('WP_DEBUG') || !WP_DEBUG) return;
        error_log(sprintf('[AKSRT Search Push] [%s] URL: %s — %s', $level, $url, $message));
    }
}