<?php
/**
 * REST API Endpoint
 */

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

class WPTheMoon_REST_API {

    public function __construct() {
        add_action( 'rest_api_init', array( $this, 'register_routes' ) );
    }

    public function register_routes() {
        $namespace = function_exists( 'wpthemoon_rest_namespace' ) ? wpthemoon_rest_namespace() : apply_filters( 'wpthemoon_rest_namespace', 'wpthemoon/v1' );

        // Chatbot endpoint removed

        register_rest_route( $namespace, '/intent/analyze', array(
            'methods'             => WP_REST_Server::CREATABLE,
            'callback'            => array( $this, 'analyze_intent' ),
            'permission_callback' => array( $this, 'check_permission' ),
        ) );

        register_rest_route( $namespace, '/article/generate', array(
            'methods'             => WP_REST_Server::CREATABLE,
            'callback'            => array( $this, 'generate_article_v2' ),
            'permission_callback' => array( $this, 'check_permission' ),
        ) );

        register_rest_route( $namespace, '/page/generate', array(
            'methods'             => WP_REST_Server::CREATABLE,
            'callback'            => array( $this, 'generate_page' ),
            'permission_callback' => array( $this, 'check_permission' ),
        ) );

        register_rest_route( $namespace, '/podcast/generate', array(
            'methods'             => WP_REST_Server::CREATABLE,
            'callback'            => array( $this, 'generate_podcast' ),
            'permission_callback' => array( $this, 'check_permission' ),
        ) );

        register_rest_route( $namespace, '/user/credits', array(
            'methods'             => WP_REST_Server::READABLE,
            'callback'            => array( $this, 'get_user_credits' ),
            'permission_callback' => array( $this, 'check_permission' ),
        ) );
    }

    public function check_permission() {
        return current_user_can( 'edit_posts' ) || current_user_can( 'edit_pages' );
    }

    /**
     * 代理播客生成接口，并将音频保存到媒体库。
     */
    public function generate_podcast( WP_REST_Request $request ) {
        $content = $request->get_param( 'content' );
        $voice   = sanitize_text_field( $request->get_param( 'voice' ) ?: 'Rachel' );

        if ( empty( $content ) ) {
            return new WP_Error( 'invalid_request', __( 'Content is required.', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $client = new WPTheMoon_API_Client();
        $result = $client->post(
            '/podcast',
            array(
                'content' => $content,
                'voice'   => $voice,
            )
        );

        if ( is_wp_error( $result ) ) {
            return $this->ensure_api_result( $result );
        }

        // 删除积分缓存，确保前端刷新时拿到最新积分
        delete_transient( 'wpthemoon_credits_cache' );

        if ( ! empty( $result['audio_url'] ) ) {
            $sideload_result = $this->sideload_audio_to_media_library( $result['audio_url'] );
            if ( ! is_wp_error( $sideload_result ) ) {
                $result['audio_url']     = $sideload_result['url'];
                $result['attachment_id'] = $sideload_result['id'];
            }
        }

        return rest_ensure_response( $result );
    }

    /**
     * 将远程音频文件下载并导入 WordPress 媒体库。
     *
     * @param string $audio_url 远程音频 URL。
     * @return array|WP_Error 包含 id 和 url 的数组，或错误。
     */
    private function sideload_audio_to_media_library( $audio_url ) {
        require_once ABSPATH . 'wp-admin/includes/file.php';
        require_once ABSPATH . 'wp-admin/includes/media.php';
        require_once ABSPATH . 'wp-admin/includes/image.php';

        $tmp_file = download_url( $audio_url, 60 );
        if ( is_wp_error( $tmp_file ) ) {
            return $tmp_file;
        }

        $path     = wp_parse_url( $audio_url, PHP_URL_PATH );
        $filename = $path ? wp_basename( $path ) : 'podcast.mp3';

        if ( false === strpos( $filename, '.' ) ) {
            $filename .= '.mp3';
        }

        $file_array = array(
            'name'     => sanitize_file_name( $filename ),
            'tmp_name' => $tmp_file,
        );

        $attachment_id = media_handle_sideload( $file_array, 0 );
        if ( is_wp_error( $attachment_id ) ) {
            @unlink( $tmp_file );
            return $attachment_id;
        }

        return array(
            'id'  => $attachment_id,
            'url' => wp_get_attachment_url( $attachment_id ),
        );
    }

    /**
     * 统一处理主站 API 响应。
     */
    private function ensure_api_result( $result ) {
        if ( is_wp_error( $result ) ) {
            $code = $result->get_error_code();
            $data = $result->get_error_data( $code );
            $status = ( is_array( $data ) && isset( $data['status'] ) ) ? $data['status'] : 500;
            
            return new WP_Error( $code, $result->get_error_message(), array( 'status' => $status ) );
        }

        return rest_ensure_response( $result );
    }

    /**
     * 代理意图分析接口。
     */
    public function analyze_intent( WP_REST_Request $request ) {
        $keyword       = sanitize_text_field( $request->get_param( 'keyword' ) );
        $topic_idea    = sanitize_textarea_field( $request->get_param( 'topicIdea' ) );
        $reference_url = esc_url_raw( $request->get_param( 'referenceUrl' ) );

        if ( empty( $keyword ) ) {
            return new WP_Error( 'invalid_request', __( 'Keyword is required.', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $api_key = get_option( 'wpthemoon_api_key' );
        $base_url = defined('WPTHEMOON_API_BASE_URL') ? WPTHEMOON_API_BASE_URL : 'https://www.wpthemoon.com/api/open/v1';

        if ( empty( $api_key ) ) {
            return new WP_Error( 'no_api_key', __( 'API Key is not configured', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $endpoint = $base_url . '/intent';

        $body = array(
            'keyword'      => $keyword,
            'topicIdea'    => $topic_idea,
            'referenceUrl' => $reference_url,
        );

        $body_json = wp_json_encode( $body );

        // 1. 设置流式响应头（application/json 用于意图分析）
        if (!headers_sent()) {
            header('Content-Type: application/json; charset=utf-8');
            header('Cache-Control: no-cache, no-transform');
            header('X-Accel-Buffering: no');
            header('Connection: keep-alive');
        }

        // 2. 关闭 PHP 输出缓冲
        while (ob_get_level()) {
            ob_end_clean();
        }

        // 3. 使用 cURL 流式透传
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $endpoint);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $body_json);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'x-api-key: ' . $api_key,
            'Content-Type: application/json',
            'Accept: application/json',
        ));
        curl_setopt($ch, CURLOPT_TIMEOUT, 120); // 2分钟超时
        curl_setopt($ch, CURLOPT_ENCODING, '');
        curl_setopt($ch, CURLOPT_HEADER, 0);
        
        // 实时输出
        curl_setopt($ch, CURLOPT_WRITEFUNCTION, function($ch, $data) {
            echo $data;
            if (ob_get_level() > 0) ob_flush();
            flush();
            return strlen($data);
        });

        curl_exec($ch);

        if (curl_errno($ch)) {
            $error_msg = curl_error($ch);
            if (strpos($error_msg, 'bad decrypt') === false && strpos($error_msg, 'LibreSSL') === false) {
                echo "\n" . wp_json_encode(array('error' => $error_msg));
            }
        }

        curl_close($ch);
        exit;
    }

    /**
     * 生成文章 (流式响应)
     */
    public function generate_article_v2( WP_REST_Request $request ) {
        $keyword         = sanitize_text_field( $request->get_param( 'keyword' ) );
        $analysis        = $request->get_param( 'analysis' );
        $article_type    = sanitize_text_field( $request->get_param( 'articleType' ) ?: 'general' );
        $topic_idea      = sanitize_textarea_field( $request->get_param( 'topicIdea' ) );
        $reference_url   = esc_url_raw( $request->get_param( 'referenceUrl' ) );
        $transcript      = $request->get_param( 'transcript' );
        $target_audience = sanitize_text_field( $request->get_param( 'targetAudience' ) ) ?: get_option( 'wpthemoon_target_audience' );

        if ( empty( $keyword ) ) {
            return new WP_Error( 'invalid_request', __( 'Keyword is required.', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        if ( empty( $analysis ) ) {
            return new WP_Error( 'invalid_request', __( 'Analysis result is required.', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $api_key = get_option( 'wpthemoon_api_key' );
        $base_url = defined('WPTHEMOON_API_BASE_URL') ? WPTHEMOON_API_BASE_URL : 'https://www.wpthemoon.com/api/open/v1';

        if ( empty( $api_key ) ) {
            return new WP_Error( 'no_api_key', __( 'API Key is not configured', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $endpoint = $base_url . '/article';

        $body = array(
            'keyword'        => $keyword,
            'analysis'       => $analysis,
            'articleType'    => $article_type,
            'topicIdea'      => $topic_idea,
            'referenceUrl'   => $reference_url,
            'transcript'     => $transcript,
            'targetAudience' => $target_audience,
        );

        $body_json = wp_json_encode( $body );

        // 1. 设置流式响应头（text/plain 以匹配 Next.js API）
        if (!headers_sent()) {
            header('Content-Type: text/plain; charset=utf-8');
            header('Cache-Control: no-cache, no-transform');
            header('X-Accel-Buffering: no'); // 禁用 Nginx 缓冲
            header('Connection: keep-alive');
        }

        // 2. 彻底关闭 PHP 输出缓冲
        while (ob_get_level()) {
            ob_end_clean();
        }

        // 3. 使用 cURL 流式透传
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $endpoint);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $body_json);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'x-api-key: ' . $api_key,
            'Content-Type: application/json',
            'Accept: text/plain', // 接受 text/plain 响应
        ));
        curl_setopt($ch, CURLOPT_TIMEOUT, 300);
        curl_setopt($ch, CURLOPT_ENCODING, ''); // 自动处理 gzip 解压
        curl_setopt($ch, CURLOPT_HEADER, 0); // 不包含响应头
        
        // 关键：实时将接收到的数据吐给客户端
        curl_setopt($ch, CURLOPT_WRITEFUNCTION, function($ch, $data) {
            echo $data;
            if (ob_get_level() > 0) ob_flush();
            flush();
            return strlen($data);
        });

        curl_exec($ch);

        if (curl_errno($ch)) {
            $error_msg = curl_error($ch);
            // macOS LibreSSL 在处理 HTTP/2 连接结束时常报 bad decrypt, errno 0。
            // 此时流数据通常已完整接收，我们忽略这个特定的底层报错。
            if (strpos($error_msg, 'bad decrypt') === false && strpos($error_msg, 'LibreSSL') === false) {
                echo "\n__ERROR__\n" . wp_json_encode(array('message' => $error_msg));
            }
        }

        curl_close($ch);

        // 必须终止，防止 WordPress 追加多余的 JSON
        exit;
    }

    /**
     * 生成页面 (流式响应)
     */
    public function generate_page( WP_REST_Request $request ) {
        $prompt     = sanitize_textarea_field( $request->get_param( 'prompt' ) );
        $page_type  = sanitize_text_field( $request->get_param( 'pageType' ) ?: 'general' );
        $page_title = sanitize_text_field( $request->get_param( 'pageTitle' ) );

        if ( empty( $prompt ) ) {
            return new WP_Error( 'invalid_request', __( 'Prompt is required.', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $api_key = get_option( 'wpthemoon_api_key' );
        $base_url = defined('WPTHEMOON_API_BASE_URL') ? WPTHEMOON_API_BASE_URL : 'https://www.wpthemoon.com/api/open/v1';

        if ( empty( $api_key ) ) {
            return new WP_Error( 'no_api_key', __( 'API Key is not configured', 'wpthemoon' ), array( 'status' => 400 ) );
        }

        $endpoint = $base_url . '/page';

        $body = array(
            'prompt'    => $prompt,
            'pageType'  => 'landing' === $page_type ? 'landing' : 'general',
            'pageTitle' => $page_title,
        );

        $body_json = wp_json_encode( $body );

        if (!headers_sent()) {
            header('Content-Type: application/json; charset=utf-8');
            header('Cache-Control: no-cache, no-transform');
            header('X-Accel-Buffering: no');
            header('Connection: keep-alive');
        }

        while (ob_get_level()) {
            ob_end_clean();
        }

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $endpoint);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $body_json);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'x-api-key: ' . $api_key,
            'Content-Type: application/json',
            'Accept: application/json',
        ));
        curl_setopt($ch, CURLOPT_TIMEOUT, 300);
        curl_setopt($ch, CURLOPT_ENCODING, '');
        curl_setopt($ch, CURLOPT_HEADER, 0);

        curl_setopt($ch, CURLOPT_WRITEFUNCTION, function($ch, $data) {
            echo $data;
            if (ob_get_level() > 0) ob_flush();
            flush();
            return strlen($data);
        });

        curl_exec($ch);

        if (curl_errno($ch)) {
            $error_msg = curl_error($ch);
            if (strpos($error_msg, 'bad decrypt') === false && strpos($error_msg, 'LibreSSL') === false) {
                echo "\n" . wp_json_encode(array('error' => $error_msg));
            }
        }

        curl_close($ch);
        exit;
    }

    /**
     * 获取用户积分（带缓存）
     */
    public function get_user_credits( WP_REST_Request $request ) {
        // 尝试从缓存获取（缓存 2 分钟，编辑器中刷新更频繁）
        $credits_info = get_transient( 'wpthemoon_credits_cache' );
        
        if ( false === $credits_info ) {
            $client = new WPTheMoon_API_Client();
            $credits_info = $client->get_credits();
            
            if ( is_wp_error( $credits_info ) ) {
                return $credits_info;
            }
            
            // 缓存成功的响应
            set_transient( 'wpthemoon_credits_cache', $credits_info, 2 * MINUTE_IN_SECONDS );
        }
        
        return rest_ensure_response( $credits_info );
    }
}