<?php
// +----------------------------------------------------------------------
// | CRMEB [ CRMEB赋能开发者，助力企业发展 ]
// +----------------------------------------------------------------------
// | Copyright (c) 2016~2023 https://www.crmeb.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed CRMEB并不是自由软件，未经许可不能去掉CRMEB相关版权
// +----------------------------------------------------------------------
// | Author: CRMEB Team <admin@crmeb.com>
// +----------------------------------------------------------------------
declare (strict_types=1);

namespace app\services\kefu;

use crmeb\services\HttpService;
use think\facade\Env;
use think\facade\Log;

/**
 * Coze 智能体调用服务
 */
class CozeServices
{
    protected $apiBase;

    protected $apiToken;

    protected $botId;

    protected $timeout;

    protected $fallbackReply;

    public function __construct()
    {
        $this->apiBase = rtrim((string)$this->env(['coze.coze_api_base', 'coze.api_base'], 'COZE_API_BASE', 'https://api.coze.cn'), '/');
        $this->apiToken = (string)$this->env(['coze.coze_access_token', 'coze.access_token', 'coze.api_token'], 'COZE_ACCESS_TOKEN', '');
        $this->botId = (string)$this->env(['coze.coze_bot_id', 'coze.bot_id'], 'COZE_BOT_ID', '');
        $this->timeout = max(1, (int)$this->env(['coze.coze_timeout', 'coze.timeout'], 'COZE_TIMEOUT', '15'));
        $this->fallbackReply = trim((string)$this->env(['coze.coze_fallback_reply', 'coze.fallback_reply'], 'COZE_FALLBACK_REPLY', ''));
    }

    public static function isEnabled(): bool
    {
        $value = Env::get('coze.coze_enable', Env::get('coze.enable', getenv('COZE_ENABLE') ?: false));
        return filter_var($value, FILTER_VALIDATE_BOOLEAN);
    }

    /**
     * 发送文本消息到 Coze，返回智能体文本回复。
     */
    public function chatText(string $userId, string $content): string
    {
        $content = trim($content);
        if (!self::isEnabled() || $content === '' || $this->apiToken === '' || $this->botId === '') {
            return '';
        }

        $payload = [
            'bot_id' => $this->botId,
            'user_id' => $userId,
            'stream' => true,
            'auto_save_history' => true,
            'additional_messages' => [
                [
                    'role' => 'user',
                    'content' => $content,
                    'content_type' => 'text',
                ],
            ],
        ];

        $response = HttpService::postRequest($this->apiBase . '/v3/chat', json_encode($payload, JSON_UNESCAPED_UNICODE), [
            'Authorization: Bearer ' . $this->apiToken,
            'Content-Type: application/json',
            'Accept: text/event-stream',
        ], $this->timeout);

        if ($response === false || $response === '') {
            Log::error('Coze 小程序客服调用失败：' . json_encode(HttpService::getStatus(), JSON_UNESCAPED_UNICODE) . ' ' . HttpService::getCurlError());
            return $this->fallbackReply;
        }

        $answer = $this->parseStreamAnswer($response);
        return $answer !== '' ? $answer : $this->fallbackReply;
    }

    protected function parseStreamAnswer(string $response): string
    {
        $answer = '';
        $event = '';
        $lines = preg_split('/\r\n|\r|\n/', $response);
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line === '') {
                continue;
            }

            if (stripos($line, 'event:') === 0) {
                $event = trim(substr($line, 6));
                continue;
            }

            if (stripos($line, 'data:') !== 0) {
                continue;
            }

            $data = trim(substr($line, 5));
            if ($data === '' || $data === '[DONE]' || $data === '"[DONE]"') {
                continue;
            }

            $json = json_decode($data, true);
            if (!is_array($json)) {
                continue;
            }

            $currentEvent = (string)($json['event'] ?? $event);
            $message = $json['message'] ?? $json['data'] ?? $json;
            if (!is_array($message)) {
                continue;
            }

            if (isset($message['type']) && $message['type'] !== 'answer') {
                continue;
            }

            if (isset($message['content']) && $message['content'] !== '') {
                if ($currentEvent === '' || stripos($currentEvent, 'delta') !== false) {
                    $answer .= (string)$message['content'];
                } elseif (stripos($currentEvent, 'completed') !== false && $answer === '') {
                    $answer = (string)$message['content'];
                }
            }
        }

        return trim($answer);
    }

    protected function env(array $keys, string $serverKey, string $default = ''): string
    {
        foreach ($keys as $key) {
            $value = Env::get($key, '');
            if ($value !== '') {
                return (string)$value;
            }
        }

        $serverValue = getenv($serverKey);
        if ($serverValue !== false && $serverValue !== '') {
            return (string)$serverValue;
        }

        return $default;
    }
}