<?php

namespace App\Services\LLM;

use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;

class DeepSeekService
{
    public static function streamedResponseChat($message): void
    {
        $headers = [
            'Authorization' => 'Bearer ' . config('llm.deepseek.key'),
            'Content-Type' => 'application/json',
        ];
        $body = [
            'model' => 'deepseek-chat',
            'messages' => $message,
            'stream' => true,
        ];

        // 3. 调用DeepSeek流式API
        $response = Http::withHeaders($headers)->timeout(300)->send('POST', 'https://api.deepseek.com/chat/completions', [
            'json' => $body
        ]);

        // 4. 流式转发数据
        $body = $response->toPsrResponse()->getBody();

        while (true) {
            if ($body->eof() || !$body->isReadable()) {
                break;
            }
            $chunk = $body->getContents();

            // 分割完整的JSON行
            $lines = explode("\n\n", $chunk);
            foreach ($lines as $line) {
                $line = trim($line);
                if ($line === '') {
                    continue; // 跳过空行
                }
                // 处理单条事件
                if (str_starts_with($line, 'data: ')) {
                    // 去除 "data: " 前缀
                    $jsonStr = substr($line, 6);
                    self::processEvent($jsonStr);
                }
            }

            // 检测连接是否中断
            if (connection_aborted()) {
                break;
            }
        }
    }

    // 处理单个事件的方法
    protected static function processEvent(string $jsonStr): void
    {
        if ($jsonStr === '[DONE]') {
            echo "event: end\n\n";
            ob_flush();
            flush();
            return;
        }

        try {
            $data = json_decode($jsonStr, true, 512, JSON_THROW_ON_ERROR);
            $content = $data['choices'][0]['delta']['content'] ?? '';
            echo "data: " . json_encode(['content' => $content], JSON_UNESCAPED_UNICODE) . "\n\n";
            ob_flush();
            flush();
        } catch (\JsonException $e) {
            Log::error('JSON 解析失败: ' . $e->getMessage());
        }
    }
}