<?php

namespace App\LLM;

use App\Logic\LLMTool;
use App\Models\User;
use App\Repositories\LLM\AIChunkMessage;
use App\Repositories\LLM\AIToolCallMessage;
use App\Repositories\LLM\History;
use App\Repositories\LLM\ToolRequestMessage;
use App\Repositories\LLM\ToolResponseMessage;
use GuzzleHttp\Client;
use GuzzleHttp\Exception\ClientException;
use GuzzleHttp\Exception\GuzzleException;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Http\Client\ConnectionException;
use Illuminate\Support\Facades\Log;

class Qwen implements BaseLLM
{
    protected string $model = 'qwen-max';

    protected History $history;

    private array $tool_info = [];

    private Collection $tools;

    private array $tool_functions = [];

    const END_OF_MESSAGE = "/\r\n\r\n|\n\n|\r\r/";

    private bool $retry = false;

    private User $user;

    public function __construct()
    {
        $this->clearToolInfo();
    }

    private function clearToolInfo(): void
    {
        $this->tool_info = [
            'function' => [
                'name' => '',
                'arguments' => '',
            ],
            'index' => 0,
            'id' => '',
            'type' => 'function',
        ];
    }

    public function setHistory(History $history): void
    {
        $this->history = $history;
    }

    public function setUser(User $user): void
    {
        $this->user = $user;
    }

    public function setTools(Collection $tools): void
    {
        $this->tools = $tools;

        foreach ($tools as $tool) {
            $this->tool_functions = array_merge($this->tool_functions, $tool->data['tool_functions']);
        }
    }

    /**
     * @throws GuzzleException
     */
    public function streamResponse()
    {
        $client = new Client([
            'headers' => [
                'Content-Type' => 'application/json',
                'Accept' => 'text/event-stream',
                'Cache-Control' => 'no-cache',
                'Authorization' => 'Bearer '.config('services.dashscope.api_key'),
            ],
        ]);

        $url = config('services.dashscope.api_base').'/compatible-mode/v1/chat/completions';

        $this->retry = true;
        while ($this->retry) {

            $ai_chunk_message = new AIChunkMessage('');

            $request_body = [
                'model' => $this->model,
                'messages' => $this->history->getForApi(),
                'stream' => true,
                'tools' => $this->tool_functions,
            ];

            try {
                $response = $client->request('POST', $url, [
                    'body' => json_encode($request_body),
                    'stream' => true,
                ]);
            } catch (ClientException $e) {
                Log::error($e->getMessage());
                Log::debug('http body', [$e->getResponse()->getBody()->getContents()]);
                // 保存 history
                Log::debug('chat history', $this->history->getMessages());

                return;
            }

            $body = $response->getBody();

            $buffer = '';

            while (! $body->eof()) {
                $data = $body->read(1);

                $buffer .= $data;

                // 读取到 \n\n 则一条消息结束
                if (preg_match(self::END_OF_MESSAGE, $buffer)) {
                    // 去掉 data:
                    $d = substr($buffer, 5);
                    // 去掉第一个空格（如果是）
                    $d = ltrim($d, ' ');

                    // 去除末尾的 END_OF_MESSAGE
                    $d = rtrim($d, self::END_OF_MESSAGE);

                    // 如果是 [DONE]
                    if ($d == '[DONE]') {
                        break;
                    }

                    if (empty($d)) {
                        return;
                    }

                    // log
                    $event = json_decode($d, true);

                    //                    Log::debug('event', $event);

                    if (isset($event['choices'][0])) {
                        $finish_reason = $event['choices'][0]['finish_reason'];
                        // 检测是不是 stop
                        if ($finish_reason == 'stop') {
                            $ai_chunk_message->processing = false;
                            $ai_message = $ai_chunk_message->toAIMessage();
                            $this->history->addMessage($ai_message);
                            yield $ai_message;

                            //                            Log::debug('stop!');

                            break;
                        } elseif ($finish_reason == 'tool_calls') {
                            $this->retry = true;
                            //                            Log::debug('finished_reason is tool call, set retry');
                        }

                        $delta = $event['choices'][0]['delta'];

                        if ($event['choices'][0]['finish_reason'] == 'tool_calls') {
                            $info = json_decode($this->tool_info['function']['arguments'], true);

                            if (isset($info['properties'])) {
                                $info = $info['properties'];
                            }

                            // 开始调用
                            $tool_req = new ToolRequestMessage(
                                content: $this->tool_info['function']['name'],
                            );

                            yield $tool_req;

                            //                            Log::debug('tool req', [$tool_req]);

                            $tool_call_message = new AIToolCallMessage(content: '');
                            $tool_call_message->tool_calls = [
                                $this->tool_info,
                            ];

                            // 调用
                            $r = $this->callTool($this->tool_info['function']['name'], $info);

                            $tool_response_message = new ToolResponseMessage(content: $r);
                            $tool_response_message->name = $this->tool_info['function']['name'];

                            $this->history->addMessage($tool_call_message);
                            $this->history->addMessage($tool_response_message);

                            //                            Log::debug('tool call message', [$tool_call_message]);
                            //                            Log::debug('tool response', [$tool_response_message]);

                            yield $tool_call_message;
                            yield $tool_response_message;

                            // 清空参数，以备二次调用
                            $this->clearToolInfo();
                        } elseif (isset($delta['tool_calls'])) {
                            // 更新 tool_info
                            $call_info = $delta['tool_calls'][0];

                            if (! empty($call_info['id'])) {
                                $this->tool_info['id'] = $call_info['id'];
                            }

                            if (! empty($call_info['index'])) {
                                $this->tool_info['index'] = $call_info['index'];
                            }

                            if (! empty($call_info['function']['name'])) {
                                $this->tool_info['function']['name'] = $call_info['function']['name'];
                            }

                            if (! empty($call_info['function']['arguments'])) {
                                $this->tool_info['function']['arguments'] .= $call_info['function']['arguments'];
                            }
                        } elseif (empty($delta['choices'][0]['finish_reason'])) {
                            if (! empty($delta['content'])) {
                                $ai_chunk_message->append($delta['content']);
                                $ai_chunk_message->processing = true;

                                yield $ai_chunk_message;

                                //                                Log::debug('chunk', [$ai_chunk_message]);
                            }

                            $this->retry = false;
                        }

                    }

                    $buffer = '';
                }
            }

        }

        $this->retry = false;

    }

    /**
     * @throws ConnectionException
     */
    private function callTool($tool_name, $args): string
    {
        // 遍历 tools, 找到
        foreach ($this->tools as $tool) {
            foreach ($tool->data['tool_functions'] as $f) {
                if ($f['function']['name'] == $tool_name) {
                    $c = new LLMTool();
                    $c->setTool($tool->data['tool_id']);

                    if (isset($this->user)) {
                        $c->setUser($this->user);
                    }

                    $r = $c->callTool($tool_name, $args);

                    return $r->result;
                }
            }

        }

        return '[Hint] 没有找到对应的工具 '.$tool_name.'，你确定是这个吗？';
    }
}