feat: chatgpt 对外api

src/pages/api/openapi/chat/chatGpt.ts

+import type { NextApiRequest, NextApiResponse } from 'next';
+import { connectToDatabase, Model } from '@/service/mongo';
+import { getOpenAIApi } from '@/service/utils/chat';
+import { httpsAgent, openaiChatFilter, authOpenApiKey } from '@/service/utils/tools';
+import { ChatCompletionRequestMessage, ChatCompletionRequestMessageRoleEnum } from 'openai';
+import { ChatItemType } from '@/types/chat';
+import { jsonRes } from '@/service/response';
+import { PassThrough } from 'stream';
+import { modelList } from '@/constants/model';
+import { pushChatBill } from '@/service/events/pushBill';
+import { gpt35StreamResponse } from '@/service/utils/openai';
+
+/* 发送提示词 */
+export default async function handler(req: NextApiRequest, res: NextApiResponse) {
+  let step = 0; // step=1时，表示开始了流响应
+  const stream = new PassThrough();
+  stream.on('error', () => {
+    console.log('error: ', 'stream error');
+    stream.destroy();
+  });
+  res.on('close', () => {
+    stream.destroy();
+  });
+  res.on('error', () => {
+    console.log('error: ', 'request error');
+    stream.destroy();
+  });
+
+  try {
+    const {
+      prompts,
+      modelId,
+      isStream = true
+    } = req.body as {
+      prompts: ChatItemType[];
+      modelId: string;
+      isStream: boolean;
+    };
+
+    if (!prompts || !modelId) {
+      throw new Error('缺少参数');
+    }
+    if (!Array.isArray(prompts)) {
+      throw new Error('prompts is not array');
+    }
+    if (prompts.length > 30 || prompts.length === 0) {
+      throw new Error('prompts length range 1-30');
+    }
+
+    await connectToDatabase();
+    let startTime = Date.now();
+
+    const { apiKey, userId } = await authOpenApiKey(req);
+
+    const model = await Model.findOne({
+      _id: modelId,
+      userId
+    });
+
+    if (!model) {
+      throw new Error('无权使用该模型');
+    }
+
+    const modelConstantsData = modelList.find((item) => item.model === model.service.modelName);
+    if (!modelConstantsData) {
+      throw new Error('模型加载异常');
+    }
+
+    // 如果有系统提示词，自动插入
+    if (model.systemPrompt) {
+      prompts.unshift({
+        obj: 'SYSTEM',
+        value: model.systemPrompt
+      });
+    }
+
+    // 控制在 tokens 数量，防止超出
+    const filterPrompts = openaiChatFilter(prompts, modelConstantsData.contextMaxToken);
+
+    // 格式化文本内容成 chatgpt 格式
+    const map = {
+      Human: ChatCompletionRequestMessageRoleEnum.User,
+      AI: ChatCompletionRequestMessageRoleEnum.Assistant,
+      SYSTEM: ChatCompletionRequestMessageRoleEnum.System
+    };
+    const formatPrompts: ChatCompletionRequestMessage[] = filterPrompts.map(
+      (item: ChatItemType) => ({
+        role: map[item.obj],
+        content: item.value
+      })
+    );
+    // console.log(formatPrompts);
+    // 计算温度
+    const temperature = modelConstantsData.maxTemperature * (model.temperature / 10);
+
+    // 获取 chatAPI
+    const chatAPI = getOpenAIApi(apiKey);
+    // 发出请求
+    const chatResponse = await chatAPI.createChatCompletion(
+      {
+        model: model.service.chatModel,
+        temperature: temperature,
+        // max_tokens: modelConstantsData.maxToken,
+        messages: formatPrompts,
+        frequency_penalty: 0.5, // 越大，重复内容越少
+        presence_penalty: -0.5, // 越大，越容易出现新内容
+        stream: isStream,
+        stop: ['.!?。']
+      },
+      {
+        timeout: 40000,
+        responseType: isStream ? 'stream' : 'json',
+        httpsAgent: httpsAgent(true)
+      }
+    );
+
+    console.log('api response time:', `${(Date.now() - startTime) / 1000}s`);
+
+    step = 1;
+    let responseContent = '';
+
+    if (isStream) {
+      const streamResponse = await gpt35StreamResponse({
+        res,
+        stream,
+        chatResponse
+      });
+      responseContent = streamResponse.responseContent;
+    } else {
+      responseContent = chatResponse.data.choices?.[0]?.message?.content || '';
+      jsonRes(res, {
+        data: responseContent
+      });
+    }
+
+    const promptsContent = formatPrompts.map((item) => item.content).join('');
+
+    // 只有使用平台的 key 才计费
+    pushChatBill({
+      isPay: true,
+      modelName: model.service.modelName,
+      userId,
+      text: promptsContent + responseContent
+    });
+  } catch (err: any) {
+    if (step === 1) {
+      // 直接结束流
+      console.log('error，结束');
+      stream.destroy();
+    } else {
+      res.status(500);
+      jsonRes(res, {
+        code: 500,
+        error: err
+      });
+    }
+  }
+}