feat: migrate gateway to nestjs

src/server/modules/proxy/clients/gemini.client.ts

@@ -0,0 +1,59 @@
+import { Injectable, Logger } from '@nestjs/common';
+import axios from 'axios';
+import { GeminiRequest, GeminiResponse } from '../interfaces/request-interfaces';
+
+@Injectable()
+export class GeminiClient {
+  private readonly logger = new Logger(GeminiClient.name);
+  // Default to v1beta for most features
+  private readonly baseUrl = 'https://generativelanguage.googleapis.com/v1beta';
+
+  async streamGenerate(model: string, content: GeminiRequest, accessToken: string): Promise<any> {
+    const url = `${this.baseUrl}/models/${model}:streamGenerateContent?alt=sse`;
+
+    try {
+      const response = await axios.post(url, content, {
+        headers: {
+          Authorization: `Bearer ${accessToken}`,
+          'Content-Type': 'application/json',
+        },
+        responseType: 'stream',
+        timeout: 60000,
+      });
+      return response.data;
+    } catch (error) {
+      if (axios.isAxiosError(error)) {
+        this.logger.error(`Gemini Stream API Error: ${error.message}`);
+        throw new Error(error.response?.data?.error?.message || error.message);
+      }
+      throw error;
+    }
+  }
+
+  async generate(
+    model: string,
+    content: GeminiRequest,
+    accessToken: string,
+  ): Promise<GeminiResponse> {
+    const url = `${this.baseUrl}/models/${model}:generateContent`;
+
+    try {
+      const response = await axios.post<GeminiResponse>(url, content, {
+        headers: {
+          Authorization: `Bearer ${accessToken}`,
+          'Content-Type': 'application/json',
+        },
+        timeout: 60000, // 60s timeout
+      });
+      return response.data;
+    } catch (error) {
+      if (axios.isAxiosError(error)) {
+        this.logger.error(
+          `Gemini API Error: ${error.message} - ${JSON.stringify(error.response?.data)}`,
+        );
+        throw new Error(error.response?.data?.error?.message || error.message);
+      }
+      throw error;
+    }
+  }
+}