Consolidate gemini.ts and openrouter.ts into a single generateContent function

Co-authored-by: na-trium-144 <100704180+na-trium-144@users.noreply.github.com>

Author: Copilot

app/actions/chatActions.ts

@@ -1,20 +1,12 @@
 "use server";
 
 // import { z } from "zod";
-import { generateContent as generateContentGemini } from "./gemini";
-import { generateContent as generateContentOpenRouter } from "./openrouter";
+import { generateContent } from "./gemini";
 import { DynamicMarkdownSection } from "../[lang]/[pageId]/pageContent";
 import { ReplCommand, ReplOutput } from "@my-code/runtime/interface";
 import { addChat, ChatWithMessages } from "@/lib/chatHistory";
 import { getPagesList, introSectionId, PagePath, SectionId } from "@/lib/docs";
 
-function generateContent(prompt: string, systemInstruction?: string) {
-  if (process.env.OPENROUTER_API_KEY && process.env.OPENROUTER_MODEL) {
-    return generateContentOpenRouter(prompt, systemInstruction);
-  }
-  return generateContentGemini(prompt, systemInstruction);
-}
-
 type ChatResult =
   | {
       error: string;

app/actions/gemini.ts

@@ -1,20 +1,56 @@
 "use server";
 
 import { GoogleGenAI } from "@google/genai";
+import OpenAI from "openai";
+
+export async function generateContent(
+  prompt: string,
+  systemInstruction?: string
+): Promise<{ text: string }> {
+  const openRouterApiKey = process.env.OPENROUTER_API_KEY;
+  const openRouterModel = process.env.OPENROUTER_MODEL;
+
+  if (openRouterApiKey && openRouterModel) {
+    const client = new OpenAI({
+      apiKey: openRouterApiKey,
+      baseURL: "https://openrouter.ai/api/v1",
+    });
+
+    const messages: OpenAI.Chat.ChatCompletionMessageParam[] = [];
+    if (systemInstruction) {
+      messages.push({ role: "system", content: systemInstruction });
+    }
+    messages.push({ role: "user", content: prompt });
+
+    const completion = await client.chat.completions.create({
+      model: openRouterModel,
+      messages,
+    });
+
+    const text = completion.choices[0]?.message?.content;
+    if (!text) {
+      throw new Error("OpenRouterからの応答が空でした");
+    }
+    return { text };
+  }
 
-export async function generateContent(prompt: string, systemInstruction?: string) {
   const params = {
     model: "gemini-2.5-flash",
     contents: prompt,
     config: {
       systemInstruction,
-    }
+    },
   };
 
   const ai = new GoogleGenAI({ apiKey: process.env.API_KEY! });
 
   try {
-    return await ai.models.generateContent(params);
+    const result = await ai.models.generateContent(params);
+    const text = result.text;
+    if (!text) {
+      throw new Error("Geminiからの応答が空でした");
+    }
+    return { text };
   } catch (e: unknown) {
     if (String(e).includes("User location is not supported")) {
       // For the new API, we can use httpOptions to set a custom baseUrl
@@ -24,7 +60,12 @@ export async function generateContent(prompt: string, systemInstruction?: string
           baseUrl: "https://gemini-proxy.utcode.net",
         },
       });
-      return await aiWithProxy.models.generateContent(params);
+      const result = await aiWithProxy.models.generateContent(params);
+      const text = result.text;
+      if (!text) {
+        throw new Error("Geminiからの応答が空でした");
+      }
+      return { text };
     } else {
       throw e;
     }