stops import: swap OpenAI for MiniMax as default AI provider

src/app/api/stops/import/route.ts

@@ -9,19 +9,25 @@ type RequestBody = {
   /** Raw file content (CSV text). AI parsing is attempted if useAI=true. */
   text: string;
   brandId: string;
-  /** If true and OPENAI_API_KEY is set, parse unstructured text with AI. */
+  /** If true and an AI API key is set, parse unstructured text with AI. */
   useAI?: boolean;
 };
 
-const AI_MODEL = "gpt-4o-mini";
+async function parseWithAI(text: string, _brandId: string): Promise<{
-
-async function parseWithAI(text: string, brandId: string): Promise<{
   stops: ParsedStop[];
   warnings: string[];
 }> {
-  const apiKey = process.env.OPENAI_API_KEY;
+  // Prefer MiniMax (env-level) — fall back to OpenAI.
+  const provider: "minimax" | "openai" =
+    process.env.MINIMAX_API_KEY ? "minimax" : process.env.OPENAI_API_KEY ? "openai" : "openai";
+  const apiKey = provider === "minimax" ? process.env.MINIMAX_API_KEY! : process.env.OPENAI_API_KEY!;
+  const baseURL = provider === "minimax"
+    ? (process.env.MINIMAX_BASE_URL || "https://api.minimax.io/v1")
+    : "https://api.openai.com/v1";
+  const model = provider === "minimax" ? "MiniMax-M3" : "gpt-4o-mini";
+
   if (!apiKey) {
-    throw new Error("OPENAI_API_KEY is not configured. Use CSV format for reliable parsing.");
+    throw new Error("MINIMAX_API_KEY or OPENAI_API_KEY is not configured. Use CSV format for reliable parsing.");
   }
 
   const systemPrompt = `You are a schedule extraction assistant. Given raw schedule text, extract all stop entries.
@@ -37,26 +43,27 @@ Return a JSON array where each entry has:
 
 If a row lacks required fields (city, state, location), omit it and add a warning.`;
 
-  const res = await fetch("https://api.openai.com/v1/chat/completions", {
+  const res = await fetch(`${baseURL}/chat/completions`, {
     method: "POST",
     headers: {
       Authorization: `Bearer ${apiKey}`,
       "Content-Type": "application/json",
     },
     body: JSON.stringify({
-      model: AI_MODEL,
+      model,
       messages: [
         { role: "system", content: systemPrompt },
         { role: "user", content: `Extract stops from this schedule:\n\n${text.slice(0, 8000)}` },
       ],
-      response_format: { type: "json_object" },
+      // response_format is OpenAI-specific. MiniMax /v1/chat/completions may not honor it.
+      ...(provider === "openai" ? { response_format: { type: "json_object" } } : {}),
       temperature: 0.1,
     }),
   });
 
   if (!res.ok) {
     const err = await res.text();
-    throw new Error(`OpenAI API error: ${res.status} — ${err}`);
+    throw new Error(`${provider} API error: ${res.status} — ${err}`);
   }
 
   const data = await res.json();