Add offline monthly insights with Ollama

src/lib/ollama.ts

@@ -0,0 +1,46 @@
+export class OllamaUnavailableError extends Error {
+  constructor(message = "Local AI runtime is unavailable.") {
+    super(message);
+    this.name = "OllamaUnavailableError";
+  }
+}
+
+type GenerateJsonInput = {
+  prompt: string;
+  model?: string;
+};
+
+export async function generateOllamaJson<T>({ prompt, model }: GenerateJsonInput): Promise<T> {
+  const baseUrl = (process.env.OLLAMA_URL ?? "http://127.0.0.1:11434").replace(/\/$/, "");
+  const selectedModel = model ?? process.env.OLLAMA_MODEL ?? "qwen3.5:9b";
+
+  let response: Response;
+
+  try {
+    response = await fetch(`${baseUrl}/api/generate`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        model: selectedModel,
+        format: "json",
+        stream: false,
+        prompt,
+      }),
+    });
+  } catch {
+    throw new OllamaUnavailableError("Ollama is not reachable at the configured URL.");
+  }
+
+  if (!response.ok) {
+    throw new OllamaUnavailableError(`Ollama request failed with status ${response.status}.`);
+  }
+
+  const payload = (await response.json()) as { response?: string; thinking?: string };
+  const jsonText = payload.response?.trim() ? payload.response : payload.thinking;
+
+  if (!jsonText) {
+    throw new OllamaUnavailableError("Ollama returned an empty response.");
+  }
+
+  return JSON.parse(jsonText) as T;
+}