backend dev: create plan

common/llm_client.py

@@ -0,0 +1,31 @@
+import json
+from openai import OpenAI
+
+class LLMClient:
+    def __init__(self, base_url, api_key: str | None = None, model: str = "gpt-4o-mini"):
+        self.model = model
+        self.client = OpenAI(base_url=base_url, api_key=api_key or "ollama")
+
+    def chat(self, system: str, user: str, json_mode: bool = False, images: list[str] | None = None) -> str | None:
+        images = images or []
+        if images:
+            content = [{"type": "text", "text": user}]
+            for b64 in images:
+                content.append({
+                    "type": "image_url",
+                    "image_url": {"url": f"data:image/png;base64,{b64}"},
+                })
+        else:
+            content = user
+
+        kwargs = {
+            "model": self.model,
+            "messages": [
+                {"role": "system", "content": system},
+                {"role": "user", "content": content},
+            ],
+        }
+        if json_mode:
+            kwargs["response_format"] = {"type": "json_object"}
+        resp = self.client.chat.completions.create(**kwargs)
+        return resp.choices[0].message.content