Primera versión del backend

backend/app/services/llm.py

@@ -0,0 +1,48 @@
+import httpx
+
+from app.core.config import Settings
+from app.core.errors import LLMUnavailableError
+
+
+class LLMClient:
+    def __init__(self, settings: Settings) -> None:
+        self.settings = settings
+
+    async def generate(self, prompt: str) -> str:
+        if not self.settings.llm_api_key:
+            raise LLMUnavailableError("LLM_API_KEY is not configured")
+
+        url = f"{self.settings.llm_base_url.rstrip('/')}/chat/completions"
+        payload = {
+            "model": self.settings.llm_model,
+            "messages": [
+                {
+                    "role": "system",
+                    "content": "You generate safe, valid JSON exam questions for Moodle imports.",
+                },
+                {"role": "user", "content": prompt},
+            ],
+            "temperature": 0.2,
+            "response_format": {"type": "json_object"},
+        }
+        headers = {
+            "Authorization": f"Bearer {self.settings.llm_api_key}",
+            "Content-Type": "application/json",
+        }
+
+        try:
+            async with httpx.AsyncClient(timeout=self.settings.llm_timeout_seconds) as client:
+                response = await client.post(url, json=payload, headers=headers)
+                response.raise_for_status()
+        except httpx.HTTPError as exc:
+            raise LLMUnavailableError("LLM request failed") from exc
+
+        data = response.json()
+        try:
+            content = data["choices"][0]["message"]["content"]
+        except (KeyError, IndexError, TypeError) as exc:
+            raise LLMUnavailableError("LLM response did not include message content") from exc
+
+        if not isinstance(content, str) or not content.strip():
+            raise LLMUnavailableError("LLM returned empty content")
+        return content