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orquestrador/app/services/llm_service.py

131 lines
4.5 KiB
Python

import asyncio
import json
from typing import Dict, Any, List, Optional
import vertexai
from google.api_core.exceptions import NotFound
from vertexai.generative_models import FunctionDeclaration, GenerativeModel, Tool
from app.core.settings import settings
from app.models.tool_model import ToolDefinition
class LLMService:
_vertex_initialized = False
_models: dict[str, GenerativeModel] = {}
_vertex_tools_cache: dict[str, Optional[List[Tool]]] = {}
def __init__(self):
"""Inicializa o cliente Vertex AI e define modelos de fallback."""
if not LLMService._vertex_initialized:
vertexai.init(
project=settings.google_project_id,
location=settings.google_location,
)
LLMService._vertex_initialized = True
configured = settings.vertex_model_name.strip()
fallback_models = ["gemini-2.5-flash", "gemini-2.0-flash-001", "gemini-1.5-pro"]
self.model_names = [configured] + [m for m in fallback_models if m != configured]
def build_vertex_tools(self, tools: List[ToolDefinition]) -> Optional[List[Tool]]:
"""Converte tools internas para o formato esperado pelo Vertex AI."""
# Vertex espera uma lista de Tool, com function_declarations agrupadas em um unico Tool.
if not tools:
return None
cache_key = json.dumps(
[
{
"name": tool.name,
"description": tool.description,
"parameters": tool.parameters,
}
for tool in tools
],
sort_keys=True,
ensure_ascii=True,
separators=(",", ":"),
)
cached = LLMService._vertex_tools_cache.get(cache_key)
if cached is not None:
return cached
function_declarations = [
FunctionDeclaration(
name=tool.name,
description=tool.description,
parameters=tool.parameters,
)
for tool in tools
]
vertex_tools = [Tool(function_declarations=function_declarations)]
LLMService._vertex_tools_cache[cache_key] = vertex_tools
return vertex_tools
def _get_model(self, model_name: str) -> GenerativeModel:
model = LLMService._models.get(model_name)
if model is None:
model = GenerativeModel(model_name)
LLMService._models[model_name] = model
return model
async def generate_response(
self,
message: str,
tools: List[ToolDefinition],
history: List[Dict[str, Any]] = None,
) -> Dict[str, Any]:
"""Gera resposta textual ou chamada de tool a partir da mensagem do usuario."""
vertex_tools = self.build_vertex_tools(tools)
response = None
last_error = None
for model_name in self.model_names:
try:
model = self._get_model(model_name)
chat = model.start_chat(history=history or [])
send_kwargs = {"tools": vertex_tools} if vertex_tools else {}
response = await asyncio.to_thread(chat.send_message, message, **send_kwargs)
break
except NotFound as err:
last_error = err
LLMService._models.pop(model_name, None)
continue
if response is None:
if last_error:
raise RuntimeError(
f"Nenhum modelo Vertex disponivel. Verifique VERTEX_MODEL_NAME e acesso no projeto. Erro: {last_error}"
) from last_error
raise RuntimeError("Falha ao gerar resposta no Vertex AI.")
part = response.candidates[0].content.parts[0]
if part.function_call:
return {
"response": None,
"tool_call": {
"name": part.function_call.name,
"arguments": dict(part.function_call.args),
},
}
return {
"response": response.text,
"tool_call": None,
}
async def warmup(self) -> None:
"""Preaquece conexao/modelo para reduzir latencia da primeira requisicao real."""
try:
await self.generate_response(
message="Responda apenas: ok",
tools=[],
)
except Exception:
# Warmup e melhor esforco; falhas nao devem bloquear inicializacao.
return