backend dev: create plan

main.py

@@ -1,7 +1,53 @@
-from fastapi import FastAPI
+import logging
+import os
+from contextlib import asynccontextmanager
 
-app = FastAPI()
+import httpx
+from dotenv import load_dotenv
+from fastapi import FastAPI, HTTPException
+from agents.backend_dev.BackendDeveloperAgent import BackendDeveloperAgent
+from agents.backend_dev.context_builder import YouTrackContextBuilder
+from common.llm_client import LLMClient
+from common.youtrack_mcp_client import YouTrackMCPClient, IssueNotFound
 
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+load_dotenv()
+def env(key: str) -> str:
+    value = os.environ.get(key)
+    if not value:
+        raise RuntimeError(f"Missing required env var: {key}")
+    return value
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    mcp = await YouTrackMCPClient(
+        str(os.getenv('YOUTRACK_MCP_SERVER')),
+        str(os.getenv('YOUTRACK_MCP_TOKEN')),
+    ).connect()
+
+    http_for_attachments = httpx.AsyncClient(
+        headers={"Authorization": f"Bearer {env('YOUTRACK_MCP_TOKEN')}"},
+        proxy=env("HTTPS_PROXY"),
+        timeout=httpx.Timeout(30.0, connect=10.0, read=60.0),
+        follow_redirects=True,
+    )
+
+    app.state.backend_agent = BackendDeveloperAgent(
+        YouTrackContextBuilder(mcp, http_for_attachments),
+        LLMClient(
+            base_url=env("LLM_ADDRESS"),
+            api_key=env("LLM_API_KEY"),
+            model=env("LLM_MODEL"),
+        ),
+    )
+
+    yield
+
+    # ---- shutdown ----
+    await mcp.close()
+app = FastAPI(lifespan=lifespan)
 
 @app.get("/")
 async def root():
@@ -11,3 +57,20 @@ async def root():
 @app.get("/hello/{name}")
 async def say_hello(name: str):
     return {"message": f"Hello {name}"}
+
+
+@app.get("/backend")
+async def backend_task(task: str):
+    agent: BackendDeveloperAgent = app.state.backend_agent
+    try:
+        logger.info(f"Received task: {task}")
+        plan = await agent.plan_issue(task)
+        logger.info("Task planning successful.")
+        print(agent.render(plan))
+        return {"plan": plan}
+    except IssueNotFound:
+        logger.error(f"Issue {task} not found.")
+        raise HTTPException(status_code=404, detail=f"Issue {task} not found")
+    except Exception as e:
+        logger.exception("An unexpected error occurred")
+        return {"error": str(e)}