import logging
import os
from contextlib import asynccontextmanager

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():
    return {"message": "Hello World"}


@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)}