import os, subprocess, json
from pathlib import Path
from fastapi import FastAPI, BackgroundTasks, HTTPException
from fastapi.responses import FileResponse, JSONResponse
from pydantic import BaseModel

app = FastAPI(title="Hermes Serverless")
SESSIONS_DIR = os.environ.get("SESSIONS_DIR", "/data/sessions")
Path(SESSIONS_DIR).mkdir(parents=True, exist_ok=True)
task_registry = {}

class AgentTask(BaseModel):
    session_id: str
    task: str

def execute_hermes(session_id: str, task: str):
    task_registry[session_id] = "running"
    workspace = Path(SESSIONS_DIR) / session_id
    workspace.mkdir(parents=True, exist_ok=True)
    log_path = workspace / "output.log"
    env = os.environ.copy()
    env.update({"HOME": "/root", "HERMES_HOME": "/root/.hermes"})
    try:
        with open(log_path, "a") as f:
            p = subprocess.Popen(["hermes", "chat", "-q", task, "--resume", session_id, "--yolo"], cwd=str(workspace), stdout=f, stderr=subprocess.STDOUT, env=env, text=True)
            rc = p.wait(timeout=1800)
        task_registry[session_id] = "completed" if rc == 0 else f"failed:{rc}"
    except Exception as e:
        task_registry[session_id] = f"error:{str(e)}"

@app.post("/agent/execute")
async def run(payload: AgentTask, bg: BackgroundTasks):
    if not payload.session_id or not payload.task:
        raise HTTPException(400, "Missing session_id or task")
    bg.add_task(execute_hermes, payload.session_id, payload.task)
    return {"status": "queued", "session_id": payload.session_id}

@app.get("/agent/status/{session_id}")
def status(session_id: str):
    st = task_registry.get(session_id, "unknown")
    log = Path(SESSIONS_DIR) / session_id / "output.log"
    logs = log.read_text()[-2000:] if log.exists() else ""
    return {"session_id": session_id, "status": st, "logs": logs}

@app.get("/agent/files/{session_id}/{filename}")
def file(session_id: str, filename: str):
    if "/" in filename or ".." in filename:
        raise HTTPException(400, "Invalid filename")
    path = Path(SESSIONS_DIR) / session_id / filename
    if not path.exists():
        raise HTTPException(404, "File not found")
    return FileResponse(str(path))

@app.get("/health")
def health():
    return {"status": "ok", "engine": "hermes-serverless"}

@app.get("/")
def root():
    return {"message": "Hermes Serverless API", "docs": "/docs"}