import json
import os
import asyncio
from fastapi import FastAPI, HTTPException
import paho.mqtt.client as mqtt
from datetime import datetime
from motor.motor_asyncio import AsyncIOMotorClient
from pydantic import BaseModel
from typing import Any, Dict

app = FastAPI(title="Radio C2 Brain")

# Configuration
MQTT_BROKER = os.getenv("MQTT_BROKER", "mqtt-broker")
MONGO_URI = os.getenv("MONGO_URI", "mongodb://admin:securepassword@db:27017/radio_c2?authSource=admin")
C2_ID = "central-brain-01"

# Database Init
mongo_client = AsyncIOMotorClient(MONGO_URI)
db = mongo_client.get_database()
nodes_col = db.get_collection("nodes")

# Local cache for quick lookups
ACTIVE_NODES_CACHE = {}
MAIN_LOOP = None

# Pydantic Models
class NodeCommand(BaseModel):
    command: str
    payload: Dict[str, Any]

def on_connect(client, userdata, flags, rc):
    print(f"Brain connected to MQTT Broker with result code {rc}")
    client.subscribe("nodes/+/checkin")
    client.subscribe("nodes/+/status")

def on_message(client, userdata, msg):
    if MAIN_LOOP:
        asyncio.run_coroutine_threadsafe(handle_message(msg), MAIN_LOOP)

async def handle_message(msg):
    topic_parts = msg.topic.split('/')
    if len(topic_parts) < 3: return
    
    node_id = topic_parts[1]
    event_type = topic_parts[2]
    
    try:
        payload = json.loads(msg.payload.decode())
        timestamp = datetime.utcnow()

        if event_type == "checkin":
            data = {
                "node_id": node_id,
                "last_seen": timestamp,
                "status": payload.get("status", "online"),
                "active_system": payload.get("active_system"),
                "available_systems": payload.get("available_systems", []),
                "config": payload,
                "radio_state": "active" if payload.get("is_listening") else "idle"
            }
            await nodes_col.update_one({"node_id": node_id}, {"$set": data}, upsert=True)
            ACTIVE_NODES_CACHE[node_id] = data

        elif event_type == "status":
            status = payload.get("status")
            await nodes_col.update_one(
                {"node_id": node_id}, 
                {"$set": {"status": status, "last_seen": timestamp}}
            )
            if node_id in ACTIVE_NODES_CACHE:
                ACTIVE_NODES_CACHE[node_id]["status"] = status

    except Exception as e:
        print(f"Error processing MQTT: {e}")

# MQTT Setup
mqtt_client = mqtt.Client(client_id=C2_ID)
mqtt_client.on_connect = on_connect
mqtt_client.on_message = on_message

@app.on_event("startup")
async def startup_event():
    global MAIN_LOOP
    MAIN_LOOP = asyncio.get_running_loop()
    mqtt_client.connect_async(MQTT_BROKER, 1883, 60)
    mqtt_client.loop_start()

@app.get("/nodes")
async def get_nodes():
    nodes = await nodes_col.find().to_list(length=100)
    # Convert ObjectId to string for JSON serialization
    for n in nodes: n["_id"] = str(n["_id"])
    return nodes

@app.post("/nodes/{node_id}/command")
async def send_command_to_node(node_id: str, command: NodeCommand):
    if node_id not in ACTIVE_NODES_CACHE:
        raise HTTPException(status_code=404, detail="Node not found or is offline")

    topic = f"nodes/{node_id}/commands"
    
    message_payload = {
        "command": command.command,
        **command.payload
    }
    
    mqtt_client.publish(topic, json.dumps(message_payload), qos=1)
    
    return {"status": "command_sent", "node_id": node_id, "command": command.command}