import json
import os
import asyncio
from functools import partial
import traceback
from fastapi import FastAPI, HTTPException
import paho.mqtt.client as mqtt
from datetime import datetime
import firebase_admin
from firebase_admin import credentials, firestore
from pydantic import BaseModel
from typing import Any, Dict

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

# Configuration
MQTT_BROKER = os.getenv("MQTT_BROKER", "mqtt-broker")
FIREBASE_CRED_JSON = os.getenv("FIREBASE_CRED_JSON")
FIRESTORE_DB_ID = os.getenv("FIRESTORE_DB_ID", "c2-server")
C2_ID = "central-brain-01"

# Database Init
if FIREBASE_CRED_JSON:
    print("Initializing Firebase with provided JSON credentials...")
    cred = credentials.Certificate(json.loads(FIREBASE_CRED_JSON))
    firebase_admin.initialize_app(cred)
else:
    print("Initializing Firebase with Application Default Credentials...")
    firebase_admin.initialize_app()

print(f"Connecting to Firestore Database: {FIRESTORE_DB_ID}")
db = firestore.client(database_id=FIRESTORE_DB_ID)

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

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

# Helper for async execution of blocking firestore calls
async def async_firestore(func, *args, **kwargs):
    loop = asyncio.get_running_loop()
    return await loop.run_in_executor(None, partial(func, *args, **kwargs))

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":
            print(f"Processing checkin for {node_id}...")
            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"
            }
            doc_ref = db.collection("nodes").document(node_id)
            print(f"Writing to Firestore: {doc_ref.path} in DB {FIRESTORE_DB_ID}")
            await async_firestore(doc_ref.set, data, merge=True)
            print(f"Successfully updated checkin for {node_id}")
            ACTIVE_NODES_CACHE[node_id] = data

        elif event_type == "status":
            print(f"Processing status update for {node_id}...")
            status = payload.get("status")
            doc_ref = db.collection("nodes").document(node_id)
            print(f"Writing to Firestore: {doc_ref.path} in DB {FIRESTORE_DB_ID}")
            await async_firestore(doc_ref.set, {"status": status, "last_seen": timestamp}, merge=True)
            print(f"Successfully updated status for {node_id}")
            if node_id in ACTIVE_NODES_CACHE:
                ACTIVE_NODES_CACHE[node_id]["status"] = status

    except Exception as e:
        print(f"Error processing MQTT message from {node_id}: {e}")
        traceback.print_exc()

# 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():
    def get_docs():
        return [
            {**doc.to_dict(), "_id": doc.id} 
            for doc in db.collection("nodes").stream()
        ]
    
    nodes = await async_firestore(get_docs)
    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}