from libs.app.common.logging import get_logger
from flask import Flask, render_template, request
from flask_socketio import SocketIO
import multiprocessing
import threading
import time

logger = get_logger()

class UIServer:
    def __init__(self, host="127.0.0.1", port=5000):
        self.host = host
        self.port = port
        self.process = None
        self.queue = multiprocessing.Queue()
        self.client_ready = multiprocessing.Value("b", False)

    @staticmethod
    def run_server(host, port, queue, client_ready):
        app = Flask(__name__)
        socketio = SocketIO(app, cors_allowed_origins="*")

        @app.route("/")
        def index():
            return render_template("index.html")
        
        @socketio.on("frontend_ready")
        def frontend_ready():
            client_ready.value = True
        
        def queue_listener():
            while True:
                event, data = queue.get()
                while not client_ready.value:
                    time.sleep(1)
                
                socketio.emit(event, data)

        threading.Thread(target=queue_listener, daemon=True).start()

        socketio.run(app, host=host, port=port, debug=False, use_reloader=False)

    def start(self):
        if self.process and self.process.is_alive():
            logger.debug("Server is already running")
            return
        self.process = multiprocessing.Process(
            target=UIServer.run_server,
            args=(self.host, self.port, self.queue, self.client_ready),
        )
        self.process.start()
        logger.debug(f"Server started on http://{self.host}:{self.port}")

    def stop(self, wait_queue=True, time_limit=5):
        while wait_queue and not self.queue.empty():
            logger.debug(f"Waiting server. {self.queue.qsize()} items in queue")
            time.sleep(1)
            time_limit-=1
            if time_limit <= 0:
                break

        if self.process and self.process.is_alive():
            self.process.terminate()
            self.process.join()
            logger.debug("Server stopped")
        self.process = None

    def restart(self):
        logger.debug("Restarting server...")
        self.stop()
        self.start()

    def emit_event(self, event, data={}):
        self.queue.put((event, data))