import socket
import selectors
import time

from msg_container import MsgContainer
from packetizer import Packetizer
from transceiver import Transceiver
from a_backend import ABackend
from nmea.GLL import Gll
from nmea.GSA import Gsa
from nmea.GSV import Gsv

class NetworkBackend(ABackend):
	def __init__(self, servers: list[dict]):
		self.sel = None
		self.sock_list = [{'name': s['name'], 'addr': (s['host'], s['port']), 'xcvr': None} for s in servers]

	def create_xcvr(self, name: str) -> Transceiver:
		obj = Transceiver(self, name)
		if not self.register_xcvr(obj):
			raise Exception(f"No socket found for \"{name}\"")
		return obj

		self.sel.register(name, selectors.EVENT_READ, data=None)
	def register_xcvr(self, xcvr: Transceiver):
		found = False
		for sock in self.sock_list:
			if xcvr.name in sock['name']:
				found = True
				sock['xcvr'] = xcvr
				break

		return found
	def find_by_addr(self, addr):
		for sock in self.sock_list:
			if sock['addr'] == addr:
				return sock
		return None

	def find_by_name(self, name: str):
		for sock in self.sock_list:
			if sock['name'] == name:
				return sock
		return None

	def _prepare(self):
		for server in self.sock_list:
			sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
			sock.setblocking(False)
			server['sock'] = sock

	def connect(self):
		self._prepare()
		self.sel = selectors.DefaultSelector()
		events = selectors.EVENT_READ
		for sock in self.sock_list:
			print(f"Starting connection {sock['name']} to {sock['addr']}")
			self.sel.register(sock['sock'], events, data=None)
			sock['sock'].connect_ex(sock['addr'])

	def disconnect(self):
		for sock in self.sock_list:
			sock['sock'].close()

	def event_loop(self):
		try:
			while True:
				events = self.sel.select(timeout=100)
				for key, mask in events:
					descr = self.find_by_addr(key.fileobj.getpeername())
					name = descr['name']
					sock = self.find_by_name(name)
					rx = sock['xcvr']
					if mask & selectors.EVENT_READ:
						timestamp = time.time()
						data = key.fileobj.recv(16)
						rx.on_recv(MsgContainer(name, timestamp, data))

		except KeyboardInterrupt:
			print("Caught keyboard interrupt, exiting")
		finally:
			self.sel.close()

if __name__ == "__main__":
	server_list = [
		{'name': "neo-f9p", 'host': "192.168.22.93", 'port': 8721},
		{'name': "zed-x20p", 'host': "192.168.22.93", 'port': 8731}
	]

	# TCPIP multi source receiver
	mc = NetworkBackend(server_list)
	xcvr_1 = mc.create_xcvr("neo-f9p")
	xcvr_2 = mc.create_xcvr("zed-x20p")

	# Packetizer for "zed-x20p"
	packetizer_0 = Packetizer()

	# Packetizer for "neo-f9p"
	packetizer_1 = Packetizer()

	xcvr_1.register_recv(packetizer_0)
	xcvr_2.register_recv(packetizer_1)

	rx_list = [
			Gll('Rx', '--'),
			Gsa('Rx', '--'),
			Gsv('Rx', '--')
		]
	# Register all Rx to all sources
	for rx in rx_list:
		packetizer_0.register_recv(rx)
		packetizer_1.register_recv(rx)

	# Connect all sources
	mc.connect()

	# receive and block
	mc.event_loop()

	# code never reached
	mc.disconnect()