from UserModel import UserModel
from CameraModel import CameraModel
import CameraCommander
from WaitActivity import WaitActivity


class UserCommand:
	class InvalidStateException(Exception):
		pass


	def __init__(self, sock, addr):
		self.sock = sock
		self.addr = addr[0]
		self.port = addr[1]

	
	def receive(self):
		data = b""
		ret = self.sock.recv(1)
		while ret and ret != b"\x00":
			data = data + ret
			ret = self.sock.recv(1)
		if not data:
			return None
		return data.decode()


	def send(self, msg):
		data = (msg + "\0").encode()
		return self.sock.send(data) == len(data)


	def close(self):
		print("[UserCommand] : Closing connection with {}:{}".format(self.addr, self.port))
		self.sock.close()
		self.sock = None
		self.addr = None
		self.port = None
	

	def callback(self, result, error_msg = None):
		print("[UserCommand] : Send reply to {}:{}".format(self.addr, self.port))
		if result:
			self.send("ok")
		elif error_msg:
			self.send("error:" + error_msg)
		else:
			self.send("error")
		self.close()


	def execute(self):
		if not self.sock:
			raise UserCommand.InvalidStateException()
		data = self.receive()
		if not data:
			print("[UserCommand] : Connection lost with {}:{}".format(self.addr, self.port))
			self.close()
			return

		words = data.split(":")
		if len(words) != 4:	
			print("[UserCommand] : Error from {}:{}, invalid data".format(self.addr, self.port))
			self.send("error:invalid_data")
			self.close()
			return

		userMdl = UserModel()
		user = userMdl.getByLogin(words[0])
		if not user:
			print("[UserCommand] : Error from {}:{}, invalid username".format(self.addr, self.port))
			self.send("error:invalid_username")
			self.close()
			return

		if user.password != words[1]:
			print("[UserCommand] : Error from {}:{}, invalid password for user ({})".format(self.addr, self.port, user.login))
			self.send("error:invalid_password")
			self.close()
			return
		
		camMdl = CameraModel()
		camera = camMdl.getById(words[3])
		if not camera:
			print("[UserCommand] : Error from user ({}) at {}:{}, invalid camera's serial number".format(user.login, self.addr, self.port))
			self.send("error:invalid_camera_id")
			self.close()
			return
		
		if not userMdl.haveCamera(user, camera):
			print("[UserCommand] : User ({}) at {}:{} is not allowed to command camera ({})".format(user.login, self.addr, self.port, camera.id))
			self.send("error:not_authorized")
			self.close()
			return
		
		context = CameraCommander.CameraCommander.GetContext(camera)
		if not context:
			print("[UserCommand] : Error from user ({}) at {}:{}, camera ({}) is not registered".format(user.login, self.addr, self.port, camera.id))
			self.send("error:camera_not_registered")
			self.close()
			return

		if not isinstance(context.state, WaitActivity):
			print("[UserCommand] : Error from user ({}) at {}:{}, camera ({}) is busy".format(user.login, self.addr, self.port, camera.id))
			self.send("error:camera_busy")
			self.close()
			return

		if words[2] == "enable":
			context.enable(self)
		elif words[2] == "disable":
			context.disable(self)
		elif words[2] == "disconnect":
			context.disconnect(self)
		else:
			print("[UserCommand] : Error from user ({}) at {}:{}, invalid command".format(user.login, self.addr, self.port))
			self.send("error:invalid_command")
			self.close()
			return