#!/usr/bin/env python3.7
import tkinter
import threading
from ChatConnection import ChatConnection


class ChatInterface(object):
    def __init__(self, connection: ChatConnection):
        # set connection to use
        self.connection = connection

        # initialise tkinter window
        self.window = tkinter.Tk()
        self.window.title("Chatter")  # window title
        # set method to trigger when window is close
        self.window.protocol("WM_DELETE_WINDOW", self.close)
        # end of window initialisation

        # initialise message frame
        self.messagesFrame = tkinter.Frame(self.window)
        # # add scrollBar to see previously recovered messages
        self.scrollBar = tkinter.Scrollbar(self.messagesFrame)
        self.scrollBar.pack(side=tkinter.RIGHT, fill=tkinter.Y)
        # # add messagesList to print recovered messages
        self.messagesList = tkinter.Listbox(
            self.messagesFrame, height=15, width=50, yscrollcommand=self.scrollBar.set)
        self.messagesList.pack(side=tkinter.LEFT, fill=tkinter.BOTH)
        self.messagesList.pack()
        self.messagesFrame.pack()
        # end of message frame initialisation

        # initialise input
        self.input = tkinter.StringVar()
        self.input.set("Type your messages here.")
        # # initialise input frame
        self.inputFrame = tkinter.Entry(self.window, textvariable=self.input)
        self.inputFrame.bind("<Return>", self.send)
        self.inputFrame.pack()
        # # initialise send button
        self.sendButton = tkinter.Button(
            self.window, text="Send", command=self.send)
        self.sendButton.pack()
        # end of input initialisation

    def close(self, event=None) -> None:
        """
        Set input to ':quit' and trigger send method
        """
        self.input.set(":quit")
        self.send()

    def send(self, event=None) -> None:
        """
        Send message to connection
        """
        msg = self.input.get()
        # check if input is quit command
        if msg != ':quit':
            # clear the input bar
            self.input.set('')
            # output the client message to message list
            self.messagesList.insert(tkinter.END, '[YOU] {}'.format(msg))
            # send the message to connection
            self.connection.send(msg)
        else:
            # close the connection and window
            self.connection.close()
            self.window.quit()

    def listener(self) -> None:
        """
        Listener method to keep receiving new message from
        connection
        """
        while True:
            try:
                # receive messages from connection
                msg = self.connection.recv()
                # add recevied message to message list
                self.messagesList.insert(tkinter.END, msg[:-1])
            except OSError:
                break

    def start(self) -> None:
        """
        Start background listener and tkinter.mainloop
        """
        # initialise background listener as daemon thread
        backgroundListener = threading.Thread(target=self.listener)
        backgroundListener.daemon = True
        backgroundListener.start()

        # start tkinter main loop and open the GUI window
        tkinter.mainloop()