Uses curses to have a proper terminal UI

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

squinnondation/squinnondation.py

@@ -1,6 +1,7 @@
 # Copyright (C) 2020 by eichhornchen, ÿnérant
 # SPDX-License-Identifier: GPL-3.0-or-later
 
+import curses
 import socket
 from argparse import ArgumentParser
 from enum import Enum
@@ -8,6 +9,8 @@ from ipaddress import IPv6Address
 from threading import Thread
 from typing import Any, List, Optional, Tuple
 
+from squinnondation.term_manager import TermManager
+
 
 class Squinnondation:
     args: Any
@@ -43,16 +46,36 @@ class Squinnondation:
         instance = Squinnondation()
         instance.parse_arguments()
 
-        squirrel = Squirrel(input("Enter your nickname: "), instance.bind_address, instance.bind_port)
+        with TermManager() as term_manager:
+            screen = term_manager.screen
+            screen.addstr(0, 0, "Enter your nickname: ")
+            nickname = screen.getstr().decode("UTF-8")
+            squirrel = Squirrel(nickname, instance.bind_address, instance.bind_port)
 
             if not instance.args.bind_only:
                 hazelnut = Hazelnut(address=instance.client_address, port=instance.client_port)
                 squirrel.hazelnuts[(instance.client_address, instance.client_port)] = hazelnut
 
+            squirrel.history = []
+
+            def refresh() -> None:
+                screen.clear()
+                screen.refresh()
+                for i, msg in enumerate(squirrel.history[max(0, len(squirrel.history) - curses.LINES + 2):]):
+                    screen.addstr(i, 0, msg)
+
+                screen.addstr(curses.LINES - 1, 0, f"<{squirrel.nickname}> ")
+                screen.refresh()
+            squirrel.refresh = refresh
+
             Worm(squirrel).start()
 
             while True:
-            msg = f"<{squirrel.nickname}> {input(f'<{squirrel.nickname}> ')}"
+                refresh()
+                msg = screen.getstr().decode("UTF-8")
+                msg = f"<{squirrel.nickname}> {msg}"
+                squirrel.history.append(msg)
+
                 for hazelnut in list(squirrel.hazelnuts.values()):
                     pkt = Packet()
                     pkt.magic = 95
@@ -61,7 +84,7 @@ class Squinnondation:
                     tlv.data = msg.encode("UTF-8")
                     tlv.sender_id = 42
                     tlv.nonce = 18
-                tlv.length = len(msg) + 1 + 1 + 8 + 4
+                    tlv.length = len(tlv.data) + 1 + 1 + 8 + 4
                     pkt.body = [tlv]
                     pkt.body_length = tlv.length + 2
                     squirrel.send_packet(hazelnut, pkt)
@@ -415,10 +438,12 @@ class Worm(Thread):
         self.squirrel = squirrel
 
     def run(self) -> None:
+        self.squirrel.history = []
         while True:
             try:
                 pkt, hazelnut = self.squirrel.receive_packet()
             except ValueError as error:
                 print("An error occured while receiving a packet: ", error)
             else:
-                print(pkt.body[0].data.decode('UTF-8'))
+                self.squirrel.history.append(pkt.body[0].data.decode('UTF-8'))
+                self.squirrel.refresh()

squinnondation/term_manager.py

@@ -0,0 +1,38 @@
+# Copyright (C) 2020 by ÿnérant, eichhornchen, nicomarg, charlse
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import curses
+from types import TracebackType
+
+
+class TermManager:  # pragma: no cover
+    """
+    The TermManager object initializes the terminal, returns a screen object and
+    de-initializes the terminal after use
+    """
+    def __init__(self):
+        self.screen = curses.initscr()
+        # convert escapes sequences to curses abstraction
+        self.screen.keypad(True)
+        # stop printing typed keys to the terminal
+        # curses.noecho()
+        # send keys through without having to press <enter>
+        # curses.cbreak()
+        # make cursor invisible
+        # curses.curs_set(False)
+        # Catch mouse events
+        curses.mousemask(True)
+        # Enable colors
+        curses.start_color()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type: type, exc_value: Exception,
+                 exc_traceback: TracebackType) -> None:
+        # restore the terminal to its original state
+        self.screen.keypad(False)
+        # curses.echo()
+        # curses.nocbreak()
+        # curses.curs_set(True)
+        curses.endwin()