import bge # Bibliothèque Blender Game Engine (UPBGE)
import threading # Multithreading
import trace
import sys
import time

###############################################################################
# twin_threading.py
# @title: Gestion des tâches (threads)
# @project: Blender-EduTech
# @lang: fr
# @authors: Philippe Roy <philippe.roy@ac-grenoble.fr>
# @copyright: Copyright (C) 2020-2023 Philippe Roy
# @license: GNU GPL
###############################################################################

scene = bge.logic.getCurrentScene()

# Threads
threads_cmd=[]
debug_thread = scene.objects['System']['debug_thread']

###############################################################################
# Méthode kill pour les tâches (threads)
###############################################################################

class thread_with_trace(threading.Thread):
    def __init__(self, *args, **keywords):
        threading.Thread.__init__(self, *args, **keywords)
        self.killed = False
     
    def start(self):
        self.__run_backup = self.run
        self.run = self.__run
        threading.Thread.start(self)

    def __run(self):
        sys.settrace(self.globaltrace)
        self.__run_backup()
        self.run = self.__run_backup
    
    def globaltrace(self, frame, event, arg):
        if event == 'call':
            return self.localtrace
        else:
            return None

    def localtrace(self, frame, event, arg):
        if self.killed:
            if event == 'line':
                raise SystemExit()
        return self.localtrace

    def kill(self):
        self.killed = True

###############################################################################
# Start et stop des tâches (threads)
###############################################################################

def thread_start(threads, type_txt, fct):
    threads.append(thread_with_trace(target = fct))
    threads[len(threads)-1].start()
    if (debug_thread):
        print ("Thread",type_txt, "#", len(threads)-1, "open.")

# Stop des threads
def thread_stop(threads, type_txt):
    i=0
    zombie_flag=False
    for t in threads:
        if not t.is_alive():
            if (debug_thread):
                print ("Thread",type_txt, "#",i,"closed.")
        else:
            if (debug_thread):
                print ("Thread",type_txt, "#",i,"still open ...")
            t.kill()
            t.join()
            if not t.is_alive():
                if (debug_thread):
                    print ("Thread",type_txt, "#",i,"killed.")
            else:
                if (debug_thread):
                    print ("Thread",type_txt, "#",i,"zombie...")
                zombie_flag=True
        i +=1
    if zombie_flag==False:
        if (debug_thread):
            print ("All threads",type_txt, "are closed.")
        scene.objects['System']['thread_cmd']=False
        return True
    else:
        if (debug_thread):
            print ("There are zombies threads",type_txt, ".")
        return False

###############################################################################
# Fonctions utilisateur
###############################################################################

def thread_cmd_start(fct):
    thread_start(threads_cmd, "commands", fct)

def thread_cmd_stop():
    thread_stop(threads_cmd, "commands")

def thread_cmd_end():
    if (debug_thread):
        print ("Thread commands is arrived.")
    time.sleep(0.125)
    scene.objects['System']['thread_cmd']=False
    time.sleep(0.125)