#!/usr/bin/env python
import PySimpleGUI as sg
import os
import signal
import psutil
import operator

CONFIRM_KILLS = False

"""
    Utility to show running processes, CPU usage and provides way to kill processes.
    Based on psutil package that is easily installed using pip
"""

def kill_proc_tree(pid, sig=signal.SIGTERM, include_parent=True,
                   timeout=None, on_terminate=None):
    """Kill a process tree (including grandchildren) with signal
    "sig" and return a (gone, still_alive) tuple.
    "on_terminate", if specified, is a callabck function which is
    called as soon as a child terminates.
    """
    if pid == os.getpid():
        raise RuntimeError("I refuse to kill myself")
    parent = psutil.Process(pid)
    children = parent.children(recursive=True)
    if include_parent:
        children.append(parent)
    for p in children:
        p.send_signal(sig)
    gone, alive = psutil.wait_procs(children, timeout=timeout,
                                    callback=on_terminate)
    return (gone, alive)


def show_list_by_name(window):
    psutil.cpu_percent(interval=.1)
    procs = psutil.process_iter()
    all_procs = [[proc.cpu_percent(), proc.name(), proc.pid] for proc in procs]
    sorted_by_cpu_procs = sorted(all_procs, key=operator.itemgetter(1), reverse=False)
    display_list = []
    for process in sorted_by_cpu_procs:
        display_list.append('{:5d} {:5.2f} {}\n'.format(process[2], process[0] / 10, process[1]))
    window['-processes-'].update(display_list)
    return display_list

def main():

    # ----------------  Create Form  ----------------
    # sg.theme('Topanga')

    layout = [[sg.Text('Process Killer - Choose one or more processes',
                       size=(45,1), font=('Helvetica', 15), text_color='red')],
              [sg.Listbox(values=[' '], size=(50, 30), select_mode=sg.SELECT_MODE_EXTENDED,  font=('Courier', 12), key='-processes-')],
              [sg.Text('Click refresh once or twice.. once for list, second to get CPU usage')],
              [sg.Text('Filter by typing name', font='ANY 14'), sg.Input(size=(15,1), font='any 14', key='-filter-')],
              [sg.Button('Sort by Name', ),
               sg.Button('Sort by % CPU', button_color=('white', 'DarkOrange2')),
               sg.Button('Kill', button_color=('white','red'), bind_return_key=True),
               sg.Exit(button_color=('white', 'sea green'))]]

    window = sg.Window('Process Killer', layout,
                       keep_on_top=True,
                       auto_size_buttons=False,
                       default_button_element_size=(12,1),
                       return_keyboard_events=True,
                       finalize=True)


    display_list = show_list_by_name(window)
    # ----------------  main loop  ----------------
    while True:
        # --------- Read and update window --------
        event, values = window.read()
        if event in (None, 'Exit'):
            break

        # skip mouse, control key and shift key events entirely
        if 'Mouse' in event or 'Control' in event or 'Shift' in event:
            continue

        # --------- Do Button Operations --------
        if event == 'Sort by Name':
            display_list = show_list_by_name(window)
            # psutil.cpu_percent(interval=.1)
            # procs = psutil.process_iter()
            # all_procs = [[proc.cpu_percent(), proc.name(), proc.pid] for proc in procs]
            # sorted_by_cpu_procs = sorted(all_procs, key=operator.itemgetter(1), reverse=False)
            # display_list = []
            # for process in sorted_by_cpu_procs:
            #     display_list.append('{:5d} {:5.2f} {}\n'.format(process[2], process[0]/10, process[1]))
            # window['-processes-'].update(display_list)
        elif event == 'Kill':
            processes_to_kill = values['-processes-']
            for proc in processes_to_kill:
                pid = int(proc[0:5])
                # if sg.popup_yes_no('About to kill {} {}'.format(pid, proc[12:]), keep_on_top=True) == 'Yes':
                try:
                    kill_proc_tree(pid=pid)
                except:
                    sg.popup_no_wait('Error killing process', auto_close_duration=1, auto_close=True)
        elif event == 'Sort by % CPU':
            psutil.cpu_percent(interval=.1)
            procs = psutil.process_iter()
            all_procs = [[proc.cpu_percent(), proc.name(), proc.pid] for proc in procs]
            sorted_by_cpu_procs = sorted(all_procs, key=operator.itemgetter(0), reverse=True)
            display_list = []
            for process in sorted_by_cpu_procs:
                display_list.append('{:5d} {:5.2f} {}\n'.format(process[2], process[0]/10, process[1]))
            window['-processes-'].update(display_list)
        else:                   # was a typed character
            if display_list is not None:
                new_output = []
                for line in display_list:
                    if values['-filter-'] in line.lower():
                        new_output.append(line)
                window['-processes-'].update(new_output)
        window.close()


if __name__ == "__main__":
    main()