#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from __future__ import division
from __future__ import print_function
try:
    import configparser
except ImportError:
    import ConfigParser as configparser  # Python 2.x import

from os import path
from sys import argv
from math import ceil
from getpass import getpass
from optparse import OptionParser
import subprocess
import base64
import time
import curses
from curses import textpad, panel

# https://github.com/zlaxy/sshch
version = "0.997"
# path to conf file, default: ~/.config/sshch.conf
conf_file = path.expanduser("~") + '/.config/sshch.conf'
# expand groups by default
expand_default = True


def AddNewAlias(alias):
    if not conf.has_section(alias):
        conf.add_section(alias)
        conf.write(open(conf_file, "w"))
        return True
    else:
        return "error: '" + alias + "' alias or group already exists"


def SetAliasString(alias, string):
    conf.set(alias, "exec_string", string)
    conf.write(open(conf_file, "w"))


def SetGroupString(alias, string):
    conf.set(alias, "group", string)
    conf.write(open(conf_file, "w"))


def SetPassword(alias, string):
    string = base64.b64encode(base64.b16encode(
                              base64.b32encode(string)))
    conf.set(alias, "password", string)
    conf.write(open(conf_file, "w"))


def RemoveAliases(aliases):
    for alias in aliases:
        conf.remove_section(alias)
        conf.write(open(conf_file, "w"))


def ConnectAlias(alias, command=False):
    exec_string = ""
    if conf.has_option(alias, "password"):
        password = base64.b32decode(base64.b16decode(
                                    base64.b64decode(conf.get(alias, "password"))))
        exec_string = 'sshpass -p "' + password + '" '
    if conf.has_option(alias, "exec_string"):
        exec_string = exec_string + conf.get(alias, "exec_string")
    if command:
        exec_string = exec_string + " " + command
    subprocess.Popen(exec_string, shell=True).communicate()[0]


def HoldConnection(alias):
    groups = []
    connectaliases = []
    for a in conf.sections():
        if conf.has_option(a, "group"):
            groups.append(a)
    if alias in groups:
        print("Can't hold connection with group.")
    else:
        print("Connecting to " + alias + ". Press CTRL+C to cancel.")
        time.sleep(1)
        while True:
            ConnectAlias(alias)
            time.sleep(5)


def CMDAdd(alias):
    alias = alias.split()[0].strip()
    result = AddNewAlias(alias)
    if result == True:
        prompt_add = ("".join(["Enter connection string for new alias ",
                               "(example: ssh user@somehost.com):\n"]))
        string = ""
        while string == "":
            string = input(prompt_add)
        SetAliasString(alias, string)
    else:
        print(result)


def CMDGroup(group):
    group = group.split()[0].strip()
    result = AddNewAlias(group)
    if result == True:
        prompt_add = ("".join(["Enter aliases for new group ",
                               "(example: alias1 alias2):\n"]))
        string = ""
        while string == "":
            string = input(prompt_add)
        SetGroupString(group, string)
    else:
        print(result)


def CMDEdit(alias):
    if conf.has_section(alias):
        if conf.has_option(alias, "string"):
            prompt_edit = ("".join(["Enter connection string for existing alias ",
                           "(example: ssh user@somehost.com):\n"]))
            string = ""
            while string == "":
                string = input(prompt_edit)
            SetAliasString(alias, string)
        elif conf.has_option(alias, "group"):
            prompt_edit = ("".join(["Enter aliases for existing group ",
                           "(example: alias1 alias2):\n"]))
            string = ""
            while string == "":
                string = input(prompt_edit)
            SetGroupString(alias, string)
        else:
            print("error: '" + alias + "' is not correct alias or group")
    else:
        print("error: '" + alias + "' alias or group does not exists")


def CMDPassword(alias):
    groups = []
    connectaliases = []
    for a in conf.sections():
        if conf.has_option(a, "group"):
            groups.append(a)
    if alias in groups:
        print("Can't set password for group.")
    else:
        if conf.has_section(alias):
            prompt_pass = ("[UNSAFE] Enter password for sshpass: ")
            string = ""
            string = getpass(prompt_pass)
            if not string == "":
                SetPassword(alias, string)
        else:
            print("error: '" + alias + "' alias does not exists")


def CMDRemove(alias):
    if conf.has_section(alias):
        prompt_remove = ("Type 'yes' if you sure to remove '" + alias + "' alias or group: ")
        string = input(prompt_remove)
        if string == "yes":
            RemoveAliases([alias])
        else:
            print("'" + alias + "' alias or group was not deleted.")
    else:
        print("error: '" + alias + "' alias or group does not exists.")


def CMDConnect(aliases, command=False):
    groups = []
    connectaliases = []
    for a in conf.sections():
        if conf.has_option(a, "group"):
            groups.append(a)
    for alias in aliases:
        if alias in groups:
            group_aliases = conf.get(alias, "group").split()
            for ga in group_aliases:
                if not ga in connectaliases:
                    connectaliases.append(ga)
        else:
            if not alias in connectaliases:
                connectaliases.append(alias)
    for alias in connectaliases:
        if conf.has_section(alias):
            print("Connecting to " + alias + "...")
            ConnectAlias(alias, command)
            print("... " + alias + " session finished.")
        else:
            print("error: '" + alias + "' alias does not exists")


def CMDList(option, opt, value, parser):
    print(' '.join(str(p) for p in conf.sections()))


def GetTreeList(strings=True, expandlist=True):
    aliases = []
    groups = []
    resultalias = []
    resultstring = []
    for a in conf.sections():
        if conf.has_option(a, "group"):
            groups.append(a)
        elif conf.has_option(a, "exec_string"):
            aliases.append(a)
    for g in groups:
        resultalias.append(g)
        resultstring.append(">> "+g)
        group_aliases = conf.get(g, "group").split()
        for ga in group_aliases:
            if expandlist == False:
                pass
            elif expandlist == True or g in expandlist:
                if conf.has_option(ga, "exec_string"):
                    resultalias.append(ga+" "+g)
                    result = "".join(["  ", str(ga), " (", (conf.get(ga, "exec_string") if
                            conf.has_option(ga, "exec_string") else ""), ")",
                            (" [password]" if conf.has_option(ga, "password") else "")])
                    resultstring.append(result)
            try:
                aliases.remove(ga)
            except ValueError:
                pass
    for a in aliases:
        resultalias.append(a)
        result = "".join([str(a), " (", (conf.get(a, "exec_string") if
                conf.has_option(a, "exec_string") else ""), ")",
                (" [password]" if conf.has_option(a, "password") else "")])
        resultstring.append(result)
    if strings:
        return resultstring;
    else:
        return resultalias;

def CMDFullList(option, opt, value, parser):
    for p in GetTreeList():
        print (p)


def CursesConnect(screen, aliases, command=False):
    curses.endwin()
    groups = []
    connectaliases = []
    for a in conf.sections():
        if conf.has_option(a, "group"):
            groups.append(a)
    for alias in aliases:
        if alias in groups:
            group_aliases = conf.get(alias, "group").split()
            for ga in group_aliases:
                if not ga in connectaliases:
                    connectaliases.append(ga)
        else:
            if not alias in connectaliases:
                connectaliases.append(alias)
    for alias in connectaliases:
        print("Connecting to " + alias + "...")
        ConnectAlias(alias, command)
        print("... " + alias + " session finished.")
    print("Press 'enter' to continue.")
    screen.getch()


def CursesExit(error=False):
    curses.endwin()
    if error:
        print(error)
    exit()


def CursesTextpadConfirm(value):
    if value == 10:
        value = 7
    return value


def CursesTextpad(screen, h, w, y, x, title="", value="",
                  text_colorpair=0, deco_colorpair=0):
    new_window = curses.newwin(h + 3, w + 2, y - 1, x - 1)
    title_window = new_window.subwin(1, w, y, x)
    title_window.addnstr(0, 0, title, w, text_colorpair)
    title_window.refresh()
    sub_window = new_window.subwin(h, w, y + 1, x)
    textbox_field = textpad.Textbox(sub_window, insert_mode=True)
    new_window.attron(deco_colorpair)
    new_window.box()
    new_window.attroff(deco_colorpair)
    new_window.refresh()
    sub_window.addnstr(0, 0, value, h * w, text_colorpair)
    sub_window.attron(text_colorpair)
    return textbox_field


def CursesPanel(screen, h, w, y, x, text,
                text_colorpair=0, deco_colorpair=0, confirm=0):
    new_window = curses.newwin(h, w, y, x)
    new_window.erase()
    new_window.attron(deco_colorpair)
    new_window.box()
    new_window.attroff(deco_colorpair)
    sub_window = new_window.subwin(h - 2, w - 2, y + 1, x + 1)
    sub_window.insstr(0, 0, text)
    panel = curses.panel.new_panel(new_window)
    curses.panel.update_panels()
    screen.refresh()
    if confirm == "password":
        hidden_password = ""
        keych = ""
        position = 2
        while True:
            keych = screen.getch()
            if keych == ord("\n"):
                break
            if keych == 27:
                hidden_password = ""
                break
            if keych == curses.KEY_BACKSPACE:
                if position > 2:
                    if position == len(hidden_password) + 2:
                        sub_window.addstr(1, position - 1, "  ",
                                          text_colorpair)
                        sub_window.refresh()
                        position = position - 1
                    hidden_password = hidden_password[0:-1]
            if keych > 31 and keych < 127:
                hidden_password += curses.keyname(keych)
                sub_window.addstr(1, position, "*", text_colorpair)
                if position < w - 4:
                    position += 1
                sub_window.refresh()
        return hidden_password
    elif confirm == "remove":
        keych = screen.getch()
        if keych == ord("y") or keych == ord("Y"):
            return "confirm"
        return False
    else:
        screen.getch()


def CMDOptions():
    class FormatedParser(OptionParser):

        def format_epilog(self, formatter):
            return self.epilog
    usage = "usage: %prog [options] [aliases]"
    progname = path.basename(__file__)
    epilog = ("".join(["Examples:\n  ",
                       progname, " existingalias\n  ",
                       progname, " -a newremoteserver\n  ",
                       progname, " --edit=newremoteserver -p newremoteserver\n  ",
                       progname, ' -c "ls -l" newremoteserver\n  ',
                       progname, " -c reboot existingalias newremoteserver\n",
                       "Examples of connection string:\n  ",
                       "ssh user@somehost.com\n  ",
                       "ssh gates@8.8.8.8 -p 667\n  ",
                       "ssh root@somehost.com -t tmux a\n",
                       "Also, you can edit config file manually: ", conf_file, "\n"]))
    opts = FormatedParser(usage=usage, version="%prog " + version,
                          epilog=epilog)
    opts.add_option('-l', '--list', action="callback",
                    callback=CMDList, help="show list of all existing aliases")
    opts.add_option('-f', '--fulllist', action="callback",
                    callback=CMDFullList, help=("show list of all existing " +
                                                "aliases with connection strings"))
    opts.add_option('-a', '--add', action="store", type="string",
                    dest="add", metavar="alias", default=False,
                    help="add new alias for connection string")
    opts.add_option('-g', '--group', action="store", type="string",
                    dest="group", metavar="group", default=False,
                    help="add new group for aliases")
    opts.add_option('-c', '--command', action="store", type="string",
                    dest="command", metavar="command", default=False,
                    help="execute command for aliases or group")
    opts.add_option('-k', '--keep', action="store", type="string",
                    dest="keep", metavar="alias", default=False,
                    help="hold connection with specified alias")
    opts.add_option('-e', '--edit', action="store", type="string",
                    dest='edit', metavar="alias", default=False,
                    help="edit existing alias or group")
    opts.add_option('-p', '--password', action="store", type="string",
                    dest='password', metavar="alias", default=False,
                    help="set and store password for sshpass [UNSAFE]")
    opts.add_option('-r', '--remove', action="store", type="string",
                    dest='remove', metavar="alias", default=False,
                    help="remove existing alias or group")
    options, alias = opts.parse_args()
    if options.add:
        CMDAdd(options.add)
    if options.group:
        CMDGroup(options.group)
    if options.edit:
        CMDEdit(options.edit)
    if options.password:
        CMDPassword(options.password)
    if options.remove:
        CMDRemove(options.remove)
    if options.keep:
        HoldConnection(options.keep)
    if alias:
        CMDConnect(alias, options.command)

# curses template from: https://stackoverflow.com/a/30828805/6224462


def CursesMain():
    help_screen = ("".join([" Press:\n",
                            "  'z'/'x' or arrows - navigation\n",
                            "  'a'/'F2' - add new alias (without spaces)\n",
                            "  'g'/'F5' - add new group (spaces will be stripped)\n",
                            "  'e'/'F4' - edit existing alias/group\n",
                            "  'p'/'F6' - set alias's password for sshpass [UNSAFE]\n",
                            "  'space'/'insert' - select\n",
                            "  'r'/'F8' - remove selected alias/aliases\n",
                            "  'c'/'F3' - execute specific command with selected alias/aliases\n",
                            "  'k'/'F7' - hold connection with selected alias\n",
                            "  'enter'/'F9' - connect to selected alias/aliases,\n",
                            "                 expand/collapse group\n",
                            "  'q'/'F10' - quit\n",
                            " Run program with '--help' option to view command line help.\n",
                            " Also, you can edit config file manually:\n",
                            "  ", conf_file]))
    if expand_default == True:
        groups = []
        for a in conf.sections():
            if conf.has_option(a, "group"):
                groups.append(a)
        expanded = groups
        strings = GetTreeList(False, expanded)
        stringsfull = GetTreeList(True, expanded)
    elif expand_default == False:
        groups = []
        expanded = groups
        strings = GetTreeList(False, expanded)
        stringsfull = GetTreeList(True, expanded)
    row_num = len(strings)
    selected_strings = [" " for i in range(0, row_num + 1)]
    screen = curses.initscr()
    curses.noecho()
    curses.cbreak()
    curses.start_color()
    screen.keypad(1)
    curses.init_pair(1, curses.COLOR_BLACK, curses.COLOR_CYAN)
    highlight_text = curses.color_pair(1)
    normal_text = curses.A_NORMAL
    height, width = screen.getmaxyx()
    screen.border(0)
    curses.curs_set(0)
    max_row = height - 5
    screen.addnstr(1, 2, "sshch " + version + ", press 'h' for help",
                   width - 4)
    box = curses.newwin(max_row + 2, width - 2, 2, 1)
    box.box()
    pages = int(ceil(row_num / max_row))
    position = 1
    page = 1
    for i in range(1, max_row + 1):
        if row_num == 0:
            box.addnstr(1, 1, "There aren't any aliases yet. Press 'a' to add new one.",
                        width - 6, highlight_text)
        else:
            exec_string = ["[", selected_strings[i], "] ", stringsfull[i - 1]]
            if (i == position):
                box.addnstr(i, 2, "".join(exec_string), width - 6, highlight_text)
            else:
                box.addnstr(i, 2, "".join(exec_string), width - 6, normal_text)
            if i == row_num:
                break
    screen.refresh()
    box.refresh()
    key_pressed = screen.getch()
    while True:
        if key_pressed == ord('q') or key_pressed == ord(
            'Q') or key_pressed == (
                27) or key_pressed == curses.KEY_F10:
            CursesExit()
        if key_pressed == ord('h') or key_pressed == ord(
                'H') or key_pressed == curses.KEY_F1:
            CursesPanel(screen, height - 4, width - 6, 2, 3,
                        help_screen, normal_text, highlight_text)
        if key_pressed == ord('a') or key_pressed == ord(
                'A') or key_pressed == curses.KEY_F2:
            curses.curs_set(1)
            new_alias_textpad = CursesTextpad(screen, 1, width - 8,
                                              (height // 2) - 1, 4, "Enter new alias:", "",
                                              normal_text, highlight_text)
            add_alias = new_alias_textpad.edit(CursesTextpadConfirm)
            add_alias = add_alias.split()[0].strip()
            if not add_alias == "":
                add_result = AddNewAlias(add_alias)
                if add_result == True:
                    add_string = ""
                    while add_string == "":
                        string_textpad = CursesTextpad(screen, 3,
                                                       width - 8, (height // 2) - 1, 4,
                                                       "Enter full execution string:",
                                                       "ssh ", normal_text, highlight_text)
                        add_string = string_textpad.edit(
                            CursesTextpadConfirm)
                    SetAliasString(add_alias,
                                   add_string.replace("\n", "").rstrip())
                    strings = GetTreeList(False, expanded)
                    stringsfull = GetTreeList(True, expanded)
                    row_num = len(strings)
                    selected_strings.append(" ")
                    pages = int(ceil(row_num / max_row))
                    box.refresh()
                else:
                    curses.curs_set(0)
                    CursesPanel(screen, 3,
                                width - 6, (height // 2) - 1, 3, add_result,
                                normal_text, highlight_text)
            curses.curs_set(0)
        if key_pressed == ord('g') or key_pressed == ord(
                'G') or key_pressed == curses.KEY_F5:
            curses.curs_set(1)
            new_group_textpad = CursesTextpad(screen, 1, width - 8,
                                              (height // 2) - 1, 4, "Enter group name (without spaces):", "",
                                              normal_text, highlight_text)
            add_group = new_group_textpad.edit(CursesTextpadConfirm)
            add_group = add_group.split()[0].strip()
            if not add_group == "":
                add_result = AddNewAlias(add_group)
                if add_result == True:
                    add_string = ""
                    while add_string.rstrip() == "":
                        string_textpad = CursesTextpad(screen, 3,
                                                       width - 8, (height // 2) - 1, 4,
                                                       "Enter aliases for new group (example: alias1 alias2):",
                                                       "", normal_text, highlight_text)
                        add_string = string_textpad.edit(
                            CursesTextpadConfirm)
                    SetGroupString(add_group,
                                   add_string.replace("\n", "").rstrip())
                    expanded.append(add_group)
                    strings = GetTreeList(False, expanded)
                    stringsfull = GetTreeList(True, expanded)
                    row_num = len(strings)
                    selected_strings = [" " for i in range(0, row_num + 1)]
                    pages = int(ceil(row_num / max_row))
                    box.refresh()
                else:
                    curses.curs_set(0)
                    CursesPanel(screen, 3,
                                width - 6, (height // 2) - 1, 3, add_result,
                                normal_text, highlight_text)
            curses.curs_set(0)
        if (key_pressed == ord('e') or key_pressed == ord(
                'E') or key_pressed == curses.KEY_F4) and row_num != 0:
            edit_string = ""
            groups = []
            for a in conf.sections():
                if conf.has_option(a, "group"):
                    groups.append(a)
            curses.curs_set(1)
            if strings[position - 1] in groups:
                while edit_string.rstrip() == "":
                    string_textpad = CursesTextpad(screen, 3, width - 8,
                                                   (height // 2) - 1, 4, "Enter new aliases for existing group:",
                                                   (conf.get(strings[position - 1],
                                                   "group") if conf.has_option(strings[position - 1],
                                                   "group") else ""),
                                                   normal_text, highlight_text)
                    edit_string = string_textpad.edit(CursesTextpadConfirm)
                SetGroupString(strings[position - 1],
                               edit_string.replace("\n", "").rstrip())
                strings = GetTreeList(False, expanded)
                stringsfull = GetTreeList(True, expanded)
                row_num = len(strings)
                selected_strings.append(" ")
                pages = int(ceil(row_num / max_row))
                box.refresh()
            else:
                while edit_string.rstrip() == "":
                    string_textpad = CursesTextpad(screen, 3, width - 8,
                                                   (height // 2) - 1, 4, "Enter new execution string:",
                                                   (conf.get(strings[position - 1].split()[0].strip(),
                                                   "exec_string") if conf.has_option(strings[position - 1].split()[0].strip(),
                                                   "exec_string") else ""),
                                                   normal_text, highlight_text)
                    edit_string = string_textpad.edit(CursesTextpadConfirm)
                SetAliasString(strings[position - 1].split()[0].strip(),
                               edit_string.replace("\n", "").rstrip())
                strings = GetTreeList(False, expanded)
                stringsfull = GetTreeList(True, expanded)
            curses.curs_set(0)
        if (key_pressed == ord('p') or key_pressed == ord(
                'P') or key_pressed == curses.KEY_F6) and row_num != 0:
            groups = []
            for a in conf.sections():
                if conf.has_option(a, "group"):
                    groups.append(a)
            if not strings[position - 1].split()[0].strip() in groups:
                set_password = ""
                set_password = CursesPanel(screen, 4, width - 6,
                                           (height // 2) - 1, 3,
                                           " Enter user password for sshpass and press 'enter':\n>",
                                           normal_text, highlight_text, "password")
                if not set_password == "":
                    SetPassword(strings[position - 1].split()[0].strip(), set_password)
                strings = GetTreeList(False, expanded)
                stringsfull = GetTreeList(True, expanded)
        if (key_pressed == ord('r') or key_pressed == ord(
                'R') or key_pressed == curses.KEY_F8 or key_pressed == (
                curses.KEY_DC)) and row_num != 0:
            selected = []
            for i in range(1, row_num + 1):
                if selected_strings[i] == "*":
                    selected.append(strings[i - 1])
            if len(selected) > 0:
                remove_confirm = (
                    "".join(["Are you sure to remove ",
                             str(len(selected)), " selected aliases? (y/N)"]))
            else:
                remove_confirm = ("".join(["Are you sure to remove '",
                                           strings[position - 1].split()[0].strip(), "' alias? (y/N)"]))
                selected.append(strings[position - 1].split()[0].strip())
            remove_result = CursesPanel(screen, 4, width - 6,
                                        (height // 2) - 1, 3, remove_confirm, normal_text,
                                        highlight_text, "remove")
            if remove_result == "confirm":
                RemoveAliases(selected)
                strings = GetTreeList(False, expanded)
                stringsfull = GetTreeList(True, expanded)
                row_num = len(strings)
                selected_strings = [" " for i in range(0, row_num + 1)]
                pages = int(ceil(row_num / max_row))
                position = 1
                page = 1
                box.refresh()
        if (key_pressed == ord('c') or key_pressed == ord(
                'C') or key_pressed == curses.KEY_F3) and row_num != 0:
            selected = []
            for i in range(1, row_num + 1):
                if selected_strings[i] == "*":
                    selected.append(strings[i - 1])
            if not len(selected) > 0:
                selected.append(strings[position - 1].split()[0].strip())
            curses.curs_set(1)
            command_textpad = CursesTextpad(screen, 3, width - 8,
                                            (height // 2) - 1, 4,
                                            "".join([
                                                "Enter specific command to execute with selected ",
                                                "alias/aliases:"]
                                            ), "", normal_text, highlight_text)
            command_string = command_textpad.edit(CursesTextpadConfirm)
            CursesConnect(screen, selected,
                          command_string.replace("\n", "").rstrip())
            curses.curs_set(0)
        if (key_pressed == ord('k') or key_pressed == ord('K') or
                key_pressed == (curses.KEY_F7)) and row_num != 0:
            groups = []
            for a in conf.sections():
                if conf.has_option(a, "group"):
                    groups.append(a)
            if not strings[position - 1] in groups:
                curses.endwin()
                HoldConnection(strings[position - 1].split()[0].strip())
        if (key_pressed == ord("\n") or key_pressed == (
                curses.KEY_F9)) and row_num != 0:
            groups = []
            for a in conf.sections():
                if conf.has_option(a, "group"):
                    groups.append(a)
            if strings[position - 1] in groups:
                if strings[position - 1] in expanded:
                    expanded.remove(strings[position - 1])
                else:
                    expanded.append(strings[position - 1])
                strings = GetTreeList(False, expanded)
                stringsfull = GetTreeList(True, expanded)
                row_num = len(strings)
                selected_strings.append(" ")
                pages = int(ceil(row_num / max_row))
                box.refresh()
            else:
                selected = []
                for i in range(1, row_num + 1):
                    if selected_strings[i] == "*":
                        selected.append(strings[i - 1])
                if not len(selected) > 0:
                    selected.append(strings[position - 1].split()[0].strip())
                CursesConnect(screen, selected)
            selected_strings = [" " for i in range(0, row_num + 1)]
        if (key_pressed == 32 or key_pressed == (
                curses.KEY_IC)) and row_num != 0:
            if selected_strings[position] == ' ':
                selected_strings[position] = '*'
            else:
                selected_strings[position] = ' '
            if page == 1:
                if position < i:
                    position = position + 1
                else:
                    if pages > 1:
                        page = page + 1
                        position = 1 + (max_row * (page - 1))
            elif page == pages:
                if position < row_num:
                    position = position + 1
            else:
                if position < max_row + (max_row * (page - 1)):
                    position = position + 1
                else:
                    page = page + 1
                    position = 1 + (max_row * (page - 1))
        if key_pressed == curses.KEY_DOWN or key_pressed == ord(
                'x') or key_pressed == ord('X'):
            if page == 1:
                if position < i:
                    position = position + 1
                else:
                    if pages > 1:
                        page = page + 1
                        position = 1 + (max_row * (page - 1))
            elif page == pages:
                if position < row_num:
                    position = position + 1
            else:
                if position < max_row + (max_row * (page - 1)):
                    position = position + 1
                else:
                    page = page + 1
                    position = 1 + (max_row * (page - 1))
        if key_pressed == curses.KEY_UP or key_pressed == ord(
                'z') or key_pressed == ord('Z'):
            if page == 1:
                if position > 1:
                    position = position - 1
            else:
                if position > (1 + (max_row * (page - 1))):
                    position = position - 1
                else:
                    page = page - 1
                    position = max_row + (max_row * (page - 1))
        if key_pressed == curses.KEY_LEFT or (key_pressed ==
                                              curses.KEY_PPAGE):
            if page > 1:
                page = page - 1
                position = 1 + (max_row * (page - 1))
        if key_pressed == curses.KEY_RIGHT or (key_pressed ==
                                               curses.KEY_NPAGE):
            if page < pages:
                page = page + 1
                position = (1 + (max_row * (page - 1)))
        if key_pressed == curses.KEY_HOME:
                page = 1
                position = 1
        if key_pressed == curses.KEY_END:
                page = pages
                position = row_num
        box.erase()
        screen.border(0)
        box.border(0)
        for i in range(1 + (max_row * (page - 1)), max_row + 1 +
                       (max_row * (page - 1))):
            if row_num == 0:
                box.addnstr(1, 1, "There aren't any aliases yet. Press 'a' to add new one.",
                            width - 6, highlight_text)
            else:
                exec_string = ["[", selected_strings[i], "] ", stringsfull[i - 1]]
                if (i + (max_row * (page - 1)) == (position + (max_row * (page - 1)))):
                    box.addnstr(i - (max_row * (page - 1)), 2, "".join(
                        exec_string), width - 6, highlight_text)
                else:
                    box.addnstr(i - (max_row * (page - 1)), 2, "".join(
                        exec_string), width - 6, normal_text)
                if i == row_num:
                    break
        screen.refresh()
        box.refresh()
        key_pressed = screen.getch()
    CursesExit()


if __name__ == "__main__":
    try:
        input = raw_input   # Fix for Python 2.x
    except NameError:
        pass

    conf = configparser.RawConfigParser()
    if not path.exists(conf_file):
        open(conf_file, 'w')
    conf.read(conf_file)
    if len(argv) > 1:
        try:
            CMDOptions()
        except KeyboardInterrupt:
            exit()
        except configparser.Error:
            print("Error: can't parse your config file, please check it manually or make new one")
            exit()
    else:
        try:
            CursesMain()
        except KeyboardInterrupt:
            CursesExit()
        except configparser.NoOptionError:
            CursesExit("".join(["Error: can't parse your config file, please ",
                       "check it manually or make new one"]))
        except curses.error:
            CursesExit("".join(["Error: can't show some curses element, maybe ",
                       "your terminal is too small"]))