EMPTY_LINE = ''
FIRST_LINE_INDEX = 0
PAGE_UP_DOWN_RANGE = 20
SHOW_UP_DOWN_RANGE = 5
WELCOME_TEXT_MESSAGE = '**************        WELCOME TO THE TEXT EDITOR!        ***************\n' \
               '************** ENTER \'help\' TO SEE ALL POSSIBLE COMMANDS ***************'
EXIT_TEXT_MESSAGE = '**************                    BYE                    ***************'
INVALID_COMMAND_MESSAGE = 'Invalid command.'
FILE_ERROR_MESSAGE = 'Such file does not exists.'

HELP = 'help'
SHOW_CURRENT_LINE = 'showline'
NEW_FILE = 'newfile'
LOAD_FILE = 'loadfile'
SAVE_FILE = 'savefile'
MOVE_UP = 'move-up'
MOVE_DOWN = 'move-down'
PAGE_UP = 'page-up'
PAGE_DOWN = 'page-down'
HEAD = 'head'
TAIL = 'tail'
INSERT_BEFORE = 'insert-before'
INSERT_AFTER = 'insert-after'
DELETE = 'delete'
REPLACE = 'replace'
SHOW = 'show'
EXIT = 'exit'

ALL_POSSIBLE_COMMANDS = [
    HELP,
    SHOW_CURRENT_LINE,
    NEW_FILE,
    LOAD_FILE,
    SAVE_FILE,
    MOVE_UP,
    MOVE_DOWN,
    PAGE_UP,
    PAGE_DOWN,
    HEAD,
    TAIL,
    INSERT_BEFORE,
    INSERT_AFTER,
    DELETE,
    REPLACE,
    SHOW,
    EXIT
]

NEW_LINE = '\n'

PRINT_LINE_FORMAT = '%s. %s'

WRITE_FILE = 'w+'
READ_FILE = 'r'
PATH_TO_FILE = '/files/%s'
