main.py

"""
Main

The input-independent means of controlling the brailler program.

This file contains the loops for
    - The entire program
    - The read cycle
    - The write cycle

Depending on how the program was compiled, this file also instantiates the
appropriate view (ViewBraille or ViewCLI).
"""
from os import listdir, mkdir
from os.path import isfile, isdir, join, normpath
from re import search
from sys import argv
import magic

from views.view_factory import ViewFactory
from reader.read import Reader

# TODO possible refactor into a database value or something
user_path = 'user'
view = None

def setup(viewtype="CLIView"):
    """Code that should only run once when the program is launched.

    Check the raspberry pi connections.
    Check that the relevant libraries have been installed.
    Check that the user_path 'user' folder exists
    """
    global view

    if not isdir(user_path): # Check that the user_path 'user' folder exists
        mkdir(user_path)
        if not isdir(user_path):
            raise OSError("Could not create the user_path directory")

    view = ViewFactory().make_view(viewtype)


def teardown():
    """Code that should only run once when the program is to be exited.
    """
    pass


def validate_file(in_file_name, user_path='user'):
    if validate_directory(in_file_name, user_path) and \
            validate_file_type(in_file_name, user_path):
        return True

    return False


def validate_directory(in_file_name, user_path='user'):
    """Checks that the file is located within the user_path directory
    """
    # regex matches 'user/<alpha_numeric-Name>.<fileType>'
    regex_str = r'^' + user_path + r'/' + r'[A-Za-z0-9_-]+' + r'.[A-Za-z]+$'
    directoryValidate = True
    in_u_p = normpath(in_file_name)

    if not in_u_p.startswith(user_path):
        view.str_print("not belong in userpath")
        directoryValidate = False
    elif not search(regex_str, in_u_p):
        print("in_file_name", in_file_name, "in_u_p", in_u_p)
        directoryValidate = False

    view.str_print(in_u_p, " ")
    view.str_print(user_path)

    print("directoryValidate", directoryValidate)
    return directoryValidate


def validate_file_type(in_file_name, user_path='user'):
    fileTypeValidate = False
    mime = magic.Magic(mime=True)
    view_select_type = mime.from_buffer(user_path + "/" + in_file_name)

    if "text/" in view_select_type:
        fileTypeValidate = True

    view.str_print(view_select_type)

    return fileTypeValidate 


def menu_read_file(user_path='user'):
    """Allows user to select a file to read from within the user_path
    """
    view_select = None
    brailleTextFile = False
    only_files = list()
    first_char_test = ''

    only_files = [f for f in listdir(user_path) if isfile(join(user_path, f))]
    view.str_print(only_files)
    view_select = view.option_select(only_files)

    if view_select == None: # User decided to not read any of the files
        return None
    # User has selected a file to read from - now determine the 'language'
    # Check that the user is opening a text file
    elif validate_file(user_path + "/" + only_files[view_select]):
        with open(user_path + "/" + only_files[view_select], 'r') as f:
            first_char_test = f.read(1)
            if ord(first_char_test) >= 10240 or ord(first_char_test) <= 10303:
                brailleTextFile = True
            else:
                brailleTextFile = False
            y = first_char_test + f.read()
            x = Reader().translate_item(y)
            view.str_print(x)
            view.str_print(y)


def menu_write_file(user_path='user'):
    """Allows user to create a file to write to within the user_path
    """
    options = ["No text translation", 
        "US Braille translation", 
        "UK Braille translation", 
        "Decide once completed",]

    only_files = [f for f in listdir(user_path) if isfile(join(user_path, f))]
    
    view.str_print("Enter a new file name to write to:")
    new_file_name = view.str_input() # TODO handling of inner and outer folders....

    encoding = view.option_select(options)

    if new_file_name in only_files:
        view.str_print("This file already exists")
    elif not validate_file(user_path + "/" + new_file_name):
        view.str_print("Invalid file name provided")
    else:
        user_input = view.str_input()
        if encoding == 3:
            encoding = view.option_select(options)
        if encoding == 1:
            pass # TODO perform translations before write to file here
        elif encoding == 2:
            pass
        with open(user_path + "/" + new_file_name, "x") as f:
            f.write(user_input)


def menu(user_path='user'):
    """Allows user to choose a menu option
    """
    function_choice = ["Read a file", "Write a new file",]
    view_select = view.option_select(function_choice)

    if view_select == 0: # Read a file
        menu_read_file()
        return(False)
    elif view_select == 1: # Write a new file
        menu_write_file()
        return(False)

    return(True)


def main_loop():
    to_exit = False
    while not to_exit:
        if menu():
            to_exit = True


if __name__ == '__main__':
    view_args = ['CLIView', 'BrailleView',]
    print(len(argv))
    print(str(argv))
    if argv[1]:
        if argv[1] == view_args[0]:
            setup(argv[1])
        elif argv[1] == view_args[1]:
            setup(argv[1])
        else:
            raise ValueError("Invalid parameter passed from CLI")
    else:
        setup()
    main_loop()
    teardown()