#!/usr/bin/python
import os
import subprocess
import re

initDirectory = os.path.dirname(os.path.realpath(__file__)) 
currentDirectory = initDirectory
version = "0.0.1"
user = os.getlogin()

print("Welcome to Mash, " + user + "! Mash is currently on version " + version)

def grabArgument(fullCommand, commandRan):
    fullCommand.replace(commandRan, "")
try:
    while True:
        command = input(currentDirectory + " > ")
        if command == "help":
            print("This is Mash, Max's Shell. Mash has a few built in commands, which you can use to run commands, view files and interact with your system.")
            print("Some commands you can run:")
            print("")
            print("pwd      Print directory you are currently in")
            print("cd       Change your directory.")
            print("cat      View contents of a file.")
            print("version  Print current version of Mash.")
            print("exit     Exit Mash.")
            print("")
            print("You can also run commands installed by your system. See your OS's documentation for more information.")
        elif command == "pwd":
            print(currentDirectory)
        elif command == "exit":
            exit()
        elif command == "cd":
            try:
                cdDirectory = input("Directory: ")
                if cdDirectory[0] == "/":
                    if os.path.isdir(cdDirectory) == False:
                        if os.path.isfile(cdDirectory) == True:
                            print("That's not a directory, that's a file!")
                        else:
                            print("That directory doesn't exist.")
                    else:
                        currentDirectory = cdDirectory
                else:
                    if os.path.isdir(currentDirectory + cdDirectory) == False:
                        if os.path.isfile(currentDirectory + cdDirectory) == True:
                            print("That's not a directory, that's a file!")
                        else:
                            print("That directory doesn't exist.")
                    else:
                        currentDirectory = cdDirectory
            except Exception:
                print("Either there was an error or that file doesn't exist.")
        elif command == ("cat"):
            try:
                catFile = input("File to catalog: ")
                catFileOpened = open(catFile)
                print(catFileOpened.read())
            except Exception:
                print("File", catFile, "either doesn't exist or isn't in this directory.")
        elif command == "version":
            print(version)
        else:
            try:
                subprocess.run(command)
            except Exception:
                print("Command", command, "either doesn't exist, isn't in the path or isn't in this directory.")
except Exception:
    print("Looks like there was an error. Exiting...")
except KeyboardInterrupt:
    print(" detected! Exiting...")