#!/usr/bin/python

# Imports, of course.
# You'll need to install colorama from Pip if you want to use colours in the terminal. I'm probably going to replace this when I get around to making a config file properly.
import os
import socket
import subprocess
import shutil
import curses
from datetime import datetime
from colorama import Fore
from os.path import expanduser


# Some initial variables
version = "0.1.0"
user = os.getlogin()
initDirectory = expanduser("~") 
currentDirectory = initDirectory
argList = ["", ""]

# Start work on checking whether a config file exists
if os.path.isfile(expanduser("~") + "/.config/mash/mash.conf") == True:
    configFile = open(expanduser("~") + "/.config/mash/mash.conf")
else:
    print("Config file does not exist. Copying default file to ~/.config/mash/mash.conf")
    shutil.copyfile("/etc/mash/mash.conf", (expanduser("~") + "/.config/mash/mash.conf"))

# Write the time to the history file
historyFile = open((expanduser("~") + "/.history.mash"), "a")
historyFile.write("\n")
historyFile.write(("Session on " + str(datetime.now())))
historyFile.write("\n")

# Welcome message. Probably going to be configurable soon enough.
print("Welcome to Mash, " + user + "@" + socket.gethostname() + "! Mash is currently on version " + version)

# Main loop.
try:
    while True:
        # Set directory and prompt for input.
        os.chdir(currentDirectory)
        command = input(Fore.GREEN + user + Fore.WHITE + "@" + socket.gethostname() + Fore.BLUE + " " + currentDirectory + Fore.WHITE + " > ")
        
        # Clean some things up for the argument parser.
        argNumber = 0
        argList.clear()

        # Argument parser
        for letter in command:
            if letter == " ":
                argNumber = argNumber + 1
            else:
                try:
                    argList[argNumber] = argList[argNumber] + letter
                except Exception:
                    argList.append(letter)
        
        # Start work on pipes.
        for word in argList:
            if word == "&&":
                print("This hasnt been implemented yet hahahahah")
        
        # Built in commands section
        if argList[0] == "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("cd       Change your directory.")
            print("history  See previously ran commands.")
            print("mat      View contents of a file. If you're on a Unix-like OS, use 'cat' instead.")
            print("mls      View all files in a directory. If you're on a Unix-like OS, use 'ls' instead.")
            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 argList[0] == "exit":
            exit()
        elif argList[0] == "version":
            print(version)
        elif argList[0] == "mat":
            matFile = open(argList[1])
            print(matFile.read())
        elif argList[0] == "mls":
            try:
                if argList[1] == "":
                    print(os.listdir(currentDirectory))
                else:
                    argList[1] = mlsDirectory
                    if mlsDirectory[0] == "/":
                        print(os.listdir(mlsDirectory))
                    else:
                        print(os.listdir(currentDirectory + "/" + mlsDirectory))
            except Exception:
                print(os.listdir(currentDirectory))
        elif argList[0] == "cd":
            try:
                directoryForCD = argList[1]
                if directoryForCD[0] == "~":
                    currentDirectory = expanduser("~") + directoryForCD.replace("~", "")
                if directoryForCD[0] == "/":
                    currentDirectory = directoryForCD
                else:
                    currentDirectory = (currentDirectory + "/" + directoryForCD)            
            except Exception:
                print("Either a directory was not provided or an error occured.")
        elif argList[0] == "history":
            historyReadFile = open((expanduser("~") + "/.history.mash"))
            print(historyReadFile.read())
        elif argList[0] == "mtime":
            print(datetime.now())
        
        # If a built in command isn't what you wanted, run a new subprocess.
        else:
            try:
                subprocess.run(argList)
            except Exception:
                print("Command", command, "either doesn't exist, isn't in the path or isn't in this directory.")
        
        # Write to the history file
        historyFile = open((expanduser("~") + "/.history.mash"), "a")
        historyFile.write(command)
        historyFile.write("\n")
        historyFile.close()

# Handle errors in the main loop
except Exception:
    print("Looks like there was an error. Exiting...")
# Handle ^C
except KeyboardInterrupt:
    print(" detected! Exiting...")