import tkinter as tk        # using tkinter for the GUI
import tkinter.ttk as ttk
# Requirements to run: python3 pytk

class Window(tk.Frame): # create a tkinter frame
    def __init__(self, master=None):
        tk.Frame.__init__(self, master)
        self.master = master

root = tk.Tk()      # some definitions for the gui
app = Window(root)

##### Functions #####

def addBase(): # the addBase function will add whatever base is in the baseInput entry box with the button is pressed
    out = []
    for base in baseDropdown['values']: # create a list that is a copy of the base list, but as integers instead of strings (so it can be sorted)
        out.append(int(base)) 
    try:
        if not int(baseInput.get()) in out: # if the base isn't already there,
            out.append(int(baseInput.get())) # then add it to the list
        baseDropdown['values'] = sorted(out) # apply the list to the dropdown, after sorting it
        functionTrigger(0,0,0) # Trigger number conversion
    except ValueError: # error is caught if the base is not a number
        displayMessage("Not a valid base!")

# functionTrigger is ran when the number input box is changed, or when a base is added
def functionTrigger(a,b,c): # Positional arguments are not used for this function to run, but still must be defined to allow the finction to be called by a tracer
    input = numberInput.get()  # Retreive the input number
    base = int(baseDropdown['values'][baseDropdown.current()]) # Retreive the current selected base
    listOut.delete(0,listOut.size()) # clear the output
    output = baseConverter(input, base) # run the conversion with the selected base and input
    for line in output:  # insert each line into the output listbox at the end
        listOut.insert(tk.END, line)
        
# displayMessage will simply write a message to the output listbox.
def displayMessage(message):
    listOut.delete(0,listOut.size()) # delete all existing entries
    listOut.insert(tk.END, message) # add a line with the message


def baseConverter(userInput, numberBase): # arguments: userInput: the user's number to be converted. numberBase: the number base of the input
    try:
        decimalNum = int(userInput,numberBase) # first, try to get the number in decimal.
    except: # If this fails, then the input from the user does not work in this base, or might not be a number at all
        displayMessage("Number entered does not match the base!")
        return
    outputList = []
    for base in baseDropdown['values']: # iterate through all bases
        outputText = "Base " + base + ": " # prepare a string for the line
        outputNumber = ""
        tempNum = decimalNum # create a temp number to modify

        while tempNum > 0: # this loop converts from decimal to any other base
            digit = int(tempNum % int(base)) # find a digit by taking remainder with the base
            tempNum = int(tempNum / int(base)) # take the result of the division and use it for the next digit
            if digit < 10: # Can be represented with 0-9
                outputNumber += str(digit) # add the digit
            else: # Alphanumeric characters needed
                outputNumber += chr(55 + digit) # ASCII character offset for capital letters
                
        outputNumber = outputNumber[::-1] # reverse the output number, as the above loop added digits in reverse
        outputText += outputNumber #add the number to the rest of the string
        outputList.append(outputText) # add each conversion to the output list
    return outputList # return the list of conversions
        
##### Variables #####

root.wm_title("Numerical converter") # window title

# Some labels. The empty ones make the spacing in the GUI better
lbl0 = tk.Label(root, text="Add a base:", font=("Arial", 12))
lbl0.grid(column=0, row=1)

lbl1 = tk.Label(root, text="\n", font=("Arial", 12))
lbl1.grid(column=1, row=0)

lbl2 = tk.Label(root, text="", font=("Arial", 12))
lbl2.grid(column=0, row=3)

# the add base button
addBaseBtn = tk.Button(root, text="Add", command=addBase)
addBaseBtn.grid(column=2, row=1)
# the entry box for the adding a base
baseInput = ttk.Entry(root,width=10, state='enabled')
baseInput.grid(column = 1, row = 1)


# some horizontal separators for the app
separator1 = ttk.Separator(root, orient='horizontal')
separator1.place(relx=0, rely=0.2, relwidth=1, relheight=1)

separator2 = ttk.Separator(root, orient='horizontal')
separator2.place(relx=0, rely=0.43, relwidth=1, relheight=1)

# the dropdown list of bases
baseDropdown = ttk.Combobox(root, width='10')
baseDropdown['values']= (2, 10, 16)
baseDropdown.current(1) #set the default item to base 10
baseDropdown.grid(column=1, row=4)

# label for the base dropdown
lbl3 = tk.Label(root, text="\nNumber Base \n of the input:\n", font=("Arial", 12))
lbl3.grid(column=0, row=4)

# create a tracable string for the text input; when this text is changed, the base conversion is ran
userInputRaw = tk.StringVar()
userInputRaw.trace_add("write", functionTrigger) # trace the changes made to the string, when it changes run functionTrigger

# number input for the user, that uses the above traced variable
numberInput = ttk.Entry(root,width=10, state='enabled', textvariable=userInputRaw)
numberInput.grid(column=1, row = 6)

# Label for number input
lbl4 = tk.Label(root, text="Number to convert:", font=("Arial", 12))
lbl4.grid(column=0, row=6)

# Label to improve spacing
lbl5 = tk.Label(root, text="", font=("Arial", 12))
lbl5.grid(column=50, row=5)

# Output listbox
listOut = tk.Listbox(root, selectmode='SINGLE', width=50)
listOut.grid(column=0, row=7, columnspan=3)


# disable app resizing
root.resizable(False, False)
root.geometry('325x400')
# run the app
root.mainloop()