main.py

import tkinter
from tkinter import ttk
from docxtpl import DocxTemplate
import datetime
from tkinter import messagebox

def clear_item():
    qty_spinbox.delete(0, tkinter.END)
    qty_spinbox.insert(0, "1")
    desc_entry.delete(0, tkinter.END)
    price_spinbox.delete(0, tkinter.END)
    price_spinbox.insert(0, "0.0")

invoice_list = []
def add_item():
    qty = int(qty_spinbox.get())
    desc = desc_entry.get()
    price = float(price_spinbox.get())
    line_total = qty*price
    invoice_item = [qty, desc, price, line_total]
    if len(desc) > 0 and not (all(i == 0 for i in invoice_item[1:])): 
        tree.insert('',0, values=invoice_item)
        clear_item()
        invoice_list.append(invoice_item)
    else:
        messagebox.showwarning("Warning", "Please fill out all fields.")
    
    
def new_invoice():
    first_name_entry.delete(0, tkinter.END)
    last_name_entry.delete(0, tkinter.END)
    phone_entry.delete(0, tkinter.END)
    clear_item()
    tree.delete(*tree.get_children())
    invoice_list.clear()



def generate_invoice():
    doc = DocxTemplate("invoice_template.docx")
    if  len(invoice_list) == 0:
        messagebox.showwarning("Error", "No items added to the invoice.")   
    elif len(first_name_entry.get()) ==0 and len(last_name_entry.get())==0:
        messagebox.showwarning("Error", "No Username added to the invoice.")   
    else:    
        name = first_name_entry.get()+last_name_entry.get()
        phone = phone_entry.get()
        subtotal = sum(item[3] for item in invoice_list) 
        salestax = 0.1
        total = subtotal*(1-salestax)
        
        doc.render({"name":name, 
                "phone":phone,
                "date":datetime.datetime.now().strftime("%Y-%m-%d"),
                "invoice_list": invoice_list,
                "subtotal":subtotal,
                "salestax":str(salestax*100)+"%",
                "total":total})
        
        doc_name = "new_invoice" + name + datetime.datetime.now().strftime("%Y-%m-%d") + ".docx"
        doc.save(doc_name)
        
        messagebox.showinfo("Invoice Complete", "Invoice has been Completed !")
        
        new_invoice()


    

window = tkinter.Tk()
window.title("Invoice Generator Form")

frame = tkinter.Frame(window)
frame.pack(padx=20, pady=10)

first_name_label = tkinter.Label(frame, text="First Name")
first_name_label.grid(row=0, column=0)
last_name_label = tkinter.Label(frame, text="Last Name")
last_name_label.grid(row=0, column=1)

first_name_entry = tkinter.Entry(frame)
last_name_entry = tkinter.Entry(frame)
first_name_entry.grid(row=1, column=0)
last_name_entry.grid(row=1, column=1)

phone_label = tkinter.Label(frame, text="Phone")
phone_label.grid(row=0, column=2)
phone_entry = tkinter.Entry(frame)
phone_entry.grid(row=1, column=2)

qty_label = tkinter.Label(frame, text="Qty")
qty_label.grid(row=2, column=0)
qty_spinbox = tkinter.Spinbox(frame, from_=1, to=100)
qty_spinbox.grid(row=3, column=0)

desc_label = tkinter.Label(frame, text="Description")
desc_label.grid(row=2, column=1)
desc_entry = tkinter.Entry(frame)
desc_entry.grid(row=3, column=1)

price_label = tkinter.Label(frame, text="Unit Price")
price_label.grid(row=2, column=2)
price_spinbox = tkinter.Spinbox(frame, from_=0.0, to=500, increment=0.5)
price_spinbox.grid(row=3, column=2)

add_item_button = tkinter.Button(frame, text = "Add item", command = add_item)
add_item_button.grid(row=4, column=2, pady=5)

columns = ('qty', 'desc', 'price', 'total')
tree = ttk.Treeview(frame, columns=columns, show="headings")
tree.heading('qty', text='Qty')
tree.heading('desc', text='Description')
tree.heading('price', text='Unit Price')
tree.heading('total', text="Total")

    
tree.grid(row=5, column=0, columnspan=3, padx=20, pady=10)


save_invoice_button = tkinter.Button(frame, text="Generate Invoice", command=generate_invoice)
save_invoice_button.grid(row=6, column=0, columnspan=3, sticky="news", padx=20, pady=5)
new_invoice_button = tkinter.Button(frame, text="New Invoice", command=new_invoice)
new_invoice_button.grid(row=7, column=0, columnspan=3, sticky="news", padx=20, pady=5)


window.mainloop()