from graphics import *

def createForm(win):
    p_t = Text(Point(50, 30), "Principal")
    p_t.draw(win)
    p_t.setSize(18)
    p_t.setStyle("bold")
    p_t.setTextColor("blue")

    p_e = Entry(Point(250, 30), 40)
    p_e.draw(win)


    r_t = Text(Point(50, 60), "Rate")
    r_t.draw(win)
    r_t.setSize(18)
    r_t.setStyle("bold")
    r_t.setTextColor("blue")

    r_e = Entry(Point(250, 60), 40)
    r_e.draw(win)

    y_t = Text(Point(50, 90), "# of Ys")
    y_t.draw(win)
    y_t.setSize(18)
    y_t.setStyle("bold")
    y_t.setTextColor("blue")

    y_e = Entry(Point(250, 90), 40)
    y_e.draw(win)

    r = Rectangle(Point(40, 140), Point(390, 120))
    r.draw(win)
    r.setFill("blue")

    rt = Text(r.getCenter(), "Compute")
    rt.draw(win)
    rt.setTextColor("white")
    rt.setStyle("bold")
    rt.setSize(14)

    bar_list = []
    bottom_bar_labels = []
    top_bar_labels = []
    
    while True:
        try:
            c = win.getMouse()
        
            while not (c.getX() > r.getP1().getX() and c.getX() < r.getP2().getX() and c.getY() < r.getP1().getY() and c.getY() > r.getP2().getY()):
                c = win.getMouse()
        except:
            break
        
        try:
            principal = float(p_e.getText())
            rate = float(r_e.getText())
            years = int(y_e.getText())

            p_e.setText("")
            r_e.setText("")
            y_e.setText("")

            for i in range(len(bar_list)):
                bar_list[i].undraw()
                bottom_bar_labels[i].undraw()
                top_bar_labels[i].undraw()

                
            bar_list.clear()
            bottom_bar_labels.clear()
            top_bar_labels.clear()

            #To keep things simple (and fit all bars in the window), we assume that the principal cannot exceed 5000 and the number of years cannot exceed 10.
            if 0.0 <= rate <= 0.3 and 0 <= years <= 10 and 0 <= principal <= 5000:
                print("Principal = ", principal, "Rate = ", rate, "Num of Years = ", years)

                initial_scale = 30
                bar_width = 35
                x1 = 30
                y1 = 600
                x2 = x1 + bar_width
                y2 = y1 - initial_scale

                bar = Rectangle(Point(x1, y1), Point(x2, y2))
                bar.setFill("red")
                bar.draw(win)
                bar_list.append(bar)
                
                b_label = Text(Point(x1+10, y1+10), 0)
                b_label.draw(win)
                bottom_bar_labels.append(b_label)
                
                t_label = Text(Point(bar.getCenter().getX(), y2-10), round(principal, 1))
                t_label.setFace("courier")
                t_label.setSize(8)
                t_label.draw(win)
                top_bar_labels.append(t_label)
                
                
                for i in range(1, years+1):
                    compounded_pr = calcInterest(principal, rate, i)
                    x1 = x2
                    x2 = x1 + bar_width
                    y2 = y1 - (compounded_pr * initial_scale/principal)
                    bar = Rectangle(Point(x1, y1), Point(x2, y2))
                    bar.setFill("red")
                    bar.draw(win)
                    bar_list.append(bar)

                    b_label = Text(Point(x1+10, y1+10), i)
                    b_label.draw(win)
                    bottom_bar_labels.append(b_label)

                    t_label = Text(Point(bar.getCenter().getX(), y2-10), round(compounded_pr, 1))
                    t_label.setFace("courier")
                    t_label.setSize(8)
                    t_label.draw(win)
                    top_bar_labels.append(t_label)
                    
                    
                
            else:
                print("The principal should not exceed 2000, the rate value should be between 0 and 1, and the number of years should be less than or equal 10.")
        
        except:
            print("You should enter a float/int value for the principal, a float value between 0 and 1 for the rate, and an int value for the number of years.")
        
        
    
    

def calcInterest(p, r, y):
    return p * ((1 + r) ** y)


    
win = GraphWin("Interest Calculation and Plotting", 800, 800)
createForm(win)