import tkinter as tk
import turtle
import math

# ---------- Tk setup ----------
root = tk.Tk()
root.title("Turtle Function Inspector")

# ---------- Canvas ----------
canvas = tk.Canvas(root, width=600, height=600)
canvas.grid(row=0, column=0, rowspan=6)

screen = turtle.TurtleScreen(canvas)
screen.setworldcoordinates(-300, -300, 300, 300)

t = turtle.RawTurtle(screen)
t.speed(0)
t.hideturtle()

# ---------- Globals ----------
scale = 40  # zoom level

# ---------- Drawing ----------
def draw_axes():
    t.clear()
    t.color("black")
    t.penup()
    t.goto(-300, 0)
    t.pendown()
    t.goto(300, 0)

    t.penup()
    t.goto(0, -300)
    t.pendown()
    t.goto(0, 300)

def plot_function():
    draw_axes()
    expr = func_entry.get()

    t.color("blue")
    t.penup()

    first = True
    for px in range(-300, 300):
        try:
            x = px / scale
            y = eval(expr, {"x": x, "math": math})
            py = y * scale

            if abs(py) > 300:
                raise ValueError

            if first:
                t.goto(px, py)
                t.pendown()
                first = False
            else:
                t.goto(px, py)
        except:
            t.penup()
            first = True

# ---------- Zoom ----------
def zoom_in():
    global scale
    scale *= 1.25
    plot_function()

def zoom_out():
    global scale
    scale /= 1.25
    plot_function()

# ---------- Mouse inspection ----------
info = tk.Label(root, text="x=0  y=0")
info.grid(row=5, column=1)

def inspect(event):
    x = (event.x - 300) / scale
    try:
        y = eval(func_entry.get(), {"x": x, "math": math})
        info.config(text=f"x={x:.3f}   y={y:.3f}")
    except:
        info.config(text="undefined")

canvas.bind("<Motion>", inspect)

# ---------- Controls ----------
tk.Label(root, text="f(x) =").grid(row=0, column=1)
func_entry = tk.Entry(root, width=20)
func_entry.insert(0, "math.sin(x)")
func_entry.grid(row=1, column=1)

tk.Button(root, text="Plot", command=plot_function).grid(row=2, column=1)
tk.Button(root, text="Zoom +", command=zoom_in).grid(row=3, column=1)
tk.Button(root, text="Zoom -", command=zoom_out).grid(row=4, column=1)

plot_function()
root.mainloop()