from tkinter import *


class MetricConverter:
    def __init__(self):
        self.conversions = {
            "cm to inches": lambda x: round(x / 2.54, 2),
            "m to feet": lambda x: round(x * 3.28084, 2),
            "km to miles": lambda x: round(x * 0.621371, 2),
        }

        self.window = Tk()
        self.window.title("Metric Conversion Tool")

        self.main_frame = Frame(self.window, padx=10, pady=10)
        self.main_frame.grid()

        self.heading = Label(self.main_frame, text="Metric Conversion Tool",
                             font=("Arial", 16, "bold"))
        self.heading.grid(row=0)

        self.instructions = Label(self.main_frame,
                                  text="Enter a value and choose conversion type:",
                                  wraplength=300, justify="left")
        self.instructions.grid(row=1)

        self.input_entry = Entry(self.main_frame, font=("Arial", 14))
        self.input_entry.grid(row=2, pady=10)

        self.selected_conversion = StringVar()
        self.selected_conversion.set("cm to inches")

        self.dropdown = OptionMenu(self.main_frame, self.selected_conversion,
                                   *self.conversions.keys())
        self.dropdown.grid(row=3)

        self.convert_button = Button(self.main_frame, text="Convert",
                                     command=self.convert_value,
                                     bg="#004C99", fg="white",
                                     font=("Arial", 12, "bold"))
        self.convert_button.grid(row=4, pady=10)

        self.result_label = Label(self.main_frame, text="", font=("Arial", 14, "bold"))
        self.result_label.grid(row=5)

        self.error_label = Label(self.main_frame, text="", fg="red")
        self.error_label.grid(row=6)

        self.window.mainloop()

    def convert_value(self):
        value = self.input_entry.get()
        self.error_label.config(text="")
        self.result_label.config(text="")

        try:
            value = float(value)
            conversion_type = self.selected_conversion.get()
            result = self.conversions[conversion_type](value)
            self.result_label.config(text=f"Result: {result}")
        except ValueError:
            self.error_label.config(text="Please enter a valid number.")


if __name__ == "__main__":
    MetricConverter()