import matplotlib.pyplot as plt
import numpy as np
import sys

class Plot:
    def __init__(self, n):
        self.fig, self.ax = plt.subplots()

        self.cid_click = self.fig.canvas.mpl_connect('button_press_event', self.onclick)
        self.cid_motion = self.fig.canvas.mpl_connect('motion_notify_event', self.on_mouse_move)
        self.cid_release = self.fig.canvas.mpl_connect('button_release_event', self.on_release)

        plt.xlim(0, 800)
        plt.ylim(0, 600)
        plt.grid()
        self.line = []
        self.controlPoints = []
        self.curvePoints = []
        self.isDrawing = False
        self.inputMode = 0
        self.n = n

    def onclick(self, event):
        if self.inputMode == 0:
            self.isDrawing = True
        if self.inputMode == 1 and len(self.controlPoints) < self.n:
            self.controlPoints.append((event.xdata, event.ydata))
        self.drawPlot()

    def on_mouse_move(self, event):
        if self.isDrawing:
            self.line.append((event.xdata, event.ydata))
            self.drawPlot()

    def on_release(self, event):
        if self.inputMode == 0:
            self.isDrawing = False
            self.inputMode = 1

    def drawPlot(self):
        self.ax.clear()
        self.ax.plot(*zip(*self.line), color='red', label='linia')
        if len(self.controlPoints) > 0:
            self.ax.scatter(*zip(*self.controlPoints), color='black', label='Punkty kontrolne')
        if len(self.controlPoints) >= self.n:
            t_values = np.linspace(0, 1, num=100)
            bezier_points = np.array([self.de_casteljau(t) for t in t_values])
            self.ax.plot(bezier_points[:, 0], bezier_points[:, 1], color='blue', label='Krzywa Béziera')
        
        self.ax.legend()
        self.ax.set_xlim(0, 800)
        self.ax.set_ylim(0, 600)
        self.ax.grid()
        plt.draw()

    def de_casteljau(self, t):
        points = np.array(self.controlPoints)
        n = len(points)
        for r in range(1, n):
            for i in range(n - r):
                points[i] = (1 - t) * points[i] + t * points[i + 1]
        return points[0]

    def run(self):
        plt.show()

n = 10
if len(sys.argv) > 1:
    n = int(sys.argv[1])
if __name__ == "__main__":
    plot = Plot(n + 1)
    plot.run()