# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import matplotlib.pyplot as plt

class IncrementalGraph:
    def __init__(self, fig, ax, x_lim = [0,10], y_lim = [0,10]):
        self.fig = fig
        self.ax = ax

        self.fig.show()
        # Create the one line that will be drawn onto the plot.
        # ``plot`` returns a list of the things plotted, so get
        # the only element of the list, the line.
        self.ln = ax.plot([0,1], [0,1], 'r-', animated=True)[0]

        self.x_lim = x_lim
        self.y_lim = y_lim
        self.ax.set_xlim(*self.x_lim)
        self.ax.set_ylim(*self.y_lim)

        # Redraw the figure when matplotlib requests a redraw.
        self.fig.canvas.mpl_connect("draw_event", self.on_draw)

        # Initialize data fed into the series
        self.x_ax = []
        self.y_ax = []

    def set_color(self, *args, **kwargs):
        self.ln.set_color(*args, **kwargs)

    def draw_event(self, *args):
        self.on_invalidated()

    def on_invalidate(self):
        """ This function redraws all data to the screen whenever the
            screen is "invalidated". This could mean a user resize,
            or an automatic axis resize. """

        self.ax.clear()
        self.ax.set_xlim(*self.x_lim)
        self.ax.set_ylim(*self.y_lim)
        #self.fig.canvas.draw()

        self.ln.set_xdata(self.x_ax)
        self.ln.set_ydata(self.y_ax)
        self.ax.draw_artist(self.ln)
        self.fig.canvas.blit(self.fig.bbox)
    def on_draw(self, *args, **kwargs):
        self.on_invalidate()

    def add(self, x, y):
        """ Add two points to the graph and redraw it.
            Returns True if the graph was redrawn. """
        haveToRedraw = False

        # If there were no previous points, do nothing. There is not
        # enough data to draw a line.
        if len(self.x_ax) == 0:
            self.x_ax = [x]
            self.y_ax = [y]
            return False

        # If there was a previous point, use it to draw a line to the
        # current point. Store the current point as data.
        prev_x = self.x_ax[-1]
        prev_y = self.y_ax[-1]
        self.x_ax.append(x)
        self.y_ax.append(y)

        # If the point is outside of the limits of the graph, change the
        # limits and redraw the graph.
        if x < self.x_lim[0]:
            self.x_lim[0] = x - 0.01*x
            haveToRedraw = True
        elif x > self.x_lim[1]:
            self.x_lim[1] = x + 0.01*x
            haveToRedraw = True

        if y < self.y_lim[0]:
            self.y_lim[0] = y - 0.01*y
            haveToRedraw = True
        elif y > self.y_lim[1]:
            self.y_lim[1] = y + 0.01*y
            haveToRedraw = True

        if haveToRedraw:
            self.fig.canvas.draw()
            return True

        print((prev_x, x), (prev_y, y))
        self.ln.set_xdata([prev_x, x])
        self.ln.set_ydata([prev_y, y])
        self.ax.draw_artist(self.ln)
        self.fig.canvas.blit(self.fig.bbox)
        self.fig.canvas.flush_events()
        return False