import matplotlib.pyplot as plt
import numpy as np
from shiny import App, ui, render

app_ui = ui.page_fluid(
    ui.layout_sidebar(
        ui.panel_sidebar(
            ui.input_file("file", "Choose a file to upload:", multiple=False),
            ui.input_slider("slider", "Choose position:", min=0, max=1, step=0.01, value=0.5),
            ui.input_switch("switch", "Vertikal - Horizontal:", value=True),
            ui.input_switch("switch2", "Links - Rechts:", value=True),
        ),
        ui.panel_main(
            ui.output_plot("plot"),
            ui.output_plot("mirror")
        )
    )
)


def server(input, output, session):
    @output
    @render.plot
    def plot():
        # print(input.file())
        if input.file() is not None:
            img = plt.imread(input.file()[0]['datapath'])
            # print(img)
            plt.imshow(img)
            # draw a vertical line at x = 0 that spans the yrange
            if input.switch():
                plt.axvline(input.slider() * img.shape[1], color="black", linestyle="--")
            else:
                plt.axhline(input.slider() * img.shape[0], color="black", linestyle="--")


    @output
    @render.plot
    def mirror():
        if input.file() is not None:
            img = plt.imread(input.file()[0]['datapath'])
            if input.switch():
                if input.switch2():
                    orig = img[:, :int(input.slider() * img.shape[1])]
                    temp = np.fliplr(orig)
                    img = np.concatenate((orig, temp), axis=1)
                else:
                    orig = img[:, int(input.slider() * img.shape[1]):]
                    temp = np.fliplr(orig)
                    img = np.concatenate((temp, orig), axis=1)
            else:
                if input.switch2():
                    orig = img[:int(input.slider() * img.shape[0]), :]
                    temp = np.flipud(orig)
                    img = np.concatenate((orig, temp), axis=0)

                else:
                    orig = img[int(input.slider() * img.shape[0]):, :]
                    temp = np.flipud(orig)
                    img = np.concatenate((temp, orig), axis=0)
            fig, ax = plt.subplots(1)
            ax.axis('off')
            fig.subplots_adjust(top=1, bottom=0, right=1, left=0, hspace=0, wspace=0)
            ax.imshow(img)


app = App(app_ui, server)