import matplotlib

matplotlib.use("Agg")  # NOQA: E402
try:
    import matplotlib.pyplot as plt
except ImportError:
    raise ImportError("Please install matplotlib.")


def plot_spectrogram(spectrogram):
    fig, ax = plt.subplots(figsize=(12, 8))
    im = ax.imshow(spectrogram, aspect="auto", origin="lower", interpolation="none")
    plt.colorbar(im, ax=ax)

    fig.canvas.draw()
    plt.close()

    return fig


def plot_alignment(alignment, info=None):
    fig, ax = plt.subplots()
    im = ax.imshow(alignment, aspect="auto", origin="lower", interpolation="none")
    fig.colorbar(im, ax=ax)
    xlabel = "Input timestep"
    if info is not None:
        xlabel += "\t" + info
    plt.xlabel(xlabel)
    plt.ylabel("Output timestep")
    fig.canvas.draw()
    plt.close()

    return fig