import matplotlib
matplotlib.use("Agg")
import matplotlib.pylab as plt
import numpy as np


def save_figure_to_numpy(fig):
    # save it to a numpy array.
    data = np.fromstring(fig.canvas.tostring_rgb(), dtype=np.uint8, sep='')
    data = data.reshape(fig.canvas.get_width_height()[::-1] + (3,))
    return data

def plot_alignment(alignment, fn):
    # [4, encoder_step, decoder_step] 
    fig, axes = plt.subplots(2, 2)
    for i in range(2):
        for j in range(2):
            g = axes[i][j].imshow(alignment[i*2+j,:,:].T,
                aspect='auto', origin='lower',
                interpolation='none')
            plt.colorbar(g, ax=axes[i][j])
    
    plt.savefig(fn)
    plt.close()
    return fn


def plot_alignment_to_numpy(alignment, info=None):
    fig, ax = plt.subplots(figsize=(6, 4))
    im = ax.imshow(alignment, aspect='auto', origin='lower',
                   interpolation='none')
    fig.colorbar(im, ax=ax)
    xlabel = 'Decoder timestep'
    if info is not None:
        xlabel += '\n\n' + info
    plt.xlabel(xlabel)
    plt.ylabel('Encoder timestep')
    plt.tight_layout()

    fig.canvas.draw()
    data = save_figure_to_numpy(fig)
    plt.close()
    return data


def plot_spectrogram_to_numpy(spectrogram):
    fig, ax = plt.subplots(figsize=(12, 3))
    im = ax.imshow(spectrogram, aspect="auto", origin="lower",
                   interpolation='none')
    plt.colorbar(im, ax=ax)
    plt.xlabel("Frames")
    plt.ylabel("Channels")
    plt.tight_layout()

    fig.canvas.draw()
    data = save_figure_to_numpy(fig)
    plt.close()
    return data


def plot_gate_outputs_to_numpy(gate_targets, gate_outputs):
    fig, ax = plt.subplots(figsize=(12, 3))
    ax.scatter(list(range(len(gate_targets))), gate_targets, alpha=0.5,
               color='green', marker='+', s=1, label='target')
    ax.scatter(list(range(len(gate_outputs))), gate_outputs, alpha=0.5,
               color='red', marker='.', s=1, label='predicted')

    plt.xlabel("Frames (Green target, Red predicted)")
    plt.ylabel("Gate State")
    plt.tight_layout()

    fig.canvas.draw()
    data = save_figure_to_numpy(fig)
    plt.close()
    return data
