from io import BytesIO

import scipy.misc

import tensorflow as tf

class Logger(object):

    def __init__(self, log_dir):

        self.writer = tf.summary.FileWriter(log_dir)

    def scalar_summary(self, tag, value, step):

        summary = tf.Summary(value=[tf.Summary.Value(tag=tag, simple_value=value)])

        self.writer.add_summary(summary, step)

        self.writer.flush()

    def image_summary(self, tag, image, step):

        s = BytesIO()

        scipy.misc.toimage(image).save(s, format="png")

        # Create an Image object

        img_sum = tf.Summary.Image(

            encoded_image_string=s.getvalue(),

            height=image.shape[0],

            width=image.shape[1],

        )

        # Create and write Summary

        summary = tf.Summary(value=[tf.Summary.Value(tag=tag, image=img_sum)])

        self.writer.add_summary(summary, step)

        self.writer.flush()

    def image_list_summary(self, tag, images, step):

        if len(images) == 0:

            return

        img_summaries = []

        for i, img in enumerate(images):

            s = BytesIO()

            scipy.misc.toimage(img).save(s, format="png")

            # Create an Image object

            img_sum = tf.Summary.Image(

                encoded_image_string=s.getvalue(),

                height=img.shape[0],

                width=img.shape[1],

            )

            # Create a Summary value

            img_summaries.append(

                tf.Summary.Value(tag="{}/{}".format(tag, i), image=img_sum)

            )

        # Create and write Summary

        summary = tf.Summary(value=img_summaries)

        self.writer.add_summary(summary, step)

        self.writer.flush()