#!/usr/bin/env python

# edit from https://gist.github.com/hysts/81a0d30ac4f33dfa0c8859383aec42c2

import argparse
import pathlib

import cv2
import numpy as np
from tensorboard.backend.event_processing import event_accumulator


def save(outdir: pathlib.Path, tag, event_acc):
    events = event_acc.Images(tag)

    for index, event in enumerate(events):
        s = np.frombuffer(event.encoded_image_string, dtype=np.uint8)
        image = cv2.imdecode(s, cv2.IMREAD_COLOR)
        outpath = outdir / f"{tag.replace('/', '_')}@{index}.png"
        cv2.imwrite(outpath.as_posix(), image)


# ffmpeg -framerate 1 -i ./tmp/test_b/%04d.jpg -vcodec mpeg4 test_b.mp4
def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--path', type=str, required=True)
    parser.add_argument('--outdir', type=str, required=True)
    parser.add_argument("--tag", type=str, required=False)
    args = parser.parse_args()

    event_acc = event_accumulator.EventAccumulator(args.path, size_guidance={'images': 0})
    event_acc.Reload()

    outdir = pathlib.Path(args.outdir)
    outdir.mkdir(exist_ok=True, parents=True)

    if args.tag is None:
        for tag in event_acc.Tags()['images']:
            save(outdir, tag, event_acc)
    else:
        assert args.tag in event_acc.Tags()['images'], f"{args.tag} not in {event_acc.Tags()['images']}"
        save(outdir, args.tag, event_acc)


if __name__ == '__main__':
    main()