from common import run_os_cmd

SEARCH_RANGE = 5.000
SEARCH_STEP = 0.100
DEBUG = False


def compare_at_time(t):
    run_os_cmd("ffmpeg -y -ss {} -i de.mp4 -vframes 1 -q:v 2 tmp/de.png 2>/dev/null".format(t), False)
    run_os_cmd("compare -metric AE -fuzz 5% tmp/en.png tmp/de.png tmp/diff.png >tmp/diff_value 2>&1", False)
    with open("tmp/diff_value") as f:
        diff_value = f.read()
    if DEBUG:
        print("{:6.3f},{}".format(t, diff_value))
    return int(diff_value)


def linear_compare(en_time, search_range=SEARCH_RANGE, search_step=SEARCH_STEP):
    run_os_cmd("ffmpeg -y -ss {} -i en.mp4 -vframes 1 -q:v 2 tmp/en.png 2>/dev/null".format(en_time), False)
    min_time, min_val, de_time = en_time, float('+inf'), en_time - search_range
    while de_time < en_time + search_range:
        de_time += search_step
        val = compare_at_time(de_time)
        if val < min_val:
            min_val, min_time = val, de_time
    compare_at_time(min_time)
    return min_time, min_val


def main():
    en_time = 10.000
    de_time, min_val = linear_compare(en_time)
    de_delta = de_time - en_time
    return de_delta


if __name__ == "__main__":
    main()