#!/usr/bin/python3

"""
Randomize the order of blocks in a MAF file. If `sample_size` is specified,
that many random blocks will be kept from the original maf

usage: %prog [sample_size] < maf > maf
"""

import random
import sys

from bx.align import maf


def __main__():
    if len(sys.argv) > 1:
        sample_size = int(sys.argv[1])

    maf_reader = maf.Reader(sys.stdin)
    maf_writer = maf.Writer(sys.stdout)

    mafs = list(maf_reader)

    # for m in maf_reader: mafs.append( m )

    random.shuffle(mafs)

    if not sample_size:
        sample_size = len(mafs)

    for i in range(0, sample_size):
        maf_writer.write(mafs[i])


if __name__ == "__main__":
    __main__()