#! /usr/bin/python3 -Es

import io
import os
import subprocess
import sys
import tempfile

sge_root = os.environ.get('SGE_ROOT', '/var/lib/gridengine')
sge_cell = os.environ.get('SGE_CELL', 'default')
account_file = 'common/accounting'

logpath = os.path.join(sge_root, sge_cell, account_file)

with open(logpath, 'rb') as logfile:
    logfile.seek(-400 * 45000 * 7, os.SEEK_END)
    # Ignore first line as it may be onlym part of a line
    logfile.readline()
    with tempfile.TemporaryDirectory() as new_sge_root:
        new_logpath = os.path.join(new_sge_root, sge_cell, account_file)
        os.makedirs(os.path.dirname(new_logpath))

        for fname in os.listdir(os.path.dirname(logpath)):
            os.symlink(
                os.path.join(os.path.dirname(logpath), fname),
                os.path.join(os.path.dirname(new_logpath), fname))

        os.remove(new_logpath)
        os.mkfifo(new_logpath)

        real_qacct = subprocess.Popen(
            ['/usr/bin/qacct'] + sys.argv[1:],
            env=dict(os.environ, SGE_ROOT=new_sge_root))

        with open(new_logpath, 'wb') as new_logfile:
            while real_qacct.poll() is None:
                data = logfile.read(io.DEFAULT_BUFFER_SIZE)
                if not data:
                    break
                new_logfile.write(data)

        sys.exit(real_qacct.wait())