#!/usr/bin/python3

#
# Imports
#
import sys
import time
import subprocess
import argparse


#
# Methods
#
def get_disk_usage(path, human_readable):
    """disk usage in human readable format (e.g. '2,1GB')"""
    arguments = "-sh" if human_readable else "-s"
    command = "du %s %s" % (arguments, path)
    status, output = subprocess.getstatusoutput(command)

    if status != 0:
        raise Exception(command)

    disk_usage = output.split()[0]
    if not human_readable:
        # du reports in units of 1024 bytes, convert to plain number of bytes
        disk_usage = int(disk_usage) * 1024
    return disk_usage


#
# Directories to scan
#
hostname = "server"
interval = 10
directories = list()

directories.append(["bram", "/host/media/helios/Bram"])
directories.append(["rik", "/host/media/helios/Rik"])
directories.append(["books", "/host/media/neptune/Books"])
directories.append(["games", "/host/media/mercury/Games"])
directories.append(["misc", "/host/media/neptune/Miscellaneous"])
directories.append(["shows", "/host/media/neptune/Video/Shows"])
directories.append(["movies", "/host/media/neptune/Video/Movies"])
directories.append(["music", "/host/media/neptune/Music"])
directories.append(["photographs", "/host/media/helios/Photographs"])
directories.append(["pictures", "/host/media/helios/Pictures"])
directories.append(["software", "/host/media/mercury/Software"])


#
# Command line arguments
#
parser = argparse.ArgumentParser(description="Get BTRFS disk usage")
parser.add_argument("-s", action="store_true", help="print in human readable format")
args = parser.parse_args()
human_readable = args.s


#
# Main
#
if human_readable:
    for (name, path) in directories:
        disk_usage = get_disk_usage(path, human_readable)
        print(("%s: %s" % (name, disk_usage)))
else:
    # RRD mode
    while True:
        for (name, path) in directories:
            disk_usage = get_disk_usage(path, human_readable)
            timestamp = int(time.time())
            size = float(disk_usage)
            print(
                (
                    "PUTVAL {}/exec-du_{}/gauge-size {}:{:.1f}".format(
                        hostname, name, timestamp, size
                    )
                )
            )
            sys.stdout.flush()
        time.sleep(interval)