saga

#!/usr/bin/env python3
#
# Saga script. This creates an entry in the saga directory.
#

import getpass
import optparse
import os
import datetime
import socket
import sys
import time

from optparse import OptionParser
from pathlib import Path


# --------------------------------------------------------
#   config
# --------------------------------------------------------
DIR_SAGA = os.path.join(Path.home(), 'saga')


# --------------------------------------------------------
#   alg
# --------------------------------------------------------
USERNAME = getpass.getuser()
HOSTNAME = socket.gethostname().split('.')[0]

def awful_hack_letter_list():
    lst = []
    for i in range(97, 122+1):
        a = chr(i)
        for j in range(97, 122+1):
            b = chr(j)
            lst.append("%s%s"%(a, b))
    return lst

def determine_unique_filename(dir, words):
    now = time.strftime("%Y%m%d")

    lst_awful = awful_hack_letter_list()
    idx_awful = 0

    letters = lst_awful[idx_awful]

    def is_current_prefix_used():
        prefix = "%s.%s.%s.%s"%( now
                               , HOSTNAME
                               , USERNAME
                               , letters
                               )
        lst = [f for f in os.listdir(dir)
                       if f.startswith(prefix)
                       ]
        if 0 == len(lst):
            return False
        else:
            return True

    while is_current_prefix_used():
        idx_awful += 1
        letters = lst_awful[idx_awful]

    return "%s.%s.%s.%s.%s"%(now, HOSTNAME, USERNAME, letters, words)

def fatal(msg):
    print("[saga] FATAL: %s"%msg)
    print("aborting")
    sys.exit(1)

def main():
    if not os.path.exists(DIR_SAGA):
        fatal("No directory %s"%DIR_SAGA)

    parser = OptionParser()
    parser.add_option( '-t', '--dry-run'
                     , action='store_true'
                     , dest='dry_run'
                     )
    parser.add_option( '-z', '--echo_most_recent_only'
                     , action='store_true'
                     , dest='just_get_last'
                     )
    (options, args) = parser.parse_args()

    if args:
        lst_words = sys.argv[1:]
        dot_words = '.'.join( [w for w in lst_words if not w.startswith('-')] )

        saganame = determine_unique_filename(DIR_SAGA, dot_words)

        if options.dry_run:
            pass
        else:
            dir_name = os.sep.join( [DIR_SAGA, saganame] )
            # gone for append here to be safe
            os.mkdir(dir_name)

        print(os.sep.join( [DIR_SAGA, saganame] ))
    else:
        filenames = sorted( [os.sep.join( [DIR_SAGA, fname] ) for fname
                                                              in os.listdir(DIR_SAGA)
                                                              ]
                          #, reverse=True
                          )
        if not filenames:
            print("ERROR: Saga directory is empty.")
            print("aborting")
            sys.exit(1)

        if options.just_get_last:
            print(filenames[-1])
        else:
            print('\n'.join(filenames))

if __name__ == '__main__':
    main()