# Generate Userlist
# 
# Rev 1.1, 10/22/22
#    - changed the -y (year of enrolement) parameter to a more general -s (suffix)
#    - updated the usage message to include that change
#    - added a lot of comments, especially regarding the default values
#    - removed the unused fileinput import
#    - changed the defaults to fit more common scenarios
# Rev 1.0, 10/20/22
#    - a simple script to generate CSV-files suitable as input
#      for the importUsers script.
#    - this script is rather specifically designed to accomodate
#      the needs of our school's user naming scheme. Different
#      naming schemes should be easy to implement though.
#    - the script generates default passwords by picking three
#      words from a file called WordList.txt living in the same
#      directory as the script file.
#  Options
#    -d,--domain: domain name for the email address, this is required
#    -g,--groups: comma-separated list of groups added to every user
#    -s,--suffix: added to every username and the resulting filename
#     in this release, the suffix is added to the last group name as well
#    -f,--file: file of usernames, first and last name separated by comma

import sys, getopt
import csv
import os,io
import random

def main(argv):
	wordList = open("WordList.txt").read().splitlines()
	# add some default values for the options
	groups = "Users" 			# add default groups for all imports here
	suffix = ""
	domainname="example.com"
	filename = "names.csv"
	# next is a list of characters common in users actual names but unsuitable for login names
	# for this script, those are specific to german names. Spaces get replaced with dashes.
	char_map = {ord("ä"):"ae", ord("ü"):"ue", ord("ö"):"oe", ord("ß"):"ss", ord(" "):"-"}

	try:
		opts, args = getopt.getopt(argv,"hg:d:s:f:",["help","groups=","domain=","suffix=","file="])
	except getopt.GetoptError:
		print("Usage: importUsers.py -d <domainname> [-g <groups>] [-s <common suffix for this import]> -f <datafile>")
		sys.exit(2)
	for opt, arg in opts:
		if opt == '-h':
			print("Usage: importUsers.py -d <domainname> [-g <groups>] -s <common suffix for this import> -f <datafile> ")
		elif opt in ('-d', '--domain'):
			domainname = arg
		elif opt in ('-g', '--groups'):
			groups = groups + "," + arg		# as per importUsers specs, the groups are comma-separated
		elif opt in ('-f', '--file'):
			filename = arg
		elif opt in ('-s', '--suffix'):
			suffix = arg
			groups = groups + suffix

	outputFileName = "users" + suffix + ".csv"
	with open(outputFileName,"w+",newline='') as outputFile:
		header = ["first_name","last_name","email_address","sis_username","user_groups","password"]
		writer = csv.DictWriter(outputFile,fieldnames=header,delimiter=";", quoting=csv.QUOTE_MINIMAL)
		writer.writeheader()
		users = open(filename,"r").read().splitlines()
		for user in users:
			first_name,last_name = tuple(user.split(","))
			username = first_name.casefold().translate(char_map) + "." + last_name.casefold().translate(char_map) + suffix
			address = username + "@" + domainname
			password = "-".join(random.sample(wordList,3))		# pick three words at ramdom, join them with a dash
			writer.writerow({"first_name":first_name,"last_name":last_name,"email_address":address,"sis_username":username,"user_groups":groups,"password":password})
	
if __name__ == "__main__":
	main(sys.argv[1:])