#!/usr/bin/python2.7

# grouper_add_members
# add a list of UNIs to the target group
# replacing current members if the replace flag is T

import httplib2
import json
import sys,string
import os

def usage():
    print('usage: grouper_add_members -f <unilist> -g <group> -r <replace flag>')
    print('-f   file containing a list of UNIs')
    print('-g   the members will be added to this group')
    print('-r   replace flag can be T or F, replace current members if replace flag is T')
    exit(1)


def main():
    # parse the command line arguments
    if len(sys.argv) != 7:
        usage()
    if sys.argv[1] != '-f':
        usage()
    inputFileName = sys.argv[2]

    if sys.argv[3] != '-g':
        usage()
    thisGroup = sys.argv[4]

    if sys.argv[5] != '-r':
        usage()
    replaceExisting = sys.argv[6]
    if replaceExisting != 'T' and replaceExisting != 'F':
        print('replace flag must be T or F')
        exit(1)

    # initialize httplib2
    http = httplib2.Http()

    # set the grouper URI (dev or prod), username, password
    grouper_ws_uri = grouperWSParameters(http)

    # verify that the target group exists and is accessible by this user
    if grouperGetUuid(http,grouper_ws_uri,thisGroup) == 0:
        print(thisGroup + " group not found (does not exist or is not accessible)")
        exit(1)

    # verify that the file exists
    if not os.path.exists(inputFileName):
        print('input file not found: ' + inputFileName)
        exit(1)

    # read the list of UNIs from the input file
    infil = open(inputFileName, 'r')
    subjectList = []
    while 1:
        line = infil.readline()
        if not line:
            break
        line = line.rstrip() # remove the newline character
        subjectList.append(line) # add this UNI to the list
    infil.close()

    # add multiple group members using a single Web Service call
    addMembers = grouperAddMembers(http,grouper_ws_uri,thisGroup,subjectList,replaceExisting)
    if addMembers and addMembers['WsAddMemberResults']['results'][0]['resultMetadata']['success']:
        print('UNIs have been added to '+thisGroup)
    else:
        print('unable to add UNIs to '+thisGroup)

def grouperAddMembers(http, grouper_ws_uri, groupName, subjectList, replaceFlag):
    # add list of group members, replace current members if replace flag is T
    if replaceFlag != 'T' and replaceFlag != 'F':
        print("replaceFlag "+replaceFlag+" must be T or F")
        return None
    # listOfSubjectDictionaries contains a list of dictionaries
    listOfSubjectDictionaries = []
    for nsubjects in range(0,len(subjectList)):
        listOfSubjectDictionaries.append({'subjectId':subjectList[nsubjects]})
    body = {
      "WsRestAddMemberRequest": {
        "wsGroupLookup": {
            "groupName": groupName
        },
        "replaceAllExisting": replaceFlag,
        "subjectLookups": listOfSubjectDictionaries
      }
    }
    result = grouperWSRequest(http, grouper_ws_uri+"/groups/"+groupName+"/members", "PUT", body)
    return result

def grouperGetUuid(http, grouper_ws_uri, groupName):
    # get UUID for the specified group
    thisuuid = 0
    body = {
      "WsRestFindGroupsRequest": {
        "wsQueryFilter": {
          "groupName": groupName,
          "queryFilterType": "FIND_BY_GROUP_NAME_EXACT",
        }
      }
    }
    findGroups = grouperWSRequest(http, grouper_ws_uri + "/groups", "POST", body)
    if findGroups and findGroups['WsFindGroupsResults']['resultMetadata']['success'] and 'groupResults' in findGroups['WsFindGroupsResults']:
        thisuuid = findGroups['WsFindGroupsResults']['groupResults'][0]['uuid']
    return thisuuid

def grouperWSRequest(http, url, method, body):
    # send a request to the Grouper Web Service
    # method can be GET, POST, or PUT
    content_type = 'application/x-www-form-urlencoded'
    if method == "POST" or method == "PUT":
        content_type = 'text/x-json; charset=UTF-8'

    try:
        resp, content = http.request(uri=url,
            method=method,
            body=json.dumps(body),
            headers={'Content-Type': content_type})
        if resp.status == 200 or resp.status == 201:
            result = json.loads(content.decode('utf-8'))
            return result
    except httplib2.ServerNotFoundError as err:
        print("Unable to connect to Grouper Web Service")
        print(err)
        return None
    # http request failed, print the response status and content
    print("http response status "+str(resp.status))
    print("http response content "+content)
    return None

def grouperWSParameters(http):
    # set the Grouper Web Service username and password
    grouper_username = 'abc1234'
    grouper_password = 'xxxxxxxxxxxxxxxxxxxx'
    http.add_credentials(name=grouper_username, password=grouper_password)

    # the Grouper Web Service URI should point to dev or prod Grouper
    devGrouperURI  = 'https://grouper-dev.cc.columbia.edu/grouper-ws/servicesRest/v2_4_000'
    prodGrouperURI = 'https://grouper.cc.columbia.edu/grouper-ws/servicesRest/v2_4_000'
    return devGrouperURI

if __name__ == '__main__':
    main()