package localenroll;

use strict;

################################
# sub fetch_enrollment
#
# connects to the institutional classlist data source,
# reads classlist data and stores in an XML file
# in /home/httpd/perl/tmp/
#
# classlist files are named as follows:
#
# DOMAIN_COURSE_INSTITUTIONALCODE_classlist.xml
#
# e.g., msu_43551dedcd43febmsul1_fs03nop590001_classlist.xml
# where DOMAIN = msu  COURSE = 43551dedcd43febmsul1 
# INSTITUTIONALCODE = fs03nop590001 
# (MSU's course naming scheme - fs03 = Fall semester 2003, nop =
# department name, 590 = course number, 001 = section number.
#
# fetch_enrollment requires three arguments -
# $dom - DOMAIN e.g., msu
# $affiliatesref - a reference to a hash of arrays that contains LON-CAPA 
# courses that are to be updated as keys, and institutional coursecodes 
# contributing enrollment to that LON-CAPA course as elements in each array.
# $replyref - a reference to a hash that contains LON-CAPA courses
# that are to be updated as keys, and the total enrollment count in all 
# affiliated sections, as determined from institutional data as hash elements. 
#
# As an example, if fetch_enrollment is called to retrieve institutional
# classlists for a single LON-CAPA course - 43551dedcd43febmsul1 which 
# corresponds to fs03nop590, sections 001, 601 and 602 , and the course
# also accommodates enrollment from a crosslisted course in the ost
# department - fs03ost580002:
#
# the affiliatesref would be a reference to %affiliates which would be:
#
# @{$affiliates{'43551dedcd43febmsul1'}} =
#   ("fs03nop590001","fs03nop590601","fs03nop590602","fs03ost580002");
#
# fetch_enrollment would create four files in /home/httpd/perl/tmp/.
# msu_43551dedcd43febmsul1_fs03nop590001_classlist.xml
# msu_43551dedcd43febmsul1_fs03nop590601_classlist.xml
# msu_43551dedcd43febmsul1_fs03nop590602_classlist.xml
# msu_43551dedcd43febmsul1_fs03ost580002_classlist.xml
#
# In each file, student data would be stored in the following format
# 
# <student username="smith">
#  <autharg>MSU.EDU</autharg>
#  <authtype>krb4</authtype>
#  <email>smith@msu.edu</email>
#  <enddate></enddate>
#  <firstname>John</firstname>
#  <generation>II</generation>
#  <groupID>fs03nop590001</groupID>
#  <lastname>Smith</lastname>
#  <middlename>D</middlename>
#  <startdate></startdate>
#  <studentID>A12345678</studentID>
# </student>
# 
# with the following at the top of the file
#<?xml version="1.0" encoding="UTF-8"?>
#<!DOCTYPE text>
#<students>
#
# (all comment - #s removed)
#
# and a closing:
#</students>
#
# The <startdate> and the <enddate> are the activation date and expiration date
# for this student's role. If they are absent, then the date set for
# first automated enrollment is used as the default activation date, and the
# date set for last automated enrollment is used as the default expiration date.
# If dates are to included in the XML file, they should be in the format
# YYYY:MM:DD:HH:MM:SS (: separators required).
#
# If there were 10 students in fs03nop590001, 5 students in fs03nop59o601, 
# 8 students in fs03nop590602, and 2 students in fs03ost580002,
# then $$reply{'43551dedcd43febmsul1'} = 25
#
# The purpose of the %reply hash is to detect cases where the institutional 
# enrollment is 0 (most likely due to a problem with the data source).
# In such a case, the LON-CAPA course roster is left unchanged (i.e., no
# students are expired, even if automated drops is enabled.
# 
# fetch_enrollment should return a 0 or 1, depending on whether a connection
# could be established to the institutional data source.
# 0 is returned if no connection could be made.
# 1 is returned if connection was successful
#
# A return of 1 is required for the calling modules to perform LON-CAPA
# roster changes based on the contents of the XML classlist file(s), e,g,,
# msu_43551dedcd43febmsul1_fs03nop590001_classlist.xml
#
# XML classlist files are temporary. They are deleted after the enrollment 
# update process in the calling module is complete.
#
################################

sub fetch_enrollment {
  my ($dom,$affiliatesref,$replyref) = @_;
     foreach my $crs (sort keys %{$affiliatesref}) {
         $$replyref{$crs} = 0;
     }
  }
  my $okflag = 0;
  return $okflag;
}

###############################
# sub get_sections
#
# This is called by the Automated Enrollment Manager interface
# (lonpopulate.pm) to create an array of valid sections for 
# a specific institutional coursecode.
# e.g., for MSU coursecode: fs03nop590
# ("001","601","602") would be returned
#
# If the array returned contains at least one element, then 
# the interface offerred to the course coordinator, lists
# official sections and provides a checkbox to use to
# select enrollment in the LON-CAPA course from each official section.  
#
# get_sections requires one argument - the instituional coursecode
# (in the MSU case this is a concatenation of semester code, department
# and course number). 
# 
# If there is no access to official course sections at your institution,
# then an empty array is returned, and the Automated Enrollment Manager
# interface will allow the course coordinator to enter section numbers
# in text boxes.
# 
################################ 

sub get_sections {
    my $coursecode = shift;
    my @secs = ();
    return @secs;
}

###############################
# sub new_course
#
# This is called by loncreatecourse.pm and 
# lonpopulate.pm to record that fact that a new course section
# has been added to LON-CAPA that requires access to institutional data
# At MSU, this is required, as institutional classlists can only made
# available to faculty who are officially assigned to a course
# 
# The new_course subroutine is used to check that the course owner
# of the LON-CAPA course is permitted to access the institutional
# classlist for any course sections and crosslisted classes that
# the course coordinator wishes to have affiliated with the course.
# 
# If access is permitted, then 'ok' is returned.
# The course section or crosslisted course will only be added to the list of
# affiliates if 'ok' is returned.
#
# new_course requires two arguments -
# the institutional courseID (in the MSU case this is a concatenation of 
# semester code, department code, course number, and section number
# e.g., fs03nop590001).
# the course owner. This is the LON-CAPA username of the course coordinator 
# assigned to the course when it is first created.
#
#################################

sub new_course  {
    my ($course_id,$owner) = @_;
    my $outcome = 'ok';
    return $outcome;
}

###############################
# sub validate_courseID
#
# This is called whenever a new course section or crosslisted course
# is being affiliated with a LON-CAPA course (i.e., by loncreatecourse.pm
# and the Automated Enrollment Manager in lonpopulate.pm).
# A check is made that the courseID that the course coordinator wishes
# to affiliate with the course is valid according to the institutional
# schedule of official classes 
#
# A valid courseID is confirmed by returning 'ok'
#
# validate_courseID requires one argument -
# the institutional courseID (in the MSU case this is a concatenation of
# semester code, department code, course number, and section number
# e.g., fs03nop590001).
#
###############################  

sub validate_courseID {
    my $course_id = shift;
    my $outcome = 'ok';
    return $outcome;   
}

###############################
# sub create_password 
#
# This is called when the authentication method set for the automated 
# enrollment process when enrolling new users in the domain is "local".
# This could be signalled for the specific user by the value of local
# for the <authtype> tag from the classlist.xml files, or if this is blank,
# the default authtype, set by the domain coordinator when creating the course
# with loncreatecourse.pm.
# 
# create_password requires one argument -
# the value of <autharg> from the classlist.xml files, or if this is blank,
# the default autharg, set by the domain coordinator when creating the course
# with loncreatecourse.pm.  
#
# Three values are returned:
# (a) the value of $authparam - which might have been changed
# (b) a flag to indicate whether a password had been created
# 0 means no password created
# 1 means password created.  In this case the calling module - Enrollment.pm
# will send the LON-CAPA username and passwod to the new user's e-mail
# (if one was provided), or to the course owner (if one was not provided and
# the new user was created by the automated process), or to the active
# course coordinator (if the new user was created using the 'update roster
# now' interface included in the Automated Enrollment Manager.  
# (c) a flag to indicate that the authentication method is correct - 'ok'.
# If $authchk is not set to 'ok' then account creation and enrollment of the 
# new user will not occur.
#    
###############################

sub create_password {
    my $authparam = shift;
    my $authchk = 'ok';
    my $create_passwd = 0;
    return ($authparam,$create_passwd,$authchk);
}

1;