#!/usr/bin/env perl
#
#Sometimes a webwork user id changes.  This script transfers the webwork data for the old user_id to the new user_id
# Update database tables
#user
#permission
#password
#key
#set_user
#problem_user
#set_locations_user
#global_achievement_user
#achievement_user
#
# Update answer_log

use strict;
use warnings;
use File::Copy;
use File::Basename;

BEGIN {
	use Mojo::File qw(curfile);
	use Env qw(WEBWORK_ROOT);

	$WEBWORK_ROOT = curfile->dirname->dirname;
}

use lib "$ENV{WEBWORK_ROOT}/lib";

use WeBWorK::CourseEnvironment;
use WeBWorK::DB;
use Data::Dumper;

if((scalar(@ARGV) != 3)) {
  print "\nSyntax is: change_user_id course_id old_user_id new_user_id";
  print "\n    (e.g.  newpassword MAT_123 jjones jsmith\n\n";
  exit();
}

my $courseID = shift;
my $old_user_id = shift;
my $new_user_id = shift;

my $ce = WeBWorK::CourseEnvironment->new({
	webwork_dir => $ENV{WEBWORK_ROOT},
	courseName  => $courseID
});

my $db = WeBWorK::DB->new($ce);
die "Error: $old_user_id does not exist!" unless $db->existsUser($old_user_id);

unless($db->existsUser($new_user_id)) {
    my $user = $db->getUser($old_user_id);
    $user->{user_id}=$new_user_id;
    $user->{comment} = $user->{comment}."Record created from $old_user_id record";
    $db->addUser($user);
}

unless($db->existsPassword($new_user_id)) {
    my $password = $db->getPassword($old_user_id);
    $password->{user_id} = $new_user_id;
    $db->addPassword($password);
}

unless($db->existsPermissionLevel($new_user_id)) {
    my $permission = $db->getPermissionLevel($old_user_id);
    $permission->{user_id} = $new_user_id;
    $db->addPermissionLevel($permission);
}

my @old_user_sets = $db->listUserSets($old_user_id);
foreach(@old_user_sets) {
    my $set_id = $_;
    my $new_set = $db->newUserSet;
    $new_set->user_id($new_user_id);
    $new_set->set_id($set_id);
    eval{$db->addUserSet($new_set)};
    my $old_set = $db->getUserSet($old_user_id,$set_id);
    foreach(keys %$old_set) {
        next if /user_id|set_id/;
        $new_set->$_($old_set->$_);
    }

    $db->putUserSet($new_set) unless $db->existsUserSet($new_user_id,$set_id);
    my @global_problems = grep { defined $_} $db->getAllGlobalProblems($set_id);
    foreach(@global_problems) {
        if($db->existsUserProblem($old_user_id,$set_id,$_->{problem_id})) {
            my $old_user_problem = $db->getUserProblem($old_user_id,$set_id,$_->{problem_id});
            my $new_user_problem = $db->newUserProblem;
            $new_user_problem->user_id($new_user_id);
            $new_user_problem->set_id($set_id);
            $new_user_problem->problem_id($_->{problem_id});
            $db->addUserProblem($new_user_problem) unless $db->existsUserProblem($new_user_id,$set_id,$_->{problem_id});
            foreach(keys %$old_user_problem) {
                next if /(user_id|set_id|problem_id)/;
                $new_user_problem->$_($old_user_problem->$_);
            }
            $db->putUserProblem($new_user_problem);
        }
    }
}

my $answer_log = $ce->{courseFiles}->{logs}->{answer_log};
my $dirname = dirname($answer_log);
copy($answer_log,"$dirname/answer_log.bak");
open(my $in,'<',"$dirname/answer_log.bak") or die "Can't open $dirname/answer_log.bak:$!";
open(my $out,'>',$answer_log);
while(<$in>) {
    s/$old_user_id/$new_user_id/g;
    print $out $_;
}