<?php
	class UsersController extends AppController {
		var $name = 'Users';

		var $uses = array('User','Host','LoginAttempt','SectionsUser');
		var $helpers = array('Javascript', 'auth', 'Pagination');
		var $components = array('auth', 'Pagination');

		function login($username = null, $password = null) {
			$error = '';
			
			if (!empty($this->data)) {
				$data = $this->data;
			} else if (!empty($username) and !empty($password)) {
				$data = array('User' => array('username' => urldecode($username), 'password' => urldecode($password)));
			}
			
			if (!empty($data)) {
				if ($user_id = $this->auth->attemptLogin($data)) {
					//$error = 'Logged in!';
					$this->redirect($this->pglms->defaultPage($user_id));
				} else {
					$error = $this->auth->error;
					if (!$error) $error = 'Internal error.';
				}
			} else if (!empty($this->uid)) {
				//$error = 'Already logged in!';
				// Shouldn't happen, but does anyway.
				$this->redirect($this->pglms->defaultPage($this->uid));
			}

			$this->auth->newSalt();
			$this->set('error', $error);
			$this->set('allowcleartext', $this->auth->allowCleartext);
			$this->set('onload', "this.document.pForm['data[User][username]'].focus()");
			$this->pageTitle = 'User Login';
		}
		
		function token() {
			// Takes various parameters, to generate a single-signon token url:
			// 'u': Client-side user uid
			// 'c': Section identifier
			// 'p': School identifier
			// 'f': User first name
			// 'l': User last name
			// 'e': User email address
			// 'r': User role
			// 'i': Course identifier
			// Also looks at server-side variables to find the school id:
			// 'PG_SSO-SystemID': eCollege identifier
			// 'PG_SSO-MAC': Message Authentication Code
			// 'PG_SSO-Timestamp': ISO8601-format timestamp
			
			// Possible error codes returned:
			// 100: Unknown error
			// 101: Missing a required parameter
			// 102: Unauthorized access (a header was missing or wrong)
			// 103: Unable to create user
			// 104: Invalid parameter value
			// 105: Invalid timestamp
			// 106: Unsupported language course
			// 107: Unknown school
			// 108: Invalid section
			
			$params = $this->params['url'];
			$messages = array();
			$param_vars = array(
				'u' => 'user_uid',      // user
				'c' => 'section_uid',   // section
				'p' => 'school_uid',    // school
				//'s' => 'user_school',
				'f' => 'first_name',    // first
				'l' => 'last_name',     // last
				'e' => 'email',
				'r' => 'user_type',     // role
				'i' => 'course_uid',    // course
				'page' => 'next_page',
			);
			
			$header_vars = array(
				'PG_SSO-SystemID' => 'system_school',
				'PG_SSO-MAC' => 'message_hash',
				'PG_SSO-Timestamp' => 'timestamp',
			);
			
			foreach ($param_vars as $key => $varname) {
				$$varname = array_key_exists($key, $params)? $params[$key]: null;
			}
			
			foreach ($header_vars as $key => $varname) {
				$ukey = 'HTTP_'.str_replace('-', '_', strtoupper($key));
				if (empty($_SERVER[$ukey])) {
					$messages[102] = 'Authentication headers not provided';
					$$varname = 'Not provided';
				} else {
					$$varname = $_SERVER[$ukey];
				}
			}
			
			if (!$messages) {
				// Check the header variables
				$this->User->School->useModel();
				$system = $this->User->School->find(array('school_name' => $system_school), array('id', 'secret'));
				if (empty($system['School']['id'])) {
					$messages[102] = 'Unrecognized system identifier';
				} else if (empty($system['School']['secret'])) {
					// Make this the same as above, to prevent security breaches
					//$messages[102] = 'Unknown shared secret.';
					$messages[102] = 'Unrecognized system identifier';
				} else if (strcmp($message_hash, $this->pglms->hmac($timestamp.$system['School']['secret'], $this->pglms->urn()))) {
					$messages[102] = 'Incorrect message authentication code';
				} else if (abs(time() - strtotime($timestamp)) > 300) {
					// The request is more than five minutes old; assume that it has been spoofed.
					// (However, it could be a simple case of a misconfigured server.)
					// Alternatively, we could store all served requests, and refuse to serve them twice.
					$messages[105] = 'Invalid timestamp';
				} else if (empty($school_uid)) {
					// Assume that we want the school for the system signon
					$school_id = $system['School']['id'];
				} else if (is_numeric($school_uid)) {
					$children = $this->User->School->findChildrenIds($system['School']['id']);
					if (in_array(intval($school_uid, $children))) {
						$school_id = intval($school_uid);
					} else {
						$messages[107] = 'Invalid school id';
					}
				} else {
					$fragments = explode('.', $school_uid);
					if (count($fragments) > 1) foreach ($fragments as $portion) if ($portion) $school_uid = $portion;
					$children = $this->User->School->findChildrenIds($system['School']['id']);
					$school_id = $this->User->School->field('id', array('School.school_name' => $school_uid, 'School.id' => $children));
					if (empty($school_id)) $messages[107] = 'Invalid school identifier';
				}
			}
			
			if (!empty($school_id)) {
				if ($first_name and $last_name and $user_type and $user_uid) {
					$user_id = $this->User->autocreate($school_id, $user_type, $first_name, $last_name, $email, $user_uid)
						or $messages[$this->User->errnum] = $this->User->error;
				}
				
				if ($section_uid and $course_uid) {
					$uid_info = explode('.', $course_uid);
					if (count($uid_info) > 1) {
						$course_uid = $uid_info[0];
						$segment = $uid_info[1];
						$num_segments = (count($uid_info) > 2)? $uid_info[2]: 2;
					} else {
						$segment = $num_segments = 1;
					}
					
					$section_id = $this->User->Section->autocreate($school_id, $course_uid,
						$segment, $num_segments, null, $section_uid, null, $system_school);
					if (empty($section_id)) $messages[$this->User->Section->errnum] = $this->User->Section->error;
				}
				
				if (!empty($user_id) and !empty($section_id)) {
					$joined = $this->User->autojoin($section_id, $user_id, $user_type)
						or $messages[108] = 'Invalid section';
					if ($joined and !$next_page) $next_page = '/sections/calendar/'.$section_id;
				}
			}
			
			if (empty($joined)) {
				if (empty($messages)) $messages[100] = 'Unknown Error';
				$url = null;
			} else {
				$this->User->School->useModel();
				$secret = $this->User->School->field('secret', array('id' => 1));
				$token = time().'.'.$user_id;
				$token .= '-'.sha1($token.'@'.$secret);
				$url = $this->pglms->full_url('/users/signon/'.$token);
				if (!empty($next_page)) $url .= '?page='.$next_page;
			}
			
			if (empty($url)) {
				if (empty($school_id)) $school_id = empty($system['School']['id'])? 1: $system['School']['id'];
				
				$subject = 'SSO Token Error';
				$body = "The SSO token-creation process has failed.\n";
				foreach ($messages as $errnum => $msg) {
					$body .= "Error #$errnum: $msg\n";
				}
				
				$body .= "\nRequest headers:\n";
				foreach ($header_vars as $key => $varname) {
					$msg = $$varname;
					$body .= "$key: $msg\n";
				}
				
				$body .= "\nRequest parameters:\n";
				foreach ($param_vars as $key => $varname) {
					$msg = is_null($$varname)? 'Not provided': $$varname;
					$body .= "$varname ($key): $msg\n";
				}
				
				$urn = $this->pglms->urn();
				$body .= "\nRequest URN:\n$urn\n$_SERVER[REQUEST_URI]\n";
				$this->User->School->mail_techs($school_id, $subject, $body);
			}
			
			$this->set('messages', $messages);
			$this->set('login_url', $url);
		}
		
		function signon($token) {
			// Function for a single-signon login.
			// The token should have been recently generated by our system.
			$error = "Your system failed to log you in properly.
				<br>If it doesn't work in a few minutes, talk to your administrator.";
			$info = explode('-', $token);
			if (count($info) == 2) {
				list($whenwho, $sha) = $info;
				$this->User->School->useModel();
				$secret = $this->User->School->field('secret', array('id' => 1));
				if ($sha === sha1($whenwho.'@'.$secret)) {
					$info = explode('.', $whenwho);
					if (count($info) == 2) {
						$when = intval($info[0]);
						$who = intval($info[1]);
						$diff = time() - $when;
						if (-30 <= $diff and $diff <= 45) {
							$this->User->useModel();
							$user = $this->User->read(null, $who);
							if ($user) {
								//pr($user); exit;
								$user_id = $who;
								$this->auth->login($user['User']);
							}
						} else if ($diff > 30) {
							$error = 'The system took too long to authenticate.<br>Please go back and try again.';
						}
					}
				}
			}
			
			if (empty($user_id)) {
				$this->flash($error, '/users/login');
			} else {
				$this->redirect($this->pglms->defaultPage($user_id));
			}
		}

		function logout() {
			$success = $this->auth->attemptLogout();
			$this->flash($success? 'Logout successful': 'Logout failed', '/');
		}

		function view($id) {
			$this->redirect('/users/profile/'.$id);
		}

		function profile($id = null) {
			// this function deprecates function view()
			if (empty($id)) {
				$id = $this->uid;
			} else if ($this->pglms->verifyUserAdmin($id, true)) {
				$this->redirect('/users/edit/'.$id);
			}
			
			$this->User->useModel(array('User'));
			$user = $this->User->findById($id, null, null, 0);
			$this->set("user", $user['User']);
			$this->pageTitle = 'User Profile';
		}

		function admin() {
			// Default landing page for school administrators
			$role = $this->pglms->verifyAdmin();
			$this->User->useModel('School');
			$user = $this->User->findById($this->uid, array('School.description', 'School.school_name'));
			$sch_name = empty($user['School']['description'])? $user['School']['school_name']: $user['School']['description'];
			$this->pageTitle = $sch_name.' Administration';
			$this->set('role', $role);
		}

		function home() {
			$this->redirect($this->pglms->defaultPage($this->uid));
		}

		function grades($section_id, $student_id=null, $filter='all') {
			if (($student_id == $this->uid) or !is_numeric($student_id)) {
				$role = $this->pglms->verifySectionUser($section_id, true);
				$student_id = $this->uid;
			} else {
				// Verify that the user is a teacher of this section
				$role = $this->pglms->verifySectionUser($section_id, false);
			}
			
			$status_lists = array(
				'all' => array(),        // Every assignment
				'done' => array(),       // Completed, and either dateless or already due
				'future' => array(),     // Not completed, but not due yet either
				'missed' => array(),     // Not completed, and past due
				'ungraded' => array(),   // Completed, but ungraded
				'extra' => array(),      // Extra Credit
				'early' => array(),      // Completed, but not due yet
				'deleted' => array(),    // Deleted grades
				'pointless' => array(),  // Not worth points
				'locked' => array(),     // Grades that lock an assignment
				'retakes' => array(),    // Grades marked as allowing a retake
			);
			
			if (is_numeric($filter)) {
				// Request for a specific assignment, usually from the section gradebook.
				// Todo: What if the assignment hasn't been completed yet?
				$grades = $this->User->Grade->findAll(array(
					'Grade.assignment_id' => $filter,
					'Grade.section_id' => $section_id,
					'Grade.user_id' => $student_id,
					'Grade.display_sequence' => '> 0',
					'Grade.completion_status' => '!= Started',
				), 'Grade.id', null, null, 1, 0);
				if (count($grades) == 1) {
					// Move directly along to the specified grade.
					$this->redirect('/grades/view/'.$grades[0]['Grade']['id']);
				} else {
					$filter = intval($filter);
					$status_lists[$filter] = array();
				}
			}
			
			$grades = array();
			$this->User->useModel();
			$student = $this->User->read(array('User.id', 'User.first_name', 'User.last_name'), $student_id);
			$calendar = $this->User->Section->calendar($section_id, $student_id);
			
			$this->User->Section->useModel('Students');
			$section = $this->User->Section->findById($section_id);
			$dateless = empty($section['Section']['start_date']);
			
			if (!$dateless) {
				$now = time();
				$now_info = getdate($now);
				$today = mktime(0,0,0, $now_info['mon'], $now_info['mday'], $now_info['year']);
			}
			
			$required = array();
			$progress = array();
			foreach ($calendar as $key => $asn) {
				$daynum = $asn['SectionsAssgmt']['day_number'];
				$aid = $asn['Assignment']['id'];
				$status = array(
					'Done' => 0,
					'Retake' => 0,
					'Locked' => 0,
					'Started' => 0,
				);
				
				if (!empty($asn[0]['completion'])) {
					foreach (explode(',', $asn[0]['completion']) as $stat) {
						if (array_key_exists($stat, $status)) {
							$status[$stat] += 1;
						} else {
							// Todo: Issue a warning, but only on dev platforms
						}
					}
				}
				
				if ($deleted = intval($asn[0]['deleted_grades'])) {
					$status_lists['deleted'][$key] = $deleted;
				}
				
				extract($status);
				//$worth = round(intval($asn['Assignment']['points']) * $asn['SectionsAssgmt']['weight'] / 100);
				$worth = intval($asn['Assignment']['points']);
				if ($calendar[$key]['worth'] = $worth) {
					$status_lists['all'][$key] = 1;
					if ($Locked) $status_lists['locked'][$key] = 1;
					if ($Retake) $status_lists['retakes'][$key] = 1;
					if ($asn['SectionsAssgmt']['extra_credit_flag']) $status_lists['extra'][$key] = 1;
					$due = (!$dateless and !empty($asn['SectionsAssgmt']['date_due']) and strtotime($asn['SectionsAssgmt']['date_due']) < $today);
					$status = $Done? (($dateless or $due)? 'done': 'early'): (($dateless or !$due)? 'future': 'missed');
					$status_lists[$status][$key] = 1;
					
					if ($Done or $Locked or $deleted) {
						$this->User->Grade->useModel();
						$grades = $this->User->Grade->findAll(array(
							'Grade.user_id' => $student_id,
							'Grade.section_id' => $section_id,
							'Grade.assignment_id' => $aid,
							'Grade.completion_status' => array('Done', 'Locked'),
						));
						
						$ungraded = 0;
						foreach ($grades as $grade) {
							if ($grade['Grade']['date_submitted'] and $grade['Grade']['display_sequence'] > 0 and !$grade['Grade']['date_graded']) {
								$parsed['ungraded'][] = $grade;
								$ungraded += 1;
							}
						}
						
						if ($ungraded) $status_lists['ungraded'][$key] = $ungraded;
						$calendar[$key]['grades'] = $grades;
					}
				} else {
					$status_lists['pointless'][$key] = 1;
				}
				
				if ($asn[0]['num_items']) {
					if (array_key_exists($daynum, $required)) {
						$required[$daynum] += 1;
						if ($Done) $progress[$daynum] += 1;
					} else {
						$required[$daynum] = 1;
						$progress[$daynum] = ($Done? 1: 0);
					}
				}
				
				if ($filter == $aid) {
					$status_lists[$filter][$key] = 1;
				}
			}
			
			// Cheat: Instead of calculating the grade, let the database do it.
			$conditions = array('Taking.id' => intval($section_id), 'User.id' => intval($student_id));
			$current_grade = $this->User->current_grades($conditions, $dateless);
			$full_grade = $this->User->full_grades($conditions);
			
			$this->set(array(
				'calendar' => $calendar,
				'required' => $required,
				'progress' => $progress,
				'student' => $student,
				'section' => $section,
				'filter' => $filter,
				'lists' => $status_lists,
				'role' => $role,
				
				'points' => intval($full_grade[0]['Summary']['earned']),
				'max_points' => intval($full_grade[0]['Summary']['possible']),
				'ptd' => intval($current_grade[0]['Summary']['earned']),
				'max_ptd' => intval($current_grade[0]['Summary']['possible']),
			));
		}
		
		function edit($id) {
			// Todo: Allow teachers to edit their own profiles
			$role = $this->pglms->verifyUserAdmin($id, true) or $this->redirect('/users/profile/'.$id);
			
			$this->User->useModel(array('User', 'Type', 'Taking', 'Teaching'));
			$user = $this->User->read(null, $id);
			$enrollment = array();
			foreach ($user[$user['Type']['name'] == 'student'? 'Taking': 'Teaching'] as $section) {
				$enrollment[] = $section['id'];
			}
			
			$this->User->Section->useModel(array('Section', 'School'));
			$sections = $this->User->Section->findAll(array(
				'Section.school_id' => $this->pglms->adminSchools(),
				'or' => array('Section.end_date' => null, 'end_date' => '>= '.$this->User->date()),
				'Section.display_sequence' => '> 0',
			), array('Section.id', 'Section.section_name', 'Section.client_section_id', 'School.school_name'));
			
			$this->pageTitle = ($this->uid == $id)? 'My Profile' : 'Edit ' . ucfirst($user['Type']['name']);
			$this->set('sections', $sections);
			$this->set('enrollment', $enrollment);
			$this->set('user', $user['User']);
			$this->set('type', $user['Type']);
			$this->set('role', $role);
		}
		
		function save($student_id) {
			if (!$this->pglms->verifyUserAdmin($student_id, true)) {
				$this->flashback('Permission Denied.', '/users/profile/'.$student_id);
			} else if (empty($this->data['User'])) {
				$this->flashback('There was a problem loading the form data', '/users/edit/'.$student_id);
			} else {
				$this->User->id = $student_id;
				if ($this->User->save($this->data['User'])) {
					// Modify the sections
					if (!empty($this->data['Section'])) {
						$user = $this->User->read(null, $student_id);
						$user_id = $user['User']['id'];
						$user_type = $user['Type']['name'];
						$user_name = $user['User']['first_name'] . ' ' . $user['User']['last_name'];
						
						$messages = array('Your changes have been saved.');
						$selected = $this->data['Section']['id'];
						
						$keepers = array();
						foreach ($user[$user['Type']['name'] == 'student'? 'Taking': 'Teaching'] as $section) {
							$section_id = $section['id'];
							if (in_array($section_id, $selected)) {
								$keepers[$section_id] = true;
							} else if (!$this->SectionsUser->del($section_id, $user_id, $user_type)) {
								$section_name = empty($section['section_name'])? 'section #'.$section_id: $section['section_name'];
								$messages[] = "$user_name could not be removed from $section_name.";
							}
						}
						
						foreach ($selected as $section_id) {
							if (empty($keepers[$section_id])) {
								$section = $this->User->Section->read(array('Section.school_id', 'Section.section_name'), $section_id);
								$section_name = empty($section['Section']['section_name'])? 'section #'.$section_id: $section['Section']['section_name'];
								
								if ($this->pglms->verifyAdmin($section['Section']['school_id'], false)) {
									$result = $this->SectionsUser->add($section_id, $user_id, $user_type);
									
									if (!$result) {
										$messages[] = "$user_name could not be added to $section_name.";
									}
								} else {
									$messages[] = "You do not have permission to add students to $section_name.";
								}
							}
						}
					}
					
					$this->flashwayback(join("\n<BR>", $messages), '/users/edit/'.$student_id);
				} else {
					$this->flashback('There was a problem saving your changes.', '/users/edit/'.$student_id);
				}
			}
		}

		function add($user_type, $school_id = null) {
			$this->pglms->verifyAdmin($school_id);
			
			if (!empty($this->data['User'])) {
				// give this user the proper role (user_type_id)
				$role = $this->User->UserType->findByName($user_type, 'UserType.id', null, 0);
				$this->data['User']['user_type_id'] = $role['UserType']['id'];
				$this->data['User']['user_type'] = $user_type;

				// give this user the proper school_id
				$this->data['User']['school_id'] = $school_id? $school_id: $this->Session->read('school_id');

				// define the creation date
				$this->data['User']['date_created'] = date('Y-m-d H:i:s');

				$this->User->id = null;
				if ($this->User->save($this->data['User'])) {
					if (!empty($this->data['Section'])) {
						$result = $this->SectionsUser->add($this->data['Section']['id'], $this->User->id, $user_type);
					} 
					
					$this->flashwayback("The new $user_type has been added.", '/users/'.$user_type);
				} else {
					$message = "There was a problem saving the $user_type data.";
					if (!empty($this->User->validationErrors)) {
						$fields = array();
						foreach ($this->User->validationErrors as $field => $invalid) {
							if ($invalid) $fields[] = $field;
						}
						
						if ($fields) {
							$field_names = $this->pglms->expand_list($fields);
							$s = count($fields) == 1? '': 's';
							$message .= "<br>Please check the $field_names field$s.";
						}
					}
					
					$this->Session->setFlash($message);
				}
			}
			
			$user = $this->User->read();
			if (in_array($user_type, array('student', 'teacher'))) {
				$this->User->Section->useModel();
				$sections = $this->User->Section->findAll(array(
					'Section.school_id' => $school_id? $school_id: $this->pglms->adminSchools(),
					'or' => array(
						'end_date' => null,
						'Section.end_date' => '>= ' . $this->User->date(),
					),
					'Section.display_sequence' => '> 0',
				));
			} else {
				$sections = null;
			}
			
			$this->set('school_id', $school_id);
			$this->set('sections', $sections);
			$this->set('user', $user['User']);
			$this->set('user_type', $user_type);
		}
		
		function delete($user_id) {
			if ($this->pglms->verifyUserAdmin($user_id, false)) {
				$result = $this->User->delete($user_id);
				$message = $result? 'User deleted.': 'Failed to delete user.';
			} else {
				$message = 'You lack permission to delete this user.';
			}
			
			$this->flashback($message, '/users/students');
		}
		
		function teaching($school_id = null, $teacher_id = null) {
			if (empty($teacher_id)) $teacher_id = $this->uid;
			$students = array();
			$conditions = array(
				'User.id' => intval($teacher_id),
				'SectionsUser.dropped' => null,
				'SectionsUser.role' => 'teacher',
			);
			
			if ($school_id) $conditions['Section.school_id'] = intval($school_id);
			$teaching = $this->SectionsUser->findAll($conditions);
			foreach ($teaching as $section) {
				$taking = $this->SectionsUser->findAll(array(
					'Section.id' => $section['Section']['id'],
					'SectionsUser.dropped' => null,
					'SectionsUser.role' => 'student',
				));
				
				foreach ($taking as $student) {
					$key = $student['User']['last_name'].'/'.$student['User']['first_name'].'/'.$student['User']['id'];
					$students[$key][] = $student;
				}
			}
			
			ksort($students);
			$this->pageTitle = 'Students in Your Sections';
			$this->set('students', $students);
			$this->set('sections', $teaching);
		}
		
		function teachers($sequence = '> 0') {
			$schools = $this->pglms->adminSchools();
			$criteria = $this->pglms->search_conditions(array(
				'User.username',
				'User.client_student_id',
				'User.first_name',
				'User.last_name',
				'User.email',
			), array(
				'User.user_type' => 'teacher',
				'User.school_id' => $schools,
				'User.display_sequence' => $sequence,
			));
			
			list($order, $limit, $page) = $this->Pagination->init($criteria);
			$order = array($order, 'User.last_name', 'User.first_name');
			$this->User->useModel('Teaching');
			$teachers = $this->User->findAll($criteria, null, $order, $limit, $page);
			
			foreach ($teachers as $key => $teacher) {
				$teachers[$key]['lag_time'] = $this->User->getLagTime($teacher['User']['id']);
			}
			
			$this->set('teachers', $teachers);
		}

		function students($sequence = '> 0') {
			$criteria = $this->pglms->search_conditions(array(
				'User.username',
				'User.client_student_id',
				'User.first_name',
				'User.last_name',
				'User.email',
			), array(
				'User.user_type' => 'student',
				'User.school_id' => $this->pglms->adminSchools(),
				'User.display_sequence' => $sequence,
			));
			
			list($order, $limit, $page) = $this->Pagination->init($criteria);
			$order = array($order, 'User.last_name', 'User.first_name');
			$this->User->useModel(array('User', 'Type', 'Taking'));
			$students = $this->User->findAll($criteria, null, $order, $limit, $page);
			$this->set('students', $students);
		}
		
		function unstarted($section_id = null) {
			// CSV report of students who haven't logged in or done anything
			$this->pglms->blankLayout();
			
			if ($section_id) {
				$sections = array($this->User->Section->read(null, $section_id));
				$this->pglms->verifyAdmin($sections[0]['Section']['school_id']);
				$unlogged = $this->SectionsUser->findAll(array(
					'User.last_login' => null,
					'SectionsUser.section_id' => $section_id,
					'SectionsUser.dropped' => null,
					'SectionsUser.role' => 'student',
				));
			} else {
				$this->pglms->verifyAdmin();
				$schools = $this->pglms->adminSchools();
				$sections = $this->User->Section->findAll(array('Section.school_id' => $schools));
				$unlogged = $this->User->findAll(array(
					'User.last_login' => null,
					'User.school_id' => $schools,
				));
			}
			
			$this->set('sections', $sections);
			$this->set('unlogged', $unlogged);
		}
		
		function dns($section_id = null) {
			// "Did Not Start" report -- students who haven't logged in or done anything
			if (!empty($this->data['Section']['id'])) $section_id = intval($this->data['Section']['id']);
			if ($section_id) {
				$this->pglms->verifySectionUser($section_id);
				$this->User->Section->useModel(array('Section', 'Teachers'));
				$section = $this->User->Section->read(null, $section_id);
				$this->set('section', $section);
				$this->SectionsUser->useModel(array('User'));
				$this->SectionsUser->User->useModel(array('School'));
				$unlogged = $this->SectionsUser->findAll(array(
					'User.last_login' => null,
					'SectionsUser.dropped' => null,
					'SectionsUser.role' => 'student',
					'SectionsUser.section_id' => $section_id,
				), null, null, null, null, 2);
			} else {
				$this->pglms->verifyAdmin();
				$schools = $this->pglms->adminSchools();
				$this->User->useModel(array('User', 'School', 'Taking'));
				$this->User->School->useModel(array());
				$this->User->Taking->useModel(array('Teachers'));
				$unlogged = $this->User->findAll(array(
					'User.last_login' => null,
					'User.school_id' => $schools,
				), null, null, null, null, 2);
			}
			
			$this->set('unlogged', $unlogged);
		}
		
		function delinquency($section_id = null, $days = null) {
			if (!empty($this->data['Days']['number'])) $days = intval($this->data['Days']['number']);
			if (!empty($this->data['Section']['id'])) $section_id = intval($this->data['Section']['id']);
			
			$conditions = array('Type.name' => 'student');
			if (!empty($section_id) and is_numeric($section_id)) {
				$this->pglms->verifySectionUser($section_id);
				$conditions['Taking.id'] = $section_id;
			} else if ($this->pglms->verifyAdmin(null, false)) {
				$school_list = $this->pglms->adminSchools();
				$conditions['and']['or'] = array(
					'Taking.school_id' => $school_list,
					'User.school_id' => $school_list,
				);
			} else {
				$this->User->useModel(array('Teaching'));
				$user = $this->User->read('User.id', $this->uid);
				$sections = array();
				foreach ($user['Teaching'] as $section) $sections[] = $section['id'];
				if ($sections) {
					$conditions['Taking.id'] = $sections;
				} else {
					$conditions['Taking.id'] = null;
					$conditions['User.id'] = $this->uid;
				}
			}
			
			if ($days and is_numeric($days)) {
				$conditions['or'] = array(
					'and' => array('User.last_login' => null),
					'User.last_login' => date('< YmdHis', time() - (60*60*24*$days)),
				);
			} else {
				$conditions['User.last_login'] = null;
			}
			
			$this->User->useModel(array('User', 'Type', 'School', 'Taking'));
			$users = $this->User->findAll($conditions, array(
				'User.first_name',
				'User.last_name',
				'User.client_student_id',
				'User.last_login',
				'Taking.section_name',
				'Taking.client_section_id',
				'School.school_name',
			), array('User.last_name', 'User.first_name'));
			
			$this->set('users', $users);
			$this->set('days', is_numeric($days)? $days: 0);
			$this->set('section_id', is_numeric($section_id)? $section_id: 'all');
		}
		
		function failing($section_id = null, $threshold = null, $flags = null) {
			if (!empty($this->data['Section']['id'])) $section_id = intval($this->data['Section']['id']);
			if (isset($this->data['Grades']['threshold'])) $threshold = $this->data['Grades']['threshold'];
			if ($threshold == 'zero') $threshold = 0;
			$flag_list = array('done' => false, 'future' => false, 'missing' => false, 'ungraded' => false, 'extra' => false, 'early' => false);
			$flags_requested = empty($flags)? array(): explode('_', $flags);
			foreach (array_keys($flag_list) as $flag) {
				if (!empty($this->data['Grades'][$flag])) $flag_list[$flag] = true;
				if (in_array($flag, $flags_requested)) $flag_list[$flag] = true;
			}
			
			$conditions = array();
			if (!empty($section_id) and is_numeric($section_id)) {
				$this->pglms->verifySectionUser($section_id);
				$conditions['Taking.id'] = $section_id;
			} else if ($this->pglms->verifyAdmin(null, false)) {
				$school_list = $this->pglms->adminSchools();
				$conditions['or'] = array(
					'Taking.school_id' => $school_list,
					'User.school_id' => $school_list,
				);
			} else {
				$this->User->useModel(array('Teaching'));
				$user = $this->User->read('User.id', $this->uid);
				$sections = array();
				foreach ($user['Teaching'] as $section) $sections[] = $section['id'];
				if ($sections) {
					$conditions['Taking.id'] = $sections;
				} else {
					$conditions['User.id'] = $this->uid;
				}
			}
			
			$users = $this->User->getStudentGrades($conditions, $threshold, $flag_list);
			
			$this->set('users', $users);
			$this->set('flags', $flag_list);
			$this->set('threshold', $threshold? $threshold: 'zero');
			$this->set('section_id', is_numeric($section_id)? $section_id: 'all');
		}
	}
?>