<?php
// ----------------------------------------------------------------------------
// student_groups.php
// Contains the Student_Groups class definition.
// ----------------------------------------------------------------------------

require_once 'student.php';
//require_once '../../xml_handler.php';
require_once '/projects/lupp/2-1-devel//www/common/xml_handler.php';

// ----------------------------------------
// The Student_Groups class contains the data for a student in
// the active students category.
//----------------------------------------
class Student_Groups {

    // ----------------------------------------
    // Instance variables
    // ----------------------------------------
    private $first_reg;
    private $jsonversion;
    private $students;
    
    // ----------------------------------------
    // Constructor
    //
    // Initiates instance variables and creates classes based
    // on the xml data received.
    //
    // Arguments:
    // $xml_data is an xml data object supposed to contain relevant
    // data retrieved from the all_students file.
    // ----------------------------------------
    public function __construct($xml_data) {

        $this->students = array();
        $this->first_reg = $xml_data->getAttribute('firstreg');
        $this->jsonversion = $xml_data->getAttribute('jsonversion');
        
        // ----------
        // Extract student data and initiate the students for the
        // group.
        // ----------
        $students_data = $xml_data->getElementsByTagName('student');
        foreach ( $students_data as $student ) {
            $this->students[] = new Student($student); 
        }
    }

    // ----------------------------------------
    // get_jsonversion
    //
    // Returns the jsonversion for this group.
    // ----------------------------------------
    public function get_jsonversion() {

        return $this->jsonversion;
    }
        
    // ----------------------------------------
    // get_first_reg
    //
    // Returns the first_reg for this group.
    // ----------------------------------------
    public function get_first_reg() {

        return $this->first_reg;
    }

    // ----------------------------------------
    // get_students
    //
    // Returns an array with all students in this group.
    // ----------------------------------------
    public function get_students() {

        return $students;
    }

    // ----------------------------------------
    // get_student_by_uid
    //
    // Returns the student with uid matching $uid, null if no such
    // student exists.
    // ----------------------------------------
    public function get_student_by_uid($uid) {

        // ----------
        // Iterative over the students and find the one we seek.
        // ----------
        foreach ( $this->students as $student ) {
            if ( $student->get_uid() == $uid or $student->get_old_uid() == $uid) {
                // Found it!
                return $student;
            }
        }

        // The student we seek did not exist.
        return null;
    }

    // ----------------------------------------
    // print_dump
    //
    // Print function for debugging / testing.
    // ----------------------------------------
    public function print_dump() {
        
        print "\tGroup first registered: " . $this->first_reg . ".\n";

        foreach ( $this->students as $student ) {
            $student->print();
        }
    }

    // ----------------------------------------
    // contains_student
    //
    // Check whether the group contains a particular student. Returns
    // true if so, false otherwise.
    //
    // Arguments:
    // $uid is a string containing the sought students UID.
    // ----------------------------------------
    function contains_student($uid) {

        if ( isset($this->students) && ! empty($this->students) ) {
            foreach ( $this->students as $student ) {
                if ( strcasecmp($student->get_uid(), $uid) == 0 ) {
                    return true;
                }
            }
        }

        return false;
    }
    
    // ----------------------------------------
    // End of Student_Groups class definition
    // ----------------------------------------
}

// ----------------------------------------------------------------------------
?>