<?php
/**
 * Copyright (C) 2024 fhcomplete.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

if (! defined('BASEPATH')) exit('No direct script access allowed');

//require_once('../../../include/studiengang.class.php');
//require_once('../../../include/student.class.php');
//require_once('../../../include/datum.class.php');
//require_once('../../../include/mail.class.php');
//require_once('../../../include/benutzerberechtigung.class.php');
//require_once('../../../include/phrasen.class.php');
//require_once('../../../include/projektarbeit.class.php');
//require_once('../../../include/projektbetreuer.class.php');

class Lehre extends FHCAPI_Controller
{
	
	/**
	 * Object initialization
	 */
	public function __construct()
	{
		parent::__construct([
			'lvStudentenMail' => self::PERM_LOGGED,
			'LV' => self::PERM_LOGGED,
			'Pruefungen' => self::PERM_LOGGED,
			'semesterAverageGrade' => self::PERM_LOGGED,
		]);
		
	}

	//------------------------------------------------------------------------------------------------------------------
	// Public methods

    /**
	 * constructs the emails of the groups from a lehrveranstaltung
	 */
    public function lvStudentenMail()
	{
        $lehreinheit_id = $this->input->get("lehreinheit_id",TRUE);
        
        // return early if the required parameter is missing
        if(!isset($lehreinheit_id))
        {
            $this->terminateWithError('Missing required parameter', self::ERROR_TYPE_GENERAL);
        }

        $this->load->model('education/Lehreinheit_model', 'LehreinheitModel');
        
        $studentenMails = $this->LehreinheitModel->getStudentenMail($lehreinheit_id);

        $studentenMails = $this->getDataOrTerminateWithError($studentenMails);

		//convert array of objects into array of strings
		$studentenMails = array_map(function($element){
			return $element->mail;
		}, $studentenMails);

        $this->terminateWithSuccess($studentenMails);
	}

	public function LV($studiensemester_kurzbz, $lehrveranstaltung_id)
	{
		$this->load->model('education/Lehrveranstaltung_model', 'LehrveranstaltungModel');

		$result = $this->LehrveranstaltungModel->getLvsByStudentWithGrades(getAuthUID(), $studiensemester_kurzbz, getUserLanguage(), $lehrveranstaltung_id);

		$result = current($this->getDataOrTerminateWithError($result));
		
		$this->terminateWithSuccess($result);
	}

	/**
	 * fetches all Pruefungen of a student for a specific lehrveranstaltung
	 * if the student passed the Pruefung on the first attempt, no information about the Pruefungen is stored in the database 
	 * @param mixed $lehrveranstaltung_id
	 * @return void
	 */
	public function Pruefungen($lehrveranstaltung_id)
	{
		$this->load->model('education/Pruefung_model', 'PruefungModel');

		$result = $this->PruefungModel->getByStudentAndLv(getAuthUID(), $lehrveranstaltung_id, getUserLanguage());

		$result = $this->getDataOrTerminateWithError($result);

		$this->terminateWithSuccess($result);
	}

	/**
	 * calculates and returns the grade average and weighted average for a specific semester
	 * @param string $studiensemester_kurzbz
	 * @return void
	 */

	public function semesterAverageGrade($studiensemester_kurzbz)
	{
		$this->load->model('education/Lehrveranstaltung_model', 'LehrveranstaltungModel');
		$semesterLvs = $this->LehrveranstaltungModel->getLvsByStudentWithGrades(getAuthUID(), $studiensemester_kurzbz, getUserLanguage());

		if (isError($semesterLvs))
			return $this->outputJsonError(getError($semesterLvs));

		$semesterLvsData = getData($semesterLvs);

		$doGradesExist = false;
		$sum = 0;
		$count = 0;
		$sumWeighted = 0;
		$sumEcts = 0;

		foreach ($semesterLvsData as $lv) {
			if (!$lv->znote || $lv->znote < 1 || $lv->znote > 5)
				continue;

			$doGradesExist = true;

			$sum += $lv->znote;
			$count++;
			$sumWeighted += $lv->znote * floatval($lv->ects);
			$sumEcts += floatval($lv->ects);
		}

		$averageGrade = null;
		$weightedAverageGrade = null;
		if ($doGradesExist) {
			$averageGrade = $sum/$count;
			$weightedAverageGrade = $sumWeighted/$sumEcts;
		}

		$this->terminateWithSuccess(['average_grade' => $averageGrade, 'weighted_average_grade' => $weightedAverageGrade]);
	}
}