AppStateESS/InternshipInventory

<?php
/**
 * This file is part of Internship Inventory.
 *
 * Internship Inventory 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.

 * Internship Inventory 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 version 3
 * along with Internship Inventory.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2011-2018 Appalachian State University
 */

namespace Intern\Command;

use \phpws2\Database;

class NormalCoursesRest {

    public function execute()
    {
        switch($_SERVER['REQUEST_METHOD']) {
            case 'POST':
                $this->post();
                exit;
            case 'DELETE':
                $this->delete();
                exit;
            case 'GET':
                $data = $this->get();
                echo (json_encode($data));
                exit;
            default:
                header('HTTP/1.1 405 Method Not Allowed');
                exit;
        }
    }
    public function post()
    {
        $subjectId = $_REQUEST['subjectId'];
        $cnum = $_REQUEST['cnum'];

        $subjectId = preg_replace("/^_/", '', $subjectId); // Remove leading underscore in the subject id

        if ($subjectId == '')
        {
            header('HTTP/1.1 500 Internal Server Error');
            echo("it is missing a subject id.");
            exit;
        }
        if ($cnum == '')
        {
            header('HTTP/1.1 500 Internal Server Error');
            echo("it is missing a course number.");
            exit;
        }

        $db = Database::newDB();
        $pdo = $db->getPDO();
        $sql = "SELECT subject_id, course_num
                  FROM intern_courses
                  WHERE subject_id=:subject_id and course_num=:cnum";
        $sth = $pdo->prepare($sql);

        $sth->execute(array('subject_id'=>$subjectId, 'cnum'=>$cnum));
        $result = $sth->fetchAll(\PDO::FETCH_ASSOC);
        if (sizeof($result) > 0)
        {
            header('HTTP/1.1 500 Internal Server Error');
            echo("it already exists.");
            exit;
        }

        $sql = "INSERT INTO intern_courses (id, subject_id, course_num)
                VALUES (nextval('intern_courses_seq'), :subject_id, :cnum)";

        $sth = $pdo->prepare($sql);

        $sth->execute(array('subject_id'=>$subjectId, 'cnum'=>$cnum));
    }
    public function delete()
    {
        $id = $_REQUEST['courseId'];
        $db = Database::newDB();
        $pdo = $db->getPDO();
        $sql = "DELETE FROM intern_courses
                WHERE id = :id";

        $sth = $pdo->prepare($sql);
        $sth->execute(array('id'=>$id));
    }
    public function get()
    {
        $db = Database::newDB();
        $pdo = $db->getPDO();
        $sql = "SELECT intern_courses.course_num,
                       intern_courses.subject_id,
                       intern_courses.id,
                       intern_subject.abbreviation,
                       intern_subject.description
                FROM intern_courses
                INNER JOIN intern_subject
                    ON intern_courses.subject_id = intern_subject.id
                ORDER BY intern_subject.description ASC, intern_courses.course_num ASC";


        $sth = $pdo->prepare($sql);
        $sth->execute();
        $result = $sth->fetchAll(\PDO::FETCH_ASSOC);

        return $result;
    }
}