<?php
// check the input 患者预约挂号 在medicalrecord里记录下来 
function check($value)
{
    if (get_magic_quotes_gpc()) {
        $value = htmlspecialchars(trim($value));
    } else {
        $value = addslashes(htmlspecialchars(trim($value)));
    }
    return $value;
}

session_start();

if (!isset($_SESSION['username']) or !isset($_SESSION['identity']) or $_SESSION['identity'] != 0) {
    header("Location:login.php");
    exit();
}
date_default_timezone_set('PRC'); //北京时间
$username = $_SESSION['username'];
$Sno = check($_POST['Sno']);
$operation = $_POST['operation_choice'];

if ($operation == 1) {  // select
    if ($Sno == "") {
        echo "
            <script>
                alert('未选择号源!!');
                window.location.href = 'patient_schedule.php';
            </script>
	    ";
        exit();
    } else {
        $db = @mysqli_connect("localhost", "root", "123456", "MIS");
        if (!$db) {
            die("Fail to connect the database!!" . mysqli_connect_error());
        }
        mysqli_query($db, "begin");
        mysqli_query($db, "set names utf8");

        $check_MedicalRecord = mysqli_query($db, "SELECT * FROM MedicalRecord WHERE Sno='$Sno' AND Pno='$username' for update");
        if (mysqli_fetch_array($check_MedicalRecord)) {
            mysqli_query($db, "commit");
			mysqli_close($db);
            echo "
                <script>
                    alert('该号已预约成功，无需重复预约！');
                    window.location.href = 'patient_schedule.php';
                </script>
            ";
            exit();
        }

        //别人已约的号不能再约
        $check_Sno = mysqli_query($db, "SELECT * FROM Schedule WHERE Sno='$Sno' for update");
        $schedule_info = mysqli_fetch_array($check_Sno);
        if ($schedule_info) {
            $appointed = $schedule_info['AppointedOrNot'];
            if (!strcmp("已约",$appointed)) { //这里应该appointed不用引号？
                mysqli_query($db, "commit");
                mysqli_close($db);
                echo "
                    <script>
                        alert('该号已被他人预约！！');
                        window.location.href = 'patient_schedule.php';
                    </script>
                ";
                exit();
            } else {
                $result1 = mysqli_query($db, " UPDATE Schedule SET AppointedOrNot = '已约' WHERE Sno='$Sno' ");
                $Dno = $schedule_info['Dno'];
                $result2 = mysqli_query($db, "INSERT INTO MedicalRecord(Pno, Sno,Dno) VALUES ('$username', '$Sno','$Dno')"); //还有Dno
                $result3 = mysqli_query($db, "INSERT INTO Prescription(Pno, Sno) VALUES ('$username', '$Sno')");
                if ($result1 && $result2 && $result3) {
                    mysqli_query($db, "commit");
                    mysqli_close($db);
                    echo "
                        <script>
                            alert('挂号成功！！');
                            window.location.href = 'patient_schedule.php';
                        </script>
                    ";
                    exit();
                } else {
                    echo '挂号失败！！', mysqli_error($db), '<br />';
                    echo 'Click here to <a href="javascript:history.back(-1);">go back</a> and retry..';
                    mysqli_query($db, "rollback");
                    mysqli_close($db);
                    exit();
                }
            }    
        } else {
            mysqli_query($db, "commit");
			mysqli_close($db);
            echo "
                <script>
                    alert('该号源不存在！！');
                    window.location.href = 'patient_schedule.php';
                </script>
            ";
            exit();
        }
    }
} elseif ($operation == -1) {   // withdraw 撤销预约挂号
    if ($Sno == "") {
        echo "
            <script>
                alert('未选择号源！！');
                window.location.href = 'patient_schedule.php';
            </script>
	    ";
        exit();
    } else {
        $db = @mysqli_connect("localhost", "root", "123456", "MIS");
        if (!$db) {
            die("Fail to connect the database!!" . mysqli_connect_error());
        }
        mysqli_query($db, "begin");
        mysqli_query($db, "set names utf8");
        

        $check_MedicalRecord = mysqli_query($db, "SELECT * FROM MedicalRecord WHERE Sno='$Sno' AND Pno='$username' for update");
        $medicalrecord = mysqli_fetch_array($check_MedicalRecord);

        $current_time = date("y-m-d h:i:s");
        $check_time = mysqli_query($db, "SELECT * FROM Schedule WHERE Sno='$Sno' for update");
        $schedule_info = mysqli_fetch_array($check_time);
        $start_time =  $schedule_info['StartTime'];
        if ($medicalrecord) {
            if (strtotime($current_time)>= strtotime($start_time) ) {
                mysqli_query($db, "commit");
                mysqli_close($db);
                echo "
                    <script>
                        alert('当前时间晚于预约时间，该预约已经无法撤销！！');
                        window.location.href = 'patient_schedule.php';
                    </script>
                ";
                exit();
            } // 可能还有点问题 主要是mysql timestamp，不知道能不能用strtotime
            $result1 = mysqli_query($db, "UPDATE Schedule SET AppointedOrNot ='未约' WHERE Sno='$Sno'");
            $result2 = mysqli_query($db, "DELETE FROM MedicalRecord WHERE Sno='$Sno' AND Pno='$username'");
            $result3 = mysqli_query($db, "DELETE FROM Prescription WHERE Sno='$Sno' AND Pno='$username'");
            if ($result1 && $result2) {
                mysqli_query($db, "commit");
                mysqli_close($db);
                echo "
                    <script>
                        alert('预约取消成功！！');
                        window.location.href = 'patient_schedule.php';
                    </script>
                ";
                exit();
            } else {
                echo '取消失败！！', mysqli_error($db), '<br />';
                echo 'Click here to <a href="javascript:history.back(-1);">go back</a> and retry..';
                mysqli_query($db, "rollback");
                mysqli_close($db);
                exit();
            }
        } else {
            mysqli_query($db, "commit");
			mysqli_close($db);
            echo "
                <script>
                    alert('相应挂号信息不存在！！');
                    window.location.href = 'patient_schedule.php';
                </script>
            ";
            exit();
        }
    }
}
?>