<?php
/* 
    * Use Case: Untuk API antara BISONE dengan DCM4CHE PACS Server
    * Location: PACS Server /data/docker/nv/html/ApiPacs.php
    * Input: JSON
    * Proses: HL7 ke DCM4CHE
    * Return: JSON
    * Version: 1.0
    * Date: 2024-12-13
*/
header('Content-Type: application/json');

// Entry point
require_once 'ApiPacs.php';

// Create an instance and route the request
$apiPacs = new ApiPacs();
$apiPacs->route();


class ApiPacs
{
    private $dcmHost = '128.199.154.150';
    private $dcmPort = 2575;

    public function route()
    {
        $path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
        $action = basename($path);

        if (method_exists($this, $action)) {
            $this->$action();
        } else {
            http_response_code(404);
            $this->sys_error("Endpoint not found");
        }
    }

    public function sendOrder()
    {
        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
            try {
                $json = file_get_contents('php://input');
                $payload = json_decode($json, true);

                if (!$payload) {
                    http_response_code(400);
                    $this->sys_error("Invalid JSON");
                    exit;
                }

                $hl7json = $this->mapToXml($payload, "XO"); // XO = Send Order

                $hl7Message = $this->mapToHL7($hl7json);

                $result = $this->sendHL7($hl7Message, $this->dcmHost, $this->dcmPort);

                $this->sys_ok([
                    'accession_no' => $payload['accession_no'],
                    'study_instance_uid' => $payload['study_instance_uid'],
                    'hl7_response' => $result,
                ], "Successfully sent order");
            } catch (\Exception $e) {
                $this->sys_error($e->getMessage());
                exit;
            }
        } else {
            http_response_code(405);
            $this->sys_error("Method not allowed");
            exit;
        }
    }

    public function cancelOrder()
    {
        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
            try {
                // Get the raw POST data
                $json = file_get_contents('php://input');
                $payload = json_decode($json, true);

                if (!$payload) {
                    http_response_code(400);
                    $this->sys_error("Invalid JSON");
                    exit;
                }

                $hl7json = $this->mapToXml($payload, "CA"); // CA = Cancel Order

                $hl7Message = $this->mapToHL7($hl7json);

                $result = $this->sendHL7($hl7Message, $this->dcmHost, $this->dcmPort);

                $this->sys_ok([
                    'accession_no' => $payload['accession_no'],
                    'study_instance_uid' => $payload['study_instance_uid'],
                    'hl7_response' => $result,
                ], "Successfully canceled order");
            } catch (\Exception $e) {
                $this->sys_error($e->getMessage());
                exit;
            }
        } else {
            http_response_code(405);
            $this->sys_error("Method not allowed");
            exit;
        }
    }

    private function mapToXml($payload, $act)
    {
        // Extract variables from JSON payload
        $DepartemenID = isset($payload['departemen_id']) ? $payload['departemen_id'] : "";
        $message_seq_id = "2006 - 1010";
        $patient_mrn = isset($payload['patient_mrn']) ? $payload['patient_mrn'] : "";
        $patient_nm = isset($payload['patient_nm']) ? $payload['patient_nm'] : "";
        $patient_birth_dt = isset($payload['patient_birth_dt']) ? $payload['patient_birth_dt'] : "";
        $patient_gender = isset($payload['patient_gender']) ? $payload['patient_gender'] : "";
        $referring_physician_id = isset($payload['referring_physician_id']) ? $payload['referring_physician_id'] : "";
        $referring_physician_nm = isset($payload['referring_physician_nm']) ? $payload['referring_physician_nm'] : "";
        $admission_dttm = isset($payload['admission_dttm']) ? $payload['admission_dttm'] : "";
        $admission_id = isset($payload['admission_id']) ? $payload['admission_id'] : "";
        $ordering_physician_id = isset($payload['ordering_physician_id']) ? $payload['ordering_physician_id'] : "";
        $ordering_physician_nm = isset($payload['ordering_physician_nm']) ? $payload['ordering_physician_nm'] : "";
        $NamaDepartemen = isset($payload['nama_departemen']) ? $payload['nama_departemen'] : "";
        $placer_order_id = isset($payload['placer_order_id']) ? $payload['placer_order_id'] : "";
        $filler_order_id = isset($payload['filler_order_id']) ? $payload['filler_order_id'] : "";
        $procedure_cd = isset($payload['procedure_cd']) ? $payload['procedure_cd'] : "";
        $procedure_nm = isset($payload['procedure_nm']) ? $payload['procedure_nm'] : "";
        $order_dttm = isset($payload['order_dttm']) ? $payload['order_dttm'] : "";
        $accession_no = isset($payload['accession_no']) ? $payload['accession_no'] : "";
        $requested_proc_id = isset($payload['requested_proc_id']) ? $payload['requested_proc_id'] : "";
        $scheduled_proc_step_id = isset($payload['scheduled_proc_step_id']) ? $payload['scheduled_proc_step_id'] : "";
        $modality_cd = isset($payload['modality_cd']) ? $payload['modality_cd'] : "";
        $study_instance_uid = isset($payload['study_instance_uid']) ? $payload['study_instance_uid'] : "";
        $scheduled_station_ae = isset($payload['scheduled_station_ae']) ? $payload['scheduled_station_ae'] : "";
        $scheduled_station_name = isset($payload['scheduled_station_name']) ? $payload['scheduled_station_name'] : "";
        $trxLayananID = isset($payload['trx_layanan_id']) ? $payload['trx_layanan_id'] : "";

        $hl7json = [
            "MSH" => [
                "MSH.3.1" => "HIMS", // Sending Application ID
                "MSH.4.1" => $DepartemenID, // Sending Facility ID 
                "MSH.5.1" => "ABPACS", // Receiving Application ID
                "MSH.6.1" => "RAD", // Receiving Facility ID
                "MSH.7.1" => $this->getCurrentDate("YmdHis"),
                "MSH.10" => $message_seq_id, /// Messeage Sequence ID
            ],
            "PID" => [
                "PID.3.1" => $patient_mrn,
                "PID.5.1" => $patient_nm,
                "PID.7.1" => date("Ymd", strtotime($patient_birth_dt)),
                "PID.8.1" => $patient_gender,
                "PID.10.1" => "2038-8",
                "PID.11.1" => "", // Street Address
                "PID.11.2" => "", // Other Designation
                "PID.11.3" => "", // City
                "PID.11.4" => "", // State or Province
                "PID.11.5" => "", // Zip Code
                "PID.13.1" => "", // Phone Number
                "PID.18.1" => "", // Patient Account Number
            ],
            "PV1" => [
                "PV1.8.1" => $referring_physician_id,
                "PV1.8.2" => $referring_physician_nm,
                "PV1.44.1" => date("YmdHis", strtotime($admission_dttm)),
                "PV1.19.1" => $admission_id, // (0038,0010) Admission ID / RegID
                "PV1.19.4" => "RSAB", // (0038,0011) Issuer of Admission ID
            ],
            "ORC" => [
                "ORC.1.1" => $act, // Action Code
                "ORC.2.1" => $placer_order_id, // Placer Order Number
                "ORC.2.2" => "HIMS", // Placer Order Application Name
                "ORC.3.1" => $filler_order_id, // Filler Order Number
                "ORC.3.2" => "", // Filler Order Application Name
                "ORC.10.1" => "", // User ID created
                "ORC.10.2" => "", // User last name who created
                "ORC.10.3" => "", // User first name who created
                "ORC.12.1" => $ordering_physician_id, // Ordering physician ID
                "ORC.12.2" => $ordering_physician_nm, // Ordering physician name
                "ORC.12.3" => "", // Given name
                "ORC.12.4" => "", // Middle initial
                "ORC.12.5" => "", // Suffix
                "ORC.12.6" => "", // Prefix
                "ORC.13.1" => $NamaDepartemen, // Enterer's point of care
                "ORC.14.1" => "", // Call back phone number
                "ORC.15.1" => "", // Order effective datetime
                "ORC.21.1" => $NamaDepartemen, // Enterer's location
            ],
            "OBR" => [
                "OBR.2.1" => $placer_order_id, // Placer Order Number
                "OBR.2.2" => "HIMS", // Placer Order Number Namespace ID
                "OBR.3.1" => $filler_order_id, // Filler Order Number
                "OBR.3.2" => "", // Filler Order Number Namespace ID
                "OBR.4.1" => $procedure_cd, // Service ID
                "OBR.4.2" => $procedure_nm, // Service Name
                "OBR.4.3" => "RSABPRC", // Coding for Service Identifier
                "OBR.4.4" => $procedure_cd, // Alternate Service ID
                "OBR.4.5" => $procedure_nm, // Alternate Service Name
                "OBR.4.6" => "L", // Name of Alternate Coding System
                "OBR.6.1" => date("YmdHis", strtotime($order_dttm)), // Order Request Datetime
                "OBR.16.1" => $ordering_physician_id, // Ordering physician ID
                "OBR.16.2" => $ordering_physician_nm, // Ordering physician name
                "OBR.18.1" => $accession_no, // Accession Number
                "OBR.19.1" => $trxLayananID, // Requested Procedure ID
                "OBR.20.1" => $scheduled_proc_step_id, // Scheduled Procedure Step ID
                "OBR.24.1" => $modality_cd, // Modality Code
                "OBR.44.1" => $procedure_cd, // Procedure Code
                "OBR.44.2" => $procedure_nm, // Study Description
                "OBR.44.3" => "RSAB-PCS", // Procedure Coding System
            ],
            "ZDS" => [
                "ZDS.1.1" => $study_instance_uid, // (0020,000D) Study Instance UID
                "ZDS.2.1" => $scheduled_station_ae, // (0040,0001) Scheduled Station AE Title
                "ZDS.3.1" => $scheduled_station_name, /// (0040,0010) Scheduled Station Name
            ],
            "TQ1" => [
                "TQ1.7.1" => date("YmdHis", strtotime($order_dttm)),
                "TQ1.9.1" => "S", // Priority S = Stat, A = ASAP
                "TQ1.12.1" => "C", // C = Time is Actuation Time
            ],
        ];

        return $hl7json;
    }

    private function mapToHL7($hl7json)
    {
        $segments = [];

        // MSH Segment
        $segments[] = "MSH|^~\\&|" .
            $hl7json["MSH"]["MSH.3.1"] . "|" .
            $hl7json["MSH"]["MSH.4.1"] . "|" .
            $hl7json["MSH"]["MSH.5.1"] . "|" .
            $hl7json["MSH"]["MSH.6.1"] . "|" .
            $hl7json["MSH"]["MSH.7.1"] . "||" .
            "ORM^O01|" .
            $hl7json["MSH"]["MSH.10"] . "|P|2.3.1";

        // PID Segment
        $segments[] = "PID|||" .
            $hl7json["PID"]["PID.3.1"] . "^^^ADT1||" .
            $hl7json["PID"]["PID.5.1"] . "||" .
            $hl7json["PID"]["PID.7.1"] . "|" .
            $hl7json["PID"]["PID.8.1"] . "||" .
            $hl7json["PID"]["PID.10.1"] . "|" .
            implode("^", [
                $hl7json["PID"]["PID.11.1"],
                $hl7json["PID"]["PID.11.2"],
                $hl7json["PID"]["PID.11.3"],
                $hl7json["PID"]["PID.11.4"],
                $hl7json["PID"]["PID.11.5"]
            ]) . "|" .
            $hl7json["PID"]["PID.13.1"] . "|" .
            $hl7json["PID"]["PID.18.1"];

        // PV1 Segment
        $segments[] = "PV1||O||||||" .
            $hl7json["PV1"]["PV1.8.1"] . "^" .
            $hl7json["PV1"]["PV1.8.2"] . "|||||||||||" .
            $hl7json["PV1"]["PV1.19.1"] . "^^^" .
            $hl7json["PV1"]["PV1.19.4"] . "||||||||" .
            $hl7json["PV1"]["PV1.44.1"];

        // ORC Segment
        $segments[] = "ORC|" . $hl7json["ORC"]["ORC.1.1"] . "|" .
            $hl7json["ORC"]["ORC.2.1"] . "^" . $hl7json["ORC"]["ORC.2.2"] . "|" .
            $hl7json["ORC"]["ORC.3.1"] . "^" . $hl7json["ORC"]["ORC.3.2"] . "||||||||" .
            $hl7json["ORC"]["ORC.10.1"] . "^" .
            $hl7json["ORC"]["ORC.10.2"] . "^" .
            $hl7json["ORC"]["ORC.10.3"] . "|||" .
            $hl7json["ORC"]["ORC.12.1"] . "^" .
            $hl7json["ORC"]["ORC.12.2"] . "^" .
            $hl7json["ORC"]["ORC.12.3"] . "^" .
            $hl7json["ORC"]["ORC.12.4"] . "^" .
            $hl7json["ORC"]["ORC.12.5"] . "^" .
            $hl7json["ORC"]["ORC.12.6"] . "|" .
            $hl7json["ORC"]["ORC.13.1"];

        // OBR Segment
        $segments[] = "OBR|1|" .
            $hl7json["OBR"]["OBR.2.1"] . "^" . $hl7json["OBR"]["OBR.2.2"] . "|" .
            $hl7json["OBR"]["OBR.3.1"] . "^" . $hl7json["OBR"]["OBR.3.2"] . "|" .
            $hl7json["OBR"]["OBR.4.1"] . "^" .
            $hl7json["OBR"]["OBR.4.2"] . "^" .
            $hl7json["OBR"]["OBR.4.3"] . "^" .
            $hl7json["OBR"]["OBR.4.4"] . "^" .
            $hl7json["OBR"]["OBR.4.5"] . "^" .
            $hl7json["OBR"]["OBR.4.6"] . "||" .
            $hl7json["OBR"]["OBR.6.1"] . "||||||||" .
            $hl7json["OBR"]["OBR.16.1"] . "^" .
            $hl7json["OBR"]["OBR.16.2"] . "||||" .
            $hl7json["OBR"]["OBR.18.1"] . "|" .
            $hl7json["OBR"]["OBR.19.1"] . "|" .
            $hl7json["OBR"]["OBR.20.1"] . "|||||||||" .
            $hl7json["OBR"]["OBR.24.1"] . "|||||||" .
            $hl7json["OBR"]["OBR.44.1"] . "^" .
            $hl7json["OBR"]["OBR.44.2"] . "^" .
            $hl7json["OBR"]["OBR.44.3"];

        // ZDS Segment
        $segments[] = "ZDS|" .
            $hl7json["ZDS"]["ZDS.1.1"] . "^100^Application^DICOM|" .
            $hl7json["ZDS"]["ZDS.2.1"] . "|" .
            $hl7json["ZDS"]["ZDS.3.1"];

        // TQ1 Segment
        $segments[] = "TQ1|||||||" .
            $hl7json["TQ1"]["TQ1.7.1"] . "||" .
            $hl7json["TQ1"]["TQ1.9.1"] . "|||" .
            $hl7json["TQ1"]["TQ1.12.1"];

        // Join all segments with newline
        return implode("\n", $segments);
    }

    private function sendHL7($hl7Message, $host, $port)
    {
        // MLLP delimiters
        define('MLLP_START', "\x0b"); // <VT>
        define('MLLP_END', "\x1c\x0d"); // <FS><CR>

        $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
        if ($socket === false) {
            $this->sys_error("Socket creation failed: " . socket_strerror(socket_last_error()));
            exit;
        }

        $result = socket_connect($socket, $host, $port);
        if ($result === false) {
            $this->sys_error("Connection failed: " . socket_strerror(socket_last_error()));
            exit;
        }

        // Wrap message in MLLP container
        $mlllpMessage = MLLP_START . $hl7Message . MLLP_END;

        // Send message
        $sentBytes = socket_write($socket, $mlllpMessage, strlen($mlllpMessage));
        if ($sentBytes === false) {
            $this->sys_error("Send failed: " . socket_strerror(socket_last_error()));
            exit;
        }

        $response = '';
        socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, ["sec" => 5, "usec" => 0]); // Set timeout

        while (($buf = socket_read($socket, 1024))) {
            $response .= $buf;

            if (strpos($response, MLLP_END)) {
                break;
            }
        }

        $returned = '';
        if (strpos($response, "MSA|AA") !== false) {
            $returned = "Application Accepted"; // Acknowledgment Accepted
        } elseif (strpos($response, "MSA|AR") !== false) {
            $returned = "Application Rejected"; // Acknowledgment Rejected
        } elseif (strpos($response, "MSA|AE") !== false) {
            $returned = "Application Error"; // Application Error
        } else {
            $returned = "Unknown Response"; // In case none of the expected segments are found
        }

        return $returned;
    }

    public function getCurrentDate($format)
    {
        return date($format);
    }

    public function sys_ok($data, $message = "")
    {
        $result = array(
            'status' => 'OK',
            'message' => $message,
            'data' => $data
        );
        echo json_encode($result);
    }

    public function sys_error($message)
    {
        $result = array(
            'status' => 'ERROR',
            'message' => $message,
            'data' => ''
        );
        echo json_encode($result);
    }
}