/**
 * @file
 * @brief command line tool that sends a BACnet service to the network:
 * You-Are message
 * @author Steve Karg <skarg@users.sourceforge.net>
 * @date June 2025
 * @copyright SPDX-License-Identifier: MIT
 */
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h> /* for time */
/* BACnet Stack defines - first */
#include "bacnet/bacdef.h"
/* BACnet Stack API */
#include "bacnet/bactext.h"
#include "bacnet/youare.h"
#include "bacnet/whoami.h"
#include "bacnet/npdu.h"
#include "bacnet/apdu.h"
#include "bacnet/version.h"
/* some demo stuff needed */
#include "bacnet/basic/binding/address.h"
#include "bacnet/basic/object/device.h"
#include "bacnet/basic/sys/filename.h"
#include "bacnet/basic/sys/mstimer.h"
#include "bacnet/basic/services.h"
#include "bacnet/basic/tsm/tsm.h"
#include "bacnet/datalink/datalink.h"
#include "bacnet/datalink/dlenv.h"

/* buffer used for receive */
static uint8_t Rx_Buf[MAX_MPDU] = { 0 };

/* parsed command line parameters */
static uint32_t Target_Device_ID = BACNET_MAX_INSTANCE;
static uint16_t Target_Vendor_ID;
static BACNET_OCTET_STRING Target_MAC_Address;
static BACNET_CHARACTER_STRING Target_Model_Name;
static BACNET_CHARACTER_STRING Target_Serial_Number;
static bool Target_Send_You_Are_Approved;
static BACNET_ADDRESS Target_Destination_Address;

/* flag for signalling errors */
static bool Error_Detected = false;

static void MyAbortHandler(
    BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t abort_reason, bool server)
{
    (void)src;
    (void)server;
    printf(
        "BACnet Abort[%u]: %s\n", (unsigned)invoke_id,
        bactext_abort_reason_name(abort_reason));
    Error_Detected = true;
}

static void
MyRejectHandler(BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t reject_reason)
{
    (void)src;
    printf(
        "BACnet Reject[%u]: %s\n", (unsigned)invoke_id,
        bactext_reject_reason_name(reject_reason));
    Error_Detected = true;
}

/**
 * A basic handler for Who-Am-I responses.
 * @param service_request [in] The received message to be handled.
 * @param service_len [in] Length of the service_request message.
 * @param src [in] The BACNET_ADDRESS of the message's source.
 */
static void My_Who_Am_I_Handler(
    uint8_t *service_request, uint16_t service_len, BACNET_ADDRESS *src)
{
    int len = 0;
    uint16_t vendor_id = 0;
    BACNET_CHARACTER_STRING model_name = { 0 };
    BACNET_CHARACTER_STRING serial_number = { 0 };

    (void)src;
    len = who_am_i_request_decode(
        service_request, service_len, &vendor_id, &model_name, &serial_number);
    if (len > 0) {
        printf("Who-Am-I Requested.\n");
        if ((Target_Vendor_ID == vendor_id) &&
            characterstring_same(&Target_Model_Name, &model_name) &&
            characterstring_same(&Target_Serial_Number, &serial_number)) {
            bacnet_address_copy(&Target_Destination_Address, src);
            Target_Send_You_Are_Approved = true;
        }
    }

    return;
}

/**
 * @brief Initialize the BACnet service handlers that this application
 *  needs to use.
 */
static void Init_Service_Handlers(void)
{
    Device_Init(NULL);
    /* we need to handle who-is
       to support dynamic device binding to us */
    apdu_set_unconfirmed_handler(SERVICE_UNCONFIRMED_WHO_IS, handler_who_is);
    /* set the handler for all the services we don't implement
       It is required to send the proper reject message... */
    apdu_set_unrecognized_service_handler_handler(handler_unrecognized_service);
    /* we must implement read property - it's required! */
    apdu_set_confirmed_handler(
        SERVICE_CONFIRMED_READ_PROPERTY, handler_read_property);
    /* handle the reply (request) coming back */
    apdu_set_unconfirmed_handler(
        SERVICE_UNCONFIRMED_WHO_AM_I, My_Who_Am_I_Handler);
    /* handle any errors coming back */
    apdu_set_abort_handler(MyAbortHandler);
    apdu_set_reject_handler(MyRejectHandler);
}

static void print_usage(const char *filename)
{
    printf(
        "Usage: %s [device-instance vendor-id model-name serial [MAC]]\n",
        filename);
    printf("       [--whois]\n");
    printf("       [--dnet][--dadr][--mac]\n");
    printf("       [--version][--help]\n");
}

static void print_help(const char *filename)
{
    printf("Send BACnet You-Are message to the network.\n");
    printf("--whois\n"
           "Optionally send a Who-Is request to 4194303 to elicit Who-Am-I.\n");
    printf("--mac A\n"
           "Optional BACnet mac address."
           "Valid ranges are from 00 to FF (hex) for MS/TP or ARCNET,\n"
           "or an IP string with optional port number like 10.1.2.3:47808\n"
           "or an Ethernet MAC in hex like 00:21:70:7e:32:bb\n");
    printf("\n");
    printf("--dnet N\n"
           "Optional BACnet network number N for directed requests.\n"
           "Valid range is from 0 to 65535 where 0 is the local connection\n"
           "and 65535 is network broadcast.\n");
    printf("\n");
    printf("--dadr A\n"
           "Optional BACnet mac address on the destination BACnet network "
           "number.\n"
           "Valid ranges are from 00 to FF (hex) for MS/TP or ARCNET,\n"
           "or an IP string with optional port number like 10.1.2.3:47808\n"
           "or an Ethernet MAC in hex like 00:21:70:7e:32:bb\n");
    printf("\n");
    printf("--repeat\n"
           "Send the message repeatedly until signalled to quit.\n"
           "Default is to not repeat, sending only a single message.\n");
    printf("\n");
    printf("--retry C\n"
           "Send the message C number of times\n"
           "Default is retry 0, only sending one time.\n");
    printf("\n");
    printf("--delay\n"
           "Delay, in milliseconds, between repeated messages.\n"
           "Default delay is 100ms.\n");
    printf("\n");
    printf("device-instance:\n"
           "the Device Object_Identifier to be assigned in the qualified\n"
           "device. BACnet device-ID 0..4194302\n");
    printf("\n");
    printf("vendor-id:\n"
           "the identity of the vendor of the device that is qualified\n"
           "to receive this You-Are service request.\n");
    printf("\n");
    printf("model-name:\n"
           "the model name of the device qualified to receive the\n"
           "You-Are service request.\n");
    printf("\n");
    printf("serial:\n"
           "the serial number of the device qualified to receive the\n"
           "You-Are service request.\n");
    printf("MAC:\n");
    printf("the device MAC address that is to be configured in the\n"
           "qualified device. Either the device-instance,\n"
           "or MAC, or both, shall be present. Accepts ASCII hexidecimal.");
    printf("\n");
    printf(
        "Example:\n"
        "To send a You-Are message of instance=1234 vendor-id=260\n"
        "model-name 456 serial-number 789 MAC 0F to the network:\n"
        "%s 1234 260 456 789 0F\n",
        filename);
}

int main(int argc, char *argv[])
{
    BACNET_ADDRESS src = { 0 }; /* address where message came from */
    uint16_t pdu_len = 0;
    long dnet = -1;
    BACNET_MAC_ADDRESS mac = { 0 };
    BACNET_MAC_ADDRESS adr = { 0 };
    BACNET_ADDRESS dest = { 0 };
    bool specific_address = false;
    bool repeat_forever = false;
    bool send_whois = false;
    unsigned timeout = 100; /* milliseconds */
    int argi = 0;
    unsigned int target_args = 0;
    const char *filename = NULL;
    long retry_count = 0;
    struct mstimer apdu_timer = { 0 };

    filename = filename_remove_path(argv[0]);
    for (argi = 1; argi < argc; argi++) {
        if (strcmp(argv[argi], "--help") == 0) {
            print_usage(filename);
            print_help(filename);
            return 0;
        }
        if (strcmp(argv[argi], "--version") == 0) {
            printf("%s %s\n", filename, BACNET_VERSION_TEXT);
            printf("Copyright (C) 2025 by Steve Karg and others.\n"
                   "This is free software; see the source for copying "
                   "conditions.\n"
                   "There is NO warranty; not even for MERCHANTABILITY or\n"
                   "FITNESS FOR A PARTICULAR PURPOSE.\n");
            return 0;
        }
        if (strcmp(argv[argi], "--mac") == 0) {
            if (++argi < argc) {
                if (bacnet_address_mac_from_ascii(&mac, argv[argi])) {
                    specific_address = true;
                }
            }
        } else if (strcmp(argv[argi], "--dnet") == 0) {
            if (++argi < argc) {
                if (!bacnet_strtol(argv[argi], &dnet)) {
                    fprintf(stderr, "dnet=%s invalid\n", argv[argi]);
                    return 1;
                }
                if ((dnet >= 0) && (dnet <= BACNET_BROADCAST_NETWORK)) {
                    specific_address = true;
                }
            }
        } else if (strcmp(argv[argi], "--dadr") == 0) {
            if (++argi < argc) {
                if (bacnet_address_mac_from_ascii(&adr, argv[argi])) {
                    specific_address = true;
                }
            }
        } else if (strcmp(argv[argi], "--whois") == 0) {
            send_whois = true;
        } else if (strcmp(argv[argi], "--repeat") == 0) {
            repeat_forever = true;
        } else if (strcmp(argv[argi], "--retry") == 0) {
            if (++argi < argc) {
                retry_count = strtol(argv[argi], NULL, 0);
                if (retry_count < 0) {
                    retry_count = 0;
                }
            }
        } else if (strcmp(argv[argi], "--delay") == 0) {
            if (++argi < argc) {
                timeout = strtol(argv[argi], NULL, 0);
            }
        } else {
            if (target_args == 0) {
                Target_Device_ID = strtol(argv[argi], NULL, 0);
                target_args++;
            } else if (target_args == 1) {
                Target_Vendor_ID = strtol(argv[argi], NULL, 0);
                target_args++;
            } else if (target_args == 2) {
                characterstring_init_ansi(&Target_Model_Name, argv[argi]);
                target_args++;
            } else if (target_args == 3) {
                characterstring_init_ansi(&Target_Serial_Number, argv[argi]);
                target_args++;
            } else if (target_args == 4) {
                octetstring_init_ascii_hex(&Target_MAC_Address, argv[argi]);
                target_args++;
            } else {
                print_usage(filename);
                return 1;
            }
        }
    }
    if (specific_address) {
        if ((dnet < 0) || (dnet > BACNET_BROADCAST_NETWORK)) {
            if (adr.len && mac.len) {
                dnet = BACNET_BROADCAST_NETWORK;
            } else if (mac.len) {
                dnet = 0;
            } else {
                dest.net = BACNET_BROADCAST_NETWORK;
            }
        }
        bacnet_address_init(&dest, &mac, dnet, &adr);
    } else {
        datalink_get_broadcast_address(&dest);
    }
    /* setup my info */
    Device_Set_Object_Instance_Number(BACNET_MAX_INSTANCE);
    Init_Service_Handlers();
    dlenv_init();
    atexit(datalink_cleanup);
    /* send the request */
    if (send_whois) {
        mstimer_set(&apdu_timer, apdu_timeout() * apdu_retries());
        Send_WhoIs_To_Network(&dest, BACNET_MAX_INSTANCE, BACNET_MAX_INSTANCE);
    } else {
        bacnet_address_copy(&Target_Destination_Address, &dest);
        Target_Send_You_Are_Approved = true;
    }
    do {
        if (Target_Send_You_Are_Approved) {
            Send_You_Are_To_Network(
                &dest, Target_Device_ID, Target_Vendor_ID, &Target_Model_Name,
                &Target_Serial_Number, &Target_MAC_Address);
            if (send_whois) {
                break;
            }
        }
        if (repeat_forever || retry_count || mstimer_interval(&apdu_timer)) {
            /* returns 0 bytes on timeout */
            pdu_len = datalink_receive(&src, &Rx_Buf[0], MAX_MPDU, timeout);
            /* process */
            if (pdu_len) {
                npdu_handler(&src, &Rx_Buf[0], pdu_len);
            }
            if (Error_Detected) {
                break;
            }
            if (retry_count > 0) {
                retry_count--;
            }
        }
    } while (repeat_forever || retry_count || !mstimer_expired(&apdu_timer));

    return 0;
}