/**
 * @file
 * @brief command line tool that sends a BACnet Who-Has request to devices,
 * and prints any I-Have responses received.  This is useful for finding
 * devices on the network, or for finding devices that support a particular
 * object type and instance range.
 * @author Steve Karg <skarg@users.sourceforge.net>
 * @date 2006
 * @copyright SPDX-License-Identifier: MIT
 */
#include <stddef.h>
#include <stdint.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/iam.h"
#include "bacnet/arf.h"
#include "bacnet/npdu.h"
#include "bacnet/apdu.h"
#include "bacnet/whohas.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/services.h"
#include "bacnet/basic/tsm/tsm.h"
#include "bacnet/datalink/datalink.h"
#include "bacnet/datalink/dlenv.h"
#include "bacport.h"

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

/* global variables used in this file */
static BACNET_OBJECT_TYPE Target_Object_Type = MAX_BACNET_OBJECT_TYPE;
static uint32_t Target_Object_Instance = BACNET_MAX_INSTANCE;
static char *Target_Object_Name = NULL;
static int32_t Target_Object_Instance_Min = -1;
static int32_t Target_Object_Instance_Max = -1;

static bool Error_Detected = false;

static void MyAbortHandler(
    BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t abort_reason, bool server)
{
    /* FIXME: verify src and invoke id */
    (void)src;
    (void)invoke_id;
    (void)server;
    printf("BACnet Abort: %s\r\n", bactext_abort_reason_name(abort_reason));
    Error_Detected = true;
}

static void
MyRejectHandler(BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t reject_reason)
{
    /* FIXME: verify src and invoke id */
    (void)src;
    (void)invoke_id;
    printf("BACnet Reject: %s\r\n", bactext_reject_reason_name(reject_reason));
    Error_Detected = true;
}

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_I_HAVE, handler_i_have);
    /* 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-min device-instance-min] "
        "<object-type object-instance | object-name> [--help]\r\n",
        filename);
}

static void print_help(const char *filename)
{
    print_usage(filename);
    printf(
        "Send BACnet WhoHas request to devices, \r\n"
        "and wait %u milliseconds (BACNET_APDU_TIMEOUT) for responses.\r\n"
        "The device-instance-min or max can be 0 to %d.\r\n"
        "\r\n"
        "Use either:\r\n"
        "The object-type can be 0 to %d, or a string e.g. analog-output.\r\n"
        "The object-instance can be 0 to %d.\r\n"
        "or:\r\n"
        "The object-name can be any string of characters.\r\n",
        BACNET_MAX_INSTANCE, (unsigned)apdu_timeout(), BACNET_MAX_OBJECT,
        BACNET_MAX_INSTANCE);
}

int main(int argc, char *argv[])
{
    BACNET_ADDRESS src = { 0 }; /* address where message came from */
    uint16_t pdu_len = 0;
    unsigned timeout = 100; /* milliseconds */
    time_t elapsed_seconds = 0;
    time_t last_seconds = 0;
    time_t current_seconds = 0;
    time_t timeout_seconds = 0;
    int argi = 0;
    unsigned object_type = 0;
    bool by_name = false;

    if (argc < 2) {
        print_usage(filename_remove_path(argv[0]));
        return 0;
    }
    /* print help if requested */
    for (argi = 1; argi < argc; argi++) {
        if (strcmp(argv[argi], "--help") == 0) {
            print_help(filename_remove_path(argv[0]));
            return 0;
        }
    }
    /* decode the command line parameters */
    if (argc < 3) {
        /* bacwh "name" */
        Target_Object_Instance_Min = Target_Object_Instance_Max = -1;
        Target_Object_Name = argv[1];
        by_name = true;
    } else if (argc < 4) {
        /* bacwh 8 1234 */
        Target_Object_Instance_Min = Target_Object_Instance_Max = -1;
        if (bactext_object_type_strtol(argv[1], &object_type) == false) {
            fprintf(stderr, "object-type=%s invalid\n", argv[1]);
            return 1;
        }
        Target_Object_Type = object_type;
        Target_Object_Instance = strtol(argv[2], NULL, 0);
    } else if (argc < 5) {
        /* bacwh 0 4194303 "name" */
        Target_Object_Instance_Min = strtol(argv[1], NULL, 0);
        Target_Object_Instance_Max = strtol(argv[2], NULL, 0);
        Target_Object_Name = argv[3];
        by_name = true;
    } else if (argc < 6) {
        /* bacwh 0 4194303 8 1234 */
        Target_Object_Instance_Min = strtol(argv[1], NULL, 0);
        Target_Object_Instance_Max = strtol(argv[2], NULL, 0);
        if (bactext_object_type_strtol(argv[3], &object_type) == false) {
            fprintf(stderr, "object-type=%s invalid\n", argv[3]);
            return 1;
        }
        Target_Object_Type = object_type;
        Target_Object_Instance = strtol(argv[4], NULL, 0);
    } else {
        print_usage(filename_remove_path(argv[0]));
        return 1;
    }
    if (by_name) {
        if (Target_Object_Name) {
            if (Target_Object_Name[0] == 0) {
                fprintf(
                    stderr, "object-name must be at least 1 character.\r\n");
                return 1;
            }
        } else {
            fprintf(stderr, "missing object-name value.\r\n");
            return 1;
        }
    } else {
        if (Target_Object_Instance > BACNET_MAX_INSTANCE) {
            fprintf(
                stderr, "object-instance=%u - not greater than %u\r\n",
                Target_Object_Instance, BACNET_MAX_INSTANCE);
            return 1;
        }
        if (Target_Object_Type > BACNET_MAX_OBJECT) {
            fprintf(
                stderr, "object-type=%u - not greater than %u\r\n",
                Target_Object_Type, BACNET_MAX_OBJECT);
            return 1;
        }
    }
    if (Target_Object_Instance_Min > BACNET_MAX_INSTANCE) {
        fprintf(
            stderr, "object-instance-min=%u - not greater than %u\r\n",
            Target_Object_Instance_Min, BACNET_MAX_INSTANCE);
        return 1;
    }
    if (Target_Object_Instance_Max > BACNET_MAX_INSTANCE) {
        fprintf(
            stderr, "object-instance-max=%u - not greater than %u\r\n",
            Target_Object_Instance_Max, BACNET_MAX_INSTANCE);
        return 1;
    }
    /* setup my info */
    Device_Set_Object_Instance_Number(BACNET_MAX_INSTANCE);
    Init_Service_Handlers();
    dlenv_init();
    atexit(datalink_cleanup);
    /* configure the timeout values */
    last_seconds = time(NULL);
    timeout_seconds = apdu_timeout() / 1000;
    /* send the request */
    if (by_name) {
        Send_WhoHas_Name(
            Target_Object_Instance_Min, Target_Object_Instance_Max,
            Target_Object_Name);
    } else {
        Send_WhoHas_Object(
            Target_Object_Instance_Min, Target_Object_Instance_Max,
            Target_Object_Type, Target_Object_Instance);
    }
    /* loop forever */
    for (;;) {
        /* increment timer - exit if timed out */
        current_seconds = time(NULL);
        /* 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;
        }
        /* increment timer - exit if timed out */
        elapsed_seconds += (current_seconds - last_seconds);
        if (elapsed_seconds > timeout_seconds) {
            break;
        }
        /* keep track of time for next check */
        last_seconds = current_seconds;
    }

    return 0;
}