/**
 * @file
 * @brief command line tool that uses BACnet SubscribeCOV service
 * message to subscribe to a BACnet object for Change-of-Value notifications
 * in a BACnet device and print the Change-of-Value notifications values
 * to the console.
 * @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 <errno.h>
#include <time.h> /* for time */
#include <ctype.h> /* for toupper */
#define PRINT_ENABLED 1
/* BACnet Stack defines - first */
#include "bacnet/bacdef.h"
/* BACnet Stack API */
#include "bacnet/bactext.h"
#include "bacnet/bacerror.h"
#include "bacnet/iam.h"
#include "bacnet/arf.h"
#include "bacnet/npdu.h"
#include "bacnet/apdu.h"
#include "bacnet/whois.h"
/* some demo stuff needed */
#include "bacnet/basic/binding/address.h"
#include "bacnet/basic/object/device.h"
#include "bacnet/datalink/datalink.h"
#include "bacnet/basic/sys/filename.h"
#include "bacnet/basic/services.h"
#include "bacnet/basic/tsm/tsm.h"
#include "bacnet/datalink/dlenv.h"
#include "bacport.h"

#if BACNET_SVC_SERVER
#error "App requires server-only features disabled! Set BACNET_SVC_SERVER=0"
#endif

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

/* converted command line arguments */
static uint32_t Target_Device_Object_Instance = BACNET_MAX_INSTANCE;
/* Process identifier for matching replies */
static uint32_t Target_Device_Process_Identifier = 0;
/* the invoke id is needed to filter incoming messages */
static uint8_t Request_Invoke_ID = 0;
/* MAC and SNET address of target */
static BACNET_ADDRESS Target_Address;
/* indication of error, reject, or abort */
static bool Error_Detected = false;
/* data used in COV subscription request */
BACNET_SUBSCRIBE_COV_DATA *COV_Subscribe_Data = NULL;
/* flags to signal early termination */
static bool Simple_Ack_Detected = false;
static bool Cancel_Requested = false;

static void MyErrorHandler(BACNET_ADDRESS *src,
    uint8_t invoke_id,
    BACNET_ERROR_CLASS error_class,
    BACNET_ERROR_CODE error_code)
{
    if (address_match(&Target_Address, src) &&
        (invoke_id == Request_Invoke_ID)) {
        printf("BACnet Error: %s: %s\n",
            bactext_error_class_name((int)error_class),
            bactext_error_code_name((int)error_code));
        Error_Detected = true;
    }
}

static void MyAbortHandler(
    BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t abort_reason, bool server)
{
    (void)server;
    if (address_match(&Target_Address, src) &&
        (invoke_id == Request_Invoke_ID)) {
        printf("BACnet Abort: %s\n",
            bactext_abort_reason_name((int)abort_reason));
        Error_Detected = true;
    }
}

static void MyRejectHandler(
    BACNET_ADDRESS *src, uint8_t invoke_id, uint8_t reject_reason)
{
    if (address_match(&Target_Address, src) &&
        (invoke_id == Request_Invoke_ID)) {
        printf("BACnet Reject: %s\n",
            bactext_reject_reason_name((int)reject_reason));
        Error_Detected = true;
    }
}

static void My_Unconfirmed_COV_Notification_Handler(
    uint8_t *service_request, uint16_t service_len, BACNET_ADDRESS *src)
{
    handler_ucov_notification(service_request, service_len, src);
}

static void My_Confirmed_COV_Notification_Handler(uint8_t *service_request,
    uint16_t service_len,
    BACNET_ADDRESS *src,
    BACNET_CONFIRMED_SERVICE_DATA *service_data)
{
    handler_ccov_notification(service_request, service_len, src, service_data);
}

static void MyWritePropertySimpleAckHandler(
    BACNET_ADDRESS *src, uint8_t invoke_id)
{
    if (address_match(&Target_Address, src) &&
        (invoke_id == Request_Invoke_ID)) {
        printf("SubscribeCOV Acknowledged!\n");
        Simple_Ack_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);
    /* handle i-am to support binding to other devices */
    apdu_set_unconfirmed_handler(SERVICE_UNCONFIRMED_I_AM, handler_i_am_bind);
    /* 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 data coming back from COV subscriptions */
    apdu_set_confirmed_handler(SERVICE_CONFIRMED_COV_NOTIFICATION,
        My_Confirmed_COV_Notification_Handler);
    apdu_set_unconfirmed_handler(SERVICE_UNCONFIRMED_COV_NOTIFICATION,
        My_Unconfirmed_COV_Notification_Handler);
    /* handle the Simple ack coming back from SubscribeCOV */
    apdu_set_confirmed_simple_ack_handler(
        SERVICE_CONFIRMED_SUBSCRIBE_COV, MyWritePropertySimpleAckHandler);
    /* handle any errors coming back */
    apdu_set_error_handler(SERVICE_CONFIRMED_SUBSCRIBE_COV, MyErrorHandler);
    apdu_set_abort_handler(MyAbortHandler);
    apdu_set_reject_handler(MyRejectHandler);
}

static void cleanup(void)
{
    BACNET_SUBSCRIBE_COV_DATA *cov_data = NULL;
    BACNET_SUBSCRIBE_COV_DATA *cov_data_old = NULL;

    cov_data = COV_Subscribe_Data;
    while (cov_data) {
        cov_data_old = cov_data;
        cov_data = cov_data->next;
        free(cov_data_old);
    }
}

static void print_usage(char *filename)
{
    printf("Usage: %s device-id object-type object-instance "
            "process-id <[un]confirmed lifetime|cancel>\n",
        filename);
}

static void print_help(char *filename)
{
    printf("Subscribe to a BACnet object for Change-of-Value notifications\n"
        "in a BACnet device and print the Change-of-Value notifications.\n");
    printf("\n");
    printf("device-id:\n"
        "The subscriber BACnet Device Object Instance number.\n");
    printf("\n");
    printf("object-type:\n"
        "The object type is object that you are reading. It\n"
        "can be defined either as the object-type name string\n"
        "as defined in the BACnet specification, or as the\n"
        "integer value of the enumeration BACNET_OBJECT_TYPE\n"
        "in bacenum.h. For example if you were reading Analog\n"
        "Output 2, the object-type would be analog-output or 1.\n");
    printf("\n");
    printf("object-instance:\n"
        "The monitored object instance number.\n");
    printf("\n");
    printf("process-id:\n"
        "Process Identifier for this COV subscription.\n");
    printf("\n");
    printf("confirmed:\n"
        "Optional flag to subscribe using Confirmed notifications.\n"
        "Use the word \'confirmed\' or \'unconfirmed\'.\n");
    printf("\n");
    printf("lifetime:\n"
        "Optional subscription lifetime is conveyed in seconds.\n");
    printf("\n");
    printf("cancel:\n"
        "Use the word \'cancel\' instead of confirm and lifetime.\n"
        "This shall indicate a cancellation request.\n");
    printf("\n");
    printf("Examples:\n");
    printf("If you want subscribe to Device 123 Analog Input 9 object\n"
        "using confirmed COV notifications for 5 minutes,\n"
        "you could send the following command:\n"
        "%s 123 0 9 1 confirmed 600\n", filename);
    printf("To send the same COV subscription request for unconfirmed\n"
        "notifications, send the following command:\n"
        "%s 123 0 9 1 unconfirmed 600\n", filename);
    printf("To cancel the same COV subscription request,\n"
        "send the following command:\n"
        "%s 123 0 9 1 cancel\n", filename);
}

int main(int argc, char *argv[])
{
    BACNET_ADDRESS src = { 0 }; /* address where message came from */
    uint16_t pdu_len = 0;
    unsigned timeout = 100; /* milliseconds */
    unsigned max_apdu = 0;
    time_t elapsed_seconds = 0;
    time_t last_seconds = 0;
    time_t current_seconds = 0;
    time_t timeout_seconds = 0;
    time_t delta_seconds = 0;
    bool found = false;
    char *filename = NULL;
    bool print_usage_terse = false;
    bool print_usage_verbose = false;
    BACNET_SUBSCRIBE_COV_DATA *cov_data = NULL;
    int argi = 0;
    int arg_remaining = 0;
    unsigned uint;

    if (argc < 6) {
        print_usage_terse = true;
    }
    if ((argc > 1) && (strcmp(argv[1], "--help") == 0)) {
        print_usage_terse = true;
        print_usage_verbose = true;
    }
    if (print_usage_terse) {
        filename = filename_remove_path(argv[0]);
        print_usage(filename);
        if (!print_usage_verbose) {
            return 0;
        }
    }
    if (print_usage_verbose) {
        print_help(filename);
        return 0;
    }
    /* decode the command line parameters */
    Target_Device_Object_Instance = strtol(argv[1], NULL, 0);
    if (Target_Device_Object_Instance > BACNET_MAX_INSTANCE) {
        fprintf(stderr, "device-instance=%u - not greater than %u\n",
            Target_Device_Object_Instance, BACNET_MAX_INSTANCE);
        return 1;
    }
    atexit(cleanup);
    COV_Subscribe_Data = calloc(1, sizeof(BACNET_SUBSCRIBE_COV_DATA));
    cov_data = COV_Subscribe_Data;
    argi = 2;
    while (cov_data) {
        if (bactext_object_type_strtol(argv[argi], &uint) == false) {
            fprintf(stderr, "Error: object-type=%s invalid\n", argv[argi]);
            return 1;
        }
        cov_data->monitoredObjectIdentifier.type = (uint16_t)uint;
        if (cov_data->monitoredObjectIdentifier.type >=
            MAX_BACNET_OBJECT_TYPE) {
            fprintf(stderr, "object-type=%u - it must be less than %u\n",
                cov_data->monitoredObjectIdentifier.type,
                MAX_BACNET_OBJECT_TYPE);
            return 1;
        }
        argi++;
        cov_data->monitoredObjectIdentifier.instance =
            strtol(argv[argi], NULL, 0);
        if (cov_data->monitoredObjectIdentifier.instance >
            BACNET_MAX_INSTANCE) {
            fprintf(stderr, "object-instance=%u - not greater than %u\n",
                cov_data->monitoredObjectIdentifier.instance,
                BACNET_MAX_INSTANCE);
            return 1;
        }
        argi++;
        cov_data->subscriberProcessIdentifier = strtol(argv[argi], NULL, 0);
        argi++;
        if (strcmp(argv[argi], "cancel") == 0) {
            cov_data->cancellationRequest = true;
            argi++;
        } else {
            cov_data->cancellationRequest = false;
            if (strcmp(argv[argi], "confirmed") == 0) {
                cov_data->issueConfirmedNotifications = true;
            } else if (strcmp(argv[argi], "unconfirmed") == 0) {
                cov_data->issueConfirmedNotifications = false;
            } else {
                fprintf(stderr, "unknown option: %s\n", argv[argi]);
                return 1;
            }
            argi++;
            arg_remaining = argc - argi;
            if (arg_remaining > 0) {
                cov_data->lifetime = strtol(argv[argi], NULL, 0);
                argi++;
            } else {
                cov_data->lifetime = 0;
            }
        }
        arg_remaining = argc - argi;
        if (arg_remaining < 5) {
            break;
        } else {
            cov_data->next = calloc(1, sizeof(BACNET_SUBSCRIBE_COV_DATA));
            cov_data = cov_data->next;
        }
    }
    /* setup my info */
    Device_Set_Object_Instance_Number(BACNET_MAX_INSTANCE);
    address_init();
    Init_Service_Handlers();
    dlenv_init();
    atexit(datalink_cleanup);
    /* configure the timeout values */
    last_seconds = time(NULL);
    timeout_seconds = (apdu_timeout() / 1000) * apdu_retries();
    /* try to bind with the device */
    found = address_bind_request(
        Target_Device_Object_Instance, &max_apdu, &Target_Address);
    if (!found) {
        Send_WhoIs(
            Target_Device_Object_Instance, Target_Device_Object_Instance);
    }
    /* start at the beginning of the subscribe list */
    cov_data = COV_Subscribe_Data;
    /* loop forever */
    for (;;) {
        /* increment timer - exit if timed out */
        current_seconds = time(NULL);
        /* at least one second has passed */
        if (current_seconds != last_seconds) {
            /* increment timer - exit if timed out */
            delta_seconds = current_seconds - last_seconds;
            elapsed_seconds += delta_seconds;
            tsm_timer_milliseconds((delta_seconds * 1000));
            datalink_maintenance_timer(delta_seconds);
            /* keep track of time for next check */
            last_seconds = current_seconds;
        }
        if (Error_Detected) {
            break;
        }
        /* wait until the device is bound, or timeout and quit */
        if (!found) {
            found = address_bind_request(
                Target_Device_Object_Instance, &max_apdu, &Target_Address);
        }
        if (found) {
            if (Request_Invoke_ID == 0) {
                Simple_Ack_Detected = false;
                if (cov_data->cancellationRequest) {
                    Cancel_Requested = true;
                } else {
                    Cancel_Requested = false;
                }
                Target_Device_Process_Identifier =
                    cov_data->subscriberProcessIdentifier;
                Request_Invoke_ID =
                    Send_COV_Subscribe(Target_Device_Object_Instance, cov_data);
                if (!cov_data->cancellationRequest &&
                    (timeout_seconds < cov_data->lifetime)) {
                    /* increase the timeout to the longest lifetime */
                    timeout_seconds = cov_data->lifetime;
                }
                printf("Sent SubscribeCOV request. "
                       " Waiting up to %u seconds....\n",
                    (unsigned)(timeout_seconds - elapsed_seconds));
            } else if (tsm_invoke_id_free(Request_Invoke_ID)) {
                if (cov_data->next) {
                    cov_data = cov_data->next;
                    Request_Invoke_ID = 0;
                } else {
                    if (Cancel_Requested && Simple_Ack_Detected) {
                        break;
                    }
                }
            } else if (tsm_invoke_id_failed(Request_Invoke_ID)) {
                fprintf(stderr, "\rError: TSM Timeout!\n");
                tsm_free_invoke_id(Request_Invoke_ID);
                Error_Detected = true;
                break;
            }
        } else {
            /* exit if timed out */
            if (elapsed_seconds > timeout_seconds) {
                Error_Detected = true;
                printf("\rError: APDU Timeout!\n");
                break;
            }
        }
        /* 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;
        }
        /* COV - so just wait until lifetime value expires */
        if (elapsed_seconds > timeout_seconds) {
            break;
        }
    }
    if (Error_Detected) {
        return 1;
    }
    return 0;
}