#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <sys/mman.h>
#include <malloc.h>
#include <string>
#include <iostream>

/****************************************************************************/

#include "ecrt.h"

/****************************************************************************/

// Application parameters
#define FREQUENCY 1000
#define CLOCK_TO_USE CLOCK_REALTIME
//#define MEASURE_TIMING

/****************************************************************************/

#define NSEC_PER_SEC (1000000000L)
#define PERIOD_NS (NSEC_PER_SEC / FREQUENCY)

#define DIFF_NS(A, B) (((B).tv_sec - (A).tv_sec) * NSEC_PER_SEC + \
    (B).tv_nsec - (A).tv_nsec)

#define TIMESPEC2NS(T) ((uint64_t) (T).tv_sec * NSEC_PER_SEC + (T).tv_nsec)

/****************************************************************************/

// EtherCAT
static ec_master_t *master = NULL;
static ec_master_state_t master_state = {};

static ec_domain_t *domain1 = NULL;
static ec_domain_state_t domain1_state = {};

static ec_slave_config_t* sc[3] = { NULL };
static ec_slave_config_state_t sc_state[3];
static std::string slave_names[3] = {"EK1100", "EL2252", "EL2252"};

/****************************************************************************/

// process data
static uint8_t *domain1_pd = NULL;

#define BusCouplerPos       0, 0
#define DigOut1SlavePos     0, 1
#define DigOut2SlavePos     0, 2

#define Beckhoff_EK1100 0x00000002, 0x044c2c52
#define Beckhoff_EL2252 0x00000002, 0x08cc3052

enum TriggerState { IDLE, SET_TRIGGER, ACTIVATE_TRIGGER };

static unsigned int counter = 0;
static unsigned int blink = 0;
static unsigned int sync_ref_counter = 1;
static TriggerState trigger = IDLE;
const struct timespec cycletime = {0, PERIOD_NS};


/* Master 0, Slave 1, "EL2252"
 * Vendor ID:       0x00000002
 * Product code:    0x08cc3052
 * Revision number: 0x00120000
 */

ec_pdo_entry_info_t slave_1_pdo_entries[] = {
    {0x1d09, 0x81, 8}, /* Activate */
    {0x1d09, 0x90, 64}, /* StartTime */
    {0x7000, 0x01, 1}, /* Output 1 */
    {0x7000, 0x02, 1}, /* TriState 1 */
    {0x7010, 0x01, 1}, /* Output 2 */
    {0x7010, 0x02, 1}, /* TriState 2 */
    {0x0000, 0x00, 4}, /* empty */
};

ec_pdo_info_t slave_1_pdos[] = {
    {0x1602, 1, slave_1_pdo_entries + 0}, /* DC Sync Activate */
    {0x1603, 1, slave_1_pdo_entries + 1}, /* DC Sync Start */
    {0x1600, 2, slave_1_pdo_entries + 2}, /* Channel 1 */
    {0x1601, 3, slave_1_pdo_entries + 4}, /* Channel 2 */
    {0x1604, 0, NULL}, /* Reserved */
};

ec_sync_info_t slave_1_syncs[] = {
    {0, EC_DIR_OUTPUT, 1, slave_1_pdos + 0, EC_WD_ENABLE},
    {1, EC_DIR_OUTPUT, 1, slave_1_pdos + 1, EC_WD_ENABLE},
    {2, EC_DIR_OUTPUT, 3, slave_1_pdos + 2, EC_WD_ENABLE},
    //{3, EC_DIR_INPUT, 2, slave_1_pdos + 5, EC_WD_DISABLE},
    {3, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
    {4, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
    {0xff}
};

/* Master 0, Slave 2, "EL2252"
 * Vendor ID:       0x00000002
 * Product code:    0x08cc3052
 * Revision number: 0x00120000
 */

ec_pdo_entry_info_t slave_2_pdo_entries[] = {
    {0x1d09, 0x81, 8}, /* Activate */
    {0x1d09, 0x90, 64}, /* StartTime */
    {0x7000, 0x01, 1}, /* Output 1 */
    {0x7000, 0x02, 1}, /* TriState 1 */
    {0x7010, 0x01, 1}, /* Output 2 */
    {0x7010, 0x02, 1}, /* TriState 2 */
    {0x0000, 0x00, 4}, /* empty */
};

ec_pdo_info_t slave_2_pdos[] = {
    {0x1602, 1, slave_2_pdo_entries + 0}, /* DC Sync Activate */
    {0x1603, 1, slave_2_pdo_entries + 1}, /* DC Sync Start */
    {0x1600, 2, slave_2_pdo_entries + 2}, /* Channel 1 */
    {0x1601, 3, slave_2_pdo_entries + 4}, /* Channel 2 */
    {0x1604, 0, NULL}, /* Reserved */
};

ec_sync_info_t slave_2_syncs[] = {
    {0, EC_DIR_OUTPUT, 1, slave_2_pdos + 0, EC_WD_ENABLE},
    {1, EC_DIR_OUTPUT, 1, slave_2_pdos + 1, EC_WD_ENABLE},
    {2, EC_DIR_OUTPUT, 3, slave_2_pdos + 2, EC_WD_ENABLE},
    //{3, EC_DIR_INPUT, 2, slave_1_pdos + 5, EC_WD_DISABLE},
    {3, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
    {4, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
    {0xff}
};

// DOMAIN 1
struct EL2252_offsets
{
    unsigned int activate;
    unsigned int start_time;
    unsigned int output_1;
    unsigned int output_1_bits;
    unsigned int tristate_1;
    unsigned int tristate_1_bits;
    unsigned int output_2;
    unsigned int output_2_bits;
    unsigned int tristate_2;
    unsigned int tristate_2_bits;
    unsigned int empty;
    unsigned int empty_bits;
};

static EL2252_offsets slave1_offsets;
static EL2252_offsets slave2_offsets;

// PDO entries of domain 1
const static ec_pdo_entry_reg_t domain1_regs[] =
{
{ DigOut1SlavePos, Beckhoff_EL2252, 0x1d09, 0x81, &slave1_offsets.activate },
{ DigOut1SlavePos, Beckhoff_EL2252, 0x1d09, 0x90, &slave1_offsets.start_time },
{ DigOut1SlavePos, Beckhoff_EL2252, 0x7000, 0x01, &slave1_offsets.output_1, &slave1_offsets.output_1_bits },
{ DigOut1SlavePos, Beckhoff_EL2252, 0x7000, 0x02, &slave1_offsets.tristate_1, &slave1_offsets.tristate_1_bits },
{ DigOut1SlavePos, Beckhoff_EL2252, 0x7010, 0x01, &slave1_offsets.output_2, &slave1_offsets.output_2_bits },
{ DigOut1SlavePos, Beckhoff_EL2252, 0x7010, 0x02, &slave1_offsets.tristate_2, &slave1_offsets.tristate_2_bits },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x1d09, 0x81, &slave2_offsets.activate },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x1d09, 0x90, &slave2_offsets.start_time },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x7000, 0x01, &slave2_offsets.output_1, &slave2_offsets.output_1_bits },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x7000, 0x02, &slave2_offsets.tristate_1, &slave2_offsets.tristate_1_bits },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x7010, 0x01, &slave2_offsets.output_2, &slave2_offsets.output_2_bits },
{ DigOut2SlavePos, Beckhoff_EL2252, 0x7010, 0x02, &slave2_offsets.tristate_2, &slave2_offsets.tristate_2_bits },
{} };

/*****************************************************************************/

struct timespec timespec_add(struct timespec time1, struct timespec time2)
{
    struct timespec result;

    if ((time1.tv_nsec + time2.tv_nsec) >= NSEC_PER_SEC) {
        result.tv_sec = time1.tv_sec + time2.tv_sec + 1;
        result.tv_nsec = time1.tv_nsec + time2.tv_nsec - NSEC_PER_SEC;
    } else {
        result.tv_sec = time1.tv_sec + time2.tv_sec;
        result.tv_nsec = time1.tv_nsec + time2.tv_nsec;
    }

    return result;
}

/*****************************************************************************/

void check_domain_state(ec_domain_t* domain, ec_domain_state_t* last_state, const char* name)
{
    ec_domain_state_t ds;
    char wc_state_string[128];

    ecrt_domain_state(domain, &ds);

    switch (ds.wc_state)
    {
    case EC_WC_ZERO:
        snprintf(wc_state_string, 128,
                "ZERO - No registered process data were exchanged");
        break;
    case EC_WC_INCOMPLETE:
        snprintf(wc_state_string, 128,
                "INCOMPLETE - Some of the registered process data were exchanged");
        break;
    case EC_WC_COMPLETE:
        snprintf(wc_state_string, 128,
                "COMPLETE - All registered process data were exchanged");
        break;
    }

    if (ds.working_counter != last_state->working_counter)
        printf("  * Domain %s working counter: %u.\n", name, ds.working_counter);
    if (ds.wc_state != last_state->wc_state)
        printf("  * Domain %s state: %s.\n", name, wc_state_string);

    *last_state = ds;
}

/*****************************************************************************/

void check_master_state(void)
{
    ec_master_state_t ms;

    ecrt_master_state(master, &ms);

    if (ms.slaves_responding != master_state.slaves_responding)
    {
        printf("%u slave(s) responding.\n", ms.slaves_responding);
    }

    if (ms.al_states != master_state.al_states)
    {
        printf("AL states:", ms.al_states);
        if((ms.al_states & 0x1) != 0) printf(" INIT");
        if((ms.al_states & 0x2) != 0) printf(" PREOP");
        if((ms.al_states & 0x4) != 0) printf(" SAFEOP");
        if((ms.al_states & 0x8) != 0) printf(" OP");
        printf("\n");
    }

    if (ms.link_up != master_state.link_up)
    {
        printf("Link is %s.\n", ms.link_up ? "up" : "down");
    }

    master_state = ms;
}

/****************************************************************************/

void check_slave_config_states(void)
{
    ec_slave_config_state_t s;

    for(unsigned int i=0; i<3; i++)
    {
        ecrt_slave_config_state(sc[i], &s);

        if (s.al_state != sc_state[i].al_state)
        {
            printf("%s:", slave_names[i].c_str(), s.al_state);
            if((s.al_state & 0x1) != 0) printf(" INIT");
            if((s.al_state & 0x2) != 0) printf(" PREOP");
            if((s.al_state & 0x4) != 0) printf(" SAFEOP");
            if((s.al_state & 0x8) != 0) printf(" OP");
            printf(" state \n");
        }

        if (s.online != sc_state[i].online)
            printf("%s: %s.\n", slave_names[i].c_str(), s.online ? "online" : "offline");

        if (s.operational != sc_state[i].operational)
            printf("%s: %soperational.\n", slave_names[i].c_str(), s.operational ? "" : "Not ");

        sc_state[i] = s;
    }
}
/****************************************************************************/

void cyclic_task()
{
    struct timespec wakeupTime, time;
    int32_t anaIn0 = 0.0;
    uint32_t meanCount = 0;

#ifdef MEASURE_TIMING
    struct timespec startTime, endTime, lastStartTime = {};
    uint32_t period_ns = 0, exec_ns = 0, latency_ns = 0,
             latency_min_ns = 0, latency_max_ns = 0,
             period_min_ns = 0, period_max_ns = 0,
             exec_min_ns = 0, exec_max_ns = 0;
    double latency_mean_ns, period_mean_ns, exec_mean_ns;

#endif

    // get current time
    clock_gettime(CLOCK_TO_USE, &wakeupTime);

    while(1) {
        wakeupTime = timespec_add(wakeupTime, cycletime);
        clock_nanosleep(CLOCK_TO_USE, TIMER_ABSTIME, &wakeupTime, NULL);

#ifdef MEASURE_TIMING
        clock_gettime(CLOCK_TO_USE, &startTime);
        latency_ns = DIFF_NS(wakeupTime, startTime);
        period_ns = DIFF_NS(lastStartTime, startTime);
        exec_ns = DIFF_NS(lastStartTime, endTime);
        lastStartTime = startTime;

        meanCount++;
        latency_mean_ns += (double) latency_ns;
        period_mean_ns += (double) period_ns;
        exec_mean_ns += (double) exec_ns;

        if (latency_ns > latency_max_ns) {
            latency_max_ns = latency_ns;
        }
        if (latency_ns < latency_min_ns) {
            latency_min_ns = latency_ns;
        }
        if (period_ns > period_max_ns) {
            period_max_ns = period_ns;
        }
        if (period_ns < period_min_ns) {
            period_min_ns = period_ns;
        }
        if (exec_ns > exec_max_ns) {
            exec_max_ns = exec_ns;
        }
        if (exec_ns < exec_min_ns) {
            exec_min_ns = exec_ns;
        }
#endif

        // receive process data
        ecrt_master_receive(master);
        ecrt_domain_process(domain1);

        // check process data state (optional)
        check_domain_state(domain1, &domain1_state, "1");

        if (counter) {
            counter--;
        } else { // do this at 1 Hz
            counter = FREQUENCY;

            // check for master state (optional)
            check_master_state();
            check_slave_config_states();

#ifdef MEASURE_TIMING
            latency_mean_ns = latency_mean_ns / (double) meanCount;
            period_mean_ns = period_mean_ns / (double) meanCount;
            exec_mean_ns = exec_mean_ns / (double) meanCount;

            // output timing stats
            printf("period     %10u ... %10u ns (mean: %f ns)\n",
                    period_min_ns, period_max_ns, period_mean_ns);
            printf("exec       %10u ... %10u ns (mean: %f ns)\n",
                    exec_min_ns, exec_max_ns, exec_mean_ns);
            printf("latency    %10u ... %10u ns (mean: %f ns)\n",
                    latency_min_ns, latency_max_ns, latency_mean_ns);
            period_max_ns = 0;
            period_min_ns = 0xffffffff;
            exec_max_ns = 0;
            exec_min_ns = 0xffffffff;
            latency_max_ns = 0;
            latency_min_ns = 0xffffffff;
            meanCount = 0;
#endif

            // calculate new process data
            blink = !blink;
            std::cout << "blink!" << std::endl;
            // Generate trigger
            trigger = SET_TRIGGER;
        }

        // DC CLOCK SYNC

        // write application time to master
        clock_gettime(CLOCK_TO_USE, &time);
        ecrt_master_application_time(master, TIMESPEC2NS(time));

        if (sync_ref_counter) {
            sync_ref_counter--;
        } else {
            sync_ref_counter = 1; // sync every cycle
            ecrt_master_sync_reference_clock(master);
        }
        ecrt_master_sync_slave_clocks(master);

        // TRIGGER

        switch(trigger)
        {
        case IDLE:
            break;
        case ACTIVATE_TRIGGER:
            // Step 2: Activate the trigger
            EC_WRITE_U8(domain1_pd + slave1_offsets.activate, 3);
            EC_WRITE_U8(domain1_pd + slave2_offsets.activate, 3);
            trigger = IDLE;
            break;
        case SET_TRIGGER:
            // Step 1: set StartTime, Output and TriState

            // Calculate trigger time 10ms and 10.010 ms later (10 us delay)
            uint64_t trigger1_time = TIMESPEC2NS(time) + (10000000);
            uint64_t trigger2_time = TIMESPEC2NS(time) + (10010000);

            EC_WRITE_U8(domain1_pd + slave1_offsets.activate, 0);
            EC_WRITE_U64(domain1_pd + slave1_offsets.start_time, trigger1_time);
            EC_WRITE_BIT(domain1_pd + slave1_offsets.output_1, slave1_offsets.output_1_bits, blink);
            EC_WRITE_BIT(domain1_pd + slave1_offsets.tristate_1, slave1_offsets.tristate_1_bits, blink);

            EC_WRITE_U8(domain1_pd + slave2_offsets.activate, 0);
            EC_WRITE_U64(domain1_pd + slave2_offsets.start_time, trigger2_time);
            EC_WRITE_BIT(domain1_pd + slave2_offsets.output_1, slave2_offsets.output_1_bits, blink);
            EC_WRITE_BIT(domain1_pd + slave2_offsets.tristate_1, slave2_offsets.tristate_1_bits, blink);

            trigger = ACTIVATE_TRIGGER;
            break;
        }

        // send process data
        ecrt_domain_queue(domain1);
        ecrt_master_send(master);

#ifdef MEASURE_TIMING
        clock_gettime(CLOCK_TO_USE, &endTime);
#endif
    }
}

/****************************************************************************/

int main(int argc, char **argv)
{
    if (mlockall(MCL_CURRENT | MCL_FUTURE) == -1) {
        perror("mlockall failed");
        return -1;
    }

    master = ecrt_request_master(0);
    if (!master)
        return -1;

    domain1 = ecrt_master_create_domain(master);
    if (!domain1)
        return -1;

    // Create configuration for bus coupler
    sc[0] = ecrt_master_slave_config(master, BusCouplerPos, Beckhoff_EK1100);
    if (!sc[0])
        return -1;

    // Create configuration for EL2252 #1

    if (!(sc[1] = ecrt_master_slave_config(master,
                    DigOut1SlavePos, Beckhoff_EL2252))) {
        fprintf(stderr, "Failed to get slave configuration for EL2252 #1.\n");
        return -1;
    }

    if (!(sc[2] = ecrt_master_slave_config(master,
                    DigOut2SlavePos, Beckhoff_EL2252))) {
        fprintf(stderr, "Failed to get slave configuration for EL2252 #2.\n");
        return -1;
    }

    printf("Configuring PDOs...\n");
    if (ecrt_slave_config_pdos(sc[1], EC_END, slave_1_syncs))
    {
        fprintf(stderr, "Failed to configure PDOs of EL2252 #1.\n");
        return -1;
    }

    if (ecrt_slave_config_pdos(sc[2], EC_END, slave_2_syncs))
    {
        fprintf(stderr, "Failed to configure PDOs of EL2252 #2.\n");
        return -1;
    }

    // Register PDOs
    printf("Configuring domains with registered PDO entries...\n");
    if (ecrt_domain_reg_pdo_entry_list(domain1, domain1_regs))
    {
        fprintf(stderr, "PDO entry registration failed for domain 1!\n");
        return -1;
    }

    // configure SYNC signals
    ecrt_slave_config_dc(sc[1], 0x0300, PERIOD_NS, 0, 0, 0);
    ecrt_slave_config_dc(sc[2], 0x0300, PERIOD_NS, 0, 0, 0);

    printf("Activating master...\n");
    if (ecrt_master_activate(master))
        return -1;

    if (!(domain1_pd = ecrt_domain_data(domain1))) {
        return -1;
    }

    // DEBUG
    std::cout << "Slave 1 slave1_offsets.activate = " << slave1_offsets.activate << std::endl;
    std::cout << "Slave 2 slave2_offsets.activate = " << slave2_offsets.activate << std::endl;
    std::cout << "Slave 1 slave1_offsets.start_time = " << slave1_offsets.start_time << std::endl;
    std::cout << "Slave 2 slave2_offsets.start_time = " << slave2_offsets.start_time << std::endl;

    pid_t pid = getpid();
    if (setpriority(PRIO_PROCESS, pid, -19))
        fprintf(stderr, "Warning: Failed to set priority: %s\n",
                strerror(errno));
    printf("Starting cyclic function.\n");
    cyclic_task();

    return 0;
}

/****************************************************************************/