/*
   The organization of this file is modelled after the motorforce example
   developed by Uros Platise.
*/
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#if !defined(_MSC_VER) && !defined(__MINGW64__)
#include <unistd.h>
#endif
#if defined(_MSC_VER)
#include <io.h>
#include <process.h>
#include <Windows.h>
#endif
#include "d_process.h"

#define DIGITAL_IN      0
#define DIGITAL_OUT     4

static int compute(uint8_t *dataout, int outsz, double time);

//#define ENABLE_DEBUGGING 1
#ifdef ENABLE_DEBUGGING
static int known_bp(int iargc)
{
    return iargc;
}
#endif

int main(int argc, char *argv[]) {    
    int i;
    int outlen = D_PROCESS_DLEN(DIGITAL_OUT);

#if defined(_MSC_VER) || defined(__MINGW64__)
#pragma pack(push, 1)
    struct in_s {
        double time;
    } in;
            
    struct out_s {
        uint8_t dout[D_PROCESS_DLEN(DIGITAL_OUT)];
    } out;
#pragma pack(pop)
#else
    struct in_s {
        double time;
    } __attribute__((packed)) in;
            
    struct out_s {
        uint8_t dout[D_PROCESS_DLEN(DIGITAL_OUT)];
    } __attribute__((packed)) out;
#endif

    int pipein = 0; // default stdin to recv from ngspice
    int pipeout= 1; // default stdout to send to ngspice
#if defined(_MSC_VER) || defined(__MINGW64__)
    _setmode(0, _O_BINARY);
    _setmode(1, _O_BINARY);
#endif

#ifdef ENABLE_DEBUGGING
#if defined(_MSC_VER) || defined(__MINGW64__)
    fprintf(stderr, "%s pid %d\n", argv[0], _getpid());
#else
    fprintf(stderr, "%s pid %d\n", argv[0], getpid());
#endif

#if !defined(_MSC_VER) && !defined(__MINGW64__)
    if (getenv("GO_TO_SLEEP")) {
        sleep(40);
    }
#endif
#if defined(__MINGW64__)
    if (getenv("GO_TO_SLEEP")) {
        sleep(40);
    }
#endif
#if defined(_MSC_VER)
    if (getenv("GO_TO_SLEEP")) {
        Sleep(60000);
    }
#endif

    (void)known_bp(argc);
#endif

    for (i=0; i<argc; i++) {
        //fprintf(stderr, "[%d] %s\n", i, argv[i]);
        if (strcmp(argv[i],"--pipe")==0) {
#if defined(_MSC_VER) || defined(__MINGW64__)
            if ((pipein = _open("graycode_in",  O_RDONLY)) < 0 || (pipeout = _open("graycode_out",  O_WRONLY)) < 0)
#else
            if ((pipein = open("graycode_in",  O_RDONLY)) < 0 || (pipeout = open("graycode_out",  O_WRONLY)) < 0)
#endif
            {
                fprintf(stderr, "Cannot open %s named pipes\n", argv[0]);
                return -1;
            }
        }
    }
    
    if (d_process_init(pipein, pipeout, DIGITAL_IN, DIGITAL_OUT) ) {
#if defined(_MSC_VER) || defined(__MINGW64__)
        while(_read(pipein, &in, sizeof(in)) == sizeof(in)) {
#else
        while(read(pipein, &in, sizeof(in)) == sizeof(in)) {
#endif

            if (!compute(out.dout, outlen, in.time)) {
                return 1;
            }

#if defined(_MSC_VER) || defined(__MINGW64__)
            _write(pipeout, &out, sizeof(out));
#else
            write(pipeout, &out, sizeof(out));
#endif
        }
        return 0;
    }
    return -1;
}

static int compute(uint8_t *dataout, int outsz, double time)
{
    static uint8_t count = 0;
    if (count < 15) {
        count++;
    } else {
        count = 0;
    }
    dataout[0] = (count ^ (count >> 1)) & 0x0F;
    return 1;
}