#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
#include <fcntl.h>
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>

#include "common.h"
#include "List.h"

int
RecvMsg(int pipe, msg_t *m)
{
    return read(pipe, m, sizeof(msg_t));
}

void
Usage(char *program)
{
    fprintf(stderr, "Usage: %s <fifoFile>\n", program);
    exit(1);
}

// if we are on a sparc/solaris
/*
double 
Time_GetSeconds() {
    struct timespec                 timeClock;
    double                          retVal;
 
    clock_gettime(CLOCK_REALTIME, &timeClock);
    retVal =  (double) timeClock.tv_sec;
    retVal += (double) timeClock.tv_nsec / (double)1e9;
    return (retVal);
}
*/

// otherwise, just use gettimeofday()
double 
Time_GetSeconds() 
{
    struct timeval t;
    int rc = gettimeofday(&t, NULL);
    assert(rc == 0);
    return (double) ((double)t.tv_sec + (double)t.tv_usec / 1e6);
}

int
main(int argc, char *argv[])
{
    if (argc != 2) {
	Usage(argv[0]);
    }
    char *fifoFile = argv[1];

    // check that it's a fifo
    if (IsFifo(fifoFile) == 0) {
	fprintf(stderr, "%s is not a FIFO!\n", fifoFile);
	Usage(argv[0]);
    }

    // open up the pipe and check for errors, exiting on a problem
    int pipe = open(fifoFile, O_RDONLY);
    if (pipe < 0) {
	perror("pipe");
	Usage(argv[0]);
    }

    // main loop - process messages until there is a problem
    List L;
    double startTime = -1.0;
    while (1) {
	msg_t m;
	int rc = RecvMsg(pipe, &m);

	// painful: could got lots of unexpected values here
	if (rc == 0) {
	    // end of pipe!
	    fprintf(stderr, "Unexpected closure of remote pipe, exiting\n");
	    exit(0);
	} else if (rc < (int) sizeof(m)) {
	    // could deal with this in a better way, but oh well
	    fprintf(stderr, "Error: Message of unexpected size (%d), ignoring\n", rc);
	    continue;
	} else if (rc < 0) {
	    perror("read");
	    continue;
	}

	// got a valid message
	if (m.type == DATA) {
	    double time;
	    if (startTime < 0.0) {
		startTime = Time_GetSeconds();
		time = 0.0;
	    } else {
		time = Time_GetSeconds() - startTime;
	    }

	    // insert data into list in time order
	    L.Insert(time, m.data);

	} else if (m.type == END) {
	    printf("Time of END message: %d\n", (int)((1e3 * (Time_GetSeconds() - startTime)) + 0.5));
	    L.Print();
	    exit(0);

	} else {
	    fprintf(stderr, "Error: message type not understood (%d)\n", (int) m.type);
	}

    }

    return 0;
}