#define _POSIX_C_SOURCE 200809L
#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include "../ipc.h"

typedef struct Key Key;
struct Key {
	int	k;
	int	mod;
};

static Key *keys;
static size_t nkeys;
static int fd;

static void
die(char *msg)
{
	perror(msg);
	exit(1);
}

static void
addkey(int k, int mod)
{
	static size_t cap;
	Key *p;

	if(nkeys >= cap){
		if(cap > SIZE_MAX / 2 / sizeof(Key)){
			fprintf(stderr, "too many keys\n");
			exit(1);
		}
		cap = cap ? cap * 2 : 256;
		p = realloc(keys, cap * sizeof(Key));
		if(!p)
			die("realloc");
		keys = p;
	}
	keys[nkeys].k = k;
	keys[nkeys].mod = mod;
	nkeys++;
}

static void
loadkeys(char *file)
{
	FILE *f;
	int c;

	f = fopen(file, "r");
	if(!f)
		die(file);
	while((c = fgetc(f)) != EOF){
		if(c == '\n' || c == '\r')
			continue;
		if(c != '^'){
			addkey(c, 0);
			continue;
		}
		c = fgetc(f);
		if(c == EOF)
			break;
		switch(c){
		case 'B':
			addkey(Kback, 0);
			break;
		case 'R':
			addkey(Kret, 0);
			break;
		case 'E':
			addkey(Kesc, 0);
			break;
		default:
			addkey(c, Mctrl);
			break;
		}
	}
	fclose(f);
	if(nkeys == 0){
		fprintf(stderr, "%s: no keys\n", file);
		exit(1);
	}
}

static uint64_t
iterations(char *s)
{
	uintmax_t n;
	char *end;

	if(*s == '\0' || *s == '-')
		goto Bad;
	errno = 0;
	n = strtoumax(s, &end, 10);
	if(errno != 0 || *end != '\0' || n == 0 || n > UINT64_MAX)
		goto Bad;
	return n;
Bad:
	fprintf(stderr, "invalid iteration count: %s\n", s);
	exit(1);
}

static void
dial(void)
{
	fd = ipcconnect();
	if(fd < 0)
		die("connect");
}

static void
sendkey(int key, int mod)
{
	unsigned char req[Ipcreqsz];

	ipcpackreq(req, 0, mod, key);
	if(ipcsend(fd, req, sizeof req) < 0)
		die("write");
}

static int
readresp(void)
{
	char buf[Ipcfieldmax+1];
	Ipcresp resp;

	return ipcreadresp(fd, 0, buf, sizeof buf, NULL, 0, &resp);
}

static double
now(void)
{
	struct timespec ts;

	clock_gettime(CLOCK_MONOTONIC, &ts);
	return ts.tv_sec + ts.tv_nsec * 1e-9;
}

int
main(int argc, char **argv)
{
	size_t j;
	uint64_t i, niter, total;
	double t0, t1, dt;

	if(argc != 2 && argc != 3){
		fprintf(stderr, "usage: bench file [niter]\n");
		exit(1);
	}

	loadkeys(argv[1]);
	niter = argc == 3 ? iterations(argv[2]) : 1000;
	if(nkeys > UINT64_MAX || niter > UINT64_MAX / nkeys){
		fprintf(stderr, "iteration count overflows key total\n");
		exit(1);
	}
	total = niter * nkeys;
	dial();
	t0 = now();
	for(i = 0; i < niter; i++)
		for(j = 0; j < nkeys; j++){
			sendkey(keys[j].k, keys[j].mod);
			if(readresp() < 0){
				fprintf(stderr, "failed at iter %" PRIu64 " key %zu\n", i, j);
				exit(1);
			}
		}
	t1 = now();
	dt = t1 - t0;
	printf("%" PRIu64 " iters x %zu keys = %" PRIu64 " keys\n",
		niter, nkeys, total);
	printf("%.3f ms total, %.3f us/key, %.3f us/iter\n",
		dt * 1000, dt * 1e6 / total, dt * 1e6 / niter);
	close(fd);
	return 0;
}