#if 0
${CC:-gcc} -s -O2 -std=c99 -Wall -o ${SPREED_INSTALL_DIR:-.}/spreed spreed.c
exit
#endif

#define _POSIX_C_SOURCE 200809L

#include <locale.h>  // setlocale
#include <stdio.h>   // getchar, stdin/out/err
#include <stdlib.h>  // getenv, strtoll
#include <string.h>  // strstr
#include <time.h>    // timespec
#include <wchar.h>   // fwide, mbrtowc, putwchar
#include <wctype.h>  // iswprint, iswspace, iswalnum

#define SPRD_VER   L"0.1"
#define CLR_FG     L"\033[31m"
#define CLR_RESET  L"\033[0m"
#define SPRD_CLOCK CLOCK_MONOTONIC
#define MS_PER_MIN (60ll * 1000000000ll)

#define SPRD_CLOCK_DIFF(t1, t2) ((((long int)t1.tv_sec * 1000000000ll) + (long int)t1.tv_nsec) - (((long int)t2.tv_sec * 1000000000ll) + (long int)t2.tv_nsec))

const unsigned char orps[9] = {0,0,0,1,1,2,2,2,2};

unsigned char get_optimal_recognition_point(size_t len) {
	if (len >= 10) return 3;
	return orps[len-1];
}

int main(int argc, char *argv[])
{
	struct timespec ts_last, ts_current, ts_sleep;
	wchar_t word[37];
	wchar_t wc;
	char *str;
	long int cooldown, wpm_ns;
	int c;
	char chararr[4];
	unsigned char u, uu, ichar, iword, b_word_break;

	setlocale(LC_ALL, "");
	fwide(stdout, 1);

	clock_getres(SPRD_CLOCK, &ts_last);
	memset(word, 0, 37 * sizeof(wchar_t));
	cooldown = 0;
	wpm_ns = MS_PER_MIN / 250;
	memset(chararr, 0, sizeof(chararr));
	ichar = 0;
	iword = 0;
	b_word_break = 0;

	if (argc > 1) {
		if (strstr(argv[1], "-v") || strstr(argv[1], "--v") || strstr(argv[1], "-V") || strstr(argv[1], "--V")) {
			c = fputws(L"spreed version " SPRD_VER L"\n", stdout);
			if (c == EOF) {
				perror("fputws()");
			}
			return 0;
		}
	}

	str = getenv("SPREED_WPM");
	if (argc > 1) {
		str = argv[1];
	}
	if (str != NULL) {
		wpm_ns = strtoll(str, NULL, 10);
		if (wpm_ns == 0) {

			fputws(L"Error: parsed wpm as 0, setting to default of 250\n", stdout);
			wpm_ns = 250;
		} else if (wpm_ns > (60 * 30)) {
			wpm_ns = 60 * 30;
			fputws(L"Limiting to 1800 wpm (30 fps)\n", stdout);
		}
		wpm_ns = MS_PER_MIN / wpm_ns;
	}

	fputws(L"          V\n", stdout);
	clock_gettime(SPRD_CLOCK, &ts_current);
	ts_last = ts_current;
	ts_last.tv_sec -= 60;
	do {
		while (cooldown > 0) {
			clock_gettime(SPRD_CLOCK, &ts_current);
			cooldown -= SPRD_CLOCK_DIFF(ts_current, ts_last);
			if (cooldown <= 0) {
				break;
			}
			ts_sleep.tv_sec = 0;
			ts_sleep.tv_nsec = cooldown > 1000000000ll ? 999999999ll : cooldown;
			nanosleep(&ts_sleep, NULL);
		}
		b_word_break = 0;
		c = getchar();
		if (c == EOF) {
			b_word_break = iword > 0;
			goto END_OF_WORD;
		}
		chararr[ichar++] = (char)c;

		switch(mbrtowc(&wc, chararr, 4, NULL)) {
			case 0:
				// null char
				if (iword == 0 && ichar == 1) {
					ichar = 0;
					memset(chararr, 0, 4 * sizeof(char));
					continue;
				} else {
					b_word_break = 1;
					goto END_OF_WORD;
				}
			case (size_t)-2:
				// incomplete wchar_t, keep reading bytes
				continue;
			case (size_t)-1:
				if (ichar == 4) {
					// emojis return (size_t)-1 until we have all the bytes
					fputws(L"\nmbrtowc encoding error\n", stderr);
					return 1;
				}
				continue;
		}

		// not a printable character, swallow
		if (!iswprint(wc) && iword == 0) {
			ichar = 0;
			memset(chararr, 0, 4 * sizeof(char));
			continue;
		}

		if (iswspace(wc)) {
			if (iword == 0) {
				ichar = 0;
				memset(chararr, 0, 4 * sizeof(char));
				continue;
			}
			b_word_break = 1;
		}

END_OF_WORD:
		ichar = 0;
		memset(chararr, 0, 4 * sizeof(char));

		if (b_word_break != 0 || iword >= 37) {
			if (iword == 0) {
				fputws(L"\n0 length word\n", stderr);
				return 2;
			}
			ichar = get_optimal_recognition_point(iword);
			uu = 0;
			putwchar('\r');
			for (u = 0; u < 48; ++u) {
				if (u < 10-ichar) {
					putwchar(L' ');
					continue;
				}
				if (uu < iword) {
					if (u == 10) {
						fputws(CLR_FG, stdout);
					}
					putwchar(word[uu++]);
					if (u == 10) {
						fputws(CLR_RESET, stdout);
					}
					continue;
				}
				putwchar(L' ');
			}

			fflush(stdout);

			while (iword > 0) {
				if (iswalnum(word[iword-1])) {
					break;
				}
				if (word[iword-1] == L'.' || word[iword-1] == L'!' || word[iword-1] == L'?') {
					cooldown += wpm_ns;
					break;
				}
				iword--;
			}
			cooldown += wpm_ns;

			iword = 0;
			memset(word, 0, 37 * sizeof(wchar_t));
			ts_last = ts_current;
		}

		ichar = 0;
		if (!iswspace(wc)) {
			word[iword++] = wc;
		}

	} while (c != EOF);

	putwchar('\n');

	return 0;
}