#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#define BUFSIZE 1024
char wordBuff[BUFSIZE];
char swipeBuff[BUFSIZE];

// fgets, but without the newline.
char *fgetst(char *restrict s, int size, FILE *restrict stream) {
	char *r = fgets(s, size, stream);
	if (r) {
		char * sp = s;
		for(; sp[0] != '\0'; sp++) {
			if (sp[0] == '\n') {
				sp[0] = '\0';
			}
		}
	}
	return r;
}

bool charcmp(char a, char b) {
	return tolower(a) == tolower(b);
}

bool swipeCompare(char *swipe, char *word) {
	if (! charcmp(swipe[0], word[0])) {
		return false;
	}
	char *swipeP = swipe;
	char *wordP = word;
	wordP++;
	bool lastMatch = false;
	for(swipeP++; swipeP[0]; swipeP++) {
		lastMatch = false;
		while (charcmp(swipeP[0], wordP[0])) {
			wordP++;
			lastMatch = true;
		}
	}

	if (wordP[0] == '\0' && lastMatch) {
		return true;
	}
	return false;
}
void query(FILE *wordFile, char *swipe, int n) {
	// TODO: UTF-8 len checking?
	if (swipe[0] == '\0' || swipe[1] == '\0') return;
	fseek(wordFile, 0, SEEK_SET);
	int found = 0;

	while (found < n && fgetst(wordBuff, BUFSIZE, wordFile)) {
		if (swipeCompare(swipe, wordBuff)) {
			if (found > 0) printf("\t");
			printf("%s", wordBuff);
			found++;
		}
	}
}

int main(int argc, char **argv) {
	if (argc < 2) {
		fprintf(stderr, "Usage: swipeGuess words.txt [n]");
		exit(1);
	}
	int n = 1;
	if (argc >= 3) {
		n = atoi(argv[2]);
	}
	FILE *wordFile = fopen(argv[1], "r");
	while (fgetst(swipeBuff, BUFSIZE, stdin)) {
		query(wordFile, swipeBuff, n);
		printf("\n");
		fflush(stdout);
	}
	fclose(wordFile);
}