#!/usr/bin/tcc -run -O2
#include <stdio.h>
#include <string.h>

int main(int argc, char const* argv[])
{
	static const char *beginning;
	static const char *ending;
	int beginning_found = 0, beginning_length = 0;
	int ending_found = 0, ending_length = 0;

	// TODO: getopt to enable this
	int multimatching = 0;

	FILE *fp;
	int read;
	char buf[4096];
	int i;

	if (argc != 4) {
		puts("Usage: partextract <file> <start token> <end token>");
		puts("");
		puts("partextract outputs everything between the start and end token");
		puts("(including the tokens). Only the first match will be output");
		puts("unless multimatching is enabled and overlapping tokens will be ignored.");
		return 1;
	}

	beginning = argv[2];
	ending = argv[3];

	beginning_length = strlen(beginning);
	ending_length = strlen(ending);

	fp = fopen(argv[1], "rb");
	if (fp == NULL) {
		perror(argv[1]);
		return 1;
	}

	while (!feof(fp)) {
		read = fread(buf, sizeof(char), sizeof(buf), fp);
		for (i = 0; i < read; i++) {
			// find the starting token
			if (beginning_found != beginning_length && ending_found != ending_length) {
				if (buf[i] == beginning[beginning_found]) {
					beginning_found++;
					if (beginning_found == beginning_length) {
						// we don't allow tokens to overlap
						ending_found = 0;

						// We only start outputting if we had the complete start token
						// This makes sure the token is in the output too
						// and jumps to the next char so the fputc below won't run for
						// the last char of the token
						fputs(beginning, stdout);
						continue;
					}
				} else if (beginning_found != beginning_length) {
					beginning_found = 0;
				}
			}

			// output until we hit the ending token
			if (beginning_found == beginning_length && ending_found != ending_length) {
				fputc(buf[i], stdout);

				if (buf[i] == ending[ending_found]) {
					ending_found++;

					if (multimatching && ending_found == ending_length) {
						beginning_found = 0;
						ending_found = 0;
					}
				} else if (ending_found != ending_length) {
					ending_found = 0;
				}
			}
		}
	}


	return 0;
}