#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define maxtofrom 10

int main(int argc, char *argv[])
{
	long from=0, to=0, end=0;
	int inflag=0, outflag=0, ocountflag=0, delflag=0, commaflag=0;
	FILE *filep;
	FILE *tdelfilep;
	char tester[100000]; /* if you have a line longer than this then you have a problem. */
	char *filename;
	filename = (char *)malloc(300);
	sprintf(filename, "%s/%s", getenv("HOME"), ".clipboard");
	char delim[32] = "------------------------------\n";
	long counter = 0;

	if (argc>1) {
		for (int i=1; argv[i]; i++) {
			if (argv[i][0]=='-' && argv[i][1] && argv[i][1]=='f' && argv[i+1]) {
				filename = argv[i+1];
				i++; /* makes cursor skip file name */
			}
			else {
				char *where = argv[i];
				int fromcount=0, tocount=0;
				char cfrom[maxtofrom+8];
				char cto[maxtofrom+8];
				for (int j=0; where[j] && j<=(maxtofrom*2+8); j++) {
					if (where[j]==',') { commaflag=1; continue; }
					switch (where[j]) {
						case 'i': inflag = 1;
					        	  break;
						case 'p': outflag = 1; 
						          break;
						case 'd': delflag = 1;; 
						          break;
						case 'c': ocountflag = 1;
						          break;
					}
					if (!commaflag) cfrom[fromcount++] = where[j];
					else cto[tocount++] = where[j];
				}
				if (commaflag) {
					from = atol(cfrom);
					to = atol(cto);
				} else {
					to = (from=atol(cfrom));
				}
				if (!from && commaflag && to) {
					fputs("clip: must have a number before comma\n", stderr);
					exit(1);
				}
				if (from > to) {
					fputs("clip: first number must be less than second\n", stderr);
					exit(1);
				}
			}
		}
		if (!inflag && !outflag && !delflag && !ocountflag) {
			fputs("usage: clip [-f filename] [justcount|in|out #,#|delete #,#]\n", stderr);
			exit(1);
		}
	} else {
		fputs("usage: clip [-f filename] [count|in|print #,#|delete #,#]\n", stderr);
		exit(1);
	}

	if ((filep=fopen(filename, "a+"))==NULL) {
		fprintf(stderr, "clip: cannot open %s", filename);
		exit(1);
	}
	if (inflag) {
		char inbuf[1000000];
		fread(inbuf, sizeof(inbuf), 1, stdin);
		fprintf(filep, "%s%s", delim, inbuf);
		goto ending;
	}

	while (fgets(tester, sizeof(tester), filep))
		if (memcmp(tester, delim, sizeof(delim)-1)==0)
			end++;
	rewind(filep);

	if (ocountflag) {
		printf("%ld\n", end);
		goto ending; /* stops program after outputting count */
	}

	if (end==0) {
		fputs("nothing to act on\n", stderr);
		fclose(filep);
		exit(1);
	}
	if (to>end) {
		fputs("clip: end point too big\n", stderr);
		fclose(filep);
		exit(1);
	}
	if (!from && !to && commaflag) { from=1; to=end; }
	if (!from && !to && !commaflag) { from = end; to = end; }
	if (delflag) {
		int delimflag=0;
		if ((tdelfilep=fopen(".clipboard~~~", "w+"))==NULL) {
			fputs("clip: cannot create temporary file\n", stderr);
			fclose(filep);
			exit(1);
		}
		while (counter <= end && fgets(tester, sizeof(tester), filep)) {
			if (memcmp(tester, delim, sizeof(delim)-1)==0) {
				counter++;
				delimflag=1;
				continue;
			}
			if (counter < from || counter > to) {
				fprintf(tdelfilep, "%s%s", delimflag?delim:"", tester);
				delimflag=0;
			}
		}
		rename(".clipboard~~~", filename);
		goto ending;
	}

	if (outflag) {
		while (counter <= end  && fgets(tester, sizeof(tester), filep)) {
			if (memcmp(tester, delim, sizeof(delim)-1)==0) {
				counter++;
				continue;
			}
			if (counter >= from && counter <= to) {
				fputs(tester, stdout);
			}
		}
	}
ending:
 	fclose(filep);
	exit(0);
}