/*
 *	typomix.c
 *
 *	Jens Kleineheismann <heinzel@heinzelwelt.de>
 */

/* include headers */
#include <ctype.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <time.h>

/* symbols */
#define TRUE 1
#define FALSE 0
#define VERSION "0.5"

/* prototypes */
int  print_version(void);
int  print_help(void);
char *scramble(char *word);
int  xisalpha(char c);

/* definition of extern objects */
char       *progname;
const char *version  = VERSION;

/*
 * main
 */

int main( int argc, char *argv[] ) {
	int      i;
	int      j;
	char     c;
	char    *p;
	char    *word;
	FILE   **input  = NULL;
	FILE   **intemp = NULL;
	size_t   extend = 1024;
	size_t   maxlen;

	/* Store program name without path */
	if( (progname = strdup(basename(argv[0]))) == NULL ) {
		fprintf(stderr, "%s: ", basename(argv[0]));
		perror(NULL);
		exit(EX_OSERR);
	}

	/* Initialize the random generator once here for scramble() */
	srand( (unsigned int) time((time_t *)NULL) );

	/* Initialize array of input streams */
	if( (input = malloc(1 * sizeof(FILE*))) == NULL ) {
		fprintf(stderr, "%s: ", progname);
		perror(NULL);
		exit(EX_OSERR);
	}
	input[0] = NULL;

	/* Parse command line options */
	for( i = 1 ; i < argc ; i++ ) {
		if(!strncmp("--", argv[i], 2)) {
		/* Current argument is a word option */
			if(!strcmp(       "--help", argv[i])) {
				print_help();
				exit(EX_OK);
			} else if(!strcmp("--version", argv[i])) {
				print_version();
				exit(EX_OK);
			} else {
				fprintf(stderr, "%s: invalid option '%s'\n", progname, argv[i]);
				fprintf(stderr, "Try '%s -h' for help.\n", progname);
				exit(EX_USAGE);
			}
		} else if(!strncmp("-", argv[i], 1)) {
		/* Current argument is one or more char options */
			p = argv[i];
			for( j = 1 ; (c = p[j]) != '\0' ; j++) {
				switch(c) {
				case 'h':
					print_help();
					exit(EX_OK);
					break;
				case 'V':
					print_version();
					exit(EX_OK);
					break;
				default:
					fprintf(stderr, "%s: invalid option -- %c\n", progname, c);
					fprintf(stderr, "Try '%s -h' for help.\n", progname);
					exit(EX_USAGE);
				}
			}
		} else {
		/* Argument */
			j = 0;
			while(input[j++] != NULL);
			
			intemp = input;
			if( (input = malloc((j + 1) * sizeof(FILE*))) == NULL ) {
				fprintf(stderr, "%s: ", progname);
				perror(NULL);
				exit(EX_OSERR);
			}
			j = 0;
			while(intemp[j] != NULL) {
				input[j] = intemp[j];
				j++;
			}

			free(intemp);

			if( (input[j++] = fopen(argv[i], "r")) == NULL ) {
				fprintf(stderr, "%s: %s: ", progname, argv[i]);
				perror(NULL);
			}

			input[j] = NULL;
		}
	}

	if( input[0] == NULL ) {
		if( (input = malloc(2 * sizeof(FILE*))) == NULL ) {
			fprintf(stderr, "%s: ", progname);
			perror(NULL);
			exit(EX_OSERR);
		}

		input[0] = stdin;
		input[1] = NULL;
	}

	for( i = 0 ; input[i] != NULL ; i++) {
		word = p = NULL;
		maxlen = j = 0;
		while( (c = getc(input[i])) != EOF ) {
			if(xisalpha(c)) {
				if(j >= maxlen) {
					p = word;
					if( (word = malloc((maxlen + extend) )) == NULL ) {
						fprintf(stderr, "%s: ", progname);
						perror(NULL);
						exit(EX_OSERR);
					}
					maxlen += extend;
					if(p) {
						strcpy(word, p);
						free(p);
					}
				}
				word[j++] = c;
			} else if(word) {

				word[j] = '\0';
				scramble(word);
				j = 0;
				while(word[j] != '\0') {
					putchar(word[j++]);
				}
				free(word);
				word = NULL;
				maxlen = 0;
				j = 0;
				putchar(c);
			} else {
				putchar(c);
			}
		}
	}
	exit(EX_OK);
}

int print_version( void ) {
	printf("%s Version %s\n",progname, version);
	return TRUE;
}

int print_help( void ) {
	printf("\n");
	printf("typomix scrambles letters within words.\n");
	printf("\n");
	printf("Usage: typomix [OPTIONS] [FILE]...\n");
	printf("\n");
	printf("If no file is given, input will be read from stdin.\n");
	printf("\n");
	printf("Options:\n");
	printf("        -h, --help\n");
	printf("        -V, --version\n");
	printf("\n");
	return TRUE;
}

char *scramble(char *word) {
	int    i;
	int    j;
	char   c;
	size_t len;

	len = strlen(word);

	/* To short to scramble */
	if( len < 4 )
		return word;


	for( i = j = 1 ; i < (len - 1) ; i++) {
		j = 1 + (int)((float)(len - 2) * rand()/(RAND_MAX+1.0));
		if( i != j ) {
			c = word[i];
			word[i] = word[j];
			word[j] = c;
			//fprintf(stderr, "%d <-> %d: %s\n", i, j, word);
		}		
	}
	return word;
} 

int xisalpha(char c) {
  switch(c) {
  case 'ä':
  case 'ö':
  case 'ü':
  case 'Ä':
  case 'Ö':
  case 'Ü':
  case 'ß':
	return 1;
  }

  return isalpha(c);
}

/* end */