/*

Copyright (c) 2001, Dr Martin Porter
Copyright (c) 2002, Richard Boulton
All rights reserved.

Redistribution and use in source and binary forms, with 
or without modification, are permitted provided that the 
following conditions are met:

*	Redistributions of source code must retain the 
	above copyright notice, this list of conditions and 
	the following disclaimer. 
*	Redistributions in binary form must reproduce 
	above copyright notice, this list of conditions and
 	the following disclaimer in the documentation and/or 
	other materials provided with the distribution. 
*	Neither the name of the <ORGANIZATION> nor the 
	names of its contributors may be used to endorse or 
	promote products derived from this software without
	specific rior written permission. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 
DAMAGE.

*/

/* This is a simple program which uses libstemmer to provide a command
 * line interface for stemming using any of the algorithms provided.
 */

#include <stdio.h>
#include <stdlib.h> /* for malloc, free */
#include <string.h> /* for memmove */
#include <ctype.h>  /* for isupper, tolower */

#include "libstemmer.h"

const char * progname;
static int pretty = 1;

static void
stem_file(struct sb_stemmer * stemmer, FILE * f_in, FILE * f_out)
{
#define INC 10
    int lim = INC;
    sb_symbol * b = (sb_symbol *) malloc(lim * sizeof(sb_symbol));

    while(1) {
        int ch = getc(f_in);
        if (ch == EOF) {
            free(b); return;
        }
        {
            int i = 0;
	    int inlen = 0;
            while(1) {
                if (ch == '\n' || ch == EOF) break;
                if (i == lim) {
                    sb_symbol * newb;
		    newb = (sb_symbol *)
			    realloc(b, (lim + INC) * sizeof(sb_symbol));
		    if (newb == 0) goto error;
		    b = newb;
                    lim = lim + INC;
                }
		/* Update count of utf-8 characters. */
		if (ch < 0x80 || ch > 0xBF) inlen += 1;
                /* force lower case: */
                if (isupper(ch)) ch = tolower(ch);

                b[i] = ch;
		i++;
                ch = getc(f_in);
            }

	    {
		const sb_symbol * stemmed = sb_stemmer_stem(stemmer, b, i);
                if (stemmed == NULL)
                {
                    fprintf(stderr, "Out of memory");
                    exit(1);
                }
                else
		{
		    if (pretty == 1) {
			fwrite(b, i, 1, f_out);
			fputs(" -> ", f_out);
		    } else if (pretty == 2) {
			fwrite(b, i, 1, f_out);
			if (sb_stemmer_length(stemmer) > 0) {
			    int j;
			    if (inlen < 30) {
				for (j = 30 - inlen; j > 0; j--)
				    fputs(" ", f_out);
			    } else {
				fputs("\n", f_out);
				for (j = 30; j > 0; j--)
				    fputs(" ", f_out);
			    }
			}
		    }

		    fputs((char *)stemmed, f_out);
		    putc('\n', f_out);
		}
            }
        }
    }
error:
    if (b != 0) free(b);
    return;
}

/** Display the command line syntax, and then exit.
 *  @param n The value to exit with.
 */
static void
usage(int n)
{
    printf("usage: %s [-l <language>] [-i <input file>] [-o <output file>] [-c <character encoding>] [-p[2]] [-h]\n"
	  "\n"
	  "The input file consists of a list of words to be stemmed, one per\n"
	  "line. Words should be in lower case, but (for English) A-Z letters\n"
	  "are mapped to their a-z equivalents anyway. If omitted, stdin is\n"
	  "used.\n"
	  "\n"
	  "If -c is given, the argument is the character encoding of the input\n"
          "and output files.  If it is omitted, the UTF-8 encoding is used.\n"
	  "\n"
	  "If -p is given the output file consists of each word of the input\n"
	  "file followed by \"->\" followed by its stemmed equivalent.\n"
	  "If -p2 is given the output file is a two column layout containing\n"
	  "the input words in the first column and the stemmed eqivalents in\n"
	  "the second column.\n"
	  "Otherwise, the output file consists of the stemmed words, one per\n"
	  "line.\n"
	  "\n"
	  "-h displays this help\n",
	  progname);
    exit(n);
}

int
main(int argc, char * argv[])
{
    char * in = 0;
    char * out = 0;
    FILE * f_in;
    FILE * f_out;
    struct sb_stemmer * stemmer;

    char * language = "english";
    char * charenc = NULL;

    char * s;
    int i = 1;
    pretty = 0;

    progname = argv[0];

    while(i < argc) {
	s = argv[i++];
	if (s[0] == '-') {
	    if (strcmp(s, "-o") == 0) {
		if (i >= argc) {
		    fprintf(stderr, "%s requires an argument\n", s);
		    exit(1);
		}
		out = argv[i++];
	    } else if (strcmp(s, "-i") == 0) {
		if (i >= argc) {
		    fprintf(stderr, "%s requires an argument\n", s);
		    exit(1);
		}
		in = argv[i++];
	    } else if (strcmp(s, "-l") == 0) {
		if (i >= argc) {
		    fprintf(stderr, "%s requires an argument\n", s);
		    exit(1);
		}
		language = argv[i++];
	    } else if (strcmp(s, "-c") == 0) {
		if (i >= argc) {
		    fprintf(stderr, "%s requires an argument\n", s);
		    exit(1);
		}
		charenc = argv[i++];
	    } else if (strcmp(s, "-p2") == 0) {
		pretty = 2;
	    } else if (strcmp(s, "-p") == 0) {
		pretty = 1;
	    } else if (strcmp(s, "-h") == 0) {
		usage(0);
	    } else {
		fprintf(stderr, "option %s unknown\n", s);
		usage(1);
	    }
	} else {
	    fprintf(stderr, "unexpected parameter %s\n", s);
	    usage(1);
	}
    }

    /* prepare the files */
    f_in = (in == 0) ? stdin : fopen(in, "r");
    if (f_in == 0) {
	fprintf(stderr, "file %s not found\n", in);
	exit(1);
    }
    f_out = (out == 0) ? stdout : fopen(out, "w");
    if (f_out == 0) {
	fprintf(stderr, "file %s cannot be opened\n", out);
	exit(1);
    }

    /* do the stemming process: */
    stemmer = sb_stemmer_new(language, charenc);
    if (stemmer == 0) {
        if (charenc == NULL) {
            fprintf(stderr, "language `%s' not available for stemming\n", language);
            exit(1);
        } else {
            fprintf(stderr, "language `%s' not available for stemming in encoding `%s'\n", language, charenc);
            exit(1);
        }
    }
    stem_file(stemmer, f_in, f_out);
    sb_stemmer_delete(stemmer);

    if (in != 0) (void) fclose(f_in);
    if (out != 0) (void) fclose(f_out);

    return 0;
}

