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

#include "regex-common.h"

int
usage(const char *prg)
{
    printf("\nUsage:\n");
    printf("%s text 'pattern'\n", prg);
    printf("%s text '[m]/pattern/[i]'\n", prg);
    printf("%s text 's/pattern/replacement/[i]'\n\n", prg);
    printf("# Match, no pattern delimiters\n%s 'Hello, world!' world\nHello, world!\n\n", prg);
    printf("# Match, case insensitive\n%s 'Hello, world!' 'm/^hello/i'\nHello, world!\n\n", prg);
    printf("# No match\n%s 'Hello, world!' 'm/^hello/'\n<no output>\n\n", prg);
    printf("# Substitution, match\n%s 'Hello, world!' 's/^Hello/Hi/'\nHi, world!\n\n", prg);
    printf("# Substitution, no match\n%s 'Hello, world!' 's/^Hola/Hi/'\nHello, world!\n\n", prg);
    return 1;
}


int
main(int argc, char *argv[])
{
    char *s_text = NULL;    /* argv[1]: original string */
    char *s_regex = NULL;   /* argv[2]: Perl regex, with possible 'm' or 's' prefix, and modifier flags 'i' */
    char *s_result = NULL;  /* Returned result from regex_perl() call */
    char *p_result = NULL;  /* Result to be printed, either s_result, input text, or NULL (no match). */

    if (argc < 3)
    {
        return usage(argv[0]);
    }

    switch (regex_perl(s_text, s_regex, &s_result))
    {
        case RE_NO_MATCH:
            printf("No match!\n");
            /* Print nothing. */
            /* p_result = NULL; */
            break;
        case RE_NO_SUBST:
            printf("No match!\n");
            /* In case of no substition, s_result is NULL and does not have to be free()'d */
            /* Print the input text. */
            p_result = s_text;
            break;
        case RE_SUCCESS:
            printf("Matched and substituted.\n");
            p_result = s_result;
            break;
        default:
            printf("Should never come here\n");
            break;
    }

    printf("Result: '%s'\n", p_result);
    if (s_result)
    {
        free(s_result);
    }
    return 0;
}