/******************************************************************************/
/* SlunkCrypt, by LoRd_MuldeR <MuldeR2@GMX.de>                                */
/* This work has been released under the CC0 1.0 Universal license!           */
/******************************************************************************/

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS 1
#endif

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

#ifdef _MSC_VER
#define strdup(X) _strdup((X))
#define strcasecmp(X,Y) _stricmp((X),(Y))
#define __inline__ __inline
#endif

#ifdef __MINGW64_VERSION_MAJOR
int _dowildcard = -1;
#endif

#define MIN_LENGTH       8U
#define MAX_LENGTH     128U
#define TABLE_SIZE 1000000U

static char *g_table[TABLE_SIZE];

static __inline__ int string_compare(void const *lhs, void const *rhs)
{
    return strcasecmp(*((const char* const*)lhs), *((const char* const*)rhs));
}

static __inline__ int is_ascii(const char *str)
{
    unsigned char chr;
    while ((chr = *str++)) {
        if ((chr < 0x20) || (chr >= 0x7F)) {
            return 0;
        }
    }
    return 1;
}

static __inline__ int append_char(char *const buffer, const size_t size, size_t *const offset, const char chr)
{
    if (*offset < size) {
        buffer[(*offset)++] = chr;
        return 1;
    }
    return 0;
}

static __inline__ int escape_char(char *const chr)
{
    switch (*chr) {
        case '\\': return 1;
        case '"' : return 1;
        case '\a': *chr = 'a'; return 2;
        case '\b': *chr = 'b'; return 2;
        case '\n': *chr = 'n'; return 2;
        case '\r': *chr = 'r'; return 2;
        case '\t': *chr = 't'; return 2;
        case '\v': *chr = 'v'; return 2;
        default:
            if ((*chr < 0x20) || (*chr == 0x7F)) {
                return -1;
            }
            return 0;
    }
}

static __inline__ int escape_str(char *const dst, const size_t capacity, const char *src)
{
    size_t offset = 0U;
    char chr;
    static const char ESC = '\\', NUL = '\0';
    while ((chr = *src++)) {
        switch (escape_char(&chr)) {
            case 1:
            case 2:
                if (!append_char(dst, capacity, &offset, ESC)) {
                    return -1;
                }
            case 0:
                if (!append_char(dst, capacity, &offset, chr)) {
                    return -1;
                }
                break;
            default:
                return 0; /* error! */
        }
    }
    if (!append_char(dst, capacity, &offset, NUL)) {
        return -1;
    }
    return 1;
}

int main(int argc, char* argv[])
{
    char *line, buffer[1024U], escaped[256U];
    FILE* file = NULL;
    size_t i, j, len, count = 0U;

    if (argc < 2) {
        fputs("Error: Input file not specified!\n", stderr);
        return 1;
    }

    for (i = 1; i < argc; ++i) {
        if (!(file = fopen(argv[i], "r"))) {
            fputs("Error: Failed to open input file!\n", stderr);
            return 1;
        }

        while ((line = fgets(buffer, sizeof(buffer), file))) {
            if ((len = strlen(line)) > 0U) {
                while ((len > 0U) && ((line[len - 1U] == '\r') || (line[len - 1U] == '\n'))) {
                    line[--len] = '\0';
                }
                while ((len > 0U) && ((line[0U] == '\x20') || (line[0U] == '\t'))) {
                    ++line; --len;
                }
                while ((len > 0U) && ((line[len - 1U] == '\x20') || (line[len - 1U] == '\t'))) {
                    line[--len] = '\0';
                }
                if ((len >= MIN_LENGTH) && (len <= MAX_LENGTH) && is_ascii(line)) {
                    for (j = 0U; j < count; ++j) {
                        if (!strcasecmp(line, g_table[j])) {
                            goto skip_line;
                        }
                    }
                    if (count >= TABLE_SIZE) {
                        fputs("Error: Too many lines!\n", stderr);
                        abort();
                    }
                    if (escape_str(escaped, sizeof(escaped), line) > 0) {
                        if (!(g_table[count++] = strdup(escaped))) {
                            fputs("Error: Memory allocation has failed!\n", stderr);
                            abort();
                        }
                    }
                    else {
                        fprintf(stderr, "Failed to encode line: \"%s\"\n", line);
                    }
                }
                skip_line:;
            }
        }

        fclose(file);
    }

    qsort(g_table, count, sizeof(const char*), string_compare);

    printf("#define WORST_PASSWD_SIZE %zuU\n\n", count);
    puts("static const char *const WORST_PASSWD[WORST_PASSWD_SIZE] =\n{");
    for (i = 0U; i < count; ++i) {
        if (i > 0U) {
            printf(",\n");
        }
        printf("\t \"%s\"", g_table[i]);
    }
    puts("\n};");

    for (i = 0U; i < count; ++i) {
        free(g_table[i]);
    }
}