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

char *partLower    = "abcdefghijklmnopqrstuvwxyz";
char *partDigit    = "0123456789";
char *partHex      = "ABCDEF";
char *partUpper    = "GHIJLKMNOPQRSTUVWXWY";
char *partPunct    = "!@#$%^&()-=+.,~`;/\\?*:|\"<>_";

char alphabet[256];

size_t num[256];
size_t scale_of_notation[256];
char *alphabet_num[256];
size_t len;

/////////////////////////////////////
void run(size_t min, size_t max, char *alphabet)
{
    // инициализация
    len = min;
    for(size_t i=0; i < min; i++)
        num[i] = 1;

    for(size_t i=0; i <= max; i++)
    {
        alphabet_num[i]=alphabet;
        scale_of_notation[i]=strlen(alphabet);
    }

    while(len <= max)
    {
        //вывод num
        char str[256];
        str[0]=0;
        size_t i = 0;
        while(num[i])
        {
            //strcat(cstr,alphabet[i][num[i] - 1]);
            str[i]=alphabet[num[i] - 1];
            i++;
        }
        str[i]=0;
        puts(str);

        // увеличиваем num на 1
        i = 0;
        size_t carry = 0;
        do
        {
            num[i]++;
            if(num[i] > scale_of_notation[i])
            {
                num[i] = 1;
                carry = 1;
            }
            else
            {
                carry = 0;
            }

            i++;
        }
        while(carry);
        if(i > len) len=i;
    }
}
/////////////////////////////////////

struct option
{
    char *opt;
    size_t code;
};

struct option options[] = {
    {"lower",1},
    {"punct",2},
    {"upper",3},
    {"xdigit",4},
    {"digit",5},
    {"\0x00",0}
};

/////////////////////////////////////
size_t find_option(char *option)
{
    size_t result = 0;

    for(size_t i=0; *options[i].opt; i++)
        if (strcmp( option, options[i].opt) == 0)
        {
            result = options[i].code;
            options[i].code = 0;
            break;
        }

    return result;
}
/////////////////////////////////////
int main(int argc,char **arg, char **env)
{
    if (argc < 3)
    {
        fprintf(stderr,"\nPassword Generation 2.0 (c) m_Sla and SQL.RU. Written in 'C' :)\n");
        fprintf(stderr,"Special thnx to: Mayton, Dima T.\n");
        fprintf(stderr,"\nUsage: pwdgen [n] [m] [options..] \n");
        fprintf(stderr,"\nWhere: options:\n");
        fprintf(stderr,"\n       lower  - Lowercase alphabetic characters [a..z]");
        fprintf(stderr,"\n       punct  - Punctuation characters [,!?..]");
        fprintf(stderr,"\n       upper  - Uppercase alphabetic characters [A..Z]");
        fprintf(stderr,"\n       xdigit - Hexidecimal characters");
        fprintf(stderr,"\n       digit  - Numeric digits [0..9]");
        fprintf(stderr,"\n");
        return -1;
    }
    else
    {
        int n = 0;
        n = atoi(arg[1]);
        int m = 0;
        m = atoi(arg[2]);
        if(m < n)
        {
            fprintf(stderr,"\n[m] cannot be less than [n]!\n");
            return -3;
        }
        if (m > 0 && n > 0)
        {
            if (argc==3)
            {
                strcat(alphabet, partLower);
                run( n, m, alphabet);
                return 0;
            }
            else
            {
                size_t i = 3;
                while(i<argc)
                {
                    switch(find_option(arg[i]))
                    {
                    case 1: // lower
                        strcat(alphabet,partLower);
                        break;
                    case 2: // punct
                        strcat(alphabet,partPunct);
                        break;
                    case 3: // upper
                        strcat(alphabet,partHex);
                        strcat(alphabet,partUpper);
                        break;
                    case 4: // xdigit
                        strcat(alphabet,partDigit);
                        strcat(alphabet,partHex);
                        break;
                    case 5: // digit
                        strcat(alphabet,partDigit);
                        break;
                    }
                    i++;
                }
                if(strlen(alphabet))
                    run( n, m, alphabet);
            }
        }
        else
        {
            fprintf(stderr,"\nArgument cannot be less than 0 or not a number!\n");
            return -2;
        }
    }
    return 0;
}
/////////////////////////////////////