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

#include <unistd.h>

#define LEFT_TO_RIGHT 0
#define RIGHT_TO_LEFT 1

char *home_to_tilde(char *s, char *home) {
   char *new_str;
   char *index;
   int x, i, sx;

   sx = strlen(s);
   
   new_str = malloc(strlen(s) + 1);
   new_str[0] = 0;
   if (!strncmp(s, home, strlen(home))) {
      strcat(new_str, "~");
      x = strlen(home);
   } else
     x = 0;
   for(i=(x) ? 1 : 0; s[x]; i++, x++)
     new_str[i] = s[x];
   
   return new_str;
}

char *cwd_to_color(char *cwd, int color) {
   static char col[2048];
   char *ptr;
   int i = 0;
   char g1[32], g2[32], g3[32], n[32];
   
   sprintf(g1, "\\[\\033[1;30m\\]");
   sprintf(g2, "\\[\\033[0;%im\\]", color);
   sprintf(g3, "\\[\\033[1;%im\\]", color);
   
   col[0] = 0;
   ptr = cwd;
   while(*ptr) {
      if (*ptr == '~' || *ptr == '/') {
	 strcat(col, g3);
	 i += strlen(g3);
      }
      col[i++] = *ptr;
      if (*ptr == '~' || *ptr == '/') {
	 strcat(col, g2);
	 i += strlen(g2);
      }
      ptr++;
   }
   
   return col;
}

char *gradient_text(char *s, int color, int direction) {
   static char user[1024];
   
   if (direction == LEFT_TO_RIGHT) {
      snprintf(user, sizeof(user), "\\[\\033[1;37m\\]%c\\[\\033[1;%im\\]%c\\[\\033[0;%im\\]",
	       s[0], color, s[1], color);
      s += 2;
      strcat(user, s);
   } else if (direction == RIGHT_TO_LEFT) {
      int x = strlen(s);
      
      snprintf(user, sizeof(user), "\\[\\033[0;%im\\]%s", color, s);
      snprintf(user + (strlen(user) - 2), sizeof(user) - (strlen(user) + 2),
	       "\\[\\033[1;%im\\]%c\\[\\033[1;37m\\]%c",
	       color, s[x - 2], s[x - 1]);
   }
   
   return user;
}

char *get_username(int color) {
   static char user[1024];
   char *user_ptr;

   user_ptr = getlogin();
   
   snprintf(user, sizeof(user), gradient_text(user_ptr, color, LEFT_TO_RIGHT));
/*   snprintf(user, sizeof(user), "\\[\\033[1;37m\\]%c\\[\\033[1;%im\\]%c\\[\\033[0;%im\\]", user_ptr[0], color, user_ptr[1], color);
   user_ptr += 2;
   strcat(user, user_ptr);*/
   
   return user;
}

char *get_hostname(int color) {
   static char host[1024];
   char *host_ptr, host_buf[1024];
   int len = 0;

   gethostname(host_buf, sizeof(host_buf));
  
   snprintf(host, sizeof(host), gradient_text(host_buf, color, LEFT_TO_RIGHT));
/*   snprintf(host, sizeof(host), "\\[\\033[1;%im\\]%c\\[\\033[0;%im\\]", color, host_buf[0], color);
   host_ptr = host_buf;
   host_ptr++;
   strcat(host, host_ptr);*/
   
   return host;
}

char *real_calc_ps1(char *cwd, char *user, char *host, int color, char dm) {
   static char ps1[2048];
   char g1[32], g2[32], g3[32], n[32];
   
   sprintf(g1, "\\[\\033[1;30m\\]");
   sprintf(g2, "\\[\\033[0;%im\\]", color);
   sprintf(g3, "\\[\\033[1;%im\\]", color);
   sprintf(n, "\\[\\033[0m\\]");

   snprintf(ps1, sizeof(ps1), "%s%c%s%c%s%c %s %s@ %s %s%c %s%s %s%c%s%c%s%c\n%s%c%s%c%s%c %s> %s",
	    g1, dm, g2, dm, g3, dm, 
	    user, 
	    g1, host, 
	    g1, dm, 
	    g2, cwd, 
	    g3, dm, g2, dm, g1, dm, 
	    g1, dm, g2, dm, g3, dm, 
	    g2, n);
   
   return ps1;
}

char *calc_ps1(int color, char dm) {
   char *cwd, *new_cwd, *color_cwd;
   char *user, *host, *ps1;
   
   cwd = get_current_dir_name();
   if (!cwd) return NULL;

   new_cwd = home_to_tilde(cwd, getenv("HOME"));
   color_cwd = cwd_to_color(new_cwd, color);
   free(new_cwd);
   
   user = get_username(color);
   host = get_hostname(color);
   ps1 = real_calc_ps1(color_cwd, user, host, color, dm);
   
   return ps1;
}

int main(int argc, char **argv) {
   char *ps1;
   
   if (argc < 3) {
      printf("ERROR passing args to jastaps1!\n");
      return 1;
   }

   ps1 = calc_ps1(atoi(argv[1]), argv[2][0]);
   if (!ps1) return 1;
   
   printf("%s\n", ps1);
   
   return 0;
}