#include "escheme.h"

#include <pwd.h>
#include <stdlib.h>

#define NAME "extension"
#define FUNCTION "info"

static Scheme_Object *get_info(int argc, Scheme_Object *argv[]) {
  struct passwd* who = NULL;
  // copied shamelessly from $plt/src/file.c
  if (argc == 0) {
    char *ptr;
    
    ptr = getenv("USER");
    if (!ptr)
      ptr = getenv("LOGNAME");
    
    if(ptr) {
      who = getpwnam(ptr);
    } else {
      who = getpwuid(getuid());
    }
  } else {
    if (SCHEME_BYTE_STRINGP(argv[0])) {
        const char* user = SCHEME_BYTE_STR_VAL(argv[0]);

        who = getpwnam(user);
        if (!who) {
          scheme_signal_error("Bad user %s", user);
        }
    } else if (SCHEME_INTP(argv[0])) {
      who = getpwuid(SCHEME_INT_VAL(argv[0]));
      if (!who) {
        scheme_signal_error("Bad user ID %d",SCHEME_INT_VAL(argv[0]));
      }
    } else {
      scheme_wrong_type(
                        "extension:get-info",
                        "bytes or integer",
                        0,
                        argc,
                        argv);
    }
  }

  Scheme_Object* result[5];
  // this should be closely synchronized with the user struct in main.ss
  result[0] = scheme_make_byte_string(who->pw_name);
  result[1] = scheme_make_integer(who->pw_uid);
  result[2] = scheme_make_integer(who->pw_gid);
  result[3] = scheme_make_byte_string(who->pw_dir);
  result[4] = scheme_make_byte_string(who->pw_shell);
  return scheme_values(5,result);
}

Scheme_Object *scheme_reload(Scheme_Env *env)
{
        Scheme_Env* mod = scheme_primitive_module(scheme_module_name(),env);
        Scheme_Object* procedure = scheme_make_prim_w_arity(get_info,FUNCTION,0,1);
        scheme_add_global(FUNCTION,procedure,mod);
        scheme_finish_primitive_module(mod);
        return procedure;
}

Scheme_Object *scheme_initialize(Scheme_Env *env)
{
  return scheme_reload(env);
}

Scheme_Object *scheme_module_name(void)
{
 return scheme_intern_symbol(NAME);
}