#include "l2su.h"
#include "macros.h"

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

char *l2_launcher__strdup(const char *);
char *l2_launcher__strapp(char *, const char *);

char *l2_launcher__find_config_path(void)
{
  /* check for $L2SU_CONFIG */
  char *config = getenv(PROJECT_NAME_UPPER "_CONFIG");
  if (config) {
    return l2_launcher__strdup(config);
  }
  
  /* check for $XDG_CONFIG_HOME */
  config = getenv("XDG_CONFIG_HOME");
  if (config) {
    /* want to append '"/" PROJECT_NAME' to our string */
    char *ret = l2_launcher__strdup(config);
    if (!ret) return NULL;

    return l2_launcher__strapp(ret, "/" PROJECT_NAME);
  }

  /* check for $HOME/.config */
  config = getenv("HOME");
  if (config) {
    char *ret = l2_launcher__strdup(config);
    if (!ret) return NULL;

    return l2_launcher__strapp(ret, "/.config/" PROJECT_NAME);
  }

  /* fail (do NOT attempt to find home directory from passwd */
  return NULL;
}

char *l2_launcher__find_data_path(void)
{
  /* check for $L2SU_DATA */
  char *config = getenv(PROJECT_NAME_UPPER "_DATA");
  if (config) {
    return l2_launcher__strdup(config);
  }

  /* check for $XDG_DATA_HOME */
  config = getenv("XDG_DATA_HOME");
  if (config) {
    char *ret = l2_launcher__strdup(config);
    if (!ret) return NULL;

    return l2_launcher__strapp(ret, "/" PROJECT_NAME);
  }

  /* check for $HOME/.local/share */
  config = getenv("HOME");
  if (config) {
    char *ret = l2_launcher__strdup(config);
    if (!ret) return NULL;

    return l2_launcher__strapp(ret, "/.local/share/" PROJECT_NAME);
  }

  return NULL;
}

int l2_launcher_init(void)
{
  /* find paths (set up l2_state.paths) */
  /* create folders if they don't exist */

  printf("project is " PROJECT_NAME "...\n");
 
  /* look for config path */
  if (!(l2_state.paths.config = l2_launcher__find_config_path())) {
    fputs("fatal: Could not decide on a configuration directory! Please define " PROJECT_NAME_UPPER "_CONFIG to a sensible value.\n", stderr);
    return 1;
  }

  if (!(l2_state.paths.data = l2_launcher__find_data_path())) {
    fputs("fatal: Could not decide on a data directory! Please define " PROJECT_NAME_UPPER "_DATA to a sensible value.\n", stderr);
    return 1;
  }

  printf("config path: %s\n", l2_state.paths.config);
  printf("data path: %s\n", l2_state.paths.data);

  return 0;
}

int main(void)
{
  int status = l2_launcher_init();
  if (status != 0) return status;

  return 0;
}

/* handcoded string functions
 *
 * NOTE: I am aware that this is inefficient but since these are used only a handful of times
 * during initialization, I don't think performance is really a huge deal here.
 *
 * remember that this is a Minecraft launcher, so the PC has to meet the minimum specs of that,
 * which are well above the minimum specs of this launcher */

char *l2_launcher__strdup(const char *in)
{
  if (!in) return NULL;

  size_t inlen = strlen(in);
  char *ret = calloc(1, inlen + 1);

  if (ret) memcpy(ret, in, inlen);

  return ret;
}

char *l2_launcher__strapp(char *buf, const char *src)
{
  size_t buflen = strlen(buf);
  size_t srclen = strlen(src);

  char *ret = realloc(buf, buflen + srclen + 1);
  if (!ret) return NULL;

  memcpy(ret + buflen, src, srclen);
  ret[buflen + srclen] = '\0';

  return ret;
}