/* SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup bke
 *
 * Access to application level directories.
 */

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

#include "BLI_fileops.h"
#include "BLI_fileops_types.h"
#include "BLI_listbase.h"
#include "BLI_path_util.h"
#include "BLI_string.h"
#include "BLI_string_utf8.h"
#include "BLI_string_utils.h"
#include "BLI_utildefines.h"

#include "BKE_appdir.h" /* own include */
#include "BKE_blender_version.h"

#include "BLT_translation.h"

#include "GHOST_Path-api.h"

#include "MEM_guardedalloc.h"

#include "CLG_log.h"

#ifdef WIN32
#  include "utf_winfunc.h"
#  include "utfconv.h"
#  include <io.h>
#  ifdef _WIN32_IE
#    undef _WIN32_IE
#  endif
#  define _WIN32_IE 0x0501
#  include "BLI_winstuff.h"
#  include <shlobj.h>
#  include <windows.h>
#else /* non windows */
#  ifdef WITH_BINRELOC
#    include "binreloc.h"
#  endif
/* #mkdtemp on OSX (and probably all *BSD?), not worth making specific check for this OS. */
#  include <unistd.h>
#endif /* WIN32 */

static const char _str_null[] = "(null)";
#define STR_OR_FALLBACK(a) ((a) ? (a) : _str_null)

/* -------------------------------------------------------------------- */
/** \name Local Variables
 * \{ */

/* local */
static CLG_LogRef LOG = {"bke.appdir"};

static struct {
  /** Full path to program executable. */
  char program_filepath[FILE_MAX];
  /** Full path to directory in which executable is located. */
  char program_dirname[FILE_MAX];
  /** Persistent temporary directory (defined by the preferences or OS). */
  char temp_dirname_base[FILE_MAX];
  /** Volatile temporary directory (owned by Blender, removed on exit). */
  char temp_dirname_session[FILE_MAX];
} g_app = {
    .temp_dirname_session = "",
};

/** \} */

/* -------------------------------------------------------------------- */
/** \name Initialization
 * \{ */

#ifndef NDEBUG
static bool is_appdir_init = false;
#  define ASSERT_IS_INIT() BLI_assert(is_appdir_init)
#else
#  define ASSERT_IS_INIT() ((void)0)
#endif

void BKE_appdir_init(void)
{
#ifndef NDEBUG
  BLI_assert(is_appdir_init == false);
  is_appdir_init = true;
#endif
}

void BKE_appdir_exit(void)
{
#ifndef NDEBUG
  BLI_assert(is_appdir_init == true);
  is_appdir_init = false;
#endif
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Internal Utilities
 * \{ */

/**
 * \returns a formatted representation of the specified version number. Non-re-entrant!
 */
static char *blender_version_decimal(const int version)
{
  static char version_str[5];
  BLI_assert(version < 1000);
  BLI_snprintf(version_str, sizeof(version_str), "%d.%d", version / 100, version % 100);
  return version_str;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Default Directories
 * \{ */

const char *BKE_appdir_folder_default(void)
{
#ifndef WIN32
  return BLI_getenv("HOME");
#else  /* Windows */
  static char documentfolder[MAXPATHLEN];

  if (BKE_appdir_folder_documents(documentfolder)) {
    return documentfolder;
  }

  return NULL;
#endif /* WIN32 */
}

const char *BKE_appdir_folder_root(void)
{
#ifndef WIN32
  return "/";
#else
  static char root[4];
  BLI_windows_get_default_root_dir(root);
  return root;
#endif
}

const char *BKE_appdir_folder_default_or_root(void)
{
  const char *path = BKE_appdir_folder_default();
  if (path == NULL) {
    path = BKE_appdir_folder_root();
  }
  return path;
}

const char *BKE_appdir_folder_home(void)
{
#ifdef WIN32
  return BLI_getenv("userprofile");
#elif defined(__APPLE__)
  return BLI_expand_tilde("~/");
#else
  return BLI_getenv("HOME");
#endif
}

bool BKE_appdir_folder_documents(char *dir)
{
  dir[0] = '\0';

  const char *documents_path = GHOST_getUserSpecialDir(GHOST_kUserSpecialDirDocuments);

  /* Usual case: Ghost gave us the documents path. We're done here. */
  if (documents_path && BLI_is_dir(documents_path)) {
    BLI_strncpy(dir, documents_path, FILE_MAXDIR);
    return true;
  }

  /* Ghost couldn't give us a documents path, let's try if we can find it ourselves. */

  const char *home_path = BKE_appdir_folder_home();
  if (!home_path || !BLI_is_dir(home_path)) {
    return false;
  }

  char try_documents_path[FILE_MAXDIR];
  /* Own attempt at getting a valid Documents path. */
  BLI_path_join(try_documents_path, sizeof(try_documents_path), home_path, N_("Documents"));
  if (!BLI_is_dir(try_documents_path)) {
    return false;
  }

  BLI_strncpy(dir, try_documents_path, FILE_MAXDIR);
  return true;
}

bool BKE_appdir_folder_caches(char *r_path, const size_t path_len)
{
  r_path[0] = '\0';

  const char *caches_root_path = GHOST_getUserSpecialDir(GHOST_kUserSpecialDirCaches);
  if (caches_root_path == NULL || !BLI_is_dir(caches_root_path)) {
    caches_root_path = BKE_tempdir_base();
  }
  if (caches_root_path == NULL || !BLI_is_dir(caches_root_path)) {
    return false;
  }

#ifdef WIN32
  BLI_path_join(
      r_path, path_len, caches_root_path, "Blender Foundation", "Blender", "Cache", SEP_STR);
#elif defined(__APPLE__)
  BLI_path_join(r_path, path_len, caches_root_path, "Blender", SEP_STR);
#else /* __linux__ */
  BLI_path_join(r_path, path_len, caches_root_path, "blender", SEP_STR);
#endif

  return true;
}

bool BKE_appdir_font_folder_default(char *dir)
{
  char test_dir[FILE_MAXDIR];
  test_dir[0] = '\0';

#ifdef WIN32
  wchar_t wpath[FILE_MAXDIR];
  if (SHGetSpecialFolderPathW(0, wpath, CSIDL_FONTS, 0)) {
    wcscat(wpath, L"\\");
    BLI_strncpy_wchar_as_utf8(test_dir, wpath, sizeof(test_dir));
  }
#elif defined(__APPLE__)
  STRNCPY(test_dir, BLI_expand_tilde("~/Library/Fonts/"));
  BLI_path_slash_ensure(test_dir, sizeof(test_dir));
#else
  STRNCPY(test_dir, "/usr/share/fonts");
#endif

  if (test_dir[0] && BLI_exists(test_dir)) {
    BLI_strncpy(dir, test_dir, FILE_MAXDIR);
    return true;
  }
  return false;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Path Presets (Internal Helpers)
 * \{ */

/**
 * Concatenates paths into \a targetpath,
 * returning true if result points to a directory.
 *
 * \param path_base: Path base, never NULL.
 * \param folder_name: First sub-directory (optional).
 * \param subfolder_name: Second sub-directory (optional).
 * \param check_is_dir: When false, return true even if the path doesn't exist.
 *
 * \note The names for optional paths only follow other usage in this file,
 * the names don't matter for this function.
 *
 * \note If it's useful we could take an arbitrary number of paths.
 * For now usage is limited and we don't need this.
 */
static bool test_path(char *targetpath,
                      size_t targetpath_len,
                      const bool check_is_dir,
                      const char *path_base,
                      const char *folder_name,
                      const char *subfolder_name)
{
  ASSERT_IS_INIT();

  /* Only the last argument should be NULL. */
  BLI_assert(!(folder_name == NULL && (subfolder_name != NULL)));
  const char *path_array[] = {path_base, folder_name, subfolder_name};
  const int path_array_num = (folder_name ? (subfolder_name ? 3 : 2) : 1);
  BLI_path_join_array(targetpath, targetpath_len, path_array, path_array_num);
  if (check_is_dir == false) {
    CLOG_INFO(&LOG, 3, "using without test: '%s'", targetpath);
    return true;
  }

  if (BLI_is_dir(targetpath)) {
    CLOG_INFO(&LOG, 3, "found '%s'", targetpath);
    return true;
  }

  CLOG_INFO(&LOG, 3, "missing '%s'", targetpath);

  /* Path not found, don't accidentally use it,
   * otherwise call this function with `check_is_dir` set to false. */
  targetpath[0] = '\0';
  return false;
}

/**
 * Puts the value of the specified environment variable into \a path if it exists.
 *
 * \param check_is_dir: When true, checks if it points at a directory.
 *
 * \returns true when the value of the environment variable is stored
 * at the address \a path points to.
 */
static bool test_env_path(char *path, const char *envvar, const bool check_is_dir)
{
  ASSERT_IS_INIT();

  const char *env_path = envvar ? BLI_getenv(envvar) : NULL;
  if (!env_path) {
    return false;
  }

  BLI_strncpy(path, env_path, FILE_MAX);

  if (check_is_dir == false) {
    CLOG_INFO(&LOG, 3, "using env '%s' without test: '%s'", envvar, env_path);
    return true;
  }

  if (BLI_is_dir(env_path)) {
    CLOG_INFO(&LOG, 3, "env '%s' found: %s", envvar, env_path);
    return true;
  }

  CLOG_INFO(&LOG, 3, "env '%s' missing: %s", envvar, env_path);

  /* Path not found, don't accidentally use it,
   * otherwise call this function with `check_is_dir` set to false. */
  path[0] = '\0';
  return false;
}

/**
 * Constructs in \a targetpath the name of a directory relative to a version-specific
 * sub-directory in the parent directory of the Blender executable.
 *
 * \param targetpath: String to return path.
 * \param folder_name: Optional folder name within version-specific directory.
 * \param subfolder_name: Optional sub-folder name within folder_name.
 *
 * \param version: To construct name of version-specific directory within #g_app.program_dirname.
 * \param check_is_dir: When false, return true even if the path doesn't exist.
 * \return true if such a directory exists.
 */
static bool get_path_local_ex(char *targetpath,
                              size_t targetpath_len,
                              const char *folder_name,
                              const char *subfolder_name,
                              const int version,
                              const bool check_is_dir)
{
  char relfolder[FILE_MAX];

  CLOG_INFO(&LOG,
            3,
            "folder='%s', subfolder='%s'",
            STR_OR_FALLBACK(folder_name),
            STR_OR_FALLBACK(subfolder_name));

  if (folder_name) { /* `subfolder_name` may be NULL. */
    const char *path_array[] = {folder_name, subfolder_name};
    const int path_array_num = subfolder_name ? 2 : 1;
    BLI_path_join_array(relfolder, sizeof(relfolder), path_array, path_array_num);
  }
  else {
    relfolder[0] = '\0';
  }

  /* Try `{g_app.program_dirname}/3.xx/{folder_name}` the default directory
   * for a portable distribution. See `WITH_INSTALL_PORTABLE` build-option. */
  const char *path_base = g_app.program_dirname;
#if defined(__APPLE__) && !defined(WITH_PYTHON_MODULE)
  /* Due new code-sign situation in OSX > 10.9.5
   * we must move the blender_version dir with contents to Resources.
   * Add 4 + 9 for the temporary `/../` path & `Resources`. */
  char osx_resourses[FILE_MAX + 4 + 9];
  BLI_path_join(osx_resourses, sizeof(osx_resourses), g_app.program_dirname, "..", "Resources");
  /* Remove the '/../' added above. */
  BLI_path_normalize(NULL, osx_resourses);
  path_base = osx_resourses;
#endif
  return test_path(targetpath,
                   targetpath_len,
                   check_is_dir,
                   path_base,
                   blender_version_decimal(version),
                   relfolder);
}
static bool get_path_local(char *targetpath,
                           size_t targetpath_len,
                           const char *folder_name,
                           const char *subfolder_name)
{
  const int version = BLENDER_VERSION;
  const bool check_is_dir = true;
  return get_path_local_ex(
      targetpath, targetpath_len, folder_name, subfolder_name, version, check_is_dir);
}

bool BKE_appdir_app_is_portable_install(void)
{
  /* Detect portable install by the existence of `config` folder. */
  char path[FILE_MAX];
  return get_path_local(path, sizeof(path), "config", NULL);
}

/**
 * Returns the path of a folder from environment variables.
 *
 * \param targetpath: String to return path.
 * \param subfolder_name: optional name of sub-folder within folder.
 * \param envvar: name of environment variable to check folder_name.
 * \param check_is_dir: When false, return true even if the path doesn't exist.
 * \return true if it was able to construct such a path and the path exists.
 */
static bool get_path_environment_ex(char *targetpath,
                                    size_t targetpath_len,
                                    const char *subfolder_name,
                                    const char *envvar,
                                    const bool check_is_dir)
{
  char user_path[FILE_MAX];

  if (test_env_path(user_path, envvar, check_is_dir)) {
    /* Note that `subfolder_name` may be NULL, in this case we use `user_path` as-is. */
    return test_path(targetpath, targetpath_len, check_is_dir, user_path, subfolder_name, NULL);
  }
  return false;
}
static bool get_path_environment(char *targetpath,
                                 size_t targetpath_len,
                                 const char *subfolder_name,
                                 const char *envvar)
{
  const bool check_is_dir = true;
  return get_path_environment_ex(targetpath, targetpath_len, subfolder_name, envvar, check_is_dir);
}

/**
 * Returns the path of a folder within the user-files area.
 *
 * \param targetpath: String to return path.
 * \param folder_name: default name of folder within user area.
 * \param subfolder_name: optional name of sub-folder within folder.
 * \param version: Blender version, used to construct a sub-directory name.
 * \param check_is_dir: When false, return true even if the path doesn't exist.
 * \return true if it was able to construct such a path.
 */
static bool get_path_user_ex(char *targetpath,
                             size_t targetpath_len,
                             const char *folder_name,
                             const char *subfolder_name,
                             const int version,
                             const bool check_is_dir)
{
  char user_path[FILE_MAX];

  if (test_env_path(user_path, "BLENDER_USER_RESOURCES", check_is_dir)) {
    /* Pass. */
  }
  else {
    /* for portable install, user path is always local */
    if (BKE_appdir_app_is_portable_install()) {
      return get_path_local_ex(
          targetpath, targetpath_len, folder_name, subfolder_name, version, check_is_dir);
    }
    user_path[0] = '\0';

    const char *user_base_path = GHOST_getUserDir(version, blender_version_decimal(version));
    if (user_base_path) {
      BLI_strncpy(user_path, user_base_path, FILE_MAX);
    }
  }

  if (!user_path[0]) {
    return false;
  }

  CLOG_INFO(&LOG,
            3,
            "'%s', folder='%s', subfolder='%s'",
            user_path,
            STR_OR_FALLBACK(folder_name),
            STR_OR_FALLBACK(subfolder_name));

  /* `subfolder_name` may be NULL. */
  return test_path(
      targetpath, targetpath_len, check_is_dir, user_path, folder_name, subfolder_name);
}
static bool get_path_user(char *targetpath,
                          size_t targetpath_len,
                          const char *folder_name,
                          const char *subfolder_name)
{
  const int version = BLENDER_VERSION;
  const bool check_is_dir = true;
  return get_path_user_ex(
      targetpath, targetpath_len, folder_name, subfolder_name, version, check_is_dir);
}

/**
 * Returns the path of a folder within the Blender installation directory.
 *
 * \param targetpath: String to return path.
 * \param folder_name: default name of folder within installation area.
 * \param subfolder_name: optional name of sub-folder within folder.
 * \param version: Blender version, used to construct a sub-directory name.
 * \param check_is_dir: When false, return true even if the path doesn't exist.
 * \return true if it was able to construct such a path.
 */
static bool get_path_system_ex(char *targetpath,
                               size_t targetpath_len,
                               const char *folder_name,
                               const char *subfolder_name,
                               const int version,
                               const bool check_is_dir)
{
  char system_path[FILE_MAX];
  char relfolder[FILE_MAX];

  if (folder_name) { /* `subfolder_name` may be NULL. */
    const char *path_array[] = {folder_name, subfolder_name};
    const int path_array_num = subfolder_name ? 2 : 1;
    BLI_path_join_array(relfolder, sizeof(relfolder), path_array, path_array_num);
  }
  else {
    relfolder[0] = '\0';
  }

  if (test_env_path(system_path, "BLENDER_SYSTEM_RESOURCES", check_is_dir)) {
    /* Pass. */
  }
  else {
    system_path[0] = '\0';
    const char *system_base_path = GHOST_getSystemDir(version, blender_version_decimal(version));
    if (system_base_path) {
      BLI_strncpy(system_path, system_base_path, FILE_MAX);
    }
  }

  if (!system_path[0]) {
    return false;
  }

  CLOG_INFO(&LOG,
            3,
            "'%s', folder='%s', subfolder='%s'",
            system_path,
            STR_OR_FALLBACK(folder_name),
            STR_OR_FALLBACK(subfolder_name));

  /* Try `$BLENDERPATH/folder_name/subfolder_name`, `subfolder_name` may be NULL. */
  return test_path(
      targetpath, targetpath_len, check_is_dir, system_path, folder_name, subfolder_name);
}

static bool get_path_system(char *targetpath,
                            size_t targetpath_len,
                            const char *folder_name,
                            const char *subfolder_name)
{
  const int version = BLENDER_VERSION;
  const bool check_is_dir = true;
  return get_path_system_ex(
      targetpath, targetpath_len, folder_name, subfolder_name, version, check_is_dir);
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Path Presets API
 * \{ */

bool BKE_appdir_folder_id_ex(const int folder_id,
                             const char *subfolder,
                             char *path,
                             size_t path_len)
{
  switch (folder_id) {
    case BLENDER_DATAFILES: /* general case */
      if (get_path_environment(path, path_len, subfolder, "BLENDER_USER_DATAFILES")) {
        break;
      }
      if (get_path_user(path, path_len, "datafiles", subfolder)) {
        break;
      }
      if (get_path_environment(path, path_len, subfolder, "BLENDER_SYSTEM_DATAFILES")) {
        break;
      }
      if (get_path_local(path, path_len, "datafiles", subfolder)) {
        break;
      }
      if (get_path_system(path, path_len, "datafiles", subfolder)) {
        break;
      }
      return false;

    case BLENDER_USER_DATAFILES:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_USER_DATAFILES")) {
        break;
      }
      if (get_path_user(path, path_len, "datafiles", subfolder)) {
        break;
      }
      return false;

    case BLENDER_SYSTEM_DATAFILES:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_SYSTEM_DATAFILES")) {
        break;
      }
      if (get_path_system(path, path_len, "datafiles", subfolder)) {
        break;
      }
      if (get_path_local(path, path_len, "datafiles", subfolder)) {
        break;
      }
      return false;

    case BLENDER_USER_AUTOSAVE:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_USER_DATAFILES")) {
        break;
      }
      if (get_path_user(path, path_len, "autosave", subfolder)) {
        break;
      }
      return false;

    case BLENDER_USER_CONFIG:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_USER_CONFIG")) {
        break;
      }
      if (get_path_user(path, path_len, "config", subfolder)) {
        break;
      }
      return false;

    case BLENDER_USER_SCRIPTS:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_USER_SCRIPTS")) {
        break;
      }
      if (get_path_user(path, path_len, "scripts", subfolder)) {
        break;
      }
      return false;

    case BLENDER_SYSTEM_SCRIPTS:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_SYSTEM_SCRIPTS")) {
        break;
      }
      if (get_path_system(path, path_len, "scripts", subfolder)) {
        break;
      }
      if (get_path_local(path, path_len, "scripts", subfolder)) {
        break;
      }
      return false;

    case BLENDER_SYSTEM_PYTHON:
      if (get_path_environment(path, path_len, subfolder, "BLENDER_SYSTEM_PYTHON")) {
        break;
      }
      if (get_path_system(path, path_len, "python", subfolder)) {
        break;
      }
      if (get_path_local(path, path_len, "python", subfolder)) {
        break;
      }
      return false;

    default:
      BLI_assert_unreachable();
      break;
  }

  return true;
}

const char *BKE_appdir_folder_id(const int folder_id, const char *subfolder)
{
  static char path[FILE_MAX] = "";
  if (BKE_appdir_folder_id_ex(folder_id, subfolder, path, sizeof(path))) {
    return path;
  }
  return NULL;
}

const char *BKE_appdir_folder_id_user_notest(const int folder_id, const char *subfolder)
{
  const int version = BLENDER_VERSION;
  static char path[FILE_MAX] = "";
  const bool check_is_dir = false;

  switch (folder_id) {
    case BLENDER_USER_DATAFILES:
      if (get_path_environment_ex(
              path, sizeof(path), subfolder, "BLENDER_USER_DATAFILES", check_is_dir)) {
        break;
      }
      get_path_user_ex(path, sizeof(path), "datafiles", subfolder, version, check_is_dir);
      break;
    case BLENDER_USER_CONFIG:
      if (get_path_environment_ex(
              path, sizeof(path), subfolder, "BLENDER_USER_CONFIG", check_is_dir)) {
        break;
      }
      get_path_user_ex(path, sizeof(path), "config", subfolder, version, check_is_dir);
      break;
    case BLENDER_USER_AUTOSAVE:
      if (get_path_environment_ex(
              path, sizeof(path), subfolder, "BLENDER_USER_AUTOSAVE", check_is_dir)) {
        break;
      }
      get_path_user_ex(path, sizeof(path), "autosave", subfolder, version, check_is_dir);
      break;
    case BLENDER_USER_SCRIPTS:
      if (get_path_environment_ex(
              path, sizeof(path), subfolder, "BLENDER_USER_SCRIPTS", check_is_dir)) {
        break;
      }
      get_path_user_ex(path, sizeof(path), "scripts", subfolder, version, check_is_dir);
      break;
    default:
      BLI_assert_unreachable();
      break;
  }

  if ('\0' == path[0]) {
    return NULL;
  }
  return path;
}

const char *BKE_appdir_folder_id_create(const int folder_id, const char *subfolder)
{
  const char *path;

  /* Only for user folders. */
  if (!ELEM(folder_id,
            BLENDER_USER_DATAFILES,
            BLENDER_USER_CONFIG,
            BLENDER_USER_SCRIPTS,
            BLENDER_USER_AUTOSAVE)) {
    BLI_assert_unreachable();
    return NULL;
  }

  path = BKE_appdir_folder_id(folder_id, subfolder);

  if (!path) {
    path = BKE_appdir_folder_id_user_notest(folder_id, subfolder);
    if (path) {
      BLI_dir_create_recursive(path);
    }
  }

  return path;
}

const char *BKE_appdir_resource_path_id_with_version(const int folder_id,
                                                     const bool check_is_dir,
                                                     const int version)
{
  static char path[FILE_MAX] = "";
  bool ok;
  switch (folder_id) {
    case BLENDER_RESOURCE_PATH_USER:
      ok = get_path_user_ex(path, sizeof(path), NULL, NULL, version, check_is_dir);
      break;
    case BLENDER_RESOURCE_PATH_LOCAL:
      ok = get_path_local_ex(path, sizeof(path), NULL, NULL, version, check_is_dir);
      break;
    case BLENDER_RESOURCE_PATH_SYSTEM:
      ok = get_path_system_ex(path, sizeof(path), NULL, NULL, version, check_is_dir);
      break;
    default:
      path[0] = '\0'; /* in case check_is_dir is false */
      ok = false;
      BLI_assert_msg(0, "incorrect ID");
      break;
  }
  return ok ? path : NULL;
}

const char *BKE_appdir_resource_path_id(const int folder_id, const bool check_is_dir)
{
  return BKE_appdir_resource_path_id_with_version(folder_id, check_is_dir, BLENDER_VERSION);
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Program Path Queries
 *
 * Access locations of Blender & Python.
 * \{ */

#ifndef WITH_PYTHON_MODULE
/**
 * Checks if name is a fully qualified filename to an executable.
 * If not it searches `$PATH` for the file. On Windows it also
 * adds the correct extension (`.com` `.exe` etc) from
 * `$PATHEXT` if necessary. Also on Windows it translates
 * the name to its 8.3 version to prevent problems with
 * spaces and stuff. Final result is returned in \a fullname.
 *
 * \param fullname: The full path and full name of the executable
 * (must be #FILE_MAX minimum)
 * \param name: The name of the executable (usually `argv[0]`) to be checked
 */
static void where_am_i(char *fullname, const size_t maxlen, const char *name)
{
#  ifdef WITH_BINRELOC
  /* Linux uses `binreloc` since `argv[0]` is not reliable, call `br_init(NULL)` first. */
  {
    const char *path = NULL;
    path = br_find_exe(NULL);
    if (path) {
      BLI_strncpy(fullname, path, maxlen);
      free((void *)path);
      return;
    }
  }
#  endif

#  ifdef _WIN32
  {
    wchar_t *fullname_16 = MEM_mallocN(maxlen * sizeof(wchar_t), "ProgramPath");
    if (GetModuleFileNameW(0, fullname_16, maxlen)) {
      conv_utf_16_to_8(fullname_16, fullname, maxlen);
      if (!BLI_exists(fullname)) {
        CLOG_ERROR(&LOG, "path can't be found: \"%.*s\"", (int)maxlen, fullname);
        MessageBox(
            NULL, "path contains invalid characters or is too long (see console)", "Error", MB_OK);
      }
      MEM_freeN(fullname_16);
      return;
    }

    MEM_freeN(fullname_16);
  }
#  endif

  /* Unix and non Linux. */
  if (name && name[0]) {

    BLI_strncpy(fullname, name, maxlen);
    if (name[0] == '.') {
      BLI_path_abs_from_cwd(fullname, maxlen);
#  ifdef _WIN32
      BLI_path_program_extensions_add_win32(fullname, maxlen);
#  endif
    }
    else if (BLI_path_slash_rfind(name)) {
      /* Full path. */
      BLI_strncpy(fullname, name, maxlen);
#  ifdef _WIN32
      BLI_path_program_extensions_add_win32(fullname, maxlen);
#  endif
    }
    else {
      BLI_path_program_search(fullname, maxlen, name);
    }
    /* Remove "/./" and "/../" so string comparisons can be used on the path. */
    BLI_path_normalize(NULL, fullname);

#  if defined(DEBUG)
    if (!STREQ(name, fullname)) {
      CLOG_INFO(&LOG, 2, "guessing '%s' == '%s'", name, fullname);
    }
#  endif
  }
}
#endif /* WITH_PYTHON_MODULE */

void BKE_appdir_program_path_init(const char *argv0)
{
#ifdef WITH_PYTHON_MODULE
  /* NOTE(@campbellbarton): Always use `argv[0]` as is, when building as a Python module.
   * Otherwise other methods of detecting the binary that override this argument
   * which must point to the Python module for data-files to be detected. */
  STRNCPY(g_app.program_filepath, argv0);
  BLI_path_abs_from_cwd(g_app.program_filepath, sizeof(g_app.program_filepath));
  BLI_path_normalize(NULL, g_app.program_filepath);

  if (g_app.program_dirname[0] == '\0') {
    /* First time initializing, the file binary path isn't valid from a Python module.
     * Calling again must set the `filepath` and leave the directory as-is. */
    BLI_split_dir_part(
        g_app.program_filepath, g_app.program_dirname, sizeof(g_app.program_dirname));
    g_app.program_filepath[0] = '\0';
  }
#else
  where_am_i(g_app.program_filepath, sizeof(g_app.program_filepath), argv0);
  BLI_split_dir_part(g_app.program_filepath, g_app.program_dirname, sizeof(g_app.program_dirname));
#endif
}

const char *BKE_appdir_program_path(void)
{
#ifndef WITH_PYTHON_MODULE /* Default's to empty when building as a Python module. */
  BLI_assert(g_app.program_filepath[0]);
#endif
  return g_app.program_filepath;
}

const char *BKE_appdir_program_dir(void)
{
  BLI_assert(g_app.program_dirname[0]);
  return g_app.program_dirname;
}

bool BKE_appdir_program_python_search(char *fullpath,
                                      const size_t fullpath_len,
                                      const int version_major,
                                      const int version_minor)
{
  ASSERT_IS_INIT();

#ifdef PYTHON_EXECUTABLE_NAME
  /* Passed in from the build-systems 'PYTHON_EXECUTABLE'. */
  const char *python_build_def = STRINGIFY(PYTHON_EXECUTABLE_NAME);
#endif
  const char *basename = "python";
#if defined(WIN32) && !defined(NDEBUG)
  const char *basename_debug = "python_d";
#endif
  char python_version[16];
  /* Check both possible names. */
  const char *python_names[] = {
#ifdef PYTHON_EXECUTABLE_NAME
    python_build_def,
#endif
#if defined(WIN32) && !defined(NDEBUG)
    basename_debug,
#endif
    python_version,
    basename,
  };
  bool is_found = false;

  SNPRINTF(python_version, "%s%d.%d", basename, version_major, version_minor);

  {
    const char *python_bin_dir = BKE_appdir_folder_id(BLENDER_SYSTEM_PYTHON, "bin");
    if (python_bin_dir) {

      for (int i = 0; i < ARRAY_SIZE(python_names); i++) {
        BLI_path_join(fullpath, fullpath_len, python_bin_dir, python_names[i]);

        if (
#ifdef _WIN32
            BLI_path_program_extensions_add_win32(fullpath, fullpath_len)
#else
            BLI_exists(fullpath)
#endif
        ) {
          is_found = true;
          break;
        }
      }
    }
  }

  if (is_found == false) {
    for (int i = 0; i < ARRAY_SIZE(python_names); i++) {
      if (BLI_path_program_search(fullpath, fullpath_len, python_names[i])) {
        is_found = true;
        break;
      }
    }
  }

  if (is_found == false) {
    *fullpath = '\0';
  }

  return is_found;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Application Templates
 * \{ */

/** Keep in sync with `bpy.utils.app_template_paths()` */
static const char *app_template_directory_search[2] = {
    "startup" SEP_STR "bl_app_templates_user",
    "startup" SEP_STR "bl_app_templates_system",
};

static const int app_template_directory_id[2] = {
    /* Only 'USER' */
    BLENDER_USER_SCRIPTS,
    /* Covers 'LOCAL' & 'SYSTEM'. */
    BLENDER_SYSTEM_SCRIPTS,
};

bool BKE_appdir_app_template_any(void)
{
  char temp_dir[FILE_MAX];
  for (int i = 0; i < ARRAY_SIZE(app_template_directory_id); i++) {
    if (BKE_appdir_folder_id_ex(app_template_directory_id[i],
                                app_template_directory_search[i],
                                temp_dir,
                                sizeof(temp_dir))) {
      return true;
    }
  }
  return false;
}

bool BKE_appdir_app_template_id_search(const char *app_template, char *path, size_t path_len)
{
  for (int i = 0; i < ARRAY_SIZE(app_template_directory_id); i++) {
    char subdir[FILE_MAX];
    BLI_path_join(subdir, sizeof(subdir), app_template_directory_search[i], app_template);
    if (BKE_appdir_folder_id_ex(app_template_directory_id[i], subdir, path, path_len)) {
      return true;
    }
  }
  return false;
}

bool BKE_appdir_app_template_has_userpref(const char *app_template)
{
  /* Test if app template provides a `userpref.blend`.
   * If not, we will share user preferences with the rest of Blender. */
  if (app_template[0] == '\0') {
    return false;
  }

  char app_template_path[FILE_MAX];
  if (!BKE_appdir_app_template_id_search(
          app_template, app_template_path, sizeof(app_template_path))) {
    return false;
  }

  char userpref_path[FILE_MAX];
  BLI_path_join(userpref_path, sizeof(userpref_path), app_template_path, BLENDER_USERPREF_FILE);
  return BLI_exists(userpref_path);
}

void BKE_appdir_app_templates(ListBase *templates)
{
  BLI_listbase_clear(templates);

  for (int i = 0; i < ARRAY_SIZE(app_template_directory_id); i++) {
    char subdir[FILE_MAX];
    if (!BKE_appdir_folder_id_ex(app_template_directory_id[i],
                                 app_template_directory_search[i],
                                 subdir,
                                 sizeof(subdir))) {
      continue;
    }

    struct direntry *dirs;
    const uint dir_num = BLI_filelist_dir_contents(subdir, &dirs);
    for (int f = 0; f < dir_num; f++) {
      if (!FILENAME_IS_CURRPAR(dirs[f].relname) && S_ISDIR(dirs[f].type)) {
        char *template = BLI_strdup(dirs[f].relname);
        BLI_addtail(templates, BLI_genericNodeN(template));
      }
    }

    BLI_filelist_free(dirs, dir_num);
  }
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Temporary Directories
 * \{ */

/**
 * Gets the temp directory when blender first runs.
 * If the default path is not found, use try $TEMP
 *
 * Also make sure the temp dir has a trailing slash
 *
 * \param tempdir: The full path to the temporary temp directory.
 * \param tempdir_len: The size of the \a tempdir buffer.
 * \param userdir: Directory specified in user preferences (may be NULL).
 * note that by default this is an empty string, only use when non-empty.
 */
static void where_is_temp(char *tempdir, const size_t tempdir_maxlen, const char *userdir)
{

  tempdir[0] = '\0';

  if (userdir && BLI_is_dir(userdir)) {
    BLI_strncpy(tempdir, userdir, tempdir_maxlen);
  }

  if (tempdir[0] == '\0') {
    const char *env_vars[] = {
#ifdef WIN32
        "TEMP",
#else
        /* Non standard (could be removed). */
        "TMP",
        /* Posix standard. */
        "TMPDIR",
#endif
    };
    for (int i = 0; i < ARRAY_SIZE(env_vars); i++) {
      const char *tmp = BLI_getenv(env_vars[i]);
      if (tmp && (tmp[0] != '\0') && BLI_is_dir(tmp)) {
        BLI_strncpy(tempdir, tmp, tempdir_maxlen);
        break;
      }
    }
  }

  if (tempdir[0] == '\0') {
    BLI_strncpy(tempdir, "/tmp/", tempdir_maxlen);
  }
  else {
    /* add a trailing slash if needed */
    BLI_path_slash_ensure(tempdir, tempdir_maxlen);
  }
}

static void tempdir_session_create(char *tempdir_session,
                                   const size_t tempdir_session_maxlen,
                                   const char *tempdir)
{
  tempdir_session[0] = '\0';

  const int tempdir_len = strlen(tempdir);
  /* 'XXXXXX' is kind of tag to be replaced by `mktemp-family` by an UUID. */
  const char *session_name = "blender_XXXXXX";
  const int session_name_len = strlen(session_name);

  /* +1 as a slash is added,
   * #_mktemp_s also requires the last null character is included. */
  const int tempdir_session_len_required = tempdir_len + session_name_len + 1;

  if (tempdir_session_len_required <= tempdir_session_maxlen) {
    /* No need to use path joining utility as we know the last character of #tempdir is a slash. */
    BLI_string_join(tempdir_session, tempdir_session_maxlen, tempdir, session_name);
#ifdef WIN32
    const bool needs_create = (_mktemp_s(tempdir_session, tempdir_session_len_required) == 0);
#else
    const bool needs_create = (mkdtemp(tempdir_session) == NULL);
#endif
    if (needs_create) {
      BLI_dir_create_recursive(tempdir_session);
    }
    if (BLI_is_dir(tempdir_session)) {
      BLI_path_slash_ensure(tempdir_session, tempdir_session_maxlen);
      /* Success. */
      return;
    }
  }

  CLOG_WARN(&LOG,
            "Could not generate a temp file name for '%s', falling back to '%s'",
            tempdir_session,
            tempdir);
  BLI_strncpy(tempdir_session, tempdir, tempdir_session_maxlen);
}

void BKE_tempdir_init(const char *userdir)
{
  /* Sets #g_app.temp_dirname_base to \a userdir if specified and is a valid directory,
   * otherwise chooses a suitable OS-specific temporary directory.
   * Sets #g_app.temp_dirname_session to a #mkdtemp
   * generated sub-dir of #g_app.temp_dirname_base. */

  where_is_temp(g_app.temp_dirname_base, sizeof(g_app.temp_dirname_base), userdir);

  /* Clear existing temp dir, if needed. */
  BKE_tempdir_session_purge();
  /* Now that we have a valid temp dir, add system-generated unique sub-dir. */
  tempdir_session_create(
      g_app.temp_dirname_session, sizeof(g_app.temp_dirname_session), g_app.temp_dirname_base);
}

const char *BKE_tempdir_session(void)
{
  return g_app.temp_dirname_session[0] ? g_app.temp_dirname_session : BKE_tempdir_base();
}

const char *BKE_tempdir_base(void)
{
  return g_app.temp_dirname_base;
}

void BKE_tempdir_session_purge(void)
{
  if (g_app.temp_dirname_session[0] && BLI_is_dir(g_app.temp_dirname_session)) {
    BLI_delete(g_app.temp_dirname_session, true, true);
  }
}

/** \} */