//! # `dir_spec`
//!
//! Cross-platform directory resolver with XDG compliance.
//!
//! This crate provides functions to resolve standard directories across Linux, macOS, and Windows
//! while respecting XDG Base Directory Specification environment variables when set.
//!
//! ## XDG Compliance
//!
//! All functions check for corresponding XDG environment variables first (e.g., `XDG_CONFIG_HOME`),
//! and only fall back to platform-specific defaults if the XDG variable is not set or contains
//! a relative path (which the XDG spec requires to be ignored).
//!
//! ## Examples
//!
//! ```rust
//! use dir_spec::{config_home, cache_home, videos};
//!
//! // Get config directory (respects XDG_CONFIG_HOME if set)
//! if let Some(config) = config_home() {
//!     println!("Config directory: {}", config.display());
//! }
//!
//! // Get cache directory (respects XDG_CACHE_HOME if set)
//! if let Some(cache) = cache_home() {
//!     println!("Cache directory: {}", cache.display());
//! }
//!
//! // Get videos directory
//! if let Some(videos) = videos() {
//!     println!("Videos directory: {}", videos.display());
//! }
//! ```

#[cfg(target_os = "linux")]
mod linux;
#[cfg(target_os = "macos")]
mod macos;
#[cfg(target_os = "windows")]
mod windows;
pub(crate) mod xdg;

use std::{env, path::PathBuf};

#[cfg(target_os = "linux")]
use linux as os;
#[cfg(target_os = "macos")]
use macos as os;
#[cfg(target_os = "windows")]
use windows as os;

/// Returns the user's binary directory.
///
/// Checks `XDG_BIN_HOME` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/.local/bin`
/// - **Windows**: `%LOCALAPPDATA%\Programs`
///
/// # Examples
///
/// ```rust
/// use dir_spec::bin_home;
/// if let Some(bin_dir) = bin_home() {
///     println!("Bin directory: {}", bin_dir.display());
/// }
/// ```
pub fn bin_home() -> Option<PathBuf> {
  os::bin_home()
}

/// Returns the user's cache directory.
///
/// Checks `XDG_CACHE_HOME` first, then falls back to platform defaults:
/// - **Linux**: `~/.cache`
/// - **macOS**: `~/Library/Caches`
/// - **Windows**: `%LOCALAPPDATA%`
///
/// # Examples
///
/// ```rust
/// use dir_spec::cache_home;
/// if let Some(cache_dir) = cache_home() {
///     println!("Cache directory: {}", cache_dir.display());
/// }
/// ```
pub fn cache_home() -> Option<PathBuf> {
  os::cache_home()
}

/// Returns the user's configuration directory.
///
/// Checks `XDG_CONFIG_HOME` first, then falls back to platform defaults:
/// - **Linux**: `~/.config`
/// - **macOS**: `~/Library/Application Support`
/// - **Windows**: `%APPDATA%`
///
/// # Examples
///
/// ```rust
/// use dir_spec::config_home;
/// if let Some(config_dir) = config_home() {
///     println!("Config directory: {}", config_dir.display());
/// }
/// ```
pub fn config_home() -> Option<PathBuf> {
  os::config_home()
}

/// Returns the user's local configuration directory (non-roaming).
///
/// This is primarily useful on Windows where it returns the local (non-roaming) config directory.
/// On other platforms, it behaves identically to `config_home()`.
///
/// Platform defaults:
/// - **Linux**: `~/.config` (same as `config_home()`)
/// - **macOS**: `~/Library/Application Support` (same as `config_home()`)
/// - **Windows**: `%LOCALAPPDATA%` (non-roaming)
///
/// # Examples
///
/// ```rust
/// use dir_spec::config_local;
/// if let Some(config_local) = config_local() {
///     println!("Local config directory: {}", config_local.display());
/// }
/// ```
pub fn config_local() -> Option<PathBuf> {
  os::config_local()
}

/// Returns the user's data directory.
///
/// Checks `XDG_DATA_HOME` first, then falls back to platform defaults:
/// - **Linux**: `~/.local/share`
/// - **macOS**: `~/Library/Application Support`
/// - **Windows**: `%APPDATA%`
///
/// # Examples
///
/// ```rust
/// use dir_spec::data_home;
/// if let Some(data_dir) = data_home() {
///     println!("Data directory: {}", data_dir.display());
/// }
/// ```
pub fn data_home() -> Option<PathBuf> {
  os::data_home()
}

/// Returns the user's local data directory (non-roaming).
///
/// This is primarily useful on Windows where it returns the local (non-roaming) data directory.
/// On other platforms, it behaves identically to `data_home()`.
///
/// Platform defaults:
/// - **Linux**: `~/.local/share` (same as `data_home()`)
/// - **macOS**: `~/Library/Application Support` (same as `data_home()`)
/// - **Windows**: `%LOCALAPPDATA%` (non-roaming)
///
/// # Examples
///
/// ```rust
/// use dir_spec::data_local;
/// if let Some(data_local) = data_local() {
///     println!("Local data directory: {}", data_local.display());
/// }
/// ```
pub fn data_local() -> Option<PathBuf> {
  os::data_local()
}

/// Returns the user's desktop directory.
///
/// Checks `XDG_DESKTOP_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Desktop`
/// - **Windows**: `%USERPROFILE%\Desktop`
///
/// # Examples
///
/// ```rust
/// use dir_spec::desktop;
/// if let Some(desktop) = desktop() {
///     println!("Desktop directory: {}", desktop.display());
/// }
/// ```
pub fn desktop() -> Option<PathBuf> {
  os::desktop()
}

/// Returns the user's documents directory.
///
/// Checks `XDG_DOCUMENTS_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Documents`
/// - **Windows**: `%USERPROFILE%\Documents`
///
/// # Examples
///
/// ```rust
/// use dir_spec::documents;
/// if let Some(documents) = documents() {
///     println!("Documents directory: {}", documents.display());
/// }
/// ```
pub fn documents() -> Option<PathBuf> {
  os::documents()
}

/// Returns the user's downloads directory.
///
/// Checks `XDG_DOWNLOAD_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Downloads`
/// - **Windows**: `%USERPROFILE%\Downloads`
///
/// # Examples
///
/// ```rust
/// use dir_spec::downloads;
/// if let Some(downloads) = downloads() {
///     println!("Downloads directory: {}", downloads.display());
/// }
/// ```
pub fn downloads() -> Option<PathBuf> {
  os::downloads()
}

/// Returns the user's fonts directory.
///
/// This directory is used for user-installed fonts.
/// Note: Returns `None` on Windows as there is no standard user fonts directory.
///
/// Platform defaults:
/// - **Linux**: `~/.local/share/fonts`
/// - **macOS**: `~/Library/Fonts`
/// - **Windows**: `None` (no standard user fonts directory)
///
/// # Examples
///
/// ```rust
/// use dir_spec::fonts;
/// if let Some(fonts) = fonts() {
///     println!("Fonts directory: {}", fonts.display());
/// } else {
///     println!("No user fonts directory on this platform");
/// }
/// ```
pub fn fonts() -> Option<PathBuf> {
  os::fonts()
}

/// Returns the user's home directory.
///
/// Uses the standard library's `std::env::home_dir()` function.
///
/// # Examples
///
/// ```rust
/// use dir_spec::home;
/// if let Some(home_dir) = home() {
///     println!("Home directory: {}", home_dir.display());
/// }
/// ```
pub fn home() -> Option<PathBuf> {
  env::home_dir()
}

/// Returns the user's music directory.
///
/// Checks `XDG_MUSIC_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Music`
/// - **Windows**: `%USERPROFILE%\Music`
///
/// # Examples
///
/// ```rust
/// use dir_spec::music;
/// if let Some(music) = music() {
///     println!("Music directory: {}", music.display());
/// }
/// ```
pub fn music() -> Option<PathBuf> {
  os::music()
}

/// Returns the user's pictures directory.
///
/// Checks `XDG_PICTURES_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Pictures`
/// - **Windows**: `%USERPROFILE%\Pictures`
///
/// # Examples
///
/// ```rust
/// use dir_spec::pictures;
/// if let Some(pictures) = pictures() {
///     println!("Pictures directory: {}", pictures.display());
/// }
/// ```
pub fn pictures() -> Option<PathBuf> {
  os::pictures()
}

/// Returns the user's preferences directory.
///
/// This is primarily used on macOS for storing .plist files using Apple's proprietary APIs.
/// On other platforms, it behaves identically to `config_home()`.
///
/// Platform defaults:
/// - **Linux**: `~/.config` (same as `config_home()`)
/// - **macOS**: `~/Library/Preferences` (for .plist files)
/// - **Windows**: `%APPDATA%` (same as `config_home()`)
///
/// # Examples
///
/// ```rust
/// use dir_spec::preferences;
/// if let Some(preferences) = preferences() {
///     println!("Preferences directory: {}", preferences.display());
/// }
/// ```
pub fn preferences() -> Option<PathBuf> {
  os::preferences()
}

/// Returns the user's public share directory.
///
/// Checks `XDG_PUBLICSHARE_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Public`
/// - **Windows**: `C:\Users\Public` (system-wide public folder)
///
/// # Examples
///
/// ```rust
/// use dir_spec::publicshare;
/// if let Some(public) = publicshare() {
///     println!("Public directory: {}", public.display());
/// }
/// ```
pub fn publicshare() -> Option<PathBuf> {
  os::publicshare()
}

/// Returns the user's runtime directory.
///
/// Checks `XDG_RUNTIME_DIR` first, then falls back to platform defaults:
/// - **Linux**: Attempts to use `$TMPDIR`, then falls back to `/tmp`
/// - **macOS**: `$TMPDIR` or `/tmp`
/// - **Windows**: `%TEMP%`
///
/// # Examples
///
/// ```rust
/// use dir_spec::runtime;
/// if let Some(runtime) = runtime() {
///     println!("Runtime directory: {}", runtime.display());
/// }
/// ```
pub fn runtime() -> Option<PathBuf> {
  os::runtime()
}

/// Returns the user's state directory.
///
/// Checks `XDG_STATE_HOME` first, then falls back to platform defaults:
/// - **Linux**: `~/.local/state`
/// - **macOS**: `~/Library/Application Support`
/// - **Windows**: `%LOCALAPPDATA%`
///
/// # Examples
///
/// ```rust
/// use dir_spec::state_home;
/// if let Some(state_dir) = state_home() {
///     println!("State directory: {}", state_dir.display());
/// }
/// ```
pub fn state_home() -> Option<PathBuf> {
  os::state_home()
}

/// Returns the user's templates directory.
///
/// Checks `XDG_TEMPLATES_DIR` first, then falls back to platform defaults:
/// - **Linux/macOS**: `~/Templates`
/// - **Windows**: `%USERPROFILE%\Templates`
///
/// # Examples
///
/// ```rust
/// use dir_spec::templates;
/// if let Some(templates) = templates() {
///     println!("Templates directory: {}", templates.display());
/// }
/// ```
pub fn templates() -> Option<PathBuf> {
  os::templates()
}

/// Returns the user's videos directory.
///
/// Checks `XDG_VIDEOS_DIR` first, then falls back to platform defaults:
/// - **Linux**: `~/Videos`
/// - **macOS**: `~/Movies` (following macOS convention)
/// - **Windows**: `%USERPROFILE%\Videos`
///
/// # Examples
///
/// ```rust
/// use dir_spec::videos;
/// if let Some(videos) = videos() {
///     println!("Videos directory: {}", videos.display());
/// }
/// ```
pub fn videos() -> Option<PathBuf> {
  os::videos()
}

#[cfg(test)]
mod tests {
  use super::*;

  mod bin_home {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_bin_home() {
      let test_path = if cfg!(windows) { "C:\\test\\bin" } else { "/test/bin" };
      with_var("XDG_BIN_HOME", Some(test_path), || {
        let result = bin_home();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_bin_home() {
      with_var("XDG_BIN_HOME", Some("relative/bin"), || {
        let result = bin_home();

        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_BIN_HOME", || {
        let result = bin_home();
        if let Some(bin_path) = result {
          assert!(bin_path.is_absolute());

          #[cfg(any(target_os = "linux", target_os = "macos"))]
          assert!(bin_path.to_string_lossy().ends_with(".local/bin"));

          #[cfg(target_os = "windows")]
          assert!(bin_path.to_string_lossy().contains("Programs"));
        }
      });
    }
  }

  mod cache_home {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_cache_home() {
      let test_path = if cfg!(windows) { "C:\\test\\cache" } else { "/test/cache" };
      with_var("XDG_CACHE_HOME", Some(test_path), || {
        let result = cache_home();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_cache_home() {
      with_var("XDG_CACHE_HOME", Some("relative/cache"), || {
        let result = cache_home();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_CACHE_HOME", || {
        let result = cache_home();
        if let Some(cache_path) = result {
          assert!(cache_path.is_absolute());

          #[cfg(target_os = "linux")]
          assert!(cache_path.to_string_lossy().ends_with(".cache"));

          #[cfg(target_os = "macos")]
          assert!(cache_path.to_string_lossy().contains("Library/Caches"));

          #[cfg(target_os = "windows")]
          {
            if let Ok(localappdata) = env::var("LOCALAPPDATA") {
              assert_eq!(cache_path, PathBuf::from(localappdata));
            }
          }
        }
      });
    }
  }

  mod config_home {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_config_home() {
      let test_path = if cfg!(windows) { "C:\\test\\config" } else { "/test/config" };
      with_var("XDG_CONFIG_HOME", Some(test_path), || {
        let result = config_home();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_config_home() {
      with_var("XDG_CONFIG_HOME", Some("relative/config"), || {
        let result = config_home();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_CONFIG_HOME", || {
        let result = config_home();
        if let Some(config_path) = result {
          assert!(config_path.is_absolute());

          #[cfg(target_os = "linux")]
          assert!(config_path.to_string_lossy().ends_with(".config"));

          #[cfg(target_os = "macos")]
          assert!(config_path.to_string_lossy().contains("Library/Application Support"));

          #[cfg(target_os = "windows")]
          {
            if let Ok(appdata) = env::var("APPDATA") {
              assert_eq!(config_path, PathBuf::from(appdata));
            }
          }
        }
      });
    }
  }

  mod config_local {
    use super::*;

    #[test]
    fn uses_localappdata_on_windows() {
      let result = config_local();
      if let Some(config_local_path) = result {
        assert!(config_local_path.is_absolute());

        #[cfg(target_os = "windows")]
        {
          if let Ok(localappdata) = env::var("LOCALAPPDATA") {
            assert_eq!(config_local_path, PathBuf::from(localappdata));
          }
        }

        #[cfg(not(target_os = "windows"))]
        {
          assert_eq!(Some(config_local_path), config_home());
        }
      }
    }

    #[test]
    fn matches_config_home_on_non_windows() {
      #[cfg(not(target_os = "windows"))]
      {
        let config_local = config_local();
        let config_home = config_home();
        assert_eq!(config_local, config_home);
      }
    }
  }

  mod data_home {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_data_home() {
      let test_path = if cfg!(windows) { "C:\\test\\data" } else { "/test/data" };
      with_var("XDG_DATA_HOME", Some(test_path), || {
        let result = data_home();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_data_home() {
      with_var("XDG_DATA_HOME", Some("relative/data"), || {
        let result = data_home();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_DATA_HOME", || {
        let result = data_home();
        if let Some(data_path) = result {
          assert!(data_path.is_absolute());

          #[cfg(target_os = "linux")]
          assert!(data_path.to_string_lossy().ends_with(".local/share"));

          #[cfg(target_os = "macos")]
          assert!(data_path.to_string_lossy().contains("Library/Application Support"));

          #[cfg(target_os = "windows")]
          {
            if let Ok(appdata) = env::var("APPDATA") {
              assert_eq!(data_path, PathBuf::from(appdata));
            }
          }
        }
      });
    }
  }

  mod data_local {
    use super::*;

    #[test]
    fn uses_localappdata_on_windows() {
      let result = data_local();
      if let Some(data_local_path) = result {
        assert!(data_local_path.is_absolute());

        #[cfg(target_os = "windows")]
        {
          if let Ok(localappdata) = env::var("LOCALAPPDATA") {
            assert_eq!(data_local_path, PathBuf::from(localappdata));
          }
        }

        #[cfg(not(target_os = "windows"))]
        {
          assert_eq!(Some(data_local_path), data_home());
        }
      }
    }

    #[test]
    fn matches_data_home_on_non_windows() {
      #[cfg(not(target_os = "windows"))]
      {
        let data_local = data_local();
        let data_home = data_home();
        assert_eq!(data_local, data_home);
      }
    }
  }

  mod desktop {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_desktop_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\desktop" } else { "/test/desktop" };
      with_var("XDG_DESKTOP_DIR", Some(test_path), || {
        let result = desktop();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_desktop_dir() {
      with_var("XDG_DESKTOP_DIR", Some("relative/desktop"), || {
        let result = desktop();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_DESKTOP_DIR", || {
        let result = desktop();
        if let Some(desktop_path) = result {
          assert!(desktop_path.is_absolute());
          assert!(desktop_path.to_string_lossy().ends_with("Desktop"));
        }
      });
    }
  }

  mod documents {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_documents_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\documents" } else { "/test/documents" };
      with_var("XDG_DOCUMENTS_DIR", Some(test_path), || {
        let result = documents();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_documents_dir() {
      with_var("XDG_DOCUMENTS_DIR", Some("relative/documents"), || {
        let result = documents();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_DOCUMENTS_DIR", || {
        let result = documents();
        if let Some(documents_path) = result {
          assert!(documents_path.is_absolute());
          assert!(documents_path.to_string_lossy().ends_with("Documents"));
        }
      });
    }
  }

  mod downloads {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_download_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\downloads" } else { "/test/downloads" };
      with_var("XDG_DOWNLOAD_DIR", Some(test_path), || {
        let result = downloads();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_download_dir() {
      with_var("XDG_DOWNLOAD_DIR", Some("relative/downloads"), || {
        let result = downloads();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_DOWNLOAD_DIR", || {
        let result = downloads();
        if let Some(downloads_path) = result {
          assert!(downloads_path.is_absolute());
          assert!(downloads_path.to_string_lossy().ends_with("Downloads"));
        }
      });
    }
  }

  mod fonts {
    use super::*;

    #[test]
    fn returns_platform_specific_path() {
      let result = fonts();

      #[cfg(target_os = "linux")]
      if let Some(fonts_path) = result {
        assert!(fonts_path.is_absolute());
        assert!(fonts_path.to_string_lossy().ends_with(".local/share/fonts"));
      }

      #[cfg(target_os = "macos")]
      if let Some(fonts_path) = result {
        assert!(fonts_path.is_absolute());
        assert!(fonts_path.to_string_lossy().ends_with("Library/Fonts"));
      }

      #[cfg(target_os = "windows")]
      assert_eq!(result, None);
    }

    #[test]
    fn returns_none_on_windows() {
      #[cfg(target_os = "windows")]
      {
        let result = fonts();
        assert_eq!(result, None);
      }
    }

    #[test]
    fn returns_some_on_unix() {
      #[cfg(any(target_os = "linux", target_os = "macos"))]
      {
        let result = fonts();
        assert!(result.is_some());
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      }
    }
  }

  mod home {
    use super::*;

    #[test]
    fn returns_absolute_path_when_available() {
      let result = home();
      if let Some(home_path) = result {
        assert!(home_path.is_absolute());
      }
    }

    #[test]
    fn delegates_to_std_env_home_dir() {
      let std_result = std::env::home_dir();
      let our_result = home();
      assert_eq!(std_result, our_result);
    }
  }

  mod music {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_music_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\music" } else { "/test/music" };
      with_var("XDG_MUSIC_DIR", Some(test_path), || {
        let result = music();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_music_dir() {
      with_var("XDG_MUSIC_DIR", Some("relative/music"), || {
        let result = music();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_MUSIC_DIR", || {
        let result = music();
        if let Some(music_path) = result {
          assert!(music_path.is_absolute());
          assert!(music_path.to_string_lossy().ends_with("Music"));
        }
      });
    }
  }

  mod pictures {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_pictures_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\pictures" } else { "/test/pictures" };
      with_var("XDG_PICTURES_DIR", Some(test_path), || {
        let result = pictures();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_pictures_dir() {
      with_var("XDG_PICTURES_DIR", Some("relative/pictures"), || {
        let result = pictures();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_PICTURES_DIR", || {
        let result = pictures();
        if let Some(pictures_path) = result {
          assert!(pictures_path.is_absolute());
          assert!(pictures_path.to_string_lossy().ends_with("Pictures"));
        }
      });
    }
  }

  mod preferences {
    use super::*;

    #[test]
    fn returns_platform_specific_path() {
      let result = preferences();
      if let Some(preferences_path) = result {
        assert!(preferences_path.is_absolute());

        #[cfg(target_os = "macos")]
        assert!(preferences_path.to_string_lossy().ends_with("Library/Preferences"));

        #[cfg(not(target_os = "macos"))]
        assert_eq!(Some(preferences_path), config_home());
      }
    }

    #[test]
    fn matches_config_home_on_non_macos() {
      #[cfg(not(target_os = "macos"))]
      {
        let preferences = preferences();
        let config_home = config_home();
        assert_eq!(preferences, config_home);
      }
    }

    #[test]
    fn uses_library_preferences_on_macos() {
      #[cfg(target_os = "macos")]
      {
        let result = preferences();
        if let Some(path) = result {
          assert!(path.to_string_lossy().ends_with("Library/Preferences"));
        }
      }
    }
  }

  mod publicshare {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_publicshare_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\public" } else { "/test/public" };
      with_var("XDG_PUBLICSHARE_DIR", Some(test_path), || {
        let result = publicshare();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_publicshare_dir() {
      with_var("XDG_PUBLICSHARE_DIR", Some("relative/public"), || {
        let result = publicshare();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_PUBLICSHARE_DIR", || {
        let result = publicshare();
        if let Some(public_path) = result {
          assert!(public_path.is_absolute());

          #[cfg(target_os = "windows")]
          assert_eq!(public_path, PathBuf::from("C:\\Users\\Public"));

          #[cfg(any(target_os = "linux", target_os = "macos"))]
          assert!(public_path.to_string_lossy().ends_with("Public"));
        }
      });
    }

    #[test]
    fn uses_system_public_on_windows() {
      #[cfg(target_os = "windows")]
      {
        with_var_unset("XDG_PUBLICSHARE_DIR", || {
          let result = publicshare();
          assert_eq!(result, Some(PathBuf::from("C:\\Users\\Public")));
        });
      }
    }
  }

  mod runtime {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_runtime_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\runtime" } else { "/test/runtime" };
      with_var("XDG_RUNTIME_DIR", Some(test_path), || {
        let result = runtime();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_runtime_dir() {
      with_var("XDG_RUNTIME_DIR", Some("relative/runtime"), || {
        let result = runtime();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_RUNTIME_DIR", || {
        let result = runtime();
        if let Some(runtime_path) = result {
          assert!(runtime_path.is_absolute());

          #[cfg(any(target_os = "linux", target_os = "macos"))]
          {
            let path_str = runtime_path.to_string_lossy();
            assert!(path_str.contains("tmp") || path_str.starts_with("/var/folders"));
          }

          #[cfg(target_os = "windows")]
          {
            if let Ok(temp) = env::var("TEMP") {
              assert_eq!(runtime_path, PathBuf::from(temp));
            }
          }
        }
      });
    }

    #[test]
    fn falls_back_to_tmp_on_unix() {
      #[cfg(any(target_os = "linux", target_os = "macos"))]
      {
        with_var_unset("XDG_RUNTIME_DIR", || {
          with_var_unset("TMPDIR", || {
            let result = runtime();
            assert_eq!(result, Some(PathBuf::from("/tmp")));
          });
        });
      }
    }
  }

  mod state_home {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_state_home() {
      let test_path = if cfg!(windows) { "C:\\test\\state" } else { "/test/state" };
      with_var("XDG_STATE_HOME", Some(test_path), || {
        let result = state_home();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_state_home() {
      with_var("XDG_STATE_HOME", Some("relative/state"), || {
        let result = state_home();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_STATE_HOME", || {
        let result = state_home();
        if let Some(state_path) = result {
          assert!(state_path.is_absolute());

          #[cfg(target_os = "linux")]
          assert!(state_path.to_string_lossy().ends_with(".local/state"));

          #[cfg(target_os = "macos")]
          assert!(state_path.to_string_lossy().contains("Library/Application Support"));

          #[cfg(target_os = "windows")]
          {
            if let Ok(localappdata) = env::var("LOCALAPPDATA") {
              assert_eq!(state_path, PathBuf::from(localappdata));
            }
          }
        }
      });
    }
  }

  mod templates {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_templates_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\templates" } else { "/test/templates" };
      with_var("XDG_TEMPLATES_DIR", Some(test_path), || {
        let result = templates();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_templates_dir() {
      with_var("XDG_TEMPLATES_DIR", Some("relative/templates"), || {
        let result = templates();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_TEMPLATES_DIR", || {
        let result = templates();
        if let Some(templates_path) = result {
          assert!(templates_path.is_absolute());
          assert!(templates_path.to_string_lossy().ends_with("Templates"));
        }
      });
    }
  }

  mod videos {
    use temp_env::{with_var, with_var_unset};

    use super::*;

    #[test]
    fn respects_xdg_videos_dir() {
      let test_path = if cfg!(windows) { "C:\\test\\videos" } else { "/test/videos" };
      with_var("XDG_VIDEOS_DIR", Some(test_path), || {
        let result = videos();
        assert_eq!(result, Some(PathBuf::from(test_path)));
      });
    }

    #[test]
    fn ignores_relative_xdg_videos_dir() {
      with_var("XDG_VIDEOS_DIR", Some("relative/videos"), || {
        let result = videos();
        if let Some(path) = result {
          assert!(path.is_absolute());
        }
      });
    }

    #[test]
    fn uses_platform_default_when_xdg_unset() {
      with_var_unset("XDG_VIDEOS_DIR", || {
        let result = videos();
        if let Some(videos_path) = result {
          assert!(videos_path.is_absolute());

          #[cfg(target_os = "linux")]
          assert!(videos_path.to_string_lossy().ends_with("Videos"));

          #[cfg(target_os = "macos")]
          assert!(videos_path.to_string_lossy().ends_with("Movies"));

          #[cfg(target_os = "windows")]
          assert!(videos_path.to_string_lossy().ends_with("Videos"));
        }
      });
    }
  }
}