Initial commit

src/io/dialog.rs

@@ -0,0 +1,85 @@
+use std::path::{Path, PathBuf};
+
+use rfd::FileDialog;
+use winit::window::Window;
+
+const DEFAULT_FILE_NAME: &str = "map.json";
+
+/// Show the platform-native Save dialog. The caller owns the returned path and
+/// decides when to write, which keeps dialogs entirely out of unit tests.
+pub fn choose_map_save_path(window: &Window, current: Option<&Path>) -> Option<PathBuf> {
+    let mut dialog = map_dialog(window, "Сохранить карту");
+    if let Some(directory) = starting_directory(current) {
+        dialog = dialog.set_directory(directory);
+    }
+    let suggested_name = current
+        .and_then(Path::file_name)
+        .and_then(|name| name.to_str())
+        .unwrap_or(DEFAULT_FILE_NAME);
+    dialog
+        .set_file_name(suggested_name)
+        .save_file()
+        .map(ensure_json_extension)
+}
+
+/// Show the platform-native Open dialog for one versioned JSON map.
+pub fn choose_map_open_path(window: &Window, current: Option<&Path>) -> Option<PathBuf> {
+    let mut dialog = map_dialog(window, "Открыть карту");
+    if let Some(directory) = starting_directory(current) {
+        dialog = dialog.set_directory(directory);
+    }
+    dialog.pick_file()
+}
+
+fn map_dialog(window: &Window, title: &str) -> FileDialog {
+    FileDialog::new()
+        .set_parent(window)
+        .set_title(title)
+        .add_filter("Карта Ray Marching (JSON)", &["json"])
+}
+
+fn starting_directory(current: Option<&Path>) -> Option<PathBuf> {
+    current
+        .and_then(|path| {
+            if path.is_dir() {
+                Some(path)
+            } else {
+                path.parent()
+            }
+        })
+        .filter(|path| !path.as_os_str().is_empty())
+        .map(Path::to_owned)
+        .or_else(|| std::env::current_dir().ok())
+}
+
+pub(crate) fn ensure_json_extension(mut path: PathBuf) -> PathBuf {
+    let is_json = path
+        .extension()
+        .and_then(|extension| extension.to_str())
+        .is_some_and(|extension| extension.eq_ignore_ascii_case("json"));
+    if !is_json {
+        path.set_extension("json");
+    }
+    path
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn save_path_gets_one_json_extension() {
+        assert_eq!(
+            ensure_json_extension(PathBuf::from("level")),
+            PathBuf::from("level.json")
+        );
+        assert_eq!(
+            ensure_json_extension(PathBuf::from("level.JSON")),
+            PathBuf::from("level.JSON")
+        );
+        assert_eq!(
+            ensure_json_extension(PathBuf::from("level.txt")),
+            PathBuf::from("level.json")
+        );
+    }
+}