Use config folder (#110)

src/migration.rs

@@ -0,0 +1,41 @@
+use std::path::Path;
+
+pub fn migrate_config() {
+    let version = &crate::settings::Settings::new()
+        .map(|s| s.config_version)
+        .unwrap_or_default();
+
+    let mut save_version = false;
+    if version.is_none() {
+        //Migration from 0 to 1
+        let old_path = &Path::new("config.toml");
+        if old_path.exists() {
+            println!("Migrating from configuration version 0 to version 1");
+            let new_path = crate::config::get_config_file();
+            println!("Your configuration file will be moved to {:?}", new_path);
+            let _ = std::fs::copy(old_path, new_path);
+            let _ = std::fs::remove_file(old_path);
+        }
+
+        let old_path = &Path::new(".thumbnails");
+        if old_path.exists() {
+            //thumbnails are just cache can be removed
+            let _ = std::fs::remove_dir_all(old_path);
+        }
+
+        let old_path = &Path::new("cache.json");
+        if old_path.exists() {
+            let new_path = crate::config::get_cache_file();
+            let _ = std::fs::copy(old_path, new_path);
+            let _ = std::fs::remove_file(old_path);
+        }
+        save_version = true;
+    }
+
+    if save_version {
+        if let Ok(mut settings) = crate::settings::Settings::new() {
+            settings.config_version = Some(1);
+            crate::ui::MyEguiApp::save_settings_to_file(&settings);
+        }
+    }
+}