fix: ensure shader assets exist

This is mainly useful for existing Tattoy users that already have the
default shader, but then update to the latest Tattoy version and
shouldn't have to manually copy the shader file from somewhere.

Author: tombh

crates/tattoy/src/config/main.rs

@@ -196,13 +196,32 @@ impl Config {
 
         std::fs::create_dir_all(path.clone())?;
 
-        let shaders_directory = path.join(SHADER_DIRECTORY_NAME);
+        *state.config_path.write().await = path;
+
+        Ok(())
+    }
+
+    /// Make sure all the shader directories and files exist.
+    fn ensure_shader_assets(config_base: &std::path::Path) -> Result<()> {
+        let shaders_directory = config_base.join(SHADER_DIRECTORY_NAME);
         std::fs::create_dir_all(shaders_directory)?;
 
-        let animated_cursor_directory = path.join(CURSOR_SHADER_DIRECTORY_NAME);
+        let animated_cursor_directory = config_base.join(CURSOR_SHADER_DIRECTORY_NAME);
         std::fs::create_dir_all(animated_cursor_directory)?;
 
-        *state.config_path.write().await = path;
+        let shader_path = config_base
+            .join(SHADER_DIRECTORY_NAME)
+            .join(DEFAULT_SHADER_FILENAME);
+        if !shader_path.exists() {
+            std::fs::write(shader_path, EXAMPLE_SHADER)?;
+        }
+
+        let animated_cursor_path = config_base
+            .join(CURSOR_SHADER_DIRECTORY_NAME)
+            .join(DEFAULT_CURSOR_SHADER_FILENAME);
+        if !animated_cursor_path.exists() {
+            std::fs::write(animated_cursor_path, EXAMPLE_CURSOR_SHADER)?;
+        }
 
         Ok(())
     }
@@ -223,20 +242,11 @@ impl Config {
             .file_name()
             .context("Couldn't get file name from config path")?;
         let is_default_config = config_file_name == crate::cli_args::DEFAULT_CONFIG_FILE_NAME;
-        if is_default_config && !config_path.exists() {
-            std::fs::write(config_path.clone(), DEFAULT_CONFIG)?;
-
-            let shader_path = Self::directory(state)
-                .await
-                .join(SHADER_DIRECTORY_NAME)
-                .join(DEFAULT_SHADER_FILENAME);
-            std::fs::write(shader_path, EXAMPLE_SHADER)?;
-
-            let animated_cursor_path = Self::directory(state)
-                .await
-                .join(CURSOR_SHADER_DIRECTORY_NAME)
-                .join(DEFAULT_CURSOR_SHADER_FILENAME);
-            std::fs::write(animated_cursor_path, EXAMPLE_CURSOR_SHADER)?;
+        if is_default_config {
+            if !config_path.exists() {
+                std::fs::write(config_path.clone(), DEFAULT_CONFIG)?;
+            }
+            Self::ensure_shader_assets(&Self::default_directory()?)?;
         }
 
         tracing::info!("(Re)loading the main Tattoy config from: {config_path:?}");