improve code for config and FileSink

packages/obs/src/config.rs

@@ -142,14 +142,20 @@ const DEFAULT_CONFIG_FILE: &str = "obs";
 /// ```
 pub fn load_config(config_dir: Option<String>) -> AppConfig {
     let config_dir = if let Some(path) = config_dir {
-        // Use the provided path
-        let path = std::path::Path::new(&path);
-        if path.extension().is_some() {
-            // If path has extension, use it as is (extension will be added by Config::builder)
-            path.with_extension("").to_string_lossy().into_owned()
+        // If a path is provided, check if it's empty
+        if path.is_empty() {
+            // If empty, use the default config file name
+            DEFAULT_CONFIG_FILE.to_string()
         } else {
-            // If path is a directory, append the default config file name
-            path.to_string_lossy().into_owned()
+            // Use the provided path
+            let path = std::path::Path::new(&path);
+            if path.extension().is_some() {
+                // If path has extension, use it as is (extension will be added by Config::builder)
+                path.with_extension("").to_string_lossy().into_owned()
+            } else {
+                // If path is a directory, append the default config file name
+                path.to_string_lossy().into_owned()
+            }
         }
     } else {
         // If no path provided, use current directory + default config file
@@ -166,11 +172,11 @@ pub fn load_config(config_dir: Option<String>) -> AppConfig {
     println!("Using config file base: {}", config_dir);
 
     let config = Config::builder()
-        .add_source(File::with_name(config_dir.as_str()).format(FileFormat::Toml))
+        .add_source(File::with_name(config_dir.as_str()).format(FileFormat::Toml).required(false))
         .add_source(File::with_name(config_dir.as_str()).format(FileFormat::Yaml).required(false))
         .add_source(config::Environment::with_prefix(""))
         .build()
-        .unwrap();
+        .unwrap_or_default();
 
-    config.try_deserialize().unwrap()
+    config.try_deserialize().unwrap_or_default()
 }

packages/obs/src/sink.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 use tokio::fs::OpenOptions;
 use tokio::io;
 use tokio::io::AsyncWriteExt;
+use tracing::debug;
 
 /// Sink Trait definition, asynchronously write logs
 #[async_trait]
@@ -268,8 +269,19 @@ impl FileSink {
         flush_interval_ms: u64,
         flush_threshold: usize,
     ) -> Result<Self, io::Error> {
-        let file = OpenOptions::new().append(true).create(true).open(&path).await?;
-
+        // check if the file exists
+        let file_exists = tokio::fs::metadata(&path).await.is_ok();
+        let file = if file_exists {
+            // If the file exists, open it in append mode
+            debug!("FileSink: File exists, opening in append mode.");
+            OpenOptions::new().append(true).create(true).open(&path).await?
+        } else {
+            // If the file does not exist, create it
+            debug!("FileSink: File does not exist, creating a new file.");
+            // Create the file and write a header or initial content if needed
+            OpenOptions::new().create(true).write(true).open(&path).await?
+        };
+        // let file = OpenOptions::new().append(true).create(true).open(&path).await?;
         let writer = io::BufWriter::with_capacity(buffer_size, file);
         let now = std::time::SystemTime::now()
             .duration_since(std::time::UNIX_EPOCH)