feat: add convenience methods to filter service and improve filter chain processing

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

src/filter_plugin/mod.rs

@@ -31,7 +31,10 @@ impl FilterChain {
     pub fn process(&mut self, data: &[u8]) -> Result<Vec<u8>> {
         let mut current_data = data.to_vec();
         for plugin in &mut self.plugins {
-            current_data = plugin.process(&current_data)?;
+            // Process the current data through the plugin
+            let processed = plugin.process(&current_data)?;
+            current_data = processed;
+            
             // Early exit if no data remains
             if current_data.is_empty() {
                 break;
@@ -42,20 +45,15 @@ impl FilterChain {
 
     pub fn finish(&mut self) -> Result<Vec<u8>> {
         let mut result = Vec::new();
-        let mut all_data = Vec::new();
         
+        // Process each plugin's finish method and collect results
         for plugin in &mut self.plugins {
-            let processed = plugin.finish()?;
-            if !processed.is_empty() {
-                all_data.extend(processed);
+            let finished_data = plugin.finish()?;
+            if !finished_data.is_empty() {
+                result.extend(finished_data);
             }
         }
         
-        // If we have any data from finish, use it
-        if !all_data.is_empty() {
-            result = all_data;
-        }
-
         Ok(result)
     }
 }

src/services/filter_service.rs

@@ -31,4 +31,29 @@ impl FilterService {
             Ok(Vec::new())
         }
     }
+
+    // Add a method to process data through the filter chain and handle finish automatically
+    pub fn process_all_data(&self, chain: &mut Option<FilterChain>, data: &[u8]) -> Result<Vec<u8>> {
+        let mut processed = if let Some(chain) = chain {
+            chain.process(data)?
+        } else {
+            data.to_vec()
+        };
+        
+        // If we have a chain, also get any remaining data from finish()
+        if chain.is_some() {
+            let finished = self.finish_processing(chain)?;
+            if !finished.is_empty() {
+                processed.extend(finished);
+            }
+        }
+        
+        Ok(processed)
+    }
+
+    // Helper method to create and process data with a filter string in one call
+    pub fn process_with_filter(&self, data: &[u8], filter_str: Option<&str>) -> Result<Vec<u8>> {
+        let mut chain = self.create_filter_chain(filter_str)?;
+        self.process_all_data(&mut chain, data)
+    }
 }