Fix: proper process_content_streaming for GptOss120bHandler to handle thinking tags during streaming

src/llm/llm_models/gpt_oss_120b.rs

@@ -1,5 +1,5 @@
-use super::deepseek_r3::strip_think_tags;
 use super::ModelHandler;
+
 #[derive(Debug)]
 pub struct GptOss120bHandler {}
 impl Default for GptOss120bHandler {
@@ -13,14 +13,69 @@ impl GptOss120bHandler {
         Self {}
     }
 }
+
+fn strip_think_tags(content: &str) -> String {
+    let result = content
+        .replace("<think>", "")
+        .replace("</think>", "")
+        .replace("**start**", "")
+        .replace("**end**", "");
+    if result.is_empty() && !content.is_empty() {
+        content.to_string()
+    } else {
+        result
+    }
+}
+
 impl ModelHandler for GptOss120bHandler {
     fn is_analysis_complete(&self, buffer: &str) -> bool {
         buffer.contains("**end**") || buffer.contains("</think>")
     }
     fn process_content(&self, content: &str) -> String {
         strip_think_tags(content)
-            .replace("**start**", "")
-            .replace("**end**", "")
+    }
+    fn process_content_streaming(&self, chunk: &str, state: &mut String) -> String {
+        let old_len = state.len();
+        state.push_str(chunk);
+
+        let mut clean_current = String::new();
+        let mut in_think = false;
+
+        let full_text = state.as_str();
+        let mut current_pos = 0;
+
+        while current_pos < full_text.len() {
+            if !in_think {
+                if full_text[current_pos..].starts_with("<think>") {
+                    in_think = true;
+                    current_pos += 7;
+                } else if full_text[current_pos..].starts_with("**start**") {
+                    current_pos += 10;
+                } else if full_text[current_pos..].starts_with("**end**") {
+                    current_pos += 7;
+                } else {
+                    let c = full_text[current_pos..].chars().next().unwrap();
+                    if current_pos >= old_len {
+                        clean_current.push(c);
+                    }
+                    current_pos += c.len_utf8();
+                }
+            } else {
+                if full_text[current_pos..].starts_with("</think>") {
+                    in_think = false;
+                    current_pos += 8;
+                } else {
+                    let c = full_text[current_pos..].chars().next().unwrap();
+                    current_pos += c.len_utf8();
+                }
+            }
+        }
+
+        if clean_current.is_empty() && chunk.len() > 0 {
+            chunk.to_string()
+        } else {
+            clean_current
+        }
     }
     fn has_analysis_markers(&self, buffer: &str) -> bool {
         buffer.contains("**start**") || buffer.contains("<think>")