refactor: gemini/vertexai blocked by safety (#386)

src/client/vertexai.rs

@@ -125,9 +125,7 @@ pub(crate) async fn send_message(builder: RequestBuilder) -> Result<String> {
     if status != 200 {
         check_error(&data)?;
     }
-    let output = data["candidates"][0]["content"]["parts"][0]["text"]
-        .as_str()
-        .ok_or_else(|| anyhow!("Invalid response data: {data}"))?;
+    let output = extract_text(&data)?;
     Ok(output.to_string())
 }
 
@@ -176,13 +174,7 @@ pub(crate) async fn send_message_streaming(
                         if balances.is_empty() {
                             let value: String = buffer[start..=i].iter().collect();
                             let value: Value = serde_json::from_str(&value)?;
-                            if let Some(text) =
-                                value["candidates"][0]["content"]["parts"][0]["text"].as_str()
-                            {
-                                handler.text(text)?;
-                            } else {
-                                bail!("Invalid response data: {value}")
-                            }
+                            handler.text(extract_text(&value)?)?;
                         }
                     }
                     ']' => {
@@ -197,6 +189,22 @@ pub(crate) async fn send_message_streaming(
     Ok(())
 }
 
+fn extract_text(data: &Value) -> Result<&str> {
+    match data["candidates"][0]["content"]["parts"][0]["text"].as_str() {
+        Some(text) => Ok(text),
+        None => {
+            if let Some("SAFETY") = data["promptFeedback"]["blockReason"]
+                .as_str()
+                .or_else(|| data["candidates"][0]["finishReason"].as_str())
+            {
+                bail!("Blocked by safety settings，consider ajusting `block_threshold` in the client configuraion")
+            } else {
+                bail!("Invalid response data: {data}")
+            }
+        }
+    }
+}
+
 fn check_error(data: &Value) -> Result<()> {
     if let Some((Some(status), Some(message))) = data[0]["error"].as_object().map(|v| {
         (