From 075b92f231012e21ef777a42df9030c377c794fa Mon Sep 17 00:00:00 2001
From: xiaoski <xiaoski@qq.com>
Date: Wed, 8 Apr 2026 08:42:56 +0800
Subject: [PATCH] fix: truncate long text content before sending to Feishu

Feishu API rejects messages with content exceeding ~64KB with error
230001 "invalid message content". Added truncation at 60,000 characters
to prevent this, with a notice appended to truncated content.
---
 src/channels/feishu.rs | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/channels/feishu.rs b/src/channels/feishu.rs
index 2d6daa1..99119dc 100644
--- a/src/channels/feishu.rs
+++ b/src/channels/feishu.rs
@@ -489,7 +489,16 @@ impl FeishuChannel {
     async fn send_message_to_feishu(&self, receive_id: &str, receive_id_type: &str, content: &str) -> Result<(), ChannelError> {
         let token = self.get_tenant_token().await?;
 
-        let text_content = serde_json::json!({ "text": content }).to_string();
+        // Feishu text messages have content limits (~64KB).
+        // Truncate if content is too long to avoid API error 230001.
+        const MAX_TEXT_LENGTH: usize = 60_000;
+        let truncated = if content.len() > MAX_TEXT_LENGTH {
+            format!("{}...\n\n[Content truncated due to length limit]", &content[..MAX_TEXT_LENGTH])
+        } else {
+            content.to_string()
+        };
+
+        let text_content = serde_json::json!({ "text": truncated }).to_string();
 
         let resp = self.http_client
             .post(format!("{}/im/v1/messages?receive_id_type={}", FEISHU_API_BASE, receive_id_type))
@@ -906,11 +915,17 @@ impl Channel for FeishuChannel {
         // Build content with media references
         let mut content_parts = Vec::new();
 
-        // Add text content if present
+        // Add text content if present (truncate if too long for Feishu)
         if !msg.content.is_empty() {
+            const MAX_TEXT_LENGTH: usize = 60_000;
+            let truncated_text = if msg.content.len() > MAX_TEXT_LENGTH {
+                format!("{}...\n\n[Content truncated due to length limit]", &msg.content[..MAX_TEXT_LENGTH])
+            } else {
+                msg.content.clone()
+            };
             content_parts.push(serde_json::json!({
                 "tag": "text",
-                "text": msg.content
+                "text": truncated_text
             }));
         }