feat(feishu): 支持 markdown 格式的消息处理，优化内容解析逻辑

src/channels/feishu.rs

@@ -1189,6 +1189,11 @@ fn parse_post_content(content: &str) -> String {
     /// Extract text from a single post element (text, link, at-mention).
     fn extract_element(el: &serde_json::Value, out: &mut Vec<String>) {
         match el.get("tag").and_then(|t| t.as_str()).unwrap_or("") {
+            "md" => {
+                if let Some(text) = el.get("text").and_then(|t| t.as_str()) {
+                    out.push(text.to_string());
+                }
+            }
             "text" => {
                 if let Some(text) = el.get("text").and_then(|t| t.as_str()) {
                     out.push(text.to_string());
@@ -1582,8 +1587,8 @@ struct MdPatterns {
 impl MdPatterns {
     fn new() -> Self {
         Self {
-            table_re: Regex::new(r"((?:^[ \t]*\|.+\|[ \t]*\n)(?:^[ \t]*\|[-:\s|]+\|[ \t]*\n)(?:^[ \t]*\|.+\|[ \t]*\n?)+)").unwrap(),
+            table_re: Regex::new(r"(?m)((?:^[ \t]*\|.+\|[ \t]*\n)(?:^[ \t]*\|[-:\s|]+\|[ \t]*\n)(?:^[ \t]*\|.+\|[ \t]*\n?)+)").unwrap(),
-            heading_re: Regex::new(r"^(#{1,6})\s+(.+)$").unwrap(),
+            heading_re: Regex::new(r"(?m)^(#{1,6})\s+(.+)$").unwrap(),
             code_block_re: Regex::new(r"(```[\s\S]*?```)").unwrap(),
             bold_re: Regex::new(r"\*\*(.+?)\*\*|__(.+?)__").unwrap(),
             // Simple pattern: detect *text* or _text_ markers (may overlap with bold, but that's ok for detection)
@@ -1591,8 +1596,8 @@ impl MdPatterns {
             italic_re: Regex::new(r"\*[^*]+\*|_[^_]+_").unwrap(),
             strike_re: Regex::new(r"~~.+?~~").unwrap(),
             link_re: Regex::new(r"\[([^\]]+)\]\((https?://[^\)]+)\)").unwrap(),
-            list_re: Regex::new(r"^[\s]*[-*+]\s+").unwrap(),
+            list_re: Regex::new(r"(?m)^[\s]*[-*+]\s+").unwrap(),
-            olist_re: Regex::new(r"^[\s]*\d+\.\s+").unwrap(),
+            olist_re: Regex::new(r"(?m)^[\s]*\d+\.\s+").unwrap(),
         }
     }
 }
@@ -1609,11 +1614,8 @@ impl FeishuChannel {
         let patterns = MdPatterns::new();
         let stripped = content.trim();
 
-        // Complex markdown (code blocks, tables, headings) → always interactive card
+        // Tables and headings are not supported by post `md` nodes, so use cards.
-        if patterns.table_re.is_match(stripped)
+        if patterns.table_re.is_match(stripped) || patterns.heading_re.is_match(stripped) {
-            || patterns.heading_re.is_match(stripped)
-            || patterns.code_block_re.is_match(stripped)
-        {
             return MsgFormat::Interactive;
         }
 
@@ -1622,21 +1624,15 @@ impl FeishuChannel {
             return MsgFormat::Interactive;
         }
 
-        // Has bold/italic/strikethrough → interactive card (post format can't render these)
+        // Markdown that is supported by Feishu post `md` should be sent as post.
         if patterns.bold_re.is_match(stripped)
             || patterns.italic_re.is_match(stripped)
             || patterns.strike_re.is_match(stripped)
+            || patterns.code_block_re.is_match(stripped)
+            || patterns.list_re.is_match(stripped)
+            || patterns.olist_re.is_match(stripped)
+            || patterns.link_re.is_match(stripped)
         {
-            return MsgFormat::Interactive;
-        }
-
-        // Has list items → interactive card (post format can't render list bullets well)
-        if patterns.list_re.is_match(stripped) || patterns.olist_re.is_match(stripped) {
-            return MsgFormat::Interactive;
-        }
-
-        // Has links → post format (supports <a> tags)
-        if patterns.link_re.is_match(stripped) {
             return MsgFormat::Post;
         }
 
@@ -1866,62 +1862,14 @@ impl FeishuChannel {
     }
 
     /// Convert markdown content to Feishu post message JSON.
-    /// Handles links [text](url) as <a> tags; everything else as text tags.
+    /// Feishu Markdown is sent via a post message with an `md` node.
     fn markdown_to_post(content: &str) -> String {
-        let patterns = MdPatterns::new();
-        let lines = content.trim().split('\n');
-        let mut paragraphs: Vec<Vec<serde_json::Value>> = Vec::new();
-
-        for line in lines {
-            let mut elements: Vec<serde_json::Value> = Vec::new();
-            let mut last_end = 0;
-
-            for cap in patterns.link_re.captures_iter(line) {
-                // Text before this link
-                let m = cap.get(0).unwrap();
-                let before = &line[last_end..m.start()];
-                if !before.is_empty() {
-                    elements.push(serde_json::json!({
-                        "tag": "text",
-                        "text": before
-                    }));
-                }
-
-                let link_text = cap.get(1).map(|g| g.as_str()).unwrap_or("");
-                let link_href = cap.get(2).map(|g| g.as_str()).unwrap_or("");
-
-                elements.push(serde_json::json!({
-                    "tag": "a",
-                    "text": link_text,
-                    "href": link_href
-                }));
-
-                last_end = m.end();
-            }
-
-            // Remaining text after last link
-            let remaining = &line[last_end..];
-            if !remaining.is_empty() {
-                elements.push(serde_json::json!({
-                    "tag": "text",
-                    "text": remaining
-                }));
-            }
-
-            // Empty line → empty paragraph for spacing
-            if elements.is_empty() {
-                elements.push(serde_json::json!({
-                    "tag": "text",
-                    "text": ""
-                }));
-            }
-
-            paragraphs.push(elements);
-        }
-
         let post_body = serde_json::json!({
             "zh_cn": {
-                "content": paragraphs
+                "content": [[{
+                    "tag": "md",
+                    "text": content.trim()
+                }]]
             }
         });
 
@@ -1972,6 +1920,33 @@ impl FeishuChannel {
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use super::{FeishuChannel, MsgFormat};
+
+    #[test]
+    fn markdown_post_uses_md_tag() {
+        let content = "**bold**\n1. item1\n2. item2\n[link](https://open.feishu.cn)";
+        let post = FeishuChannel::markdown_to_post(content);
+        let parsed: serde_json::Value = serde_json::from_str(&post).unwrap();
+
+        assert_eq!(parsed["zh_cn"]["content"][0][0]["tag"], "md");
+        assert_eq!(parsed["zh_cn"]["content"][0][0]["text"], content);
+    }
+
+    #[test]
+    fn multiline_markdown_is_not_misclassified_as_plain_post() {
+        let content = "intro\n1. item1\n2. item2";
+        assert_eq!(FeishuChannel::detect_msg_format(content), MsgFormat::Post);
+    }
+
+    #[test]
+    fn headings_still_use_interactive() {
+        let content = "intro\n## heading";
+        assert_eq!(FeishuChannel::detect_msg_format(content), MsgFormat::Interactive);
+    }
+}
+
 #[async_trait]
 impl Channel for FeishuChannel {
     fn name(&self) -> &str {