fix(wechatcomapp): split long text messages into multiple parts

common/utils.py

@@ -32,3 +32,20 @@ def compress_imgfile(file, max_size):
         if fsize(out_buf) <= max_size:
             return out_buf
         quality -= 5
+
+
+def split_string_by_utf8_length(string, max_length, max_split=0):
+    encoded = string.encode("utf-8")
+    start, end = 0, 0
+    result = []
+    while end < len(encoded):
+        if max_split > 0 and len(result) >= max_split:
+            result.append(encoded[start:].decode("utf-8"))
+            break
+        end = min(start + max_length, len(encoded))
+        # 如果当前字节不是 UTF-8 编码的开始字节，则向前查找直到找到开始字节为止
+        while end < len(encoded) and (encoded[end] & 0b11000000) == 0b10000000:
+            end -= 1
+        result.append(encoded[start:end].decode("utf-8"))
+        start = end
+    return result