refactor(zalo): share outbound chunker

src/plugin-sdk/text-chunking.ts

@@ -0,0 +1,31 @@
+export function chunkTextForOutbound(text: string, limit: number): string[] {
+  if (!text) {
+    return [];
+  }
+  if (limit <= 0 || text.length <= limit) {
+    return [text];
+  }
+  const chunks: string[] = [];
+  let remaining = text;
+  while (remaining.length > limit) {
+    const window = remaining.slice(0, limit);
+    const lastNewline = window.lastIndexOf("\n");
+    const lastSpace = window.lastIndexOf(" ");
+    let breakIdx = lastNewline > 0 ? lastNewline : lastSpace;
+    if (breakIdx <= 0) {
+      breakIdx = limit;
+    }
+    const rawChunk = remaining.slice(0, breakIdx);
+    const chunk = rawChunk.trimEnd();
+    if (chunk.length > 0) {
+      chunks.push(chunk);
+    }
+    const brokeOnSeparator = breakIdx < remaining.length && /\s/.test(remaining[breakIdx]);
+    const nextStart = Math.min(remaining.length, breakIdx + (brokeOnSeparator ? 1 : 0));
+    remaining = remaining.slice(nextStart).trimStart();
+  }
+  if (remaining.length) {
+    chunks.push(remaining);
+  }
+  return chunks;
+}