add summarize_story

tool_core.js

@@ -349,6 +349,26 @@ module.exports = {
     }
   },
 
+  summarize_story (story = []) {
+    // story is an array of objects, each object could either be {text:'some string'}, {image: url} or {video:url}. Please construct a summary object as result: { textLength, imageCount, VideoCount }
+    return story.reduce(
+      (summary, { text, image, video, file } = {}) => {
+        if (text) {
+          summary.textLength += text.length
+          summary.wordCount += text.split(/\s+/).length
+        } else if (image) {
+          summary.imageCount++
+        } else if (video) {
+          summary.videoCount++
+        } else if (file) {
+          summary.fileCount++
+        }
+        return summary
+      },
+      { textLength: 0, wordCount: 0, imageCount: 0, videoCount: 0 }
+    )
+  },
+
   is_empty (data) {
     // empty: undefined, null, false, 0, NaN, '', '空格，tab, \n等', [], {}
     if (data) {