core&ui: support pasting image in editor

packages/hydrooj/src/handler/problem.ts

@@ -790,8 +790,20 @@ export class ProblemCreateHandler extends Handler {
         domainId: string, title: string, content: string, pid: string,
         hidden = false, difficulty = 0, tag: string[] = [], assign: string[] = [],
     ) {
-        if (pid && await problem.get(domainId, pid)) throw new BadRequestError('invalid pid');
+        if (pid && await problem.get(domainId, pid)) throw new BadRequestError('ProblemID already exists');
         const docId = await problem.add(domainId, pid, title, content, this.user._id, tag ?? [], hidden, assign);
+        const files = new Set(Array.from(content.matchAll(/file:\/\/([a-zA-Z0-9_-]+\.[a-zA-Z0-9]+)/g)).map((i) => i[1]));
+        const tasks = [];
+        for (const file of files) {
+            if (this.user._files.find((i) => i.name === file)) {
+                tasks.push(
+                    storage.rename(`user/${this.user._id}/${file}`, `problem/${domainId}/${docId}/additional_file/${file}`)
+                        .then(() => problem.addAdditionalFile(domainId, docId, file, '', true)),
+                    user.setById(this.user._id, { _files: this.user._files.filter((i) => i.name !== file) }),
+                );
+            }
+        }
+        await Promise.all(tasks);
         if (difficulty) await problem.edit(domainId, docId, { difficulty });
         this.response.body = { pid: pid || docId };
         this.response.redirect = this.url('problem_files', { pid: pid || docId });