Supports obtaining PDF documents from web pages (#1107)

### What problem does this PR solve?

Knowledge base management supports crawling information from web pages
and generating PDF documents

### Type of change
- [x] New Feature (Support document from web pages)

api/apps/document_app.py

@@ -39,6 +39,7 @@ from api.settings import RetCode
 from api.utils.api_utils import get_json_result
 from rag.utils.minio_conn import MINIO
 from api.utils.file_utils import filename_type, thumbnail
+from api.utils.web_utils import html2pdf, is_valid_url
 
 
 @manager.route('/upload', methods=['POST'])
@@ -289,7 +290,7 @@ def run():
                 return get_data_error_result(retmsg="Tenant not found!")
             ELASTICSEARCH.deleteByQuery(
                 Q("match", doc_id=id), idxnm=search.index_name(tenant_id))
-            
+
             if str(req["run"]) == TaskStatus.RUNNING.value:
                 TaskService.filter_delete([Task.doc_id == id])
                 e, doc = DocumentService.get_by_id(id)
@@ -416,3 +417,69 @@ def get_image(image_id):
         return response
     except Exception as e:
         return server_error_response(e)
+
+
+@manager.route('/web_crawl', methods=['POST'])
+@login_required
+def web_crawl():
+    kb_id = request.form.get("kb_id")
+    if not kb_id:
+        return get_json_result(
+            data=False, retmsg='Lack of "KB ID"', retcode=RetCode.ARGUMENT_ERROR)
+    name = request.form.get("name")
+    url = request.form.get("url")
+    if not name:
+        return get_json_result(
+            data=False, retmsg='Lack of "name"', retcode=RetCode.ARGUMENT_ERROR)
+    if not url:
+        return get_json_result(
+            data=False, retmsg='Lack of "url"', retcode=RetCode.ARGUMENT_ERROR)
+    if not is_valid_url(url):
+        return get_json_result(
+            data=False, retmsg='The URL format is invalid', retcode=RetCode.ARGUMENT_ERROR)
+    e, kb = KnowledgebaseService.get_by_id(kb_id)
+    if not e:
+        raise LookupError("Can't find this knowledgebase!")
+
+    root_folder = FileService.get_root_folder(current_user.id)
+    pf_id = root_folder["id"]
+    FileService.init_knowledgebase_docs(pf_id, current_user.id)
+    kb_root_folder = FileService.get_kb_folder(current_user.id)
+    kb_folder = FileService.new_a_file_from_kb(kb.tenant_id, kb.name, kb_root_folder["id"])
+
+    try:
+        filename = duplicate_name(
+            DocumentService.query,
+            name=name+".pdf",
+            kb_id=kb.id)
+        filetype = filename_type(filename)
+        if filetype == FileType.OTHER.value:
+            raise RuntimeError("This type of file has not been supported yet!")
+
+        location = filename
+        while MINIO.obj_exist(kb_id, location):
+            location += "_"
+        blob = html2pdf(url)
+        MINIO.put(kb_id, location, blob)
+        doc = {
+            "id": get_uuid(),
+            "kb_id": kb.id,
+            "parser_id": kb.parser_id,
+            "parser_config": kb.parser_config,
+            "created_by": current_user.id,
+            "type": filetype,
+            "name": filename,
+            "location": location,
+            "size": len(blob),
+            "thumbnail": thumbnail(filename, blob)
+        }
+        if doc["type"] == FileType.VISUAL:
+            doc["parser_id"] = ParserType.PICTURE.value
+        if re.search(r"\.(ppt|pptx|pages)$", filename):
+            doc["parser_id"] = ParserType.PRESENTATION.value
+        DocumentService.insert(doc)
+        FileService.add_file_from_kb(doc, kb_folder["id"], kb.tenant_id)
+    except Exception as e:
+        return get_json_result(
+            data=False, retmsg=e, retcode=RetCode.SERVER_ERROR)
+    return get_json_result(data=True)