From c4b0f900f8444ff2417ea116cc541e40110cab1a Mon Sep 17 00:00:00 2001
From: simon <simobilleter@gmail.com>
Date: Wed, 17 Nov 2021 17:54:47 +0700
Subject: [PATCH] dedicated search_after class to scroll through index

---
 tubearchivist/home/src/index.py | 78 +++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/tubearchivist/home/src/index.py b/tubearchivist/home/src/index.py
index 49a7d23..2294f18 100644
--- a/tubearchivist/home/src/index.py
+++ b/tubearchivist/home/src/index.py
@@ -707,6 +707,84 @@ class WatchState:
             print(request.text)
 
 
+class IndexPaginate:
+    """use search_after to go through whole index"""
+
+    CONFIG = AppConfig().config
+    ES_URL = CONFIG["application"]["es_url"]
+    ES_AUTH = CONFIG["application"]["es_auth"]
+    HEADERS = {"Content-type": "application/json"}
+    DEFAULT_SIZE = 500
+
+    def __init__(self, index_name, data, size=False):
+        self.index_name = index_name
+        self.data = data
+        self.pit_id = False
+        self.size = size
+
+    def get_results(self):
+        """get all results"""
+        self.get_pit()
+        self.validate_data()
+        all_results = self.run_loop()
+        self.clean_pit()
+        return all_results
+
+    def get_pit(self):
+        """get pit for index"""
+        url = f"{self.ES_URL}/{self.index_name}/_pit?keep_alive=10m"
+        response = requests.post(url, auth=self.ES_AUTH)
+        json_data = json.loads(response.text)
+
+        self.pit_id = json_data["id"]
+
+    def validate_data(self):
+        """add pit and size to data"""
+        if "sort" not in self.data.keys():
+            print(self.data)
+            raise ValueError("missing sort key in data")
+
+        size = self.size or self.DEFAULT_SIZE
+
+        self.data["size"] = size
+        self.data["pit"] = {"id": self.pit_id, "keep_alive": "10m"}
+
+    def run_loop(self):
+        """loop through results until last hit"""
+        query_str = json.dumps(self.data)
+        url = self.ES_URL + "/_search"
+
+        all_results = []
+        while True:
+            response = requests.get(
+                url, data=query_str, headers=self.HEADERS, auth=self.ES_AUTH
+            )
+            json_data = json.loads(response.text)
+            all_hits = json_data["hits"]["hits"]
+            if all_hits:
+                for hit in all_hits:
+                    source = hit["_source"]
+                    search_after = hit["sort"]
+                    all_results.append(source)
+                # update search_after with last hit data
+                self.data["search_after"] = search_after
+                query_str = json.dumps(self.data)
+            else:
+                break
+
+        return all_results
+
+    def clean_pit(self):
+        """delete pit from elastic search"""
+        query_str = json.dumps({"id": self.pit_id})
+        requests.delete(
+            self.ES_URL + "/_pit",
+            data=query_str,
+            headers=self.HEADERS,
+            auth=self.ES_AUTH,
+        )
+
+
 def index_new_video(youtube_id, missing_vid=False):
     """combine video and channel classes for new video index"""
     vid_handler = YoutubeVideo(youtube_id)