Added search data component

data.py

@@ -70,6 +70,15 @@ def parse_ignore_file() -> list:
     return ignore_names
 
 
+def get_id_from_parent(parent_id: str, link_data: list) -> int:
+    """given a parent ID, return the ID for the parent record or -1"""
+    assert parent_id != ""
+    for record in link_data:
+        if record[0] == parent_id.partition("+")[2]:
+            return record[0]
+    return -1
+
+
 class LinkData:
     """Class that contains link_data, categories and categories count tables,
     plus methods to generate and update these items"""
@@ -173,3 +182,24 @@ class LinkData:
                         cat_record["count"] += 1
                         if cat_record["last_updated"] < timestamp:
                             cat_record["last_updated"] = timestamp
+
+    def search(self, keyword: str) -> list:
+        """returns a unique list of link_data record IDs for posts that contain
+        the specified keyword"""
+        assert keyword != ""
+
+        query = (record for record in self.link_data if keyword in record)
+
+        if query:
+            search_results: set = set()
+            for record in query:
+                post_id = record[0]
+                parent_id = record[3]
+                if post_id:
+                    search_results.add(record[0])
+                else:
+                    parent_post_id = get_id_from_parent(parent_id, self.link_data)
+                    if parent_post_id >= 0:
+                        search_results.add(parent_post_id)
+
+        return sorted(search_results)