From 1c21d3739ba474ad0156cf72e16feb00eb158f8b Mon Sep 17 00:00:00 2001
From: Kasper Timm Hansen <hey@kaspth.com>
Date: Tue, 21 Jan 2025 01:27:35 +0100
Subject: [PATCH] Refactor Speaker indexing into a Speaker::Index record.

Follow-up to https://github.com/adrienpoly/rubyvideo/pull/540
---
 app/models/speaker/index.rb                   | 27 +++++++++++
 app/models/speaker/searchable.rb              | 48 +++++--------------
 ...2175230_create_speaker_full_text_search.rb |  2 +-
 test/test_helper.rb                           |  2 +-
 4 files changed, 41 insertions(+), 38 deletions(-)
 create mode 100644 app/models/speaker/index.rb

diff --git a/app/models/speaker/index.rb b/app/models/speaker/index.rb
new file mode 100644
index 00000000..46a35339
--- /dev/null
+++ b/app/models/speaker/index.rb
@@ -0,0 +1,27 @@
+class Speaker::Index < ApplicationRecord
+  self.table_name = :speakers_search_index
+
+  include ActiveRecord::SQLite::Index # Depends on `table_name` being assigned.
+  class_attribute :index_columns, default: {name: 0, github: 1}
+
+  belongs_to :speaker, foreign_key: :rowid
+
+  def self.search(query)
+    query = query&.gsub(/[^[:word:]]/, " ") || "" # remove non-word characters
+    query = query.split.map { |word| "#{word}*" }.join(" ") # wildcard search
+    where("#{table_name} match ?", query)
+  end
+
+  def self.snippets(**)
+    index_columns.each_key.reduce(all) { |relation, column| relation.snippet(column, **) }
+  end
+
+  def self.snippet(column, tag: "mark", omission: "…", limit: 32)
+    offset = index_columns.fetch(column)
+    select("snippet(#{table_name}, #{offset}, '<#{tag}>', '</#{tag}>', '#{omission}', #{limit}) AS #{column}_snippet")
+  end
+
+  def reindex
+    update! id: speaker.id, name: speaker.name, github: speaker.github
+  end
+end
diff --git a/app/models/speaker/searchable.rb b/app/models/speaker/searchable.rb
index 08149a8e..528a331d 100644
--- a/app/models/speaker/searchable.rb
+++ b/app/models/speaker/searchable.rb
@@ -2,38 +2,27 @@ module Speaker::Searchable
   extend ActiveSupport::Concern
 
   included do
-    scope :ft_search, ->(query) do
-      query = query&.gsub(/[^[:word:]]/, " ") || "" # remove non-word characters
-      query = query.split.map { |word| "#{word}*" }.join(" ") # wildcard search
-      joins("join speakers_search_index idx on speakers.id = idx.rowid")
-        .where("speakers_search_index match ?", query)
-    end
+    has_one :index, foreign_key: :rowid, dependent: :destroy
+
+    scope :ft_search, ->(query) { select("speakers.*").joins(:index).merge(Speaker::Index.search(query)) }
 
     scope :with_snippets, ->(**options) do
-      select("speakers.*")
-        .select_snippet("name", 0, **options)
-        .select_snippet("github", 1, **options)
+      select("speakers.*").merge(Speaker::Index.snippets(**options))
     end
 
     scope :ranked, -> do
       select("speakers.*,
           bm25(speakers_search_index, 2, 1) AS combined_score")
-        .order(Arel.sql("combined_score ASC"))
+        .order(combined_score: :asc)
     end
 
-    after_create_commit :create_in_index
-    after_update_commit :update_in_index
-    after_destroy_commit :remove_from_index
+    after_save_commit :reindex
   end
 
   class_methods do
-    def rebuild_search_index
-      connection.execute("DELETE FROM speakers_search_index")
-      Speaker.find_each(&:create_in_index)
-    end
-
-    def select_snippet(column, offset, tag: "mark", omission: "…", limit: 32)
-      select("snippet(speakers_search_index, #{offset}, '<#{tag}>', '</#{tag}>', '#{omission}', #{limit}) AS #{column}_snippet")
+    def reindex_all
+      Speaker::Index.delete_all
+      Speaker.find_each(&:reindex)
     end
   end
 
@@ -41,21 +30,8 @@ def name_with_snippet
     try(:name_snippet) || name
   end
 
-  def create_in_index
-    execute_sql_with_binds "insert into speakers_search_index(rowid, name, github) values (?, ?, ?)", id, name, github
-  end
-
-  def update_in_index
-    execute_sql_with_binds "update speakers_search_index set name = ?, github = ? where rowid = ?", name, github, id
-  end
-
-  def remove_from_index
-    execute_sql_with_binds "delete from speakers_search_index where rowid = ?", id
-  end
-
-  private
-
-  def execute_sql_with_binds(*statement)
-    self.class.connection.execute self.class.sanitize_sql(statement)
+  def index
+    super || build_index
   end
+  delegate :reindex, to: :index
 end
diff --git a/db/migrate/20250102175230_create_speaker_full_text_search.rb b/db/migrate/20250102175230_create_speaker_full_text_search.rb
index 50ca6cc8..516abab9 100644
--- a/db/migrate/20250102175230_create_speaker_full_text_search.rb
+++ b/db/migrate/20250102175230_create_speaker_full_text_search.rb
@@ -4,7 +4,7 @@ def up
       "name", "github", "tokenize = porter"
     ]
 
-    Speaker.rebuild_search_index
+    Speaker.reindex_all
   end
 
   def down
diff --git a/test/test_helper.rb b/test/test_helper.rb
index b94fea19..d7b98590 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -23,7 +23,7 @@ class ActiveSupport::TestCase
     # end
 
     Talk.reindex_all
-    Speaker.rebuild_search_index
+    Speaker.reindex_all
   end
   # Run tests in parallel with specified workers
   parallelize(workers: :number_of_processors)