feat: use gin index for message search (#11107)

This PR updates the search implementation to better utilize the GIN
indexes. The option is toggled behind a feature flag for us to test it
internally before making it available publicly

app/services/search_service.rb

@@ -35,12 +35,66 @@ class SearchService
   end
 
   def filter_messages
-    @messages = current_account.messages.where(inbox_id: accessable_inbox_ids)
+    start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
-                               .where('messages.content ILIKE :search', search: "%#{search_query}%")
+
-                               .where('created_at >= ?', 3.months.ago)
+    @messages = if use_gin_search
+                  filter_messages_with_gin
+                else
+                  filter_messages_with_like
+                end
+
+    log_search_performance(start_time)
+    @messages
+  end
+
+  def filter_messages_with_gin
+    base_query = message_base_query
+
+    if search_query.present?
+      # Use the @@ operator with to_tsquery for better GIN index utilization
+      # Convert search query to tsquery format with prefix matching
+
+      # Use this if we wanna match splitting the words
+      # split_query = search_query.split.map { |term| "#{term} | #{term}:*" }.join(' & ')
+
+      # This will do entire sentence matching using phrase distance operator
+      tsquery = search_query.split.join(' <-> ')
+
+      # Apply the text search using the GIN index
+      base_query.where('content @@ to_tsquery(?)', tsquery)
                 .reorder('created_at DESC')
                 .page(params[:page])
                 .per(15)
+    else
+      base_query.reorder('created_at DESC')
+                .page(params[:page])
+                .per(15)
+    end
+  end
+
+  def filter_messages_with_like
+    message_base_query
+      .where('messages.content ILIKE :search', search: "%#{search_query}%")
+      .reorder('created_at DESC')
+      .page(params[:page])
+      .per(15)
+  end
+
+  def message_base_query
+    current_account.messages.where(inbox_id: accessable_inbox_ids)
+                   .where('created_at >= ?', 3.months.ago)
+  end
+
+  def log_search_performance(start_time)
+    end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+    search_type = use_gin_search ? 'GIN' : 'ILIKE'
+    duration_ms = (end_time - start_time) * 1000
+
+    Rails.logger.info "[SearchService][#{current_account.id}] #{search_type} search query time: #{duration_ms}ms for #{search_query}"
+  end
+
+  def use_gin_search
+    current_account.feature_enabled?('search_with_gin')
   end
 
   def filter_contacts

config/features.yml

@@ -154,3 +154,6 @@
   display_name: Contact Chatwoot Support Team
   enabled: true
   chatwoot_internal: true
+- name: search_with_gin
+  display_name: Search messages with GIN
+  enabled: false

spec/services/search_service_spec.rb

@@ -67,16 +67,61 @@ describe SearchService do
     end
 
     context 'when message search' do
+      let!(:message2) { create(:message, account: account, inbox: inbox, content: 'harry is cool') }
+
       it 'searches across message content and return in created_at desc' do
         # random messages in another account
         create(:message, content: 'Harry Potter is a wizard')
         # random messsage in inbox with out access
         create(:message, account: account, inbox: create(:inbox, account: account), content: 'Harry Potter is a wizard')
-        message2 = create(:message, account: account, inbox: inbox, content: 'harry is cool')
         params = { q: 'Harry' }
         search = described_class.new(current_user: user, current_account: account, params: params, search_type: 'Message')
         expect(search.perform[:messages].map(&:id)).to eq([message2.id, message.id])
       end
+
+      context 'with feature flag for search type' do
+        let(:params) { { q: 'Harry' } }
+        let(:search_type) { 'Message' }
+
+        it 'uses LIKE search when search_with_gin feature is disabled' do
+          allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(false)
+          search_service = described_class.new(current_user: user, current_account: account, params: params, search_type: search_type)
+
+          expect(search_service).to receive(:filter_messages_with_like).and_call_original
+          expect(search_service).not_to receive(:filter_messages_with_gin)
+
+          search_service.perform
+        end
+
+        it 'uses GIN search when search_with_gin feature is enabled' do
+          allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(true)
+          search_service = described_class.new(current_user: user, current_account: account, params: params, search_type: search_type)
+
+          expect(search_service).to receive(:filter_messages_with_gin).and_call_original
+          expect(search_service).not_to receive(:filter_messages_with_like)
+
+          search_service.perform
+        end
+
+        it 'returns same results regardless of search type' do
+          # Create test messages
+          message3 = create(:message, account: account, inbox: inbox, content: 'Harry is a wizard apprentice')
+
+          # Test with GIN search
+          allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(true)
+          gin_search = described_class.new(current_user: user, current_account: account, params: params, search_type: search_type)
+          gin_results = gin_search.perform[:messages].map(&:id)
+
+          # Test with LIKE search
+          allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(false)
+          like_search = described_class.new(current_user: user, current_account: account, params: params, search_type: search_type)
+          like_results = like_search.perform[:messages].map(&:id)
+
+          # Both search types should return the same messages
+          expect(gin_results).to match_array(like_results)
+          expect(gin_results).to include(message.id, message2.id, message3.id)
+        end
+      end
     end
 
     context 'when conversation search' do
@@ -99,4 +144,23 @@ describe SearchService do
       end
     end
   end
+
+  describe '#use_gin_search' do
+    let(:params) { { q: 'test' } }
+
+    it 'checks if the account has the search_with_gin feature enabled' do
+      expect(account).to receive(:feature_enabled?).with('search_with_gin')
+      search.send(:use_gin_search)
+    end
+
+    it 'returns true when search_with_gin feature is enabled' do
+      allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(true)
+      expect(search.send(:use_gin_search)).to be true
+    end
+
+    it 'returns false when search_with_gin feature is disabled' do
+      allow(account).to receive(:feature_enabled?).with('search_with_gin').and_return(false)
+      expect(search.send(:use_gin_search)).to be false
+    end
+  end
 end