FEATURE: support search click through tracking for user, category and tags

https://meta.discourse.org/t/search-logs-page/73281/11?u=techapj

This commit adds following features:

- support for tracking click through to user, tag and category
- new filter for search type (header, full page)

This commit also removes "most viewed topic" field from search logs page because we are now tracking multiple click through entities, so topic is not a special entity anymore. This also improves query perf. The query now takes `20.5ms` to runs, as opposed to `655.9ms` previously.

spec/controllers/search_controller_spec.rb

@@ -187,14 +187,14 @@ describe SearchController do
       }
 
       expect(response).to be_success
-      expect(SearchLog.find(search_log_id).clicked_topic_id).to be_blank
+      expect(SearchLog.find(search_log_id).search_result_id).to be_blank
     end
 
     it "records the click for a logged in user" do
       user = log_in(:user)
 
       _, search_log_id = SearchLog.log(
-        term: 'kitty',
+        term: 'foobar',
         search_type: :header,
         user_id: user.id,
         ip_address: '127.0.0.1'
@@ -203,11 +203,12 @@ describe SearchController do
       post :click, params: {
         search_log_id: search_log_id,
         search_result_id: 12345,
-        search_result_type: 'topic'
+        search_result_type: 'user'
       }, format: :json
 
       expect(response).to be_success
-      expect(SearchLog.find(search_log_id).clicked_topic_id).to eq(12345)
+      expect(SearchLog.find(search_log_id).search_result_id).to eq(12345)
+      expect(SearchLog.find(search_log_id).search_result_type).to eq(SearchLog.search_result_types[:user])
     end
 
     it "records the click for an anonymous user" do
@@ -226,7 +227,8 @@ describe SearchController do
       }, format: :json
 
       expect(response).to be_success
-      expect(SearchLog.find(search_log_id).clicked_topic_id).to eq(22222)
+      expect(SearchLog.find(search_log_id).search_result_id).to eq(22222)
+      expect(SearchLog.find(search_log_id).search_result_type).to eq(SearchLog.search_result_types[:topic])
     end
 
     it "doesn't record the click for a different IP" do
@@ -245,7 +247,48 @@ describe SearchController do
       }
 
       expect(response).to be_success
-      expect(SearchLog.find(search_log_id).clicked_topic_id).to be_blank
+      expect(SearchLog.find(search_log_id).search_result_id).to be_blank
+    end
+
+    it "records the click for search result type category" do
+      request.remote_addr = '192.168.0.1';
+
+      _, search_log_id = SearchLog.log(
+        term: 'dev',
+        search_type: :header,
+        ip_address: '192.168.0.1'
+      )
+
+      post :click, params: {
+        search_log_id: search_log_id,
+        search_result_id: 23456,
+        search_result_type: 'category'
+      }, format: :json
+
+      expect(response).to be_success
+      expect(SearchLog.find(search_log_id).search_result_id).to eq(23456)
+      expect(SearchLog.find(search_log_id).search_result_type).to eq(SearchLog.search_result_types[:category])
+    end
+
+    it "records the click for search result type tag" do
+      request.remote_addr = '192.168.0.1';
+       tag = Fabricate(:tag, name: 'test')
+
+      _, search_log_id = SearchLog.log(
+        term: 'test',
+        search_type: :header,
+        ip_address: '192.168.0.1'
+      )
+
+      post :click, params: {
+        search_log_id: search_log_id,
+        search_result_id: tag.name,
+        search_result_type: 'tag'
+      }, format: :json
+
+      expect(response).to be_success
+      expect(SearchLog.find(search_log_id).search_result_id).to eq(tag.id)
+      expect(SearchLog.find(search_log_id).search_result_type).to eq(SearchLog.search_result_types[:tag])
     end
   end
 end