1 files changed, 87 insertions, 0 deletions
diff --git a/app/services/tag_search_service.rb b/app/services/tag_search_service.rb
new file mode 100644
index 000000000..b78d65625
--- /dev/null
+++ b/app/services/tag_search_service.rb
@@ -0,0 +1,87 @@
+# frozen_string_literal: true
+
+class TagSearchService < BaseService
+  def call(query, options = {})
+    @query   = query.strip.gsub(/\A#/, '')
+    @offset  = options.delete(:offset).to_i
+    @limit   = options.delete(:limit).to_i
+    @options = options
+
+    results   = from_elasticsearch if Chewy.enabled?
+    results ||= from_database
+
+    results
+  end
+
+  private
+
+  def from_elasticsearch
+    query = {
+      function_score: {
+        query: {
+          multi_match: {
+            query: @query,
+            fields: %w(name.edge_ngram name),
+            type: 'most_fields',
+            operator: 'and',
+          },
+        },
+
+        functions: [
+          {
+            field_value_factor: {
+              field: 'usage',
+              modifier: 'log2p',
+              missing: 0,
+            },
+          },
+
+          {
+            gauss: {
+              last_status_at: {
+                scale: '7d',
+                offset: '14d',
+                decay: 0.5,
+              },
+            },
+          },
+        ],
+
+        boost_mode: 'multiply',
+      },
+    }
+
+    filter = {
+      bool: {
+        should: [
+          {
+            term: {
+              reviewed: {
+                value: true,
+              },
+            },
+          },
+
+          {
+            match: {
+              name: {
+                query: @query,
+              },
+            },
+          },
+        ],
+      },
+    }
+
+    definition = TagsIndex.query(query)
+    definition = definition.filter(filter) if @options[:exclude_unreviewed]
+
+    definition.limit(@limit).offset(@offset).objects.compact
+  rescue Faraday::ConnectionFailed, Parslet::ParseFailed
+    nil
+  end
+
+  def from_database
+    Tag.search_for(@query, @limit, @offset, @options)
+  end
+end