Account:: namespace simplifications and cleanup (#2110)

* Flatten Holding model

* Flatten balance model

* Entries domain renames

* Fix valuations reference

* Fix trades stream

* Fix brakeman warnings

* Fix tests

* Replace existing entryable type references in DB

app/models/transaction/search.rb

@@ -0,0 +1,101 @@
+class Transaction::Search
+  include ActiveModel::Model
+  include ActiveModel::Attributes
+
+  attribute :search, :string
+  attribute :amount, :string
+  attribute :amount_operator, :string
+  attribute :types, array: true
+  attribute :accounts, array: true
+  attribute :account_ids, array: true
+  attribute :start_date, :string
+  attribute :end_date, :string
+  attribute :categories, array: true
+  attribute :merchants, array: true
+  attribute :tags, array: true
+
+  def build_query(scope)
+    query = scope.joins(entry: :account)
+                 .joins(transfer_join)
+
+    query = apply_category_filter(query, categories)
+    query = apply_type_filter(query, types)
+    query = apply_merchant_filter(query, merchants)
+    query = apply_tag_filter(query, tags)
+    query = EntrySearch.apply_search_filter(query, search)
+    query = EntrySearch.apply_date_filters(query, start_date, end_date)
+    query = EntrySearch.apply_amount_filter(query, amount, amount_operator)
+    query = EntrySearch.apply_accounts_filter(query, accounts, account_ids)
+
+    query
+  end
+
+  private
+    def transfer_join
+      <<~SQL
+        LEFT JOIN (
+          SELECT t.*, t.id as transfer_id, a.accountable_type
+          FROM transfers t
+          JOIN entries ae ON ae.entryable_id = t.inflow_transaction_id
+          AND ae.entryable_type = 'Transaction'
+        JOIN accounts a ON a.id = ae.account_id
+        ) transfer_info ON (
+          transfer_info.inflow_transaction_id = transactions.id OR
+            transfer_info.outflow_transaction_id = transactions.id
+        )
+      SQL
+    end
+
+    def apply_category_filter(query, categories)
+      return query unless categories.present?
+
+      query = query.left_joins(:category).where(
+        "categories.name IN (?) OR (
+        categories.id IS NULL AND (transfer_info.transfer_id IS NULL OR transfer_info.accountable_type = 'Loan')
+      )",
+        categories
+      )
+
+      if categories.exclude?("Uncategorized")
+        query = query.where.not(category_id: nil)
+      end
+
+      query
+    end
+
+    def apply_type_filter(query, types)
+      return query unless types.present?
+      return query if types.sort == [ "expense", "income", "transfer" ]
+
+      transfer_condition = "transfer_info.transfer_id IS NOT NULL"
+      expense_condition = "entries.amount >= 0"
+      income_condition = "entries.amount <= 0"
+
+      condition = case types.sort
+      when [ "transfer" ]
+        transfer_condition
+      when [ "expense" ]
+        Arel.sql("#{expense_condition} AND NOT (#{transfer_condition})")
+      when [ "income" ]
+        Arel.sql("#{income_condition} AND NOT (#{transfer_condition})")
+      when [ "expense", "transfer" ]
+        Arel.sql("#{expense_condition} OR #{transfer_condition}")
+      when [ "income", "transfer" ]
+        Arel.sql("#{income_condition} OR #{transfer_condition}")
+      when [ "expense", "income" ]
+        Arel.sql("NOT (#{transfer_condition})")
+      end
+
+      query.where(condition)
+    end
+
+    def apply_merchant_filter(query, merchants)
+      return query unless merchants.present?
+      query.joins(:merchant).where(merchants: { name: merchants })
+    end
+
+    def apply_tag_filter(query, tags)
+      return query unless tags.present?
+      query.joins(:tags).where(tags: { name: tags })
+    end
+end