1 files changed, 72 insertions, 0 deletions
diff --git a/activerecord/lib/arel/tree_manager.rb b/activerecord/lib/arel/tree_manager.rb
new file mode 100644
index 0000000000..0476399618
--- /dev/null
+++ b/activerecord/lib/arel/tree_manager.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  class TreeManager
+    include Arel::FactoryMethods
+
+    module StatementMethods
+      def take(limit)
+        @ast.limit = Nodes::Limit.new(Nodes.build_quoted(limit)) if limit
+        self
+      end
+
+      def offset(offset)
+        @ast.offset = Nodes::Offset.new(Nodes.build_quoted(offset)) if offset
+        self
+      end
+
+      def order(*expr)
+        @ast.orders = expr
+        self
+      end
+
+      def key=(key)
+        @ast.key = Nodes.build_quoted(key)
+      end
+
+      def key
+        @ast.key
+      end
+
+      def wheres=(exprs)
+        @ast.wheres = exprs
+      end
+
+      def where(expr)
+        @ast.wheres << expr
+        self
+      end
+    end
+
+    attr_reader :ast
+
+    def initialize
+      @ctx = nil
+    end
+
+    def to_dot
+      collector = Arel::Collectors::PlainString.new
+      collector = Visitors::Dot.new.accept @ast, collector
+      collector.value
+    end
+
+    def to_sql(engine = Table.engine)
+      collector = Arel::Collectors::SQLString.new
+      collector = engine.connection.visitor.accept @ast, collector
+      collector.value
+    end
+
+    def initialize_copy(other)
+      super
+      @ast = @ast.clone
+    end
+
+    def where(expr)
+      if Arel::TreeManager === expr
+        expr = expr.ast
+      end
+      @ctx.wheres << expr
+      self
+    end
+  end
+end