e-travel/agnostic_backend

module AgnosticBackend
  module Queryable
    module Elasticsearch
      class Visitor < AgnosticBackend::Queryable::Visitor

        private

        def visit_criteria_equal(subject)
          { "term" => { visit(subject.attribute) => visit(subject.value) } }
        end

        def visit_criteria_not_equal(subject)
          { "must_not" => visit_criteria_equal(subject) }
        end

        def visit_criteria_greater(subject)
          {
            "range" => {
              visit(subject.attribute) => {
                "gt" => visit(subject.value)
              }
            }
          }
        end

        def visit_criteria_less(subject)
          {
            "range" => {
              visit(subject.attribute) => {
                "lt" => visit(subject.value)
              }
            }
          }
        end

        def visit_criteria_greater_equal(subject)
          {
            "range" => {
              visit(subject.attribute) => {
                "gte" => visit(subject.value)
              }
            }
          }
        end

        def visit_criteria_less_equal(subject)
          {
            "range" => {
              visit(subject.attribute) => {
                "lte" => visit(subject.value)
              }
            }
          }
        end

        def visit_criteria_greater_and_less(subject)
          {
            "range" => {
              visit(subject.attribute) => {
                "gt" => visit(subject.left_value),
                "lt" => visit(subject.right_value)
              }
            }
          }
        end

        def visit_criteria_greater_equal_and_less(subject)
           {
            "range" => {
              visit(subject.attribute) => {
                "gte" => visit(subject.left_value),
                "lt" => visit(subject.right_value)
              }
            }
          }
        end

        def visit_criteria_greater_and_less_equal(subject)
           {
            "range" => {
              visit(subject.attribute) => {
                "gt" => visit(subject.left_value),
                "lte" => visit(subject.right_value)
              }
            }
          }
        end

        def visit_criteria_greater_equal_and_less_equal(subject)
           {
            "range" => {
              visit(subject.attribute) => {
                "gte" => visit(subject.left_value),
                "lte" => visit(subject.right_value)
              }
            }
          }
        end

        def visit_criteria_contains(subject)
          { "wildcard" => { visit(subject.attribute) => '*' + visit(subject.value) + '*'} }
        end

        def visit_criteria_starts(subject)
          { "wildcard" => { visit(subject.attribute) => '*' +   visit(subject.value) } }
        end

        def visit_operations_not(subject)
          {"bool" =>  { "must_not" => subject.operands.map{|o| visit(o)} } }
        end

        def visit_operations_and(subject)
          {"bool" =>  { "must" => subject.operands.map{|o| visit(o)} } }
        end

        def visit_operations_or(subject)
          {"bool" => { "should" => subject.operands.map{|o| visit(o)} } }
        end

        def visit_operations_ascending(subject)
          { visit(subject.attribute) => {"order" => "asc" } }
        end

        def visit_operations_descending(subject)
          { visit(subject.attribute) => {"order" => "desc" } }
        end

        def visit_query(subject)
          result = {}
          subject.children.each do |c|
            result.merge!(visit(c)) do |key, v1, v2|
              v1 + v2
            end
          end
          result
        end

        def visit_expressions_where(subject)
          { "filter" => visit(subject.criterion)  }
        end

        def visit_expressions_select(subject)
          { "fields" => subject.projections.map{|c| visit(c)} } #return=
        end

        def visit_expressions_order(subject)
          { "sort" => subject.qualifiers.map{|o| visit(o)} }
        end

        def visit_expressions_limit(subject)
          { "size" =>  visit(subject.limit) }
        end

        def visit_expressions_offset(subject)
          { "from" =>  visit(subject.offset) }
        end

        def visit_expressions_scroll_cursor(subject)
          result =  { 
            "scroll" => "1m"
          }

          result.merge!(
            {
              "scroll_id" => visit(subject.scroll_cursor)
            }
          ) if visit(subject.scroll_cursor) != 'initial'

          result
        end

        def visit_attribute(subject)
          subject.name.split('.').join('__')
        end

        def visit_value(subject)
          case subject.type
          when :integer
            subject.value
          when :date,:date_array
            "#{subject.value.utc.strftime("%Y-%m-%dT%H:%M:%SZ")}"
          when :double
            subject.value
          when :boolean
            subject.value
          when :string,:string_array,:text,:text_array
            subject.value
          else
            subject.value
          end
        end
      end
    end
  end
end