47colborne/cloud-sesame

module CloudSesame
    module Query
        module DSL
            module LiteralChainingMethods

                # NOT
                # =======================================
                def not(*values)
                    parents[1] = { klass: AST::Not, options: extract_options(values) }
                  insert values
                end

                alias_method :is_not, :not

                # NEAR
                # =======================================
                def near(*values)
                    parents[0] = { klass: AST::Near, options: extract_options(values) }
                  insert values
                end

                alias_method :sloppy, :near

                # PREFIX
                # =======================================
                def prefix(*values)
                  parents[0] = { klass: AST::Prefix, options: extract_options(values) }
                  insert values
                end

                alias_method :start_with, :prefix
                alias_method :begin_with, :prefix

                def insert(values = [])
                    values.each do |value|
                        _scope << create_parents(build_literal(value))
                    end
                    parents.clear unless values.empty?
                  _return != _scope ? _return : self
                end

                private

                def extract_options(values)
                    values[-1].is_a?(Hash) ? values.delete_at(-1) : {}
                end

                def create_parents(child)
                    parents.compact.each do |parent|
                        node = parent[:klass].new _context, parent[:options]
                        node << child
                        child = node
                    end
                    child
                end

                def build_literal(value)
                    if value.kind_of?(AST::Abstract::SingleExpressionOperator) || value.is_a?(AST::Literal)
                        value.is_for field, _context[:fields][field]
                        value
                    else
                        AST::Literal.new field, value, _context[:fields][field]
                    end
                end

            end
        end
    end
end