module ActiveRecord
  module ConnectionAdapters
    module Sqlserver
      class SchemaCache < ActiveRecord::ConnectionAdapters::SchemaCache
        attr_reader :view_information

        def initialize(conn)
          super
          @table_names = nil
          @view_names = nil
          @view_information = {}
          @quoted_names = {}
        end

        # Superclass Overrides

        def table_exists?(table_name)
          return false if table_name.blank?
          key = table_name_key(table_name)
          return @tables[key] if @tables.key? key
          @tables[key] = connection.table_exists?(table_name)
        end

        def clear!
          super
          @table_names = nil
          @view_names = nil
          @view_information.clear
          @quoted_names.clear
        end

        def clear_table_cache!(table_name)
          key = table_name_key(table_name)
          super(key)
          super(table_name)
          # SQL Server Specific
          if @table_names
            @table_names.delete key
            @table_names.delete table_name
          end
          if @view_names
            @view_names.delete key
            @view_names.delete table_name
          end
          @view_information.delete key
        end

        # SQL Server Specific

        def table_names
          @table_names ||= connection.tables
        end

        def view_names
          @view_names ||= connection.views
        end

        def view_exists?(table_name)
          table_exists?(table_name)
        end

        def view_information(table_name)
          key = table_name_key(table_name)
          return @view_information[key] if @view_information.key? key
          @view_information[key] = connection.send(:view_information, table_name)
        end

        def quote_name(name, split_on_dots = true)
          return @quoted_names[name] if @quoted_names.key? name

          @quoted_names[name] = if split_on_dots
                                  name.to_s.split('.').map { |n| quote_name_part(n) }.join('.')
                                else
                                  quote_name_part(name.to_s)
                                end
        end

        private

        def quote_name_part(part)
          part =~ /^\[.*\]$/ ? part : "[#{part.to_s.gsub(']', ']]')}]"
        end

        def table_name_key(table_name)
          Utils.unqualify_table_name(table_name)
        end
      end
    end
  end
end