# Copyright 2011-2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

module AWS
  class CloudFormation

    # = Stack Summaries
    #
    # Stack summaries contain information about CloudFormation
    # stacks.  You can filter the stacks you want summary information
    # for by one or more statuses.  You can even get information
    # about deleted stacks for up to 90 days.
    #
    # == Enumerating Stack Summaries
    #
    # You can enumerate all available summaries using enumerable
    # methods.  Yielded summaries are simple hashes.
    #
    #   cfm = AWS::CloudFormation.new
    #   cfm.stack_summaries.each do |summary|
    #     puts summary.to_yaml
    #   end
    #
    # == Filtering Stack Summaries
    #
    # You can optionally provide one or more stack stasus values
    # to filter the results by.  Only stacks with the given status(es)
    # will be enumerated.
    #
    #   cfm.stack_summaries.with_status(:create_failed).each do |summary|
    #     # ...
    #   end
    #
    #   # enumerate stacks with various delete statuses
    #   statuses = %w(delete_in_progress delete_failed delete_complete)
    #   cf.stack_summaries.with_status(statuses).each do |summary|
    #     # ...
    #   end
    #
    class StackSummaryCollection

      include Core::Collection::Simple

      # @private
      def initialize options = {}
        @filters = options[:filters]
        super
      end

      # Limits the stacks summaries that are enumerated.
      #
      #   cfm.stack_summaries.with_status(:create_complete).each do |summary|
      #     puts summary[:stack_name]
      #   end
      #
      # You can provide multiple statuses:
      #
      #   statuses = [:create_failed, :rollback_failed]
      #   cfm.stack_summaries.with_status(statuses).each do |summary|
      #     puts summary[:stack_name]
      #   end
      #
      # Status names may be symbolized (snake-cased) or upper-cased strings
      # (e.g. :create_in_progress, 'CREATE_IN_PROGRESS').
      # 
      # @param [Symbol,String] status_filters One or more statuses to filter
      #   stacks with. Valid values include:
      #   * +:create_in_progress+
      #   * +:create_failed+
      #   * +:create_complete+
      #   * +:rollback_in_progress+
      #   * +:rollback_failed+
      #   * +:rollback_complete+
      #   * +:delete_in_progress+
      #   * +:delete_failed+
      #   * +:delete_complete+
      #   * +:update_in_progress+
      #   * +:update_complete_cleanup_in_progress+
      #   * +:update_complete+
      #   * +:update_rollback_in_progress+
      #   * +:update_rollback_failed+
      #   * +:update_rollback_complete_cleanup_in_progress+
      #   * +:update_rollback_complete+
      #
      # @return [StackSummaryCollection] Returns a new stack summary
      #   collection that restricts what stack summariess will be 
      #   enumerated.
      #
      def with_status *status_filters
        StackSummaryCollection.new(
          :filters => status_filters.flatten.map(&:to_s).map(&:upcase),
          :config => config)
      end

      protected

      def _each_item options = {}
        next_token = nil
        begin
          
          client_opts = {}
          client_opts[:next_token] = next_token if next_token
          client_opts[:stack_status_filter] = @filters if @filters
          resp = client.list_stacks(client_opts)

          resp.stack_summaries.each do |summary|
            yield(summary.to_hash)
          end

          next_token = resp.data[:next_token]

        end while next_token
      end

    end
  end
end