# Copyright 2011 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

  # A utility class to provide indifferent access to hash data.  
  #
  # Inspired by ActiveSupport's HashWithIndifferentAccess, this class
  # has a few notable differences:
  #
  # * ALL keys are converted to strings (via #to_s)
  # * It does not deep merge/convert hashes indifferently
  # * It will not perserve default value behaviours
  #
  # These features were omitted because our primary use for this class is to
  # wrap a 1-level hash as a return value, but we want the user to access
  # the values with string or symbol keys.
  # 
  # @private
  class IndifferentHash < Hash

    def initialize *args
      if args.first.is_a?(Hash)
        super()
        merge!(*args)
      else
        super(*args)
      end
    end

    alias_method :_getter, :[]
    alias_method :_setter, :[]=

    def []=(key, value)
      _setter(_convert_key(key), value)
    end
    alias_method :store, :[]=

    def [] key
      _getter(_convert_key(key))
    end

    def merge! hash
      hash.each_pair do |key,value|
        self[key] = value 
      end
      self
    end
    alias_method :update, :merge!

    def merge hash
      self.dup.merge!(hash)
    end

    def has_key? key
      super(_convert_key(key))
    end
    alias_method :key?, :has_key?
    alias_method :member?, :has_key?
    alias_method :include?, :has_key?

    def fetch key, *extras, &block
      super(_convert_key(key), *extras, &block)
    end

    def delete key
      super(_convert_key(key))
    end

    private
    def _convert_key key
      key.is_a?(String) ? key : key.to_s
    end

  end
end