#
# Author:: John Keiser (<jkeiser@opscode.com>)
# Copyright:: Copyright (c) 2013 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License 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.
#

require_relative "data_already_exists_error"
require_relative "data_not_found_error"
require_relative "interface_v2"

module ChefZero
  module DataStore
    class MemoryStoreV2 < ChefZero::DataStore::InterfaceV2
      def initialize
        clear
      end

      attr_reader :data

      def clear
        @data = {}
      end

      def create_dir(path, name, *options)
        parent = _get(path, options.include?(:recursive))

        if parent.key?(name)
          unless options.include?(:recursive)
            raise DataAlreadyExistsError.new(path + [name])
          end
        else
          parent[name] = {}
        end
      end

      def create(path, name, data, *options)
        unless data.is_a?(String)
          raise "set only works with strings (given data: #{data.inspect})"
        end

        parent = _get(path, options.include?(:create_dir))

        if parent.key?(name)
          raise DataAlreadyExistsError.new(path + [name])
        end

        parent[name] = data
      end

      def get(path, request = nil)
        value = _get(path)
        if value.is_a?(Hash)
          raise "get() called on directory #{path.join("/")}"
        end

        value
      end

      def set(path, data, *options)
        unless data.is_a?(String)
          raise "set only works with strings: #{path} = #{data.inspect}"
        end

        # Get the parent
        parent = _get(path[0..-2], options.include?(:create_dir))

        if !options.include?(:create) && !parent[path[-1]]
          raise DataNotFoundError.new(path)
        end

        parent[path[-1]] = data
      end

      def delete(path)
        parent = _get(path[0, path.length - 1])
        unless parent.key?(path[-1])
          raise DataNotFoundError.new(path)
        end
        unless parent[path[-1]].is_a?(String)
          raise "delete only works with strings: #{path}"
        end

        parent.delete(path[-1])
      end

      def delete_dir(path, *options)
        parent = _get(path[0, path.length - 1])
        unless parent.key?(path[-1])
          raise DataNotFoundError.new(path)
        end
        unless parent[path[-1]].is_a?(Hash)
          raise "delete_dir only works with directories: #{path}"
        end

        parent.delete(path[-1])
      end

      def list(path)
        dir = _get(path)
        unless dir.is_a? Hash
          raise "list only works with directories (#{path} = #{dir.class})"
        end

        dir.keys.sort
      end

      def exists?(path, options = {})
        value = _get(path)
        if value.is_a?(Hash) && !options[:allow_dirs]
          raise "exists? does not work with directories (#{path} = #{value.class})"
        end

        true
      rescue DataNotFoundError
        false
      end

      def exists_dir?(path)
        dir = _get(path)
        unless dir.is_a? Hash
          raise "exists_dir? only works with directories (#{path} = #{dir.class})"
        end

        true
      rescue DataNotFoundError
        false
      end

      private

      def _get(path, create_dir = false)
        value = @data
        path.each_with_index do |path_part, index|
          unless value.key?(path_part)
            if create_dir
              value[path_part] = {}
            else
              raise DataNotFoundError.new(path[0, index + 1])
            end
          end
          value = value[path_part]
        end
        value
      end
    end
  end
end