#
# Author:: Jay Mundrawala (<jdm@chef.io>)
#
# Copyright:: Copyright (c) 2015 Chef Software, Inc.
#
# 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 'chef/util/powershell/cmdlet'
require 'chef/util/powershell/cmdlet_result'
require 'chef/exceptions'

class Chef
class Util
class DSC
  class ResourceStore

    def self.instance
      @@instance ||= ResourceStore.new.tap do |store|
        store.send(:populate_cache)
      end
    end

    def resources
      @resources ||= []
    end

    def find(name, module_name=nil)
      found = find_resources(name, module_name, resources)

      # We don't have it, query for the resource...it might
      # have been added since we last queried
      if found.length == 0
        rs = query_resource(name)
        add_resources(rs)
        found = find_resources(name, module_name, rs)
      end

      found
    end

    private

    def add_resource(new_r)
      count = resources.count do |r|
        r['ResourceType'].casecmp(new_r['ResourceType']) == 0
      end
      if count == 0
        resources << new_r
      end
    end

    def add_resources(rs)
      rs.each do |r|
        add_resource(r)
      end
    end

    def populate_cache
      @resources = query_resources
    end

    def find_resources(name, module_name, rs)
      found = rs.find_all do |r|
        name_matches = r['Name'].casecmp(name) == 0
        if name_matches
          module_name == nil || (r['Module'] and r['Module']['Name'].casecmp(module_name) == 0)
        else
          false
        end
      end
    end


    # Returns a list of dsc resources
    def query_resources
      cmdlet = Chef::Util::Powershell::Cmdlet.new(nil, 'get-dscresource',
          :object)
      result = cmdlet.run
      result.return_value
    end

    # Returns a list of dsc resources matching the provided name
    def query_resource(resource_name)
      cmdlet = Chef::Util::Powershell::Cmdlet.new(nil, "get-dscresource #{resource_name}",
          :object)
      result = cmdlet.run
      ret_val = result.return_value
      if ret_val.nil?
        []
      elsif ret_val.is_a? Array
        ret_val
      else
        [ret_val]
      end
    end
  end
end
end
end
