module Fog
  module Compute
    class AWS
      class Real
        require 'fog/aws/parsers/compute/basic'

        # Remove tags from resources
        #
        # ==== Parameters
        # * resources<~String> - One or more resources to remove tags from
        # * tags<~String> - hash of key value tag pairs to remove
        #
        # ==== Returns
        # * response<~Excon::Response>:
        #   * body<~Hash>:
        #     * 'requestId'<~String> - Id of request
        #     * 'return'<~Boolean> - success?
        #
        # {Amazon API Reference}[http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DeleteTags.html]
        def delete_tags(resources, tags)
          resources = [*resources]
          params = {}
          params.merge!(Fog::AWS.indexed_param('ResourceId', resources))

          # can not rely on indexed_param because nil values should be omitted
          tags.keys.each_with_index do |key, index|
            index += 1 # should start at 1 instead of 0
            params.merge!("Tag.#{index}.Key" => key)
            unless tags[key].nil?
              params.merge!("Tag.#{index}.Value" => tags[key])
            end
          end

          request({
            'Action'            => 'DeleteTags',
            :parser             => Fog::Parsers::Compute::AWS::Basic.new
          }.merge!(params))
        end
      end

      class Mock
        def delete_tags(resources, tags)
          tagged = Array(resources).map do |resource_id|
            type = case resource_id
            when /^ami\-[a-z0-9]{8}$/i
              'image'
            when /^i\-[a-z0-9]{8}$/i
              'instance'
            when /^snap\-[a-z0-9]{8}$/i
              'snapshot'
            when /^vol\-[a-z0-9]{8}$/i
              'volume'
            end
            if type && ((type == 'image' && visible_images[resource_id]) || self.data[:"#{type}s"][resource_id])
              { 'resourceId' => resource_id, 'resourceType' => type }
            else
              raise(Fog::Service::NotFound.new("The #{type} ID '#{resource_id}' does not exist"))
            end
          end

          tags.each do |key, value|
            self.data[:tags][key][value] = self.data[:tags][key][value] - tagged
          end

          tagged.each do |resource|
            tags.each do |key, value|
              tagset = self.data[:tag_sets][resource['resourceId']]
              tagset.delete(key) if tagset.key?(key) && (value.nil? || tagset[key] == value)
            end
          end

          response = Excon::Response.new
          response.status = true
          response.body = {
            'requestId' => Fog::AWS::Mock.request_id,
            'return'    => true
          }
          response
        end
      end
    end
  end
end