module Fog
  module AWS
    class RDS < Fog::Service
      extend Fog::AWS::CredentialFetcher::ServiceMethods

      class IdentifierTaken < Fog::Errors::Error; end

      class AuthorizationAlreadyExists < Fog::Errors::Error; end

      requires :aws_access_key_id, :aws_secret_access_key
      recognizes :region, :host, :path, :port, :scheme, :persistent, :use_iam_profile, :aws_session_token, :aws_credentials_expire_at, :version, :instrumentor, :instrumentor_name

      request_path 'fog/aws/requests/rds'
      request :describe_events
      request :create_db_instance
      request :modify_db_instance
      request :describe_db_instances
      request :delete_db_instance
      request :reboot_db_instance
      request :create_db_instance_read_replica
      request :describe_db_engine_versions
      request :describe_db_reserved_instances

      request :add_tags_to_resource
      request :list_tags_for_resource
      request :remove_tags_from_resource

      request :describe_db_snapshots
      request :create_db_snapshot
      request :delete_db_snapshot

      request :create_db_parameter_group
      request :delete_db_parameter_group
      request :modify_db_parameter_group
      request :describe_db_parameter_groups

      request :describe_db_security_groups
      request :create_db_security_group
      request :delete_db_security_group
      request :authorize_db_security_group_ingress
      request :revoke_db_security_group_ingress

      request :describe_db_parameters

      request :restore_db_instance_from_db_snapshot
      request :restore_db_instance_to_point_in_time

      request :create_db_subnet_group
      request :describe_db_subnet_groups
      request :delete_db_subnet_group
      # TODO: :modify_db_subnet_group

      request :describe_orderable_db_instance_options

      request :describe_db_log_files
      request :download_db_logfile_portion

      request :promote_read_replica

      request :describe_event_subscriptions
      request :create_event_subscription
      request :delete_event_subscription

      model_path 'fog/aws/models/rds'
      model       :server
      collection  :servers

      model       :snapshot
      collection  :snapshots

      model       :parameter_group
      collection  :parameter_groups

      model       :parameter
      collection  :parameters

      model       :security_group
      collection  :security_groups

      model       :subnet_group
      collection  :subnet_groups

      model       :instance_option
      collection  :instance_options

      model       :log_file
      collection  :log_files

      model       :event_subscription
      collection  :event_subscriptions

      class Mock
        def self.data
          @data ||= Hash.new do |hash, region|
            hash[region] = Hash.new do |region_hash, key|
              region_hash[key] = {
                :servers             => {},
                :security_groups     => {},
                :subnet_groups       => {},
                :snapshots           => {},
                :event_subscriptions => {},
                :db_engine_versions  => [
                  {
                    'Engine'                     => "mysql",
                    'DBParameterGroupFamily'     => "mysql5.1",
                    'DBEngineDescription'        => "MySQL Community Edition",
                    'EngineVersion'              => "5.1.57",
                    'DBEngineVersionDescription' => "MySQL 5.1.57"
                  },
                  {
                    'Engine'                     => "postgres",
                    'DBParameterGroupFamily'     => "postgres9.3",
                    'DBEngineDescription'        => "PostgreSQL",
                    'EngineVersion'              => "9.3.5",
                    'DBEngineVersionDescription' => "PostgreSQL 9.3.5"
                  },
                ],
                :parameter_groups    => {
                  "default.mysql5.1" => {
                    "DBParameterGroupFamily" => "mysql5.1",
                    "Description"            => "Default parameter group for mysql5.1",
                    "DBParameterGroupName"   => "default.mysql5.1"
                  },
                  "default.mysql5.5" => {
                    "DBParameterGroupFamily" => "mysql5.5",
                    "Description"            => "Default parameter group for mysql5.5",
                    "DBParameterGroupName"   => "default.mysql5.5"
                  }
                }
              }
            end
          end
        end

        def self.reset
          @data = nil
        end

        attr_accessor :region

        def initialize(options={})
          @use_iam_profile = options[:use_iam_profile]
          @region          = options[:region] || 'us-east-1'

          unless ['ap-northeast-1', 'ap-southeast-1', 'ap-southeast-2', 'eu-central-1', 'eu-west-1', 'us-east-1', 'us-west-1', 'us-west-2', 'sa-east-1'].include?(@region)
            raise ArgumentError, "Unknown region: #{@region.inspect}"
          end

          setup_credentials(options)
        end

        def data
          self.class.data[@region][@aws_access_key_id]
        end

        def reset_data
          self.class.data[@region].delete(@aws_access_key_id)
        end

        def setup_credentials(options)
          @aws_access_key_id = options[:aws_access_key_id]
        end
      end

      class Real
        attr_reader :region

        include Fog::AWS::CredentialFetcher::ConnectionMethods
        # Initialize connection to ELB
        #
        # ==== Notes
        # options parameter must include values for :aws_access_key_id and
        # :aws_secret_access_key in order to create a connection
        #
        # ==== Examples
        #   elb = ELB.new(
        #    :aws_access_key_id => your_aws_access_key_id,
        #    :aws_secret_access_key => your_aws_secret_access_key
        #   )
        #
        # ==== Parameters
        # * options<~Hash> - config arguments for connection.  Defaults to {}.
        #   * region<~String> - optional region to use. For instance, 'eu-west-1', 'us-east-1' and etc.
        #
        # ==== Returns
        # * ELB object with connection to AWS.
        def initialize(options={})
          @use_iam_profile = options[:use_iam_profile]
          @instrumentor       = options[:instrumentor]
          @instrumentor_name  = options[:instrumentor_name] || 'fog.aws.rds'
          @connection_options     = options[:connection_options] || {}

          @region     = options[:region]      || 'us-east-1'
          @host       = options[:host]        || "rds.#{@region}.amazonaws.com"
          @path       = options[:path]        || '/'
          @persistent = options[:persistent]  || false
          @port       = options[:port]        || 443
          @scheme     = options[:scheme]      || 'https'
          @connection = Fog::XML::Connection.new("#{@scheme}://#{@host}:#{@port}#{@path}", @persistent, @connection_options)
          @version    = options[:version] || '2013-05-15'

          setup_credentials(options)
        end

        def owner_id
          @owner_id ||= security_groups.get('default').owner_id
        end

        def reload
          @connection.reset
        end

        private

        def setup_credentials(options)
          @aws_access_key_id      = options[:aws_access_key_id]
          @aws_secret_access_key  = options[:aws_secret_access_key]
          @aws_session_token     = options[:aws_session_token]
          @aws_credentials_expire_at = options[:aws_credentials_expire_at]

          @signer = Fog::AWS::SignatureV4.new( @aws_access_key_id, @aws_secret_access_key,@region,'rds')
        end

        def request(params)
          refresh_credentials_if_expired

          idempotent  = params.delete(:idempotent)
          parser      = params.delete(:parser)

          body, headers = Fog::AWS.signed_params_v4(
            params,
            {'Content-Type' => 'application/x-www-form-urlencoded' },
            {
              :aws_session_token  => @aws_session_token,
              :signer             => @signer,
              :host               => @host,
              :path               => @path,
              :port               => @port,
              :version            => @version,
              :method             => 'POST'
            }
          )

          if @instrumentor
            @instrumentor.instrument("#{@instrumentor_name}.request", params) do
              _request(body, headers, idempotent, parser)
            end
          else
            _request(body, headers, idempotent, parser)
          end
        end

        def _request(body, headers, idempotent, parser)
          @connection.request({
            :body       => body,
            :expects    => 200,
            :headers    => headers,
            :idempotent => idempotent,
            :method     => 'POST',
            :parser     => parser
          })
        rescue Excon::Errors::HTTPStatusError => error
          match = Fog::AWS::Errors.match_error(error)
          if match.empty?
            case error.message
            when 'Not Found'
              raise Fog::AWS::RDS::NotFound.slurp(error, 'RDS Instance not found')
            else
              raise
            end
          else
            raise case match[:code]
                  when 'DBInstanceNotFound', 'DBParameterGroupNotFound', 'DBSnapshotNotFound', 'DBSecurityGroupNotFound', 'SubscriptionNotFound'
                    Fog::AWS::RDS::NotFound.slurp(error, match[:message])
                  when 'DBParameterGroupAlreadyExists'
                    Fog::AWS::RDS::IdentifierTaken.slurp(error, match[:message])
                  when 'AuthorizationAlreadyExists'
                    Fog::AWS::RDS::AuthorizationAlreadyExists.slurp(error, match[:message])
                  else
                    Fog::AWS::RDS::Error.slurp(error, "#{match[:code]} => #{match[:message]}")
                  end
          end
        end
      end
    end
  end
end