module Fog
  module AWS
    class RDS
      class Real
        require 'fog/aws/parsers/rds/describe_db_instances'

        # Describe all or specified load db instances
        # http://docs.amazonwebservices.com/AmazonRDS/latest/APIReference/API_DescribeDBInstances.html
        # ==== Parameters
        # * DBInstanceIdentifier <~String> - ID of instance to retrieve information for. if absent information for all instances is returned
        # ==== Returns
        # * response<~Excon::Response>:
        #   * body<~Hash>:
        def describe_db_instances(identifier=nil, opts={})
          params = {}
          params['DBInstanceIdentifier'] = identifier if identifier
          if opts[:marker]
            params['Marker'] = opts[:marker]
          end
          if opts[:max_records]
            params['MaxRecords'] = opts[:max_records]
          end

          request({
            'Action'  => 'DescribeDBInstances',
            :parser   => Fog::Parsers::AWS::RDS::DescribeDBInstances.new
          }.merge(params))
        end
      end

      class Mock
        def describe_db_instances(identifier=nil, opts={})
          response = Excon::Response.new
          server_set = []
          if identifier
            if specified_server = self.data[:servers][identifier]
              server_set << specified_server
            else
              raise Fog::AWS::RDS::NotFound.new("DBInstance #{identifier} not found")
            end
          else
            server_set = self.data[:servers].values
          end

          server_set.each do |server|
             case server["DBInstanceStatus"]
             when "creating"
               if Time.now - server['InstanceCreateTime'] >= Fog::Mock.delay * 2
                 server["DBInstanceStatus"] = "available"
                 server["AvailabilityZone"] ||= region + 'a'
                 server["Endpoint"] = {"Port"=>3306,
                                       "Address"=> Fog::AWS::Mock.rds_address(server["DBInstanceIdentifier"],region) }
                 server["PendingModifiedValues"] = {}
               end
              when "rebooting"
                if Time.now - self.data[:reboot_time] >= Fog::Mock.delay
                  # apply pending modified values
                  server.merge!(server["PendingModifiedValues"])
                  server["PendingModifiedValues"] = {}

                  server["DBInstanceStatus"] = 'available'
                  self.data.delete(:reboot_time)
                end
              when "modifying"
                # TODO there are some fields that only applied after rebooting
                if Time.now - self.data[:modify_time] >= Fog::Mock.delay
                  if new_id = server["PendingModifiedValues"] && server["PendingModifiedValues"]["DBInstanceIdentifier"]
                    self.data[:servers][new_id] = self.data[:servers].delete(server["DBInstanceIdentifier"])
                  end

                  server.merge!(server["PendingModifiedValues"])
                  server["PendingModifiedValues"] = {}
                  server["DBInstanceStatus"] = 'available'
                end
              when "available" # I'm not sure if amazon does this
                unless server["PendingModifiedValues"].empty?
                  server["DBInstanceStatus"] = 'modifying'
                end
             end
          end

          response.status = 200
          response.body = {
            "ResponseMetadata"          => { "RequestId"   => Fog::AWS::Mock.request_id },
            "DescribeDBInstancesResult" => { "DBInstances" => server_set }
          }
          response
        end
      end
    end
  end
end