module Bosh::Stemcell
  module Infrastructure
    def self.for(name)
      case name
        when 'openstack'
          OpenStack.new
        when 'aws'
          Aws.new
        when 'vsphere'
          Vsphere.new
        when 'warden'
          Warden.new
        when 'vcloud'
          Vcloud.new
        when 'null'
          NullInfrastructure.new
        else
          raise ArgumentError.new("invalid infrastructure: #{name}")
      end
    end

    class Base
      attr_reader :name, :hypervisor, :default_disk_size, :disk_formats

      def initialize(options = {})
        @name = options.fetch(:name)
        @supports_light_stemcell = options.fetch(:supports_light_stemcell, false)
        @hypervisor = options.fetch(:hypervisor)
        @default_disk_size = options.fetch(:default_disk_size)
        @disk_formats = options.fetch(:disk_formats)
      end

      def default_disk_format
        disk_formats.first
      end

      def additional_cloud_properties
        {}
      end

      def ==(other)
        name == other.name &&
          hypervisor == other.hypervisor &&
          default_disk_size == other.default_disk_size
      end
    end

    class NullInfrastructure < Base
      def initialize
        super(name: 'null', hypervisor: 'null', default_disk_size: -1, disk_formats: [])
      end
    end

    class OpenStack < Base
      def initialize
        super(name: 'openstack', hypervisor: 'kvm', default_disk_size: 3072, disk_formats: ['qcow2', 'raw'])
      end

      def additional_cloud_properties
        {'auto_disk_config' => true}
      end
    end

    class Vsphere < Base
      def initialize
        super(name: 'vsphere', hypervisor: 'esxi', default_disk_size: 3072, disk_formats: ['ovf'])
      end

      def additional_cloud_properties
        {'root_device_name' => '/dev/sda1'}
      end
    end

    class Vcloud < Base
      def initialize
        super(name: 'vcloud', hypervisor: 'esxi', default_disk_size: 3072, disk_formats: ['ovf'])
      end

      def additional_cloud_properties
        {'root_device_name' => '/dev/sda1'}
      end
    end

    class Aws < Base
      def initialize
        super(
          name: 'aws',
          hypervisor: 'xen',
          supports_light_stemcell: true,
          default_disk_size: 2048,
          disk_formats: ['raw']
        )
      end

      def additional_cloud_properties
        {'root_device_name' => '/dev/sda1'}
      end
    end

    class Warden < Base
      def initialize
        super(name: 'warden', hypervisor: 'boshlite', default_disk_size: 2048, disk_formats: ['files'])
      end

      def additional_cloud_properties
        {'root_device_name' => '/dev/sda1'}
      end
    end
  end
end