require "json"
require "pretty_print"
require "http"
require "uuid"

struct Nil
  def as_s?
    self
  end
end

module OBS
  extend self

  # How should this be used?
  @[Flags]
  enum EventSubscription : UInt32
    Unused1
    Config
    Scenes
    Inputs
    Transitions
    Filters
    Outputs
    SceneItems
    MediaInputs
    Vendors
    Ui
    Unused11
    Unused12
    Unused13
    Unused14
    Unused15
    InputVolumeMeters
    InputActiveStateChanged
    InputShowStateChanged
    SceneItemTransformChanged
    # "All" in the protocol docs is not actually "all events", but "all non-high-volume events" because reasons???
    # The unused enums are presumably reserved for that class.
    AllNonHigh  = Config|Scenes|Inputs|Transitions|Filters|Outputs|SceneItems|MediaInputs|Vendors|Ui|Unused11|Unused12|Unused13|Unused14|Unused15
    ORMCritical =        Scenes|Inputs|            Filters|Outputs|SceneItems|SceneItemTransformChanged
  end

  def req( type : String, data : ( String | Nil | JSON::Any ) = nil, id : String = UUID.random.to_s )
    request = JSON.build do |json|
      json.object do
        json.field "op", 6
        json.field "d" do
          json.object do
            json.field "requestType", type
            json.field "requestId", id
            if data
              json.field "requestData", data
            end
          end
        end
      end
    end
    return( request.to_s )
  end

  class PasswordMissingException < Exception
  end

  class SourceMissingException < Exception
  end

  class StudioModeException < Exception
  end

  class ResponseDataMissingException < Exception
  end

  class WebSocket
    # A bunch of these get initialized in OBS::WebSocket.initialize,
    # but we still want a class-wide typedef here to avoid managing Nils
    @inputs          : OBS::Inputs          = OBS::Inputs.allocate
    @scenes          : OBS::SceneList       = OBS::SceneList.allocate
    @sources         : OBS::Sources         = OBS::Sources.allocate
    @scenecollection : OBS::SceneCollection = OBS::SceneCollection.allocate
    @outputs         : OBS::Outputs         = OBS::Outputs.allocate
    @video           : OBS::VideoSettings   = OBS::VideoSettings.allocate
    @stats           : OBS::Stats           = OBS::Stats.allocate
    @studiomode : Bool | Nil = nil
    @eventsubs = Array( Tuple( Channel(JSON::Any), UInt32 ) ).new # convert this to Hash if anyone ever wants eventsub_remove()
    @openrequests = Hash( String, Channel( JSON::Any ) ).new
    @negotiated = false
    @negotiationdelayqueue = 0
    @negotiationdelay = Channel( Exception | Nil ).new
    @connecterror = 0
    @shutdown = false
    @closed = true
    @eventmask : UInt32 = (EventSubscription::AllNonHigh|EventSubscription::ORMCritical).value
    def closed?
      return @closed
    end
    def studiomode : Bool
      if @studiomode == nil
        d = self.send_sync( OBS.req( "GetStudioModeEnabled" ) )
        @studiomode = d["responseData"]["studioModeEnabled"].as_bool
      end
      @studiomode.not_nil!
    end
    def studiomode=( state : Bool ) : Bool
      unless self.studiomode == state
        d = self.send_sync( OBS.req( "SetStudioModeEnabled", JSON.parse( { "studioModeEnabled" => state }.to_json ) ) )
        d["requestStatus"]["result"].as_bool && ( @studiomode = state )
      end
      return state
    end
    def studiomodecache=( state : Bool )
      @studiomode = state
    end
    def eventsub_add( channel : Channel( JSON::Any ), mask : UInt32 = @eventmask )
      unless @eventmask.bits_set?( mask )
        @eventmask = @eventmask|( mask ) # bitwise OR
        if @websocket
          STDERR.puts( "Warning: eventsub_add mask requesting more bits than negotiated. Reconnecting." )
          STDERR.puts( "Warning: To avoid this, initialize OBS::WebSocket with eventmask: #{@eventmask}" )
          @websocket.not_nil!.close
        end
      end
      @eventsubs.push( { channel, mask } )
    end
    def negotiated?
      return @negotiated
    end
    def scenecollection
      return @scenecollection
    end
    def scenes
      return @scenes
    end
    def inputs
      return @inputs
    end
    def outputs
      return @outputs
    end
    def sources
      return @sources
    end
    def video
      return @video
    end
    def stats
      return @stats
    end
    def transition!
      if self.studiomode
        self.send_sync( OBS.req( "TriggerStudioModeTransition" ) )
      else
        raise StudioModeException.new("Not currently in Studio Mode.")
      end
    end
    def block_until_negotiated
      unless @negotiated
        @negotiationdelayqueue += 1
        negotiationresult = @negotiationdelay.receive
        if negotiationresult.is_a?( Exception )
          raise negotiationresult
        end
        @negotiated || return false # not sure why this condition would occur without an exception
      end
    end
    # Asynchronous send
    def send( json : String )
      self.block_until_negotiated()
      STDERR.puts( "SENT: #{JSON.parse(json).pretty_inspect}" )
      @websocket && @websocket.not_nil!.send( json )
    end
    # Block until response
    def send_sync( json : String )
      self.block_until_negotiated()
      reschan = Channel( JSON::Any ).new
      STDERR.puts( "SENT: #{JSON.parse(json).pretty_inspect}" )
      @openrequests[ JSON.parse( json )["d"]["requestId"].as_s ] = reschan
      @websocket && @websocket.not_nil!.send( json )
      return reschan.receive
    end
    def initialize( uri : String, password : String | Nil = nil, retry : Bool = true, @eventmask : UInt32 = @eventmask )
      @scenecollection.initialize( self )
      @inputs.initialize( self )
      @scenes.initialize( self )
      @sources.initialize( self )
      @outputs.initialize( self )
      @video.initialize( self )
      @stats.initialize( self )

      unless @eventmask.bits_set?( EventSubscription::ORMCritical.value )
        STDERR.puts( "WARNING: ORM-critical event subscriptions are missing. Expect broken statekeeping." )
      end

      spawn do
        loop do
          if @shutdown
            break
          end
          # FFS why is HTTP::WebSocket.initialize protected?
          # Now we have to .not_nil! this shit everywhere
          # @websocket.initialize( HTTP::WebSocket::Protocol.new( URI.parse( uri ), HTTP::Headers{"Cookie" => "SESSIONID=1235", "Sec-WebSocket-Protocol" => "OBS.json"}  ) )
          @websocket = HTTP::WebSocket.new( URI.parse( uri ), HTTP::Headers{"Cookie" => "SESSIONID=1235", "Sec-WebSocket-Protocol" => "OBS.json"}  )
          @websocket.not_nil!.on_close do | message | # for some reason HTTP::WebSocket.closed? SIGSEGVs on a dangling pointer on the 1.6 runtime, so we hack around it with our own state variable for now.
            @closed = true
          end
          @closed = false
          @websocket.not_nil!.on_message do | message |
            json = JSON.parse( message )
            STDERR.print( "RECEIVED: ")
            STDERR.print( json.to_pretty_json )
            STDERR.print( "\n")
            if json["error"]?
              STDERR.puts( json["error"] )
              next
            end
            case json["op"].as_i64
            when 0 # hello
              hello = JSON.build do |j|
                j.object do
                  j.field "op", 1
                  j.field "d" do
                    j.object do
                      j.field "rpcVersion", 1
                      j.field "eventSubscriptions", @eventmask
                      if json["d"]["authentication"]?
                        if password
                          secret = Base64.encode(OpenSSL::Digest.new("sha256").update( password + json["d"]["authentication"]["salt"].as_s    ).final).chomp
                          auth =   Base64.encode(OpenSSL::Digest.new("sha256").update( secret + json["d"]["authentication"]["challenge"].as_s ).final).chomp
                          j.field "authentication", auth
                        else
                          raise PasswordMissingException.new( "Negotiation: missing password" )
                        end
                      end
                    end
                  end
                end
              end

              STDERR.puts( "SENT: #{hello.pretty_inspect}" )
              @websocket.not_nil!.send( hello.to_s )
            when 2 # identified
              @negotiated = true
              @negotiationdelayqueue.times do
                @negotiationdelay.send( nil )
                @negotiationdelayqueue -= 1
              end
              @connecterror = 0
            when 5 # event
              @eventsubs.each do | eventsub |
                if ( eventsub[1].bits_set?( json["d"]["eventIntent"].as_i ) )
                  eventsub[0].send( json["d"] )
                end
              end
              # A Fiber.yield occurs immediately after this to make sure "json" doesn't get overwritten before we can use it.
              spawn do
                d = json["d"]
                case d["eventType"].as_s
                when "CurrentPreviewSceneChanged"
                  edata = d["eventData"]
                  @scenes.previewcache( edata["sceneName"].as_s )
                when "CurrentProgramSceneChanged"
                  edata = d["eventData"]
                  @scenes.programcache( edata["sceneName"].as_s )
                when "CurrentSceneCollectionChanging"
                  @scenecollection.deletecache()
                  @scenes.deletecache()
                when "CurrentSceneCollectionChanged"
                  @scenecollection.deletecache()
                  @scenes.deletecache()
                  edata = d["eventData"]
                  @scenecollection.currentcache( edata["sceneCollectionName"].as_s )
                when "SceneCollectionListChanged"
                  @scenecollection.deletecache()
                  # We could probably save requests by using the edata here.
                when "CurrentProfileChanging"
                when "CurrentProfileChanged"
                when "ProfileListChanged"
                when "SceneListChanged"
                  @scenes.deletecache
                  # We could probably save requests by using the edata here.
                when "SceneCreated"
                  @scenes.deletecache
                  # We could probably save requests by using the edata here.
                when "SceneRemoved"
                  @scenes.deletecache
                  # We could probably save requests by using the edata here.
                when "SceneNameChanged"
                  @scenes.deletecache
                  # We could probably save requests by using the edata here.
                when "InputCreated"
                  edata = d["eventData"]
                  @inputs[edata["inputName"].to_s] = OBS::Input.new( self, edata )
                when "InputNameChanged"
                  edata = d["eventData"]
                  @inputs.renamecache( edata["oldInputName"].as_s, edata["inputName"].as_s )
                when "InputRemoved"
                  edata = d["eventData"]
                  @inputs.deletecache( edata["inputName"].as_s )
                when "InputActiveStateChanged"
                when "InputShowStateChanged"
                when "InputMuteStateChanged"
                when "InputVolumeChanged"
                when "InputAudioBalanceChanged"
                when "InputAudioSyncOffsetChanged"
                when "InputAudioTracksChanged"
                when "InputAudioMonitorTypeChanged"
                when "InputVolumeMeters"
                when "MediaInputPlaybackStarted"
                when "MediaInputPlaybackEnded"
                when "MediaInputActionTriggered"
                when "CurrentSceneTransitionChanged"
                when "CurrentSceneTransitionDurationChanged"
                when "StudioModeStateChanged"
                  edata = d["eventData"]
                  @studiomode = edata["studioModeEnabled"].as_bool
                when "SceneTransitionStarted"
                when "SceneTransitionEnded"
                when "SceneTransitionVideoEnded"
                when "SceneItemSelected"
                when "SceneItemCreated"
                  edata = d["eventData"]
                  @scenes[edata["sceneName"].to_s].deletecache()
                  # This could probably be made more efficient using the eventData
                when "SceneItemRemoved"
                  edata = d["eventData"]
                  @scenes[edata["sceneName"].to_s].deletecache( edata["sceneItemId"].as_i64, edata["sourceName"].as_s )
                when "SceneItemEnableStateChanged"
                  edata = d["eventData"]
                  @scenes[edata["sceneName"].as_s][edata["sceneItemId"].as_i64].enabledcache( edata["sceneItemEnabled"].as_bool )
                when "SceneItemListReindexed"
                  edata = d["eventData"]
                  @scenes[edata["sceneName"].to_s].deletecache()
                  # This could probably be made more efficient using the eventData
                when "SceneItemLockStateChanged"
                when "SceneItemTransformChanged"
                  edata = d["eventData"]
                  transform = edata["sceneItemTransform"]
                  sceneitem = @scenes[edata["sceneName"].as_s][edata["sceneItemId"].as_i64]
                  sceneitem.transform.cache( transform )
                  if ( transform["sourceHeight"].as_f.to_i64 > 0 ) && ( transform["sourceWidth"].as_f.to_i64 > 0 )
                    sources.last_known_real_transform_add( sceneitem.name, transform )
                  end
                when "SourceDestroyed"
                  # We always dynamically assemble sources from inputs and scenes, so this event is ignored.
                when "SourceFilterEnableStateChanged"
                  edata = json["d"]["eventData"]
                  if ( source = @sources[edata["sourceName"].as_s]? )
                      STDERR.puts( "SourceFilterEnableStateChanged: #{source.class}" )
                      source.filters[edata["filterName"].as_s].enabledcache( edata["filterEnabled"].as_bool )
                  else
                    raise SourceMissingException.new( "SourceFilterEnableStateChanged: missing source #{ edata["sourceName"].as_s}" )
                  end
                when "SourceFilterListReindexed"
                  # FIXME
                when "SourceFilterCreated"
                  # FIXME
                when "SourceFilterRemoved"
                  # FIXME
                when "SourceFilterNameChanged"
                  # FIXME
                when "StreamStateChanged"
                when "RecordStateChanged"
                when "ReplayBufferStateChanged"
                when "VirtualcamStateChanged"
                when "ReplayBufferSaved"
                end
              end
              Fiber.yield
            when 7 # response
              # A Fiber.yield occurs immediately after this to make sure "json" doesn't get overwritten before we can use it.
              spawn do
                d = json["d"]
                if d["requestStatus"]["result"].as_bool == false
                  STDERR.puts( "ERROR: #{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
                end
                if @openrequests[ d["requestId"].as_s ]?
                  channel = @openrequests[ d["requestId"].as_s ]
                  channel.send( d )
                  channel.close
                  @openrequests.delete( d["requestId"].as_s )
                else
                  STDERR.puts( "PUBSUBREAD THREAD: no response channel known for requestId: #{ d["requestId"].as_s }" )
                end
              end
              Fiber.yield
            end
          end
          @websocket.not_nil!.run
        rescue ex : Socket::ConnectError | IO::Error
          if @connecterror < 3
            STDERR.print( ex.message )
            @connecterror += 1
            ( @connecterror == 3 ) && ( @connecterror += 1 ) && STDERR.print( ". Suppressing further repeat errors." )
            STDERR.print( "\n" )
          end
          unless retry
            @negotiationdelayqueue.times do
              @negotiationdelay.send( ex )
              @negotiationdelayqueue -= 1
            end
          end
          @closed || @websocket && @websocket.not_nil!.close
          @negotiated = false
          sleep 5
        rescue ex
          STDERR.print( ex.pretty_inspect )
          STDERR.print( ex.backtrace?.pretty_inspect )
          @closed || @websocket && @websocket.not_nil!.close
          @negotiated = false
          sleep 5
        ensure
          @closed || @websocket && @websocket.not_nil!.close
          @negotiated = false
          unless retry
            @negotiationdelayqueue.times do
              @negotiationdelay.send( nil )
              @negotiationdelayqueue -= 1
            end
          end
          # invalidate state on everything
          @scenecollection = OBS::SceneCollection.new( self )
          @inputs = OBS::Inputs.new( self )
          @scenes = OBS::SceneList.new( self )
          @sources = OBS::Sources.new( self )
          @outputs = OBS::Outputs.new( self )
          @video = OBS::VideoSettings.new( self )
          @stats = OBS::Stats.new( self )
          retry || ( @shutdown = true )
        end
      end
    end
    def close
      @shutdown = true
      @websocket && @websocket.close
    end
  end

  class Outputs
    @outputs = Hash( String, OBS::Output ).new
    def initialize( @obs : OBS::WebSocket )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetOutputList" ) )
      if ( rdata = d["responseData"]? )
        STDERR.print( "OUTPUTS THREAD: " )
        STDERR.print( rdata.pretty_inspect )
        rdata["outputs"].as_a.each do | output |
          @outputs[output["outputName"].as_s] = OBS::Output.new( @obs, output )
        end
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []( key : String )
      @outputs[key]? || populate
      @outputs[key]
    end
    def to_h
      @outputs.empty? && populate
      @outputs
    end
  end

  class Output
    getter status : OBS::OutputStatus
    getter flags : Hash( String, Bool )
    getter state : Hash( String, String | Bool | Int64 | Float64 | Hash( String, Bool ) )
    def initialize( @obs : OBS::WebSocket, json : JSON::Any )
      @flags = Hash( String, Bool ).from_json(json["outputFlags"].to_json)
      @status = OBS::OutputStatus.new( @obs, json["outputName"].as_s )
      @state = Hash(String, String | Bool | Int64 | Float64 | Hash( String, Bool ) ).from_json(json.to_json)
    end
  end

  class OutputStatus
    @age = Int64.new( 0 )
    @status = Hash(String, String | Bool | Int64 | Float64 ).new
    getter name : String
    def initialize( @obs : OBS::WebSocket, @name : String )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetOutputStatus", JSON.parse( { "outputName" => @name }.to_json ) ) )
      if ( rdata = d["responseData"]? )
        @age = Time.utc.to_unix
        @status = Hash(String, String | Bool | Int64 | Float64 ).from_json(rdata.to_json)
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []( key : String )
      ( @age < ( Time.utc.to_unix - 10 ) ) && populate
      @status[key]? || populate
      @status[key]
    end
    def to_h : Hash(String, String | Bool | Int64 | Float64 )
      ( @age < ( Time.utc.to_unix - 10 ) ) && populate
      @status.empty? && populate
      @status
    end
  end

  class VideoSettings
    @settings = Hash(String, String | Bool | Int64 | Float64 ).new
    def initialize( @obs : OBS::WebSocket )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetVideoSettings" ) )
      if ( rdata = d["responseData"]? )
        @settings = Hash(String, String | Bool | Int64 | Float64 ).from_json(rdata.to_json)
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def settings
      @settings.empty? && populate
      @settings
    end
    def []( key : String )
      @settings[key]? || populate
      @settings[key]
    end
    def to_h
      @settings.empty? && populate
      @settings
    end
  end

  class Stats
    @stats = Hash(String, String | Bool | Int64 | Float64 ).new
    @age = Int64.new( 0 )
    def initialize( @obs : OBS::WebSocket )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetStats" ) )
      if ( rdata = d["responseData"]? )
        @stats = Hash(String, String | Bool | Int64 | Float64 ).from_json(rdata.to_json)
        @age = Time.utc.to_unix
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []( key : String )
      ( @age < ( Time.utc.to_unix - 10 ) ) && populate
      @stats[key]? || populate
      @stats[key]
    end
    def to_h : Hash(String, String | Bool | Int64 | Float64 )
      @stats.empty? && populate
      @stats
    end
  end

  class SceneCollection # Note: distinct from SceneList
    @inputs : OBS::Inputs
    @current = String.new
    @list = Hash( String, OBS::SceneList ).new
    def initialize( @obs : OBS::WebSocket )
      @inputs = @obs.inputs
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetSceneCollectionList" ) )
      if ( rdata = d["responseData"]? )
        @current = rdata["currentSceneCollectionName"].as_s
        rdata["sceneCollections"].as_a.each{ | scenecollection |
          @list[scenecollection.as_s] = OBS::SceneList.new( @obs )
        }
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
      return true
    end
    def current()
       @current.empty? && populate()
       return @current
    end
    def []( scenelist : String )
      if list[scenelist]?
        return list[scenelist]
      else
        self.populate
      end
    end
    def deletecache()
      @current = String.new
      @list = Hash( String, OBS::SceneList ).new
    end
    def currentcache( @current : String )
    end
  end

  class SceneList # Note: distinct from SceneCollection
    @scenes_by_index = Array(String).new
    @scenes = Hash(String, OBS::Scene).new
    @program = String.new
    @preview : Nil | String = nil
    def initialize( @obs : OBS::WebSocket )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetSceneList" ) )
      if ( rdata = d["responseData"]? )
        @program = rdata["currentProgramSceneName"].as_s
        if @preview = rdata["currentPreviewSceneName"].as_s?
          @obs.studiomodecache=true
        else
          @obs.studiomodecache=false
        end
        rdata["scenes"].as_a.each_with_index{ | scene, i |
          name = scene["sceneName"].as_s
          @scenes_by_index.push(name)
          @scenes[name] = OBS::Scene.new( @obs, name, self )
        }
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
      return true
    end
    def programcache( v : String )
      @program = v
    end
    def program
      @program.empty? && populate()
      @scenes[@program]
    end
    def previewcache( v : String )
      @preview = v
    end
    def preview
      @preview || populate()
      if @preview
        return @scenes[@preview]
      else
        return @preview
      end
    end
    def current
      @program.empty? && populate
      @scenes[@program]
    end
    def []( index : Int ) : OBS::Scene
      @scenes_by_index[index]? || populate
      @scenes[@scenes_by_index[index]]? || populate
      @scenes[@scenes_by_index[index]]
    end
    def []( index : String ) : OBS::Scene
      @scenes[index]? || populate
      @scenes[index]
    end
    def []?( index : String ) : OBS::Scene | Nil
      @scenes[index]? || populate
      @scenes[index]?
    end
    def to_h : Hash( String, OBS::Scene )
      @scenes.empty? && populate
      return @scenes
    end
    def deletecache()
      @scenes_by_index = Array(String).new
      @scenes = Hash(String, OBS::Scene).new
      @program = String.new
      @preview = String.new
    end
  end

  class Scene
    @items_by_id    = Hash( Int64, OBS::SceneItem ).new
    @items_by_name  = Hash( String, Int64 ).new
    @items_by_index = Array( Int64 ).new
    @subscenes      = Array( OBS::Scene ).new
    getter filters  : OBS::SourceFilters
    getter name     : String
    getter parent   : OBS::SceneList # needed for reverse metasceneitem lookup
    @age            = Int64.new( 0 )
    def initialize( @obs : OBS::WebSocket, @name : String, @parent : OBS::SceneList )
      @filters  = OBS::SourceFilters.new( @obs, @name )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetSceneItemList", JSON.parse( { "sceneName" => @name }.to_json ) ) )
      if ( rdata = d["responseData"]? )
        # handle "sourceType": "OBS_SOURCE_TYPE_SCENE"
        rdata["sceneItems"].as_a.each_with_index{ | item, i |
          sname = item["sourceName"].as_s
          siid   = item["sceneItemId"].as_i64
          @items_by_id[siid] = OBS::SceneItem.new( @obs, @name, item )
          @items_by_index.push( siid )
          @items_by_name[sname] = siid
          if item["sourceType"].as_s == "OBS_SOURCE_TYPE_SCENE"
            @subscenes.push( @parent[sname] )
          end
        }
      @age = Time.utc.to_unix
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
      return true
    end
    # Sources may be present a scene via other scenes.
    # We can still look these up by source name.
    # Note: OBS refuses to create a referential loop
    def metascene : Hash( String, Array( OBS::SceneItem ) )
      @subscenes.empty? && populate
      metascene = Hash( String, Array( OBS::SceneItem ) ).new
      newsubscenes = [ self ]
      while ( subscene = newsubscenes.shift? )
        subscene.to_h.each do | siname, sceneitem |
          if sceneitem.type == "OBS_SOURCE_TYPE_SCENE"
            newsubscenes.push( parent[siname] )
          end
          metascene[ siname ]? || ( metascene[ siname ] = Array( OBS::SceneItem ).new )
          metascene[ siname ].push( sceneitem )
          # We can have the same scene included in the scene graph multiple times, which will duplicate all its sceneitems in the resulting metascene array. Might be a good idea to add a uniqueness constraint at some point? Not sure anyone would really care one way or the other.
        end
      end
      return metascene
    end
    # returns first SceneItem it finds or Nil
    # less requests are generated with this method
    # but managing Nil unions is more annoying
    def metasceneitem?( name : String ) : OBS::SceneItem | Nil
      result = nil
      newsubscenes = [ self ]
      while ( subscene = newsubscenes.shift? )
        subscene.to_h.each do | siname, sceneitem |
          if sceneitem.type == "OBS_SOURCE_TYPE_SCENE"
            newsubscenes.push( parent[siname] )
          end
          if siname == name
            result = sceneitem
            break
          end
        end
      end
      return result
    end
    def []?( name : String ) : OBS::SceneItem | Nil
      ( @items_by_name[name]? || ( @age > 0 ) ) || populate
      if @items_by_name[name]?
        ( @items_by_id[ @items_by_name[name] ]? || ( @age > 0 ) ) || populate
        return @items_by_id[ @items_by_name[name] ]
      else
        return nil
      end
    end
    def []( name : String ) : OBS::SceneItem
      @items_by_name[name]? || populate
      @items_by_id[ @items_by_name[name] ]? || populate
      return @items_by_id[ @items_by_name[name] ]
    end
    def []( id : Int64 ) : OBS::SceneItem
      @items_by_id[id]? || populate
      return @items_by_id[id]
    end
    def by_index( index : Int64 )
      @items_by_index[index]? || populate
      @items_by_id[ @items_by_index[index] ]? || populate
      return @items_by_id[ @items_by_index[index] ]
    end
    def to_h : Hash( String, OBS::SceneItem )
      @items_by_id.empty? && populate
      hash = Hash( String, OBS::SceneItem ).new
      @items_by_name.each do | key, value |
        hash[key] = @items_by_id[value]
      end
      return hash
    end
    def current!
      program!
    end
    def program!
      # we get weird behavior on transitions unless we block here
      @obs.send_sync( OBS.req( "SetCurrentProgramScene", JSON.parse( { "sceneName" => @name }.to_json ) ) )
    end
    def preview!
      # we get weird behavior on transitions unless we block here
      @obs.studiomode || @obs.send_sync( OBS.req( "SetStudioModeEnabled", JSON.parse( { "studioModeEnabled" => true }.to_json ) ) )
      @obs.send_sync( OBS.req( "SetCurrentPreviewScene", JSON.parse( { "sceneName" => @name }.to_json ) ) )
    end
    def createinput( iname : String, kind : String, settings : OBS::InputSettings | Hash( String, String | Bool | Int64 | Float64 ) | Nil = nil, enabled : Bool = true )
      reqdata = ( Hash( String, String | Bool | Int64 | Float64 | Hash( String, String | Bool | Int64 | Float64 ) ) ).new
      reqdata["sceneName"] = @name
      reqdata["inputName"] = iname
      reqdata["inputKind"] = kind
      if settings
        reqdata["inputSettings"] = settings.to_h
      end
      unless enabled
        reqdata["sceneItemEnabled"] = false
      end

      d = @obs.send_sync( OBS.req( "CreateInput", JSON.parse(reqdata.to_json) ) )
      # maybe block until the event comes in?
      # will have to depend on the @eventsubscription state
      if d["requestStatus"]["result"].as_bool # success?
        # "responseData": { "sceneItemId": 219 }
        # Is this ever useful? It's a lot more requests than to just redo the entire GetSceneItemList
        #siid = d["responseData"]["sceneItemId"].as_i64
        @obs.inputs.deletecache
        self.deletecache
      end
      return d

    end
    def deletecache( )

      @items_by_id    = Hash( Int64, OBS::SceneItem ).new
      @items_by_name  = Hash( String, Int64 ).new
      @items_by_index = Array( Int64 ).new
      @subscenes      = Array( OBS::Scene ).new
    end
    def deletecache( siid : Int64, siname : String )
      @items_by_id.delete( siid )
      @items_by_name.delete( siname )
      @items_by_index.delete( siid )
    end
  end

  class SceneItem
    getter id        : Int64
    getter name      : String
    getter kind      : ( String | Nil )
    getter type      : String
    getter scenename : String
    getter enabled   : Bool
    getter blendmode : ( String | Nil )
    getter locked    : Bool
    getter transform : OBS::SceneItemTransform
    def initialize( @obs : OBS::WebSocket, @scenename : String, json : JSON::Any )
      @id      = json["sceneItemId"].as_i64
      @name    = json["sourceName"].as_s
      @kind    = json["inputKind"]?.as_s?
      @type    = json["sourceType"].as_s
      @locked  = json["sceneItemLocked"].as_bool
      @enabled = json["sceneItemEnabled"].as_bool
      @blendmode = json["sceneItemBlendmode"]?.as_s?
      @transform = OBS::SceneItemTransform.new( @obs, json["sceneItemTransform"], @name, @id )
    end
    def enabledcache( v : Bool )
      @enabled = v
    end
    def enabled
      @enabled
    end
    def toggle!
      if @enabled
        disable!
      else
        enable!
      end
    end
    def enable!
      @obs.send_sync( OBS.req( "SetSceneItemEnabled", JSON.parse( { "sceneName" => @scenename, "sceneItemId" => @id, "sceneItemEnabled" => true }.to_json ) ) )
    end
    def disable!
      @obs.send_sync( OBS.req( "SetSceneItemEnabled", JSON.parse( { "sceneName" => @scenename, "sceneItemId" => @id, "sceneItemEnabled" => false }.to_json ) ) )
    end
    def transform( newtransform : OBS::SceneItemTransform | Hash( String, String | Bool | Int64 | Float64 ) )
      reqdata = ( Hash( String, String | Bool | Int64 | Float64 | Hash( String, String | Bool | Int64 | Float64 ) ) ).new
      reqdata["sceneItemId"] = @id.to_i64
      reqdata["sceneName"] = @scenename
      reqdata["sceneItemTransform"] = Hash( String, String | Bool | Int64 | Float64).new.merge( newtransform.to_h )
      @obs.send_sync( OBS.req( "SetSceneItemTransform", JSON.parse(reqdata.to_json) ) )
    end
  end

  class SceneItemTransform
    @sceneitemtransform = Hash(String, String | Bool | Int64 | Float64 ).new
    def initialize( @obs : OBS::WebSocket, json : JSON::Any, @sceneitemname : String, @sceneitemid : Int64 )
      @sceneitemtransform = Hash(String, String | Bool | Int64 | Float64 ).from_json(json.to_json)
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetSceneItemTransform", JSON.parse( { "sceneName" => @sceneitemname, "sceneItemId" => @sceneitemid }.to_json ) ) )
      if ( rdata = d["responseData"]? )
        @sceneitemtransform = Hash(String, String | Bool | Int64 | Float64 ).from_json(rdata["sceneItemTransform"].to_json)
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []( key : String )
      @sceneitemtransform[key]? || populate
      @sceneitemtransform[key]
    end
    def to_h
      @sceneitemtransform.empty? && populate
      @sceneitemtransform
    end
    def cache( newtransform = JSON::Any | Hash(String, String | Bool | Int64 | Float64 ) )
        @sceneitemtransform = Hash(String, String | Bool | Int64 | Float64 ).from_json(newtransform.to_json)
    end
  end

  class Sources
    @last_known_real_transform = Hash( String, OBS::SceneItemTransform ).new
    def initialize( @obs : OBS::WebSocket )
    end
    def []( index : String ) : OBS::Scene | OBS::Input
      if @obs.inputs[index]?
        return @obs.inputs[index]
      elsif @obs.scenes[index]?
        return @obs.scenes[index]
      else
        raise IndexError.new("Source unknown.")
      end
    end
    def []?( index : String ) : OBS::Scene | OBS::Input | Nil
      if @obs.inputs[index]?
        return @obs.inputs[index]
      elsif @obs.scenes[index]?
        return @obs.scenes[index]
      else
        return nil
      end
    end
    def to_h() : Hash( String, OBS::Scene | OBS::Input )
      return @obs.@inputs.to_h.merge( @obs.@scenes.to_h )
    end
    def last_known_real_transform_add( sourcename : String, transform : JSON::Any )
      @last_known_real_transform[ sourcename ] = OBS::SceneItemTransform.new( @obs, transform, sourcename, 0.to_i64 )
    end
    def last_known_real_transform( sourcename : String ) : OBS::SceneItemTransform
      @last_known_real_transform[ sourcename ]
    end
    def last_known_real_transform?( sourcename : String ) : OBS::SceneItemTransform | Nil
      @last_known_real_transform[ sourcename ]?
    end
  end

  class Inputs
    @inputs = Hash( String, OBS::Input ).new
    def initialize( @obs : OBS::WebSocket )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetInputList") )
      if ( rdata = d["responseData"]? )
        rdata["inputs"].as_a.each{ | input |
          @inputs[input["inputName"].as_s] = OBS::Input.new( @obs, input )
        }
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []?( index : String ) : OBS::Input | Nil
      @inputs[index]? || populate
      return @inputs[index]?
    end
    def []( index : String )
      @inputs[index]? || populate
      return @inputs[index]
    end
    def []=( index : String, input = OBS::Input )
      @inputs[index] = input
    end
    def to_h : Hash( String, OBS::Input )
      @inputs.empty? && populate
      return @inputs
    end
    def renamecache( old : String, new : String )
      @inputs[new] = @inputs[old]
      @inputs.delete( old )
      @inputs[new].namecache( new )
    end
    def deletecache()
      @inputs = Hash( String, OBS::Input ).new
    end
    def deletecache( input : String )
      @inputs.delete( input )
    end
  end

  class Input
    getter kind : String
    getter name : String
    getter settings : OBS::InputSettings
    getter filters  : OBS::SourceFilters
    def initialize( @obs : OBS::WebSocket, json : JSON::Any )
      @kind = json["inputKind"].as_s
      @name = json["inputName"].as_s
      @settings = OBS::InputSettings.new( @obs, @name )
      @filters  = OBS::SourceFilters.new( @obs, @name )
    end
    def delete!( )
      @obs.send_sync( OBS.req( "RemoveInput", JSON.parse({ "inputName" => @name }.to_json) ) )
    end
    def namecache( name : String )
      @name = name
      @settings.namecache( name )

      @filters.to_h.values.each do | value |
        value.sourcenamecache( name )
      end
    end
  end

  class InputSettings
    @inputsettings = Hash(String, String | Bool | Int64 | Float64 ).new
    @inputkind = String.new
    getter name : String
    def initialize( @obs : OBS::WebSocket, @name : String )
    end
    def initialize( @obs : OBS::WebSocket, @name : String, @inputkind : String, @inputsettings : Hash( String, String | Bool | Int64 | Float64 ) )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetInputSettings", JSON.parse( { "inputName" => @name }.to_json ) ) )
      if ( rdata = d["responseData"]? )
        @inputsettings = Hash(String, String | Bool | Int64 | Float64 ).from_json(rdata["inputSettings"].to_json)
        @inputkind = rdata["inputKind"].as_s
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def kind
      @inputkind.empty? && populate
      @inputkind
    end
    def []( key : String )
      @inputsettings[key]? || populate
      @inputsettings[key]
    end
    def to_h
      @inputsettings.empty? && populate
      @inputsettings
    end
    def namecache( name : String)
      @name = name
    end
  end

  class SourceFilters # Note: a property of both OBS::Input and OBS::Scene
    @filters_by_name = Hash( String, OBS::SourceFilter ).new
    @filters_by_index = Array( String ).new
    getter sourcename : String
    def initialize( @obs : OBS::WebSocket, @sourcename : String )
    end
    def populate
      d = @obs.send_sync( OBS.req( "GetSourceFilterList", JSON.parse( { "sourceName" => @sourcename }.to_json ) ) )
      if ( rdata = d["responseData"]? )
        rdata["filters"].as_a.each do | filter |
          name = filter["filterName"].as_s
          @filters_by_index.push( name )
          @filters_by_name[name] = OBS::SourceFilter.new( @obs, @sourcename, filter )
        end
      else
        raise ResponseDataMissingException.new( "#{d["requestType"].as_s} #{d["requestStatus"]["code"].as_i64}: #{d["requestStatus"]["comment"].as_s}" )
      end
    end
    def []( index : Int64 )
      @filters_by_index[index]? || populate
      @filters_by_name[@filters_by_index[index]]? || populate
      @filters_by_name[@filters_by_index[index]]
    end
    def []?( key : String ) : OBS::SourceFilter | Nil
      @filters_by_name[key]? || populate
      @filters_by_name[key]?
    end
    def []( key : String )
      @filters_by_name[key]? || populate
      @filters_by_name[key]
    end
    def to_h
      @filters_by_name.empty? && populate
      @filters_by_name
    end
  end

  class SourceFilter
    getter name       : String
    getter kind       : String
    getter enabled    : Bool
    getter settings   : OBS::SourceFilterSettings
    getter sourcename : String
    def initialize( @obs : OBS::WebSocket, @sourcename, json : JSON::Any )
      @kind = json["filterKind"].as_s
      @name = json["filterName"].as_s
      @enabled = json["filterEnabled"].as_bool
      @settings = OBS::SourceFilterSettings.new( @obs, @name, json["filterSettings"] )
    end
    def toggle!
      if @enabled
        disable!
      else
        enable!
      end
    end
    def enable!
      d = @obs.send_sync( OBS.req( "SetSourceFilterEnabled", JSON.parse( { "sourceName" => @sourcename, "filterName" => @name, "filterEnabled" => true }.to_json ) ) )
      return d["requestStatus"]["result"].as_bool
    end
    def disable!
      d = @obs.send_sync( OBS.req( "SetSourceFilterEnabled", JSON.parse( { "sourceName" => @sourcename, "filterName" => @name, "filterEnabled" => false }.to_json ) ) )
      return d["requestStatus"]["result"].as_bool
    end
    def enabledcache( bool : Bool )
      @enabled = bool
    end
    def sourcenamecache( name : String )
      @sourcename = name
    end
  end

  class SourceFilterSettings
    getter settings : Hash(String, String | Bool | Int64 | Float64 )
    getter sourcename : String
    def initialize( @obs : OBS::WebSocket, @sourcename, json : JSON::Any )
      @settings = Hash(String, String | Bool | Int64 | Float64 ).from_json(json.to_json)
    end
    # do we need to populate() this somehow?
    # SetSourceFilterSettings is available, but
    # GetSourceFilterSettings is not. Must use
    # GetSourceFilters instead.
    def []( key : String )
      @settings[key]
    end
    def to_h
      @settings
    end

  end
end