module Youtube
  class BroadcastService
    class Error < StandardError; end

    def initialize(team)
      @team = team
      @credential = team.youtube_credential
    end

    def create_broadcast!(title:, privacy_status: "unlisted", scheduled_at: nil)
      return mock_broadcast if @credential.blank? || missing_oauth_config?

      client = authorized_client
      broadcast = Google::Apis::YoutubeV3::LiveBroadcast.new(
        snippet: Google::Apis::YoutubeV3::LiveBroadcastSnippet.new(
          title: title,
          scheduled_start_time: scheduled_at&.iso8601
        ),
        status: Google::Apis::YoutubeV3::LiveBroadcastStatus.new(
          privacy_status: privacy_status,
          self_declared_made_for_kids: false
        ),
        content_details: Google::Apis::YoutubeV3::LiveBroadcastContentDetails.new(
          enable_auto_start: true,
          enable_auto_stop: true
        )
      )
      result = client.insert_live_broadcast("snippet,status,contentDetails", broadcast)

      stream = Google::Apis::YoutubeV3::LiveStream.new(
        snippet: Google::Apis::YoutubeV3::LiveStreamSnippet.new(title: "#{title} stream"),
        cdn: Google::Apis::YoutubeV3::CdnSettings.new(
          frame_rate: "30fps",
          ingestion_type: "rtmp",
          resolution: "720p"
        )
      )
      stream_result = client.insert_live_stream("snippet,cdn", stream)
      client.bind_live_broadcast(result.id, "id,contentDetails", stream_result.id)

      {
        broadcast_id: result.id,
        stream_id: stream_result.id,
        stream_key: stream_result.cdn.ingestion_info.stream_name,
        rtmp_url: stream_result.cdn.ingestion_info.ingestion_address
      }
    rescue Google::Apis::Error => e
      raise Error, e.message
    end

    def complete_broadcast!(broadcast_id)
      return if @credential.blank? || missing_oauth_config?

      client = authorized_client
      client.transition_live_broadcast(broadcast_id, "complete")
    rescue Google::Apis::Error
      nil
    end

    def viewer_count(broadcast_id)
      return 0 if @credential.blank? || missing_oauth_config?

      client = authorized_client
      resp = client.list_live_broadcasts("statistics", id: broadcast_id)
      resp.items&.first&.statistics&.concurrent_viewers.to_i
    rescue Google::Apis::Error
      0
    end

    private

    def mock_broadcast
      {
        broadcast_id: "mock_#{SecureRandom.hex(8)}",
        stream_id: "mock_stream",
        stream_key: ENV.fetch("YOUTUBE_MOCK_STREAM_KEY", "mock-stream-key"),
        rtmp_url: "rtmp://a.rtmp.youtube.com/live2"
      }
    end

    def missing_oauth_config?
      ENV["YOUTUBE_CLIENT_ID"].blank?
    end

    def authorized_client
      OauthRefresh.new(@credential).apply!(Google::Apis::YoutubeV3::YouTubeService.new)
    end
  end
end