/// <summary>
/// Called by the web controller to start an effect (after first stopping any active effect).
/// Configuration and active state is persisted to file.
/// </summary>
/// <param name="config"></param>
/// <param name="handler"></param>
/// <returns></returns>
public async Task StartEffect(EffectConfig config, EffectHandler handler)
{
// Cancel previous handler if there is one
_effectCancellationTokenSource?.Cancel();
// Start the new handler
_effectCancellationTokenSource = new CancellationTokenSource();
handler.Start(_effectCancellationTokenSource.Token);
ActiveHandler = handler;
// Save config including state
var otherConfig = config.GetType() == typeof(XmasEffectConfig)
? (EffectConfig)await _storageService.LoadConfig <WarmupEffectConfig>()
: (EffectConfig)await _storageService.LoadConfig <XmasEffectConfig>();
otherConfig.Active = false;
config.Active = true;
await _storageService.SaveConfig(otherConfig);
await _storageService.SaveConfig(config);
}