private async Task <bool> HandleCreateNewRequest(
HttpContext httpContext,
IStateMachineContextStorage contextStorage,
IStateMachineContentStorage contentStorage,
IEnumerable <IStatemachineDefinition> definitions,
ITransitionDispatcher dispatcher)
{
var segments = this.routeMatcher.Match(this.options.RoutePrefix + "/{name}", httpContext.Request.Path);
if (segments?.ContainsKey("name") == true)
{
this.logger.LogInformation($"statemachine: create new (name={segments["name"]})");
var definition = definitions.Safe()
.FirstOrDefault(d => d.Name.Equals(segments["name"] as string, StringComparison.OrdinalIgnoreCase));
if (definition == null)
{
httpContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
var details = new ProblemDetails()
{
Title = "state machine definition not found",
Status = (int)HttpStatusCode.BadRequest,
Instance = $"{this.options.RoutePrefix}/{segments["name"]}",
};
httpContext.Response.ContentType = "application/json";
await httpContext.Response.WriteAsync(JsonConvert.SerializeObject(details, JsonSerializerSettings.Create()), Encoding.UTF8).ConfigureAwait(false);
return(true);
}
var context = new StateMachineContext()
{
Created = DateTime.UtcNow, Updated = DateTime.UtcNow
};
httpContext.Request.Query.ForEach(i => context.Properties.AddOrUpdate(i.Key, i.Value));
var instance = definition.CreateInstance(context, dispatcher);
instance.Activate();
await this.StoreContent(httpContext, "_current", context, contextStorage, contentStorage).ConfigureAwait(false);
await this.StoreContent(httpContext, context.State, context, contextStorage, contentStorage).ConfigureAwait(false);
httpContext.Response.StatusCode = (int)HttpStatusCode.Created;
httpContext.Response.ContentType = "application/json";
httpContext.Response.Headers.Add("Location", $"{this.options.RoutePrefix}/{segments["name"]}/{context.Id}");
await httpContext.Response.WriteAsync(JsonConvert.SerializeObject(context, JsonSerializerSettings.Create()), Encoding.UTF8).ConfigureAwait(false);
return(true);
}
return(false);
}
public async Task Invoke(
HttpContext httpContext,
IStateMachineContextStorage contextStorage,
IStateMachineContentStorage contentStorage,
IEnumerable <IStatemachineDefinition> definitions)
{
if (httpContext.Request.Path.StartsWithSegments(this.options.RoutePrefix, StringComparison.OrdinalIgnoreCase))
{
if (httpContext.Request.Method.SafeEquals("get"))
{
if (await this.HandleGetAllRequest(httpContext, contextStorage).ConfigureAwait(false))
{
return;
}
if (await this.HandleGetByIdRequest(httpContext, contextStorage).ConfigureAwait(false))
{
return;
}
if (await this.HandleGetTriggersRequest(httpContext, contextStorage, definitions, httpContext.RequestServices.GetService <ITransitionDispatcher>()).ConfigureAwait(false))
{
return;
}
}
else if (httpContext.Request.Method.SafeEquals("post"))
{
if (await this.HandleCreateNewRequest(httpContext, contextStorage, contentStorage, definitions, httpContext.RequestServices.GetService <ITransitionDispatcher>()).ConfigureAwait(false))
{
return;
}
}
else if (httpContext.Request.Method.SafeEquals("put"))
{
if (await this.HandleFireTriggerRequest(httpContext, contextStorage, contentStorage, definitions, httpContext.RequestServices.GetService <ITransitionDispatcher>()).ConfigureAwait(false))
{
return;
}
}
}
await this.next(httpContext).ConfigureAwait(false);
}
private async Task StoreContent(HttpContext httpContext, string key, StateMachineContext context, IStateMachineContextStorage contextStorage, IStateMachineContentStorage contentStorage)
{
var contentLength = httpContext.Request.ContentLength ?? 0;
if (httpContext.Request.Body != null && contentLength > 0)
{
httpContext.Request.EnableBuffering(); // allow multiple reads
httpContext.Request.Body.Position = 0;
try
{
using (var stream = new MemoryStream())
{
await httpContext.Request.Body.CopyToAsync(stream).ConfigureAwait(false);
this.logger.LogInformation($"statemachine: store content (name={context.Name}, id={context.Id}, key={key}, size={stream.Length}, type={httpContext.Request.ContentType})");
contentStorage.Save(context, $"{key}", stream, httpContext.Request.ContentType);
context.AddContent(key, httpContext.Request.ContentType, stream.Length);
}
}
catch (Exception ex)
{
this.logger.LogWarning(ex, $"save content failed: {ex.Message}");
}
httpContext.Request.Body.Position = 0;
}
contextStorage.Save(context);
}
private async Task <bool> HandleFireTriggerRequest(
HttpContext httpContext,
IStateMachineContextStorage contextStorage,
IStateMachineContentStorage contentStorage,
IEnumerable <IStatemachineDefinition> definitions,
ITransitionDispatcher dispatcher)
{
var segments = this.routeMatcher.Match(this.options.RoutePrefix + "/{name}/{id}/triggers/{trigger}", httpContext.Request.Path);
if (segments?.ContainsKey("name") == true && segments?.ContainsKey("id") == true && segments?.ContainsKey("trigger") == true)
{
this.logger.LogInformation($"statemachine: fire trigger (name={segments["name"]}, id={segments["id"]}, trigger={segments["trigger"]})");
var definition = definitions.Safe()
.FirstOrDefault(d => d.Name.Equals(segments["name"] as string, StringComparison.OrdinalIgnoreCase));
if (definition == null)
{
httpContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
var details = new ProblemDetails()
{
Title = "state machine definition not found",
Status = (int)HttpStatusCode.BadRequest,
Instance = $"{this.options.RoutePrefix}/{segments["name"]}/{segments["id"]}",
};
httpContext.Response.ContentType = "application/json";
await httpContext.Response.WriteAsync(JsonConvert.SerializeObject(details, JsonSerializerSettings.Create()), Encoding.UTF8).ConfigureAwait(false);
return(true);
}
var context = contextStorage.FindById(segments["id"] as string);
if (context == null)
{
httpContext.Response.StatusCode = (int)HttpStatusCode.NotFound;
return(true);
}
if (context.IsExpired())
{
httpContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
var details = new ProblemDetails()
{
Title = "state machine is expired",
Status = (int)HttpStatusCode.BadRequest,
Instance = $"{this.options.RoutePrefix}/{context.Name}/{context.Id}",
};
httpContext.Response.ContentType = "application/json";
await httpContext.Response.WriteAsync(JsonConvert.SerializeObject(details, JsonSerializerSettings.Create()), Encoding.UTF8).ConfigureAwait(false);
return(true);
}
if (!context.Name.Equals(segments["name"] as string, StringComparison.OrdinalIgnoreCase))
{
httpContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
return(true);
}
httpContext.Request.Query.ForEach(i => context.Properties.AddOrUpdate(i.Key, i.Value));
var instance = definition.CreateInstance(context, dispatcher);
try
{
await this.StoreContent(httpContext, "_current", context, contextStorage, contentStorage).ConfigureAwait(false);
if (await instance.FireAsync(segments["trigger"] as string).ConfigureAwait(false))
{
await this.StoreContent(httpContext, context.State, context, contextStorage, contentStorage).ConfigureAwait(false);
this.logger.LogInformation($"statemachine: trigger successfull (name={segments["name"]}, id={segments["id"]}, trigger={segments["trigger"]})");
contextStorage.Save(context);
httpContext.Response.StatusCode = (int)HttpStatusCode.OK;
}
else
{
this.logger.LogError($"statemachine: trigger invalid (name={segments["name"]}, id={segments["id"]}, trigger={segments["trigger"]})");
httpContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
}
}
catch (Exception ex)
{
this.logger.LogCritical(ex, $"statemachine: trigger failed (name={segments["name"]}, id={segments["id"]}, trigger={segments["trigger"]}) {ex.Message}");
httpContext.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
}
finally
{
this.logger.LogInformation($"statemachine: permitted triggers={string.Join("|", instance.PermittedTriggers)}");
contextStorage.Save(context);
}
return(true);
}
return(false);
}