public static async Task <IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", "put", "patch", "delete", Route = "fhirproxy/{res?}/{id?}/{hist?}/{vid?}")] HttpRequest req,
ILogger log, ClaimsPrincipal principal, string res, string id, string hist, string vid)
{
if (!Utils.isServerAccessAuthorized(req))
{
return(new ContentResult()
{
Content = Utils.genOOErrResponse("auth-access", req.Headers[Utils.AUTH_STATUS_MSG_HEADER].First()), StatusCode = (int)System.Net.HttpStatusCode.Unauthorized, ContentType = "application/json"
});
}
//Load Request Body
string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
//Call Configured Pre-Processor Modules
ProxyProcessResult prerslt = ProxyProcessManager.RunPreProcessors(requestBody, req, log, principal, res, id, hist, vid);
if (!prerslt.Continue)
{
//Pre-Processor didn't like something or exception was called so return
FHIRResponse preresp = prerslt.Response;
if (preresp == null)
{
string errmsg = (string.IsNullOrEmpty(prerslt.ErrorMsg) ? "No message" : prerslt.ErrorMsg);
FHIRResponse fer = new FHIRResponse();
fer.StatusCode = System.Net.HttpStatusCode.InternalServerError;
fer.Content = Utils.genOOErrResponse("internalerror", $"A Proxy Pre-Processor halted execution for an unknown reason. Check logs. Message is {errmsg}");
return(generateJSONResult(fer));
}
return(generateJSONResult(preresp));
}
log.LogInformation("Calling FHIR Server...");
//Proxy the call to the FHIR Server
FHIRResponse serverresponse = FHIRClientFactory.callFHIRServer(prerslt.Request, req, log, res, id, hist, vid);
//Call Configured Post-Processor Modules
ProxyProcessResult postrslt = ProxyProcessManager.RunPostProcessors(serverresponse, req, log, principal, res, id, hist, vid);
if (postrslt.Response == null)
{
string errmsg = (string.IsNullOrEmpty(postrslt.ErrorMsg) ? "No message" : postrslt.ErrorMsg);
postrslt.Response = new FHIRResponse();
postrslt.Response.StatusCode = System.Net.HttpStatusCode.InternalServerError;
postrslt.Response.Content = Utils.genOOErrResponse("internalerror", $"A Proxy Post-Processor halted execution for an unknown reason. Check logs. Message is {errmsg}");
}
//Reverse Proxy Response
postrslt.Response = Utils.reverseProxyResponse(postrslt.Response, req, res);
//return ActionResult
if (postrslt.Response.StatusCode == HttpStatusCode.NoContent)
{
return(null);
}
return(generateJSONResult(postrslt.Response));
}
public static async Task <ProxyProcessResult> RunPostProcessors(FHIRResponse response, HttpRequest req, ILogger log, ClaimsPrincipal principal, string res, string id, string hist, string vid)
{
ProxyProcessResult rslt = new ProxyProcessResult();
//Default to server response
rslt.Response = response;
//Get Configured PostProcessors
string pps = System.Environment.GetEnvironmentVariable("POST_PROCESSOR_TYPES");
if (string.IsNullOrEmpty(pps))
{
return(rslt);
}
string[] types = pps.Split(",");
foreach (string cls in types)
{
try
{
string ic = cls;
DateTimeOffset os = DateTimeOffset.Now;
if (cls.Contains(":"))
{
string[] x = cls.Split(":");
ic = x[0];
int exp = DEF_EXP_MINS;
int.TryParse(x[1], out exp);
os = os.AddMinutes(exp);
}
else
{
os = os.AddMinutes(DEF_EXP_MINS);
}
IProxyPostProcess ip = (IProxyPostProcess)cache.GetOrAdd(cls, () => GetInstance(ic), os);
log.LogInformation($"ProxyProcessManager is running {cls} post-process...");
rslt = await ip.Process(rslt.Response, req, log, principal, res, id, hist, vid);
if (!rslt.Continue)
{
return(rslt);
}
}
catch (InvalidCastException ece)
{
log.LogWarning($"{cls} does not seem to implement IProxyPostProcess and will not be executed:{ece.Message}");
}
catch (Exception e)
{
log.LogError(e, $"Error trying to instanciate/execute post-process {cls}: {e.Message}");
FHIRResponse fhirresp = new FHIRResponse();
fhirresp.StatusCode = System.Net.HttpStatusCode.InternalServerError;
fhirresp.Content = Utils.genOOErrResponse("internalerror", $"Error trying to instanciate/execute post-process {cls}: {e.Message}");
return(new ProxyProcessResult(false, "internalerror", "", fhirresp));
}
}
return(rslt);
}
