Add implementation of PRESTO middleware. (#73)

* Add implementation of PRESTO middleware and tests for it.

* Address review comments.

* Recover log statements which still has sense.

presto/agent.nim

@@ -9,7 +9,7 @@
 
 {.push raises: [].}
 
-import strutils
+import std/strutils
 
 const
   PrestoName* = "nim-presto"

presto/client.nim

@@ -13,7 +13,7 @@ import std/[macros, options, uri, sequtils]
 import chronos, chronos/apps/http/[httpcommon, httptable, httpclient]
 import chronicles except error
 import httputils, stew/base10
-import segpath, common, macrocommon, agent
+import "."/[segpath, common, macrocommon, agent]
 export chronos, httpclient, httptable, httpcommon, options, agent, httputils
 export SocketFlags
 

presto/middleware.nim

@@ -0,0 +1,33 @@
+#
+#         REST API framework implementation
+#             (c) Copyright 2021-Present
+#         Status Research & Development GmbH
+#
+#              Licensed under either of
+#  Apache License, version 2.0, (LICENSE-APACHEv2)
+#              MIT license (LICENSE-MIT)
+
+{.push raises: [].}
+
+import chronos, chronos/apps/http/httpserver
+import "."/[route, servercommon, serverprivate]
+export httpserver, servercommon, serverprivate
+
+proc new*(
+    t: typedesc[RestServerMiddlewareRef],
+    router: RestRouter,
+    errorHandler: RestRequestErrorHandler = nil): HttpServerMiddlewareRef =
+
+  proc middlewareCallback(
+      middleware: HttpServerMiddlewareRef,
+      request: RequestFence,
+      handler: HttpProcessCallback2): Future[HttpResponseRef] {.
+      async: (raises: [CancelledError], raw: true).} =
+    let restmw = RestServerMiddlewareRef(middleware)
+    restmw.nextHandler = handler
+    processRestRequest[RestServerMiddlewareRef](restmw, request)
+
+  let middleware =
+    RestServerMiddlewareRef(router: router, errorHandler: errorHandler,
+                            handler: middlewareCallback)
+  HttpServerMiddlewareRef(middleware)

presto/route.nim

@@ -13,9 +13,7 @@ import std/[macros, options]
 import chronos, chronos/apps/http/[httpcommon, httptable, httpserver]
 import httputils
 import stew/bitops2
-import btrees
-import common, segpath, macrocommon
-
+import "."/[btrees, common, segpath, macrocommon]
 export chronos, options, common, httpcommon, httptable, httpserver
 
 when defined(metrics):

presto/secureserver.nim

@@ -13,7 +13,7 @@ import std/options
 import chronos, chronos/apps/http/shttpserver
 import chronicles
 import stew/results
-import route, common, segpath, servercommon, serverprivate, agent
+import "."/[route, common, segpath, servercommon, serverprivate, agent]
 export options, chronos, shttpserver, servercommon, chronicles, agent
 
 type

presto/segpath.nim

@@ -12,7 +12,7 @@
 import std/[uri, strutils]
 import stew/[bitops2, results]
 import chronos/apps
-import common
+import "."/common
 export common, apps
 
 type

presto/server.nim

@@ -13,7 +13,7 @@ import std/[options, json, strutils]
 import chronos, chronos/apps/http/httpserver
 import chronicles
 import stew/results
-import route, common, segpath, servercommon, serverprivate, agent
+import "."/[route, common, segpath, servercommon, serverprivate, agent]
 export options, chronos, httpserver, servercommon, chronicles, agent
 
 type

presto/servercommon.nim

@@ -12,8 +12,8 @@
 import std/options
 import chronos, chronos/apps/http/httpserver
 import chronicles
-import common
-export chronicles, options
+import "."/[common, route]
+export chronicles, options, httpserver
 
 chronicles.formatIt(HttpTable):
   var res = newSeq[string]()
@@ -45,3 +45,8 @@ type
     error: RestRequestError,
     request: HttpRequestRef): Future[HttpResponseRef] {.
       async: (raises: [CancelledError]).}
+
+  RestServerMiddlewareRef* = ref object of HttpServerMiddlewareRef
+    router*: RestRouter
+    errorHandler*: RestRequestErrorHandler
+    nextHandler*: HttpProcessCallback2