From f303f76f01fe1994fc4294464bc41e7c7c5b168e Mon Sep 17 00:00:00 2001
From: tdakkota <tanc13@yandex.ru>
Date: Tue, 13 Sep 2022 14:31:44 +0300
Subject: [PATCH] feat(middleware): add match wrappers

---
 middleware/match.go           | 79 +++++++++++++++++++++++++++++++++++
 middleware/middleware.go      |  8 ++--
 middleware/middleware_test.go |  5 +--
 3 files changed, 85 insertions(+), 7 deletions(-)
 create mode 100644 middleware/match.go

diff --git a/middleware/match.go b/middleware/match.go
new file mode 100644
index 000000000..c12960ebd
--- /dev/null
+++ b/middleware/match.go
@@ -0,0 +1,79 @@
+package middleware
+
+import (
+	"regexp"
+
+	"github.com/ogen-go/ogen/internal/xmaps"
+)
+
+// OperationID calls the next middleware if request operation ID matches the given operationID.
+func OperationID(m Middleware, operationID ...string) Middleware {
+	switch len(operationID) {
+	case 0:
+		return justCallNext
+	case 1:
+		val := operationID[0]
+		return func(req Request, next Next) (Response, error) {
+			if req.OperationID == val {
+				return m(req, next)
+			}
+			return next(req)
+		}
+	default:
+		set := xmaps.BuildSet(operationID...)
+		return func(req Request, next Next) (Response, error) {
+			if _, ok := set[req.OperationID]; ok {
+				return m(req, next)
+			}
+			return next(req)
+		}
+	}
+}
+
+// OperationName calls the next middleware if request operation name matches the given operationName.
+func OperationName(m Middleware, operationName ...string) Middleware {
+	switch len(operationName) {
+	case 0:
+		return justCallNext
+	case 1:
+		val := operationName[0]
+		return func(req Request, next Next) (Response, error) {
+			if req.OperationName == val {
+				return m(req, next)
+			}
+			return next(req)
+		}
+	default:
+		set := xmaps.BuildSet(operationName...)
+		return func(req Request, next Next) (Response, error) {
+			if _, ok := set[req.OperationName]; ok {
+				return m(req, next)
+			}
+			return next(req)
+		}
+	}
+}
+
+// PathRegex calls the next middleware if request path matches the given regex.
+func PathRegex(re *regexp.Regexp, m Middleware) Middleware {
+	if re == nil {
+		return justCallNext
+	}
+
+	return func(req Request, next Next) (Response, error) {
+		if re.MatchString(req.Raw.URL.Path) {
+			return m(req, next)
+		}
+		return next(req)
+	}
+}
+
+// BodyType calls the next middleware if request body type matches the given type.
+func BodyType[T any](m Middleware) Middleware {
+	return func(req Request, next Next) (Response, error) {
+		if _, ok := req.Body.(T); ok {
+			return m(req, next)
+		}
+		return next(req)
+	}
+}
diff --git a/middleware/middleware.go b/middleware/middleware.go
index ef6f90403..162b936c7 100644
--- a/middleware/middleware.go
+++ b/middleware/middleware.go
@@ -35,12 +35,14 @@ type (
 	Middleware func(req Request, next Next) (Response, error)
 )
 
+func justCallNext(req Request, next Next) (Response, error) {
+	return next(req)
+}
+
 // ChainMiddlewares chains middlewares into a single middleware, which will be executed in the order they are passed.
 func ChainMiddlewares(m ...Middleware) Middleware {
 	if len(m) == 0 {
-		return func(req Request, next Next) (Response, error) {
-			return next(req)
-		}
+		return justCallNext
 	}
 	tail := ChainMiddlewares(m[1:]...)
 	return func(req Request, next Next) (Response, error) {
diff --git a/middleware/middleware_test.go b/middleware/middleware_test.go
index e4dee0dda..b3a252bef 100644
--- a/middleware/middleware_test.go
+++ b/middleware/middleware_test.go
@@ -58,14 +58,11 @@ func TestChainMiddlewares(t *testing.T) {
 
 func BenchmarkChainMiddlewares(b *testing.B) {
 	const N = 20
-	noop := func(req Request, next Next) (Response, error) {
-		return next(req)
-	}
 
 	var (
 		chain = ChainMiddlewares(func() (r []Middleware) {
 			for i := 0; i < N; i++ {
-				r = append(r, noop)
+				r = append(r, justCallNext)
 			}
 			return r
 		}()...)