cleanup and simplify middleware implementations, refactor some other code

internal/net/http/middleware/middleware_builder.go

@@ -2,11 +2,9 @@ package middleware
 
 import (
 	"fmt"
-	"net/http"
 	"os"
 	"path"
 
-	"github.com/yusing/go-proxy/internal/common"
 	E "github.com/yusing/go-proxy/internal/error"
 	"gopkg.in/yaml.v3"
 )
@@ -56,7 +54,7 @@ func BuildMiddlewareFromChainRaw(name string, defs []map[string]any) (*Middlewar
 			continue
 		}
 		delete(def, "use")
-		m, err := base.WithOptionsClone(def)
+		m, err := base.New(def)
 		if err != nil {
 			chainErr.Add(err.Subjectf("%s[%d]", name, i))
 			continue
@@ -67,56 +65,5 @@ func BuildMiddlewareFromChainRaw(name string, defs []map[string]any) (*Middlewar
 	if chainErr.HasError() {
 		return nil, chainErr.Error()
 	}
-	return BuildMiddlewareFromChain(name, chain), nil
-}
-
-// TODO: check conflict or duplicates.
-func BuildMiddlewareFromChain(name string, chain []*Middleware) *Middleware {
-	m := &Middleware{name: name, children: chain}
-
-	var befores []*Middleware
-	var modResps []*Middleware
-
-	for _, comp := range chain {
-		if comp.before != nil {
-			befores = append(befores, comp)
-		}
-		if comp.modifyResponse != nil {
-			modResps = append(modResps, comp)
-		}
-		comp.parent = m
-	}
-
-	if len(befores) > 0 {
-		m.before = buildBefores(befores)
-	}
-	if len(modResps) > 0 {
-		m.modifyResponse = func(res *Response) error {
-			errs := E.NewBuilder("modify response errors")
-			for _, mr := range modResps {
-				if err := mr.modifyResponse(res); err != nil {
-					errs.Add(E.From(err).Subject(mr.name))
-				}
-			}
-			return errs.Error()
-		}
-	}
-
-	if common.IsDebug {
-		m.EnableTrace()
-		m.AddTracef("middleware created")
-	}
-	return m
-}
-
-func buildBefores(befores []*Middleware) BeforeFunc {
-	if len(befores) == 1 {
-		return befores[0].before
-	}
-	nextBefores := buildBefores(befores[1:])
-	return func(next http.HandlerFunc, w ResponseWriter, r *Request) {
-		befores[0].before(func(w ResponseWriter, r *Request) {
-			nextBefores(next, w, r)
-		}, w, r)
-	}
+	return NewMiddlewareChain(name, chain), nil
 }