From 715445ee5d97017472776b0cd680818eb8f1325d Mon Sep 17 00:00:00 2001
From: Maxim Lebedev <git@toby3d.me>
Date: Sat, 27 Jan 2024 13:47:23 +0600
Subject: [PATCH] :recycle: Refactored custom headers support into middleware

---
 internal/cmd/home/home.go     | 37 +++----------------
 internal/domain/headers.go    | 17 +++++++++
 internal/domain/server.go     |  4 +--
 internal/middleware/header.go | 67 +++++++++++++++++++++++++++++++++++
 4 files changed, 90 insertions(+), 35 deletions(-)
 create mode 100644 internal/domain/headers.go
 create mode 100644 internal/middleware/header.go

diff --git a/internal/cmd/home/home.go b/internal/cmd/home/home.go
index 98ba2c5..e7bc90b 100644
--- a/internal/cmd/home/home.go
+++ b/internal/cmd/home/home.go
@@ -77,23 +77,6 @@ func NewApp(logger *log.Logger, config *domain.Config) (*App, error) {
 			return
 		}
 
-		siteServer, err := serverer.Do(r.Context(), *s)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-
-			return
-		}
-
-		for i := range siteServer.Headers {
-			if !siteServer.Headers[i].IsMatched(r.URL.Path) {
-				continue
-			}
-
-			for name, value := range siteServer.Headers[i].Values {
-				w.Header().Add(name, value)
-			}
-		}
-
 		if s.IsMultiLingual() {
 			head, tail := urlutil.ShiftPath(r.URL.Path)
 			if head == "" {
@@ -132,22 +115,6 @@ func NewApp(logger *log.Logger, config *domain.Config) (*App, error) {
 			return
 		}
 
-		if siteServer, err = serverer.Do(r.Context(), *s); err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-
-			return
-		}
-
-		for i := range siteServer.Headers {
-			if !siteServer.Headers[i].IsMatched(r.URL.Path) {
-				continue
-			}
-
-			for name, value := range siteServer.Headers[i].Values {
-				w.Header().Add(name, value)
-			}
-		}
-
 		p, err := pager.Do(r.Context(), lang, r.URL.Path)
 		if err != nil {
 			if !errors.Is(err, page.ErrNotExist) {
@@ -216,6 +183,10 @@ func NewApp(logger *log.Logger, config *domain.Config) (*App, error) {
 			Siter:    siter,
 			Serverer: serverer,
 		}),
+		middleware.Header(middleware.HeaderConfig{
+			Siter:    siter,
+			Serverer: serverer,
+		}),
 	}
 
 	return &App{server: &http.Server{
diff --git a/internal/domain/headers.go b/internal/domain/headers.go
new file mode 100644
index 0000000..096c7aa
--- /dev/null
+++ b/internal/domain/headers.go
@@ -0,0 +1,17 @@
+package domain
+
+type Headers []Header
+
+func (h Headers) Match(p string) []Header {
+	result := make(Headers, 0, len(h))
+
+	for i := range h {
+		if !h[i].IsMatched(p) {
+			continue
+		}
+
+		result = append(result, h[i])
+	}
+
+	return result
+}
diff --git a/internal/domain/server.go b/internal/domain/server.go
index d10004d..e997ff8 100644
--- a/internal/domain/server.go
+++ b/internal/domain/server.go
@@ -1,13 +1,13 @@
 package domain
 
 type Server struct {
-	Headers   []Header
+	Headers   Headers
 	Redirects Redirects
 }
 
 func NewServer() *Server {
 	return &Server{
-		Headers:   make([]Header, 0),
+		Headers:   make(Headers, 0),
 		Redirects: make(Redirects, 0),
 	}
 }
diff --git a/internal/middleware/header.go b/internal/middleware/header.go
new file mode 100644
index 0000000..fd7ba57
--- /dev/null
+++ b/internal/middleware/header.go
@@ -0,0 +1,67 @@
+package middleware
+
+import (
+	"net/http"
+
+	"source.toby3d.me/toby3d/home/internal/domain"
+	"source.toby3d.me/toby3d/home/internal/server"
+	"source.toby3d.me/toby3d/home/internal/site"
+	"source.toby3d.me/toby3d/home/internal/urlutil"
+)
+
+type HeaderConfig struct {
+	Skipper  Skipper
+	Siter    site.UseCase
+	Serverer server.UseCase
+}
+
+func Header(config HeaderConfig) Interceptor {
+	if config.Skipper == nil {
+		config.Skipper = DefaultSkipper
+	}
+
+	if config.Siter == nil {
+		panic("middleware: header: Siter is nil")
+	}
+
+	if config.Serverer == nil {
+		panic("middleware: header: Serverer is nil")
+	}
+
+	return func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+		if config.Skipper(r) {
+			next(w, r)
+
+			return
+		}
+
+		lang, path := domain.LanguageUnd, r.URL.Path
+		if head, tail := urlutil.ShiftPath(r.URL.Path); head != "" {
+			if lang = domain.NewLanguage(head); lang != domain.LanguageUnd {
+				path = tail
+			}
+		}
+
+		site, err := config.Siter.Do(r.Context(), lang)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+
+		server, err := config.Serverer.Do(r.Context(), *site)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+
+		for _, header := range server.Headers.Match(path) {
+			for k, v := range header.Values {
+				w.Header().Add(k, v)
+			}
+		}
+
+		next(w, r)
+	}
+}