From 2558a14d8ca7e1cbae5c082ecd0a02acf136b40e Mon Sep 17 00:00:00 2001
From: Maxim Lebedev <git@toby3d.me>
Date: Mon, 13 Nov 2023 08:13:56 +0600
Subject: [PATCH] :building_construction: Support mono and multilang sites

---
 main.go | 61 ++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 20 deletions(-)

diff --git a/main.go b/main.go
index 7f39afa..e83ef30 100644
--- a/main.go
+++ b/main.go
@@ -25,7 +25,6 @@ import (
 
 	"github.com/caarlos0/env/v10"
 	"golang.org/x/text/language"
-	"golang.org/x/text/message"
 
 	"source.toby3d.me/toby3d/home/internal/common"
 	"source.toby3d.me/toby3d/home/internal/domain"
@@ -81,26 +80,9 @@ func NewApp(ctx context.Context, config *domain.Config) (*App, error) {
 	pages := pagefsrepo.NewFileSystemPageRepository(contentDir)
 	pager := pageucase.NewPageUseCase(pages, resources)
 
-	matcher := language.NewMatcher(message.DefaultCatalog.Languages())
-
 	server := &http.Server{
 		Addr: config.AddrPort().String(),
 		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			head, tail := urlutil.ShiftPath(r.URL.Path)
-
-			if head == "" {
-				tags, _, err := language.ParseAcceptLanguage(r.Header.Get(common.HeaderAcceptLanguage))
-				if err != nil || len(tags) == 0 {
-					tags = append(tags, language.English)
-				}
-
-				lang, _, _ := matcher.Match(tags...)
-
-				http.Redirect(w, r, "/"+lang.String()+"/", http.StatusSeeOther)
-
-				return
-			}
-
 			// TODO(toby3d): use exists static use case or split that on static and resource modules?
 			// INFO(toby3d): any static file is public and unprotected by design, so it's safe to search it
 			// first before deep down to any page or it's resource which might be secured by middleware or
@@ -112,8 +94,7 @@ func NewApp(ctx context.Context, config *domain.Config) (*App, error) {
 				return
 			}
 
-			lang := domain.NewLanguage(head)
-			r.URL.Path = tail
+			lang := domain.LanguageUnd
 
 			s, err := siter.Do(r.Context(), lang)
 			if err != nil {
@@ -122,6 +103,46 @@ func NewApp(ctx context.Context, config *domain.Config) (*App, error) {
 				return
 			}
 
+			if s.IsMultiLingual() {
+				head, tail := urlutil.ShiftPath(r.URL.Path)
+
+				if head == "" {
+					supported := make([]language.Tag, len(s.Languages))
+					for i := range s.Languages {
+						supported[i] = language.Make(s.Languages[i].Lang())
+					}
+
+					if s.DefaultLanguage != domain.LanguageUnd {
+						supported = append(
+							[]language.Tag{language.Make(s.DefaultLanguage.Code())},
+							supported...,
+						)
+					}
+
+					requested, _, err := language.ParseAcceptLanguage(
+						r.Header.Get(common.HeaderAcceptLanguage))
+					if err != nil || len(requested) == 0 {
+						requested = append(requested, language.English)
+					}
+
+					matched, _, _ := language.NewMatcher(supported).Match(requested...)
+					lang = domain.NewLanguage(matched.String())
+
+					http.Redirect(w, r, "/"+lang.Lang()+"/", http.StatusSeeOther)
+
+					return
+				}
+
+				lang = domain.NewLanguage(head)
+				r.URL.Path = tail
+			}
+
+			if s, err = siter.Do(r.Context(), lang); err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+
+				return
+			}
+
 			p, err := pager.Do(r.Context(), lang, r.URL.Path)
 			if err != nil {
 				if !errors.Is(err, page.ErrNotExist) {