add translationsi18n

4 files changed, 199 insertions, 31 deletions

diff --git a/cmd/site/html.go b/cmd/site/html.go
index f42b947..1037baf 100644
--- a/cmd/site/html.go
+++ b/cmd/site/html.go
@@ -19,29 +19,39 @@ func logTemplateTime(name string, from time.Time) {
 func (s *Site) renderTemplatePage(templateFname string, data interface{}) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		defer logTemplateTime(templateFname, time.Now())
-		s.tlock.RLock()
-		defer s.tlock.RUnlock()
 
-		var t *template.Template
-		var err error
-
-		if s.templates[templateFname] == nil {
-			t, err = template.ParseFiles("templates/base.html", "templates/"+templateFname)
+		getTranslation := func(group, key string, vals ...interface{}) string {
+			var lc locale
+			var ok bool
+			locale, err := GetPreferredLocale(r)
 			if err != nil {
-				w.WriteHeader(http.StatusInternalServerError)
-				ln.Error(context.Background(), err, ln.F{"action": "renderTemplatePage", "page": templateFname})
-				fmt.Fprintf(w, "error: %v", err)
+				ln.Error(r.Context(), err)
+				lc = s.t.locales["en"]
+				goto overwith
 			}
 
-			ln.Log(context.Background(), ln.F{"action": "loaded_new_template", "fname": templateFname})
+			lc, ok = s.t.Get(locale.Lang)
+			if !ok {
+				ln.Log(r.Context(), ln.F{"msg": "unknown language requested", "lang": locale.Lang, "header": r.Header.Get("Accept-Language")})
+				lc = s.t.locales["en"]
+				goto overwith
+			}
 
-			s.tlock.RUnlock()
-			s.tlock.Lock()
-			s.templates[templateFname] = t
-			s.tlock.Unlock()
-			s.tlock.RLock()
-		} else {
-			t = s.templates[templateFname]
+		overwith:
+			return lc.Value(group, key, vals...)
+		}
+		funcMap := template.FuncMap{
+			"trans": getTranslation,
+		}
+
+		var t *template.Template = template.New(templateFname).Funcs(funcMap)
+		var err error
+
+		t, err = t.ParseFiles("templates/base.html", "templates/"+templateFname)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			ln.Error(context.Background(), err, ln.F{"action": "renderTemplatePage", "page": templateFname})
+			fmt.Fprintf(w, "error: %v", err)
 		}
 
 		err = t.Execute(w, data)
diff --git a/cmd/site/i18n.go b/cmd/site/i18n.go
new file mode 100644
index 0000000..6c8fc92
--- /dev/null
+++ b/cmd/site/i18n.go
@@ -0,0 +1,46 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type locale map[string]map[string]string
+
+func (l locale) Value(group, key string, args ...interface{}) string {
+	sg, ok := l[group]
+	if !ok {
+		return "no group " + group
+	}
+
+	result, ok := sg[key]
+	if !ok {
+		return fmt.Sprintf("in group %s, no key %s", group, key)
+	}
+
+	return fmt.Sprintf(result, args...)
+}
+
+type translations struct {
+	locales map[string]locale
+}
+
+func (t *translations) LoadLocale(name string, r io.Reader) error {
+	l := locale{}
+	d := json.NewDecoder(r)
+	err := d.Decode(&l)
+	if err == nil {
+		t.locales[name] = l
+	}
+	return err
+}
+
+func (t *translations) Get(name string) (locale, bool) {
+	l, ok := t.locales[name]
+	if !ok {
+		return nil, false
+	}
+
+	return l, ok
+}
diff --git a/cmd/site/locale.go b/cmd/site/locale.go
new file mode 100644
index 0000000..a65034a
--- /dev/null
+++ b/cmd/site/locale.go
@@ -0,0 +1,97 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// Locale is locale value from the Accept-Language header in request
+type Locale struct {
+	Lang, Country string
+	Qual          float64
+}
+
+// Name returns the locale value in 'lang' or 'lang_country' format
+// eg: de_DE, en_US, gb
+func (l *Locale) Name() string {
+	if len(l.Country) > 0 {
+		return l.Lang + "_" + l.Country
+	}
+	return l.Lang
+}
+
+// ParseLocale creates a Locale from a locale string
+func ParseLocale(locale string) Locale {
+	locsplt := strings.Split(locale, "_")
+	resp := Locale{}
+	resp.Lang = locsplt[0]
+	if len(locsplt) > 1 {
+		resp.Country = locsplt[1]
+	}
+	return resp
+}
+
+const (
+	acceptLanguage = "Accept-Language"
+)
+
+func supportedLocales(alstr string) []Locale {
+	locales := make([]Locale, 0)
+	alstr = strings.Replace(alstr, " ", "", -1)
+	if alstr == "" {
+		return locales
+	}
+	al := strings.Split(alstr, ",")
+	for _, lstr := range al {
+		locales = append(locales, Locale{
+			Lang:    parseLang(lstr),
+			Country: parseCountry(lstr),
+			Qual:    parseQual(lstr),
+		})
+	}
+	return locales
+}
+
+// GetLocales returns supported locales for the given requet
+func GetLocales(r *http.Request) []Locale {
+	return supportedLocales(r.Header.Get(acceptLanguage))
+}
+
+// GetPreferredLocale return preferred locale for the given reuqest
+// returns error if there is no preferred locale
+func GetPreferredLocale(r *http.Request) (*Locale, error) {
+	locales := GetLocales(r)
+	if len(locales) == 0 {
+		return &Locale{}, errors.New("No locale found")
+	}
+	return &locales[0], nil
+}
+
+func parseLang(val string) string {
+	locale := strings.Split(val, ";")[0]
+	lang := strings.Split(locale, "-")[0]
+	return lang
+}
+
+func parseCountry(val string) string {
+	locale := strings.Split(val, ";")[0]
+	spl := strings.Split(locale, "-")
+	if len(spl) > 1 {
+		return spl[1]
+	}
+	return ""
+}
+
+func parseQual(val string) float64 {
+	spl := strings.Split(val, ";")
+	if len(spl) > 1 {
+		qual, err := strconv.ParseFloat(strings.Split(spl[1], "=")[1], 64)
+		if err != nil {
+			return 1
+		}
+		return qual
+	}
+	return 1
+}
diff --git a/cmd/site/main.go b/cmd/site/main.go
index e9b4d21..83cbeb2 100644
--- a/cmd/site/main.go
+++ b/cmd/site/main.go
@@ -9,7 +9,6 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/Xe/jsonfeed"
@@ -46,10 +45,8 @@ type Site struct {
 
 	mux *http.ServeMux
 
-	templates map[string]*template.Template
-	tlock     sync.RWMutex
-
 	segment analytics.Client
+	t       *translations
 }
 
 func (s *Site) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -78,31 +75,49 @@ func Build() (*Site, error) {
 		Date  string
 	}
 
+	t := &translations{
+		locales: map[string]locale{},
+	}
+
+	for _, lang := range []string{"en", "tp"} {
+		fin, err := os.Open(filepath.Join("locales", lang+".json"))
+		if err != nil {
+			return nil, err
+		}
+		defer fin.Close()
+
+		err = t.LoadLocale(lang, fin)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	l := t.locales["en"]
+
 	s := &Site{
 		rssFeed: &feeds.Feed{
-			Title:       "Christine Dodrill's Blog",
+			Title:       l.Value("blog", "title"),
 			Link:        &feeds.Link{Href: "https://christine.website/blog"},
-			Description: "My blog posts and rants about various technology things.",
+			Description: l.Value("blog", "description"),
 			Author:      &feeds.Author{Name: "Christine Dodrill", Email: "me@christine.website"},
 			Created:     bootTime,
-			Copyright:   "This work is copyright Christine Dodrill. My viewpoints are my own and not the view of any employer past, current or future.",
+			Copyright:   l.Value("meta", "rss_copyright"),
 		},
 		jsonFeed: &jsonfeed.Feed{
 			Version:     jsonfeed.CurrentVersion,
-			Title:       "Christine Dodrill's Blog",
+			Title:       l.Value("blog", "title"),
 			HomePageURL: "https://christine.website",
 			FeedURL:     "https://christine.website/blog.json",
-			Description: "My blog posts and rants about various technology things.",
-			UserComment: "This is a JSON feed of my blogposts. For more information read: https://jsonfeed.org/version/1",
+			Description: l.Value("blog", "description"),
+			UserComment: l.Value("meta", "json_feed"),
 			Icon:        icon,
 			Favicon:     icon,
 			Author: jsonfeed.Author{
-				Name:   "Christine Dodrill",
+				Name:   l.Value("header", "name"),
 				Avatar: icon,
 			},
 		},
-		mux:       http.NewServeMux(),
-		templates: map[string]*template.Template{},
+		mux: http.NewServeMux(),
 	}
 
 	if wk := os.Getenv("SEGMENT_WRITE_KEY"); wk != "" {