From 715bb6ad842d3e2c326c7eb3cf469373b4699d48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20Tikvi=C4=87?= <marko.tikvic@to-net.rs>
Date: Tue, 17 Jul 2018 11:29:11 +0200
Subject: [PATCH] parsing of accepted languages header

---
 localization.go | 82 +++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 57 insertions(+), 25 deletions(-)

diff --git a/localization.go b/localization.go
index 4cf0df6..78f6955 100644
--- a/localization.go
+++ b/localization.go
@@ -2,10 +2,10 @@ package webutility
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"path"
+	"strconv"
 	"strings"
 	"sync"
 )
@@ -17,10 +17,12 @@ type Dictionary struct {
 	defaultLocale string
 }
 
-func NewDictionary() *Dictionary {
-	return &Dictionary{
+func NewDictionary(def string) *Dictionary {
+	d := Dictionary{
 		locales: map[string]map[string]string{},
 	}
+	d.defaultLocale = def
+	return &d
 }
 
 func (d *Dictionary) AddTranslations(directory string) error {
@@ -60,13 +62,27 @@ func (d *Dictionary) AddTranslations(directory string) error {
 		d.supported = append(d.supported, loc)
 	}
 
+	if d.defaultLocale == "" {
+		if len(d.supported) > 0 {
+			d.defaultLocale = d.supported[0]
+		}
+	}
+
 	return nil
 }
 
-func (d *Dictionary) GetBestMatchLocale(acceptedLanguages string) (best string) {
-	accepted := d.parseAcceptedLanguageHeader(acceptedLanguages)
-	best = accepted[0]
-	return
+func (d *Dictionary) GetBestMatchLocale(langs string) (best string) {
+	accepted := d.parseAcceptedLanguages(langs)
+
+	for i, _ := range accepted {
+		for j, _ := range d.supported {
+			if accepted[i].Code == d.supported[j] {
+				return d.supported[j]
+			}
+		}
+	}
+
+	return d.defaultLocale
 }
 
 func (d *Dictionary) Translate(loc, key string) string {
@@ -82,30 +98,46 @@ func (d *Dictionary) hasLocale(loc string) bool {
 	return false
 }
 
-func (d *Dictionary) setDefaultLocale(loc string) error {
-	if !d.hasLocale(loc) {
-		return errors.New("dictionary does not contain translations for " + loc)
-	}
-	d.defaultLocale = loc
-	return nil
+type LangWeight struct {
+	Code   string
+	Weight float64
 }
 
-func (d *Dictionary) getDefaultLocale() string {
-	return d.defaultLocale
-}
-
-func (d *Dictionary) parseAcceptedLanguageHeader(acceptedLanguages string) (langs []string) {
-	if acceptedLanguages == "" {
-		langs = append(langs, d.getDefaultLocale())
-		return
+func (d *Dictionary) parseAcceptedLanguages(accepted string) (langs []LangWeight) {
+	if accepted == "" {
+		langs = append(langs, LangWeight{Code: d.defaultLocale, Weight: 1.0})
+		return langs
 	}
 
-	parts := strings.Split(acceptedLanguages, ",")
-	for _, p := range parts {
-		langs = append(langs, p)
+	parts := strings.Split(accepted, ",")
+	for i, _ := range parts {
+		parts[i] = strings.Trim(parts[i], "")
+
+		var code string = ""
+		var weight float64 = 0.0
+
+		cw := strings.Split(parts[i], ";")
+		paramCount := len(cw)
+
+		if paramCount == 1 {
+			// default weight of 1
+			code = cw[0]
+			weight = 1.0
+		} else if paramCount == 2 {
+			// parse weight
+			code = cw[0]
+			weight, _ = strconv.ParseFloat(cw[1], 64)
+
+		}
+
+		fmt.Println(parts[i], code, weight)
+
+		langs = append(langs, LangWeight{Code: code, Weight: weight})
 	}
 
-	return
+	// TODO(marko): sort langs by weights
+
+	return langs
 }
 
 func stripFileExtension(full string) (stripped string) {
-- 
1.8.1.2