initial commit. Cloned timetracker repository

app/delivery/middleware/language.go

@@ -0,0 +1,114 @@
+package middleware
+
+import (
+	"strconv"
+	"strings"
+
+	"git.ma-al.com/goc_marek/timetracker/app/service/langs"
+	"github.com/gofiber/fiber/v3"
+)
+
+// LanguageMiddleware discovers client's language and stores it in context
+// Priority: Query param > Cookie > Accept-Language header > Default language
+func LanguageMiddleware() fiber.Handler {
+	langService := langs.LangSrv
+
+	return func(c fiber.Ctx) error {
+		var langID uint
+
+		// 1. Check query parameter
+		langIDStr := c.Query("lang_id", "")
+		if langIDStr != "" {
+			if id, err := strconv.ParseUint(langIDStr, 10, 32); err == nil {
+				langID = uint(id)
+				if langID > 0 {
+					lang, err := langService.GetLanguageById(langID)
+					if err == nil {
+						c.Locals("langID", langID)
+						c.Locals("lang", lang)
+						return c.Next()
+					}
+				}
+			}
+		}
+
+		// 2. Check cookie
+		cookieLang := c.Cookies("lang_id", "")
+		if cookieLang != "" {
+			if id, err := strconv.ParseUint(cookieLang, 10, 32); err == nil {
+				langID = uint(id)
+				if langID > 0 {
+					lang, err := langService.GetLanguageById(langID)
+					if err == nil {
+						c.Locals("langID", langID)
+						c.Locals("lang", lang)
+						return c.Next()
+					}
+				}
+			}
+		}
+
+		// 3. Check Accept-Language header
+		acceptLang := c.Get("Accept-Language", "")
+		if acceptLang != "" {
+			// Parse the Accept-Language header (e.g., "en-US,en;q=0.9,pl;q=0.8")
+			isoCode := parseAcceptLanguage(acceptLang)
+			if isoCode != "" {
+				lang, err := langService.GetLanguageByISOCode(isoCode)
+				if err == nil && lang != nil {
+					langID = uint(lang.ID)
+					c.Locals("langID", langID)
+					c.Locals("lang", lang)
+					return c.Next()
+				}
+			}
+		}
+
+		// 4. Fall back to default language
+		defaultLang, err := langService.GetDefaultLanguage()
+		if err == nil && defaultLang != nil {
+			langID = uint(defaultLang.ID)
+			c.Locals("langID", langID)
+			c.Locals("lang", defaultLang)
+		}
+
+		return c.Next()
+	}
+}
+
+// parseAcceptLanguage extracts the primary language ISO code from Accept-Language header
+func parseAcceptLanguage(header string) string {
+	// Split by comma
+	parts := strings.Split(header, ",")
+	if len(parts) == 0 {
+		return ""
+	}
+
+	// Get the first part (highest priority)
+	first := strings.TrimSpace(parts[0])
+	if first == "" {
+		return ""
+	}
+
+	// Remove any quality value (e.g., ";q=0.9")
+	if idx := strings.Index(first, ";"); idx != -1 {
+		first = strings.TrimSpace(first[:idx])
+	}
+
+	// Handle cases like "en-US" or "en"
+	// Return the primary language code (first part before dash)
+	if idx := strings.Index(first, "-"); idx != -1 {
+		return strings.ToLower(first[:idx])
+	}
+
+	return strings.ToLower(first)
+}
+
+// GetLanguageID extracts language ID from context
+func GetLanguageID(c fiber.Ctx) uint {
+	langID, ok := c.Locals("langID").(uint)
+	if !ok {
+		return 0
+	}
+	return langID
+}