Switch from net/http to gin-gonic web framework

- Added gin-gonic v1.10.0 dependency
- Refactored router.go: clean route groups with middleware chains
- Refactored all handlers to use gin.Context instead of http.ResponseWriter/*http.Request
- Simplified response helpers (JSON, Error, Success, Created, NoContent)
- Clean auth middleware using Gin's c.Set() for context
- Cleaner route definitions with path parameters (e.g., /domains/:name/users/:id)
- Admin routes moved to /api/admin group with RequireAdmin middleware

backend/internal/api/handlers/aliases.go

@@ -1,11 +1,10 @@
 package handlers
 
 import (
-	"encoding/json"
 	"net/http"
 	"strconv"
-	"strings"
 
+	"github.com/gin-gonic/gin"
 	"github.com/imc-vibe/backend/internal/db"
 )
 
@@ -18,143 +17,115 @@ func NewAliasHandler(database *db.DB) *AliasHandler {
 }
 
 type CreateAliasRequest struct {
-	Source      string `json:"source"`
-	Destination string `json:"destination"`
+	Source      string `json:"source" binding:"required"`
+	Destination string `json:"destination" binding:"required"`
 }
 
-func (h *AliasHandler) List(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodGet {
-		Error(w, http.StatusMethodNotAllowed, "method not allowed")
-		return
-	}
-
-	domainName := extractDomainNameFromPath(r.URL.Path)
+func (h *AliasHandler) List(c *gin.Context) {
+	domainName := c.Param("name")
 	if domainName == "" {
-		Error(w, http.StatusBadRequest, "domain name required")
+		Error(c, http.StatusBadRequest, "domain name required")
 		return
 	}
 
-	authCtx := GetAuthContext(r)
+	authCtx := GetAuthContext(c)
 	if authCtx == nil {
-		Error(w, http.StatusUnauthorized, "authentication required")
+		Error(c, http.StatusUnauthorized, "authentication required")
 		return
 	}
 
 	canAccess, _ := h.db.CanAccessDomain(authCtx.UserID, domainName, authCtx.IsAdmin())
 	if !canAccess {
-		Error(w, http.StatusForbidden, "access denied")
+		Error(c, http.StatusForbidden, "access denied")
 		return
 	}
 
 	domain, err := h.db.GetDomainByName(domainName)
 	if err != nil {
-		Error(w, http.StatusNotFound, "domain not found")
+		Error(c, http.StatusNotFound, "domain not found")
 		return
 	}
 
 	aliases, err := h.db.GetAliasesByDomain(domain.ID)
 	if err != nil {
-		Error(w, http.StatusInternalServerError, "database error")
+		Error(c, http.StatusInternalServerError, "database error")
 		return
 	}
 
-	Success(w, aliases)
+	Success(c, aliases)
 }
 
-func (h *AliasHandler) Create(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodPost {
-		Error(w, http.StatusMethodNotAllowed, "method not allowed")
-		return
-	}
-
-	domainName := extractDomainNameFromPath(r.URL.Path)
+func (h *AliasHandler) Create(c *gin.Context) {
+	domainName := c.Param("name")
 	if domainName == "" {
-		Error(w, http.StatusBadRequest, "domain name required")
+		Error(c, http.StatusBadRequest, "domain name required")
 		return
 	}
 
-	authCtx := GetAuthContext(r)
+	authCtx := GetAuthContext(c)
 	if authCtx == nil {
-		Error(w, http.StatusUnauthorized, "authentication required")
+		Error(c, http.StatusUnauthorized, "authentication required")
 		return
 	}
 
 	canAccess, _ := h.db.CanAccessDomain(authCtx.UserID, domainName, authCtx.IsAdmin())
 	if !canAccess {
-		Error(w, http.StatusForbidden, "access denied")
+		Error(c, http.StatusForbidden, "access denied")
 		return
 	}
 
 	domain, err := h.db.GetDomainByName(domainName)
 	if err != nil {
-		Error(w, http.StatusNotFound, "domain not found")
+		Error(c, http.StatusNotFound, "domain not found")
 		return
 	}
 
 	var req CreateAliasRequest
-	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
-		Error(w, http.StatusBadRequest, "invalid request body")
-		return
-	}
-
-	if req.Source == "" || req.Destination == "" {
-		Error(w, http.StatusBadRequest, "source and destination required")
+	if err := c.ShouldBindJSON(&req); err != nil {
+		Error(c, http.StatusBadRequest, "invalid request body")
 		return
 	}
 
 	alias, err := h.db.CreateAliasInDomain(req.Source, req.Destination, domain.ID)
 	if err != nil {
-		Error(w, http.StatusInternalServerError, "failed to create alias")
+		Error(c, http.StatusInternalServerError, "failed to create alias")
 		return
 	}
 
-	Created(w, alias)
+	Created(c, alias)
 }
 
-func (h *AliasHandler) Delete(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodDelete {
-		Error(w, http.StatusMethodNotAllowed, "method not allowed")
-		return
-	}
-
-	pathParts := strings.Split(r.URL.Path, "/")
-	var domainName, idStr string
-	for i, part := range pathParts {
-		if part == "domains" && i+1 < len(pathParts) {
-			domainName = pathParts[i+1]
-		}
-		if part == "aliases" && i+1 < len(pathParts) {
-			idStr = pathParts[i+1]
-		}
-	}
+func (h *AliasHandler) Delete(c *gin.Context) {
+	domainName := c.Param("name")
+	idStr := c.Param("id")
 
 	if domainName == "" || idStr == "" {
-		Error(w, http.StatusBadRequest, "invalid path")
+		Error(c, http.StatusBadRequest, "domain name and alias id required")
 		return
 	}
 
-	authCtx := GetAuthContext(r)
+	authCtx := GetAuthContext(c)
 	if authCtx == nil {
-		Error(w, http.StatusUnauthorized, "authentication required")
+		Error(c, http.StatusUnauthorized, "authentication required")
 		return
 	}
 
 	canAccess, _ := h.db.CanAccessDomain(authCtx.UserID, domainName, authCtx.IsAdmin())
 	if !canAccess {
-		Error(w, http.StatusForbidden, "access denied")
+		Error(c, http.StatusForbidden, "access denied")
 		return
 	}
 
 	id, err := strconv.ParseUint(idStr, 10, 64)
 	if err != nil {
-		Error(w, http.StatusBadRequest, "invalid alias id")
+		Error(c, http.StatusBadRequest, "invalid alias id")
 		return
 	}
 
 	if err := h.db.DeleteAlias(uint(id)); err != nil {
-		Error(w, http.StatusInternalServerError, "failed to delete alias")
+		Error(c, http.StatusInternalServerError, "failed to delete alias")
 		return
 	}
 
-	NoContent(w)
+	NoContent(c)
 }