Initial commit: dating app backend (Go/Gin/GORM/Postgres)

Phone+OTP auth, staged onboarding, admin approval workflow, and a
full discovery/swipe/match/chat system with photo upload and
approximate distance (haversine) based on user location.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/utils/jwt.go

@@ -0,0 +1,101 @@
+package utils
+
+import (
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+var (
+	ErrInvalidToken = errors.New("توکن نامعتبر است")
+	ErrExpiredToken = errors.New("توکن منقضی شده است")
+)
+
+// TokenType نوع توکن، برای جلوگیری از استفاده از refresh token به‌جای access و برعکس
+type TokenType string
+
+const (
+	AccessToken  TokenType = "access"
+	RefreshToken TokenType = "refresh"
+)
+
+// Claims دیتای داخل JWT
+type Claims struct {
+	UserID  uint      `json:"user_id"`
+	IsAdmin bool      `json:"is_admin"`
+	Type    TokenType `json:"type"`
+	jwt.RegisteredClaims
+}
+
+// JWTManager تولید و اعتبارسنجی توکن‌ها
+type JWTManager struct {
+	accessSecret  []byte
+	refreshSecret []byte
+	accessTTL     time.Duration
+	refreshTTL    time.Duration
+}
+
+func NewJWTManager(accessSecret, refreshSecret string, accessTTL, refreshTTL time.Duration) *JWTManager {
+	return &JWTManager{
+		accessSecret:  []byte(accessSecret),
+		refreshSecret: []byte(refreshSecret),
+		accessTTL:     accessTTL,
+		refreshTTL:    refreshTTL,
+	}
+}
+
+func (m *JWTManager) GenerateAccessToken(userID uint, isAdmin bool) (string, error) {
+	return m.generate(userID, isAdmin, AccessToken, m.accessSecret, m.accessTTL)
+}
+
+func (m *JWTManager) GenerateRefreshToken(userID uint, isAdmin bool) (string, error) {
+	return m.generate(userID, isAdmin, RefreshToken, m.refreshSecret, m.refreshTTL)
+}
+
+func (m *JWTManager) generate(userID uint, isAdmin bool, tokenType TokenType, secret []byte, ttl time.Duration) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		UserID:  userID,
+		IsAdmin: isAdmin,
+		Type:    tokenType,
+		RegisteredClaims: jwt.RegisteredClaims{
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(now.Add(ttl)),
+		},
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(secret)
+}
+
+func (m *JWTManager) ParseAccessToken(tokenStr string) (*Claims, error) {
+	return m.parse(tokenStr, m.accessSecret, AccessToken)
+}
+
+func (m *JWTManager) ParseRefreshToken(tokenStr string) (*Claims, error) {
+	return m.parse(tokenStr, m.refreshSecret, RefreshToken)
+}
+
+func (m *JWTManager) parse(tokenStr string, secret []byte, expectedType TokenType) (*Claims, error) {
+	claims := &Claims{}
+	token, err := jwt.ParseWithClaims(tokenStr, claims, func(t *jwt.Token) (interface{}, error) {
+		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, ErrInvalidToken
+		}
+		return secret, nil
+	})
+
+	if err != nil {
+		if errors.Is(err, jwt.ErrTokenExpired) {
+			return nil, ErrExpiredToken
+		}
+		return nil, ErrInvalidToken
+	}
+	if !token.Valid {
+		return nil, ErrInvalidToken
+	}
+	if claims.Type != expectedType {
+		return nil, ErrInvalidToken
+	}
+	return claims, nil
+}