Initial commit: party-mix-app with prefetch cache, audio preload optimizations

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/backend/internal/handlers/auth.go

@@ -0,0 +1,103 @@
+package handlers
+
+import (
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"github.com/toyffee/party-mix/internal/models"
+	"golang.org/x/crypto/bcrypt"
+	"gorm.io/gorm"
+)
+
+type registerReq struct {
+	Username string `json:"username" binding:"required,min=3,max=50"`
+	Email    string `json:"email" binding:"required,email"`
+	Password string `json:"password" binding:"required,min=6"`
+}
+
+func Register(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var req registerReq
+		if err := c.ShouldBindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+
+		hash, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "internal error"})
+			return
+		}
+
+		user := models.User{
+			ID:           uuid.NewString(),
+			Username:     req.Username,
+			Email:        strings.ToLower(req.Email),
+			PasswordHash: string(hash),
+			CreatedAt:    time.Now(),
+		}
+
+		if err := db.Create(&user).Error; err != nil {
+			if strings.Contains(err.Error(), "duplicate key") || strings.Contains(err.Error(), "unique") {
+				c.JSON(http.StatusConflict, gin.H{"error": "username or email already taken"})
+				return
+			}
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "could not create user"})
+			return
+		}
+
+		c.JSON(http.StatusCreated, user)
+	}
+}
+
+type loginReq struct {
+	Email    string `json:"email" binding:"required"`
+	Password string `json:"password" binding:"required"`
+}
+
+func Login(db *gorm.DB, jwtSecret string) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var req loginReq
+		if err := c.ShouldBindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+
+		var user models.User
+		if err := db.Where("email = ?", strings.ToLower(req.Email)).First(&user).Error; err != nil {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+			return
+		}
+
+		if err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(req.Password)); err != nil {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+			return
+		}
+
+		token, err := generateToken(user.ID, jwtSecret)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "could not generate token"})
+			return
+		}
+
+		c.JSON(http.StatusOK, gin.H{
+			"token": token,
+			"user":  user,
+		})
+	}
+}
+
+func Me(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userID := currentUserID(c)
+		var user models.User
+		if err := db.First(&user, "id = ?", userID).Error; err != nil {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
+			return
+		}
+		c.JSON(http.StatusOK, user)
+	}
+}