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/versions.go

@@ -0,0 +1,84 @@
+package handlers
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"github.com/toyffee/party-mix/internal/models"
+	"gorm.io/gorm"
+)
+
+func GetVersions(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userID := currentUserID(c)
+		var rows []models.UserVersion
+		if err := db.Where("user_id = ?", userID).Find(&rows).Error; err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		result := make(map[string]gin.H, len(rows))
+		for _, r := range rows {
+			result[r.TrackTitle] = gin.H{
+				"title":    r.VersionTitle,
+				"artist":   r.VersionArtist,
+				"duration": r.VersionDuration,
+			}
+		}
+		c.JSON(http.StatusOK, result)
+	}
+}
+
+type saveVersionReq struct {
+	TrackTitle      string `json:"track_title" binding:"required"`
+	VersionTitle    string `json:"title" binding:"required"`
+	VersionArtist   string `json:"artist"`
+	VersionDuration string `json:"duration"`
+}
+
+func SaveVersion(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userID := currentUserID(c)
+		var req saveVersionReq
+		if err := c.ShouldBindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+		var row models.UserVersion
+		err := db.Where("user_id = ? AND track_title = ?", userID, req.TrackTitle).First(&row).Error
+		if err != nil {
+			row = models.UserVersion{
+				ID:        uuid.NewString(),
+				UserID:    userID,
+				TrackTitle: req.TrackTitle,
+				CreatedAt: time.Now(),
+			}
+		}
+		row.VersionTitle = req.VersionTitle
+		row.VersionArtist = req.VersionArtist
+		row.VersionDuration = req.VersionDuration
+		if err := db.Save(&row).Error; err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.Status(http.StatusNoContent)
+	}
+}
+
+type deleteVersionReq struct {
+	TrackTitle string `json:"track_title" binding:"required"`
+}
+
+func DeleteVersion(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userID := currentUserID(c)
+		var req deleteVersionReq
+		if err := c.ShouldBindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+		db.Where("user_id = ? AND track_title = ?", userID, req.TrackTitle).Delete(&models.UserVersion{})
+		c.Status(http.StatusNoContent)
+	}
+}