Improve Sheet model

src/database/connection.go

@@ -18,10 +18,10 @@ func InitDatabase() {
 	}
 
 	// Auto migrate the schema
-	err = DB.AutoMigrate(&models.User{}, &models.MusicSheet{})
+	err = DB.AutoMigrate(&models.User{}, &models.Sheet{})
 	if err != nil {
 		log.Fatal("Failed to migrate database:", err)
 	}
 
 	log.Println("Database connected and migrated successfully")
-}
+}

src/go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.14.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect

src/go.sum

@@ -29,6 +29,8 @@ github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaS
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
 github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=

src/handlers/auth.go

@@ -11,7 +11,7 @@ import (
 	"golang.org/x/crypto/bcrypt"
 )
 
-var jwtSecret = []byte("your-secret-key") // In production, use environment variable
+var jwtSecret = []byte("your-secret-key") // TODO: In production, use environment variable
 
 type RegisterRequest struct {
 	Username string `json:"username" binding:"required"`

src/handlers/sheets.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -8,10 +9,12 @@ import (
 	"path/filepath"
 	"sheetless-server/database"
 	"sheetless-server/models"
+	"sheetless-server/utils"
 	"strconv"
 	"time"
 
 	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 )
 
 const uploadDir = "./uploads"
@@ -79,14 +82,29 @@ func UploadSheet(c *gin.Context) {
 		return
 	}
 
+	fileHash, err := utils.FileHashFromUpload(out)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed calculating hash"})
+		return
+	}
+
+	uuid, err := GenerateNonexistentSheetUuid()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed generating sheet uuid"})
+		return
+	}
+
 	// Create database record
-	sheet := models.MusicSheet{
+	sheet := models.Sheet{
+		Uuid:        *uuid,
 		Title:       title,
 		Composer:    composer,
 		Description: description,
 		FilePath:    filePath,
 		FileSize:    fileInfo.Size(),
-		UserID:      userID.(uint),
+		FileHash:    fileHash,
+		CreatedAt:   time.Now(),
+		UpdatedAt:   time.Now(),
 	}
 
 	if err := database.DB.Create(&sheet).Error; err != nil {
@@ -103,7 +121,7 @@ func UploadSheet(c *gin.Context) {
 }
 
 func ListSheets(c *gin.Context) {
-	var sheets []models.MusicSheet
+	var sheets []models.Sheet
 
 	query := database.DB.Preload("User")
 
@@ -131,7 +149,7 @@ func DownloadSheet(c *gin.Context) {
 		return
 	}
 
-	var sheet models.MusicSheet
+	var sheet models.Sheet
 	if err := database.DB.First(&sheet, uint(id)).Error; err != nil {
 		c.JSON(http.StatusNotFound, gin.H{"error": "Sheet not found"})
 		return
@@ -147,4 +165,26 @@ func DownloadSheet(c *gin.Context) {
 	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", filepath.Base(sheet.FilePath)))
 	c.Header("Content-Type", "application/pdf")
 	c.File(sheet.FilePath)
-}
+}
+
+func GenerateNonexistentSheetUuid() (*uuid.UUID, error) {
+	for i := 0; i < 10; i++ {
+		uuid := uuid.New()
+
+		var exists bool
+		err := database.DB.Model(&models.Sheet{}).
+			Select("count(*) > 0").
+			Where("uuid = ?", uuid).
+			Find(&exists).
+			Error
+
+		if err != nil {
+			return nil, err
+		}
+
+		if !exists {
+			return &uuid, nil
+		}
+	}
+	return nil, errors.New("Somehow unable to generate new uuid for sheet.")
+}

src/models/sheet.go

@@ -3,19 +3,20 @@ package models
 import (
 	"time"
 
+	"github.com/google/uuid"
 	"gorm.io/gorm"
 )
 
-type MusicSheet struct {
+type Sheet struct {
-	ID          uint           `json:"id" gorm:"primaryKey"`
+	Uuid        uuid.UUID      `json:"uuid" gorm:"primaryKey"`
 	Title       string         `json:"title" gorm:"not null"`
 	Composer    string         `json:"composer"`
 	Description string         `json:"description"`
 	FilePath    string         `json:"file_path" gorm:"not null"`
 	FileSize    int64          `json:"file_size"`
-	UserID      uint           `json:"user_id"`
+	FileHash    uint64         `json:"file_hash"`
 	User        User           `json:"user" gorm:"foreignKey:UserID"`
 	CreatedAt   time.Time      `json:"created_at"`
 	UpdatedAt   time.Time      `json:"updated_at"`
 	DeletedAt   gorm.DeletedAt `json:"-" gorm:"index"`
-}
+}

src/routes/routes.go

@@ -22,8 +22,8 @@ func SetupRoutes(r *gin.Engine) {
 		sheets := api.Group("/sheets")
 		{
 			sheets.POST("/upload", handlers.UploadSheet)
-			sheets.GET("", handlers.ListSheets)
+			sheets.GET("/list", handlers.ListSheets)
-			sheets.GET("/download/:id", handlers.DownloadSheet)
+			sheets.GET("/get/:id", handlers.DownloadSheet)
 		}
 	}
 }

src/utils/filehash.go

@@ -0,0 +1,32 @@
+package utils
+
+import (
+	"hash/fnv"
+	"io"
+	"mime/multipart"
+	"os"
+)
+
+func FileHashFromUpload(file multipart.File) (uint64, error) {
+	h := fnv.New64a()
+	if _, err := io.Copy(h, file); err != nil {
+		return 0, err
+	}
+
+	return h.Sum64(), nil
+}
+
+func FileHash(path string) (uint64, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+
+	h := fnv.New64a()
+	if _, err := io.Copy(h, f); err != nil {
+		return 0, err
+	}
+
+	return h.Sum64(), nil
+}