implemented upgrade, and fixed some bugs

internal/errors/errors.go

@@ -6,4 +6,6 @@ var (
 	ErrResponseNot200OK     = errors.New("the request is not 200, download failed")
 	ErrCantFindManifestTOML = errors.New("can't find manifest.toml when trying to read the packagefile")
 	ErrInvalidSignature     = errors.New("the signature is invalid")
+	ErrNotInstalled         = errors.New("the package isn't installed")
+	ErrAlredyUpToDate       = errors.New("alredy up to date")
 )

internal/utils/utils.go

@@ -252,8 +252,12 @@ func CheckIfPackageInstalled(name string) (bool, error) {
 	}
 	defer db.Close()
 
+	if strings.Contains(name, "@") {
+		name = strings.SplitN(name, "@", 2)[0]
+	}
+
 	var exists bool
-	err = db.QueryRow("SELECT EXISTS(SELECT 1 FROM packages WHERE id = ? OR query_name = ?)", name, name).Scan(&exists)
+	err = db.QueryRow("SELECT EXISTS(SELECT 1 FROM packages WHERE query_name = ?)", name).Scan(&exists)
 	if err != nil {
 		return false, err
 	}