author is now on separate table

internal/routes/bookpostcreate.go

@@ -1,9 +1,12 @@
 package routes
 
 import (
+	"errors"
+
 	"git.artlef.fr/PersonalLibraryManager/internal/appcontext"
 	"git.artlef.fr/PersonalLibraryManager/internal/model"
 	"git.artlef.fr/PersonalLibraryManager/internal/myvalidator"
+	"gorm.io/gorm"
 )
 
 type bookPostCreate struct {
@@ -29,8 +32,8 @@ func PostBookHandler(ac appcontext.AppContext) {
 		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
 		return
 	}
-	bookDb := bookWsToDb(book, &user)
-	err = ac.Db.Model(&model.Book{}).Save(&bookDb).Error
+
+	err = saveBookToDb(ac, book, &user)
 	if err != nil {
 		myvalidator.ReturnErrorsAsJsonResponse(&ac, err)
 		return
@@ -38,14 +41,38 @@ func PostBookHandler(ac appcontext.AppContext) {
 	ac.C.String(200, "Success")
 }
 
-func bookWsToDb(b bookPostCreate, user *model.User) model.Book {
+func saveBookToDb(ac appcontext.AppContext, b bookPostCreate, user *model.User) error {
+	author, err := fetchOrCreateAuthor(ac, b.Author)
+	if err != nil {
+		return err
+	}
 	book := model.Book{
-		Title:   b.Title,
-		Author:  b.Author,
-		AddedBy: *user,
+		Title:    b.Title,
+		AuthorID: author.ID,
+		AddedBy:  *user,
 	}
 	if b.CoverID > 0 {
 		book.CoverID = b.CoverID
 	}
-	return book
+	return ac.Db.Save(&book).Error
+}
+
+func fetchOrCreateAuthor(ac appcontext.AppContext, name string) (*model.Author, error) {
+	var author model.Author
+	res := ac.Db.Where("name = ?", name)
+	err := res.Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			author = model.Author{Name: name}
+			err = ac.Db.Save(&author).Error
+			if err != nil {
+				return &author, err
+			}
+			return &author, nil
+		} else {
+			return &author, err
+		}
+	} else {
+		return &author, nil
+	}
 }