create categories and subcategories in database and categories logic

backend/database/categories.go

@@ -0,0 +1,93 @@
+package database
+
+import (
+	"backend/model"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"gorm.io/gorm"
+)
+
+func CreateCategory(category *model.Category) error {
+	e := Db.Where(model.Category{
+		Title: category.Title,
+	}).FirstOrCreate(&category).Error
+	if e != nil {
+		return e
+	}
+	return nil
+}
+
+func GetCategoryById(id string) (*model.Category, error) {
+	var category model.Category
+	e := Db.First(&category, "id = ?", id).Error
+	if e != nil {
+		if errors.Is(e, gorm.ErrRecordNotFound) {
+			return nil, fmt.Errorf("user not found")
+		}
+		return nil, e
+	}
+	return &category, nil
+}
+
+func GetCategoryByTitle(title string) (*model.Category, error) {
+	var category model.Category
+	e := Db.First(&category, "username = ?", title).Error
+	if e != nil {
+		if errors.Is(e, gorm.ErrRecordNotFound) {
+			return nil, fmt.Errorf("user not found")
+		}
+		return nil, e
+	}
+	return &category, nil
+}
+
+func DeleteCategory(id string) error {
+	var category model.Category
+	e := Db.First(&category, "id = ?", id).Error
+	if e != nil {
+		if errors.Is(e, gorm.ErrRecordNotFound) {
+			return fmt.Errorf("user not found")
+		}
+		return e
+	}
+	e = Db.Unscoped().Delete(&category).Error
+	if e != nil {
+		if errors.Is(e, gorm.ErrRecordNotFound) {
+			return fmt.Errorf("user not found")
+		}
+		return e
+	}
+	return nil
+}
+
+func GetCategoriesFromFile(filename string) []model.Category {
+	data, e := os.ReadFile(filename)
+	if e != nil {
+		panic(e)
+	}
+	decoder := json.NewDecoder(strings.NewReader(string(data)))
+	var res []model.Category
+	decoder.Decode(&res)
+	return res
+}
+
+func GetAllCategories() ([]model.Category, error) {
+	var categories []model.Category
+	e := Db.Find(&categories).Error
+	if e != nil {
+		return nil, e
+	}
+	for i := range categories {
+		var subcategories []model.Subcategory
+		e := Db.Where(model.Subcategory{CategoryID: categories[i].ID}).Find(&subcategories).Error
+		if e != nil {
+			return nil, e
+		}
+		categories[i].Subcategories = subcategories
+	}
+	return categories, nil
+}

backend/database/db.go

@@ -43,4 +43,11 @@ func InitDatabase() {
 			CreateUser(&allusers[i])
 		}
 	}
+
+	if os.Getenv("DEFAULT_CATEGORIES_FILE") != "" {
+		default_categories := GetCategoriesFromFile(os.Getenv("DEFAULT_CATEGORIES_FILE"))
+		for i := range default_categories {
+			CreateCategory(&default_categories[i])
+		}
+	}
 }