func ReadCategories()

in categories/categories.go [25:68]
41 lines of code
7 McCabe index (conditional complexity)

func ReadCategories(r io.Reader) (Categories, error) {
	var categoriesFile struct {
		Categories map[string]struct {
			Title         string `yaml:"title"`
			Subcategories map[string]struct {
				Title string `yaml:"title"`
			} `yaml:"subcategories"`
		} `yaml:"categories"`
	}
	dec := yaml.NewDecoder(r)
	err := dec.Decode(&categoriesFile)
	if err != nil {
		return nil, fmt.Errorf("failed to decode categories: %w", err)
	}

	categories := make(Categories)
	addCategory := func(name, title string, parent *Category) error {
		if _, found := categories[name]; found {
			return fmt.Errorf("ambiguous definition for category %q", name)
		}
		categories[name] = Category{
			Name:   name,
			Title:  title,
			Parent: parent,
		}
		return nil
	}
	for name, category := range categoriesFile.Categories {
		err := addCategory(name, category.Title, nil)
		if err != nil {
			return nil, err
		}

		for subname, subcategory := range category.Subcategories {
			parent := categories[name]
			err := addCategory(subname, subcategory.Title, &parent)
			if err != nil {
				return nil, err
			}
		}
	}

	return categories, nil
}