From 85473656174b1b1d6221d3bb76cc12fa5f7f7e8d Mon Sep 17 00:00:00 2001
From: Laria Carolin Chabowski <laria@laria.me>
Date: Fri, 1 Jan 2021 14:46:54 +0100
Subject: Initial commit

---
 menu/menu.go | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 menu/menu.go

(limited to 'menu')

diff --git a/menu/menu.go b/menu/menu.go
new file mode 100644
index 0000000..3916649
--- /dev/null
+++ b/menu/menu.go
@@ -0,0 +1,92 @@
+package menu
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+)
+
+type MenuItem struct {
+	Title    string
+	Ident    string
+	Url      string
+	Children []*MenuItem
+	Parent   *MenuItem
+}
+
+func (it MenuItem) IsRoot() bool {
+	return it.Parent == nil
+}
+
+type Menu struct {
+	byIdent map[string]*MenuItem
+	root    *MenuItem
+}
+
+func (m Menu) Root() *MenuItem {
+	return m.root
+}
+
+func (m Menu) ByIdent(ident string) *MenuItem {
+	return m.byIdent[ident]
+}
+
+type JsonMenuItem struct {
+	Title    string
+	Ident    string
+	Url      string
+	Children []JsonMenuItem `json:",omitempty"`
+}
+
+type JsonMenu []JsonMenuItem
+
+func (m *Menu) addJsonMenuItems(jsonItems []JsonMenuItem, parent *MenuItem) {
+	for _, jsonItem := range jsonItems {
+		item := MenuItem{
+			Title:    jsonItem.Title,
+			Ident:    jsonItem.Ident,
+			Url:      jsonItem.Url,
+			Children: make([]*MenuItem, 0, len(jsonItem.Children)),
+			Parent:   parent,
+		}
+
+		parent.Children = append(parent.Children, &item)
+		m.byIdent[jsonItem.Ident] = &item
+
+		m.addJsonMenuItems(jsonItem.Children, &item)
+	}
+}
+
+func (jm JsonMenu) toMenu() *Menu {
+	root := MenuItem{
+		Children: make([]*MenuItem, 0, len(jm)),
+	}
+
+	menu := &Menu{
+		byIdent: make(map[string]*MenuItem),
+		root:    &root,
+	}
+
+	menu.addJsonMenuItems(jm, &root)
+
+	return menu
+}
+
+func Parse(r io.Reader) (*Menu, error) {
+	var jsonMenu JsonMenu
+	if err := json.NewDecoder(r).Decode(&jsonMenu); err != nil {
+		return nil, err
+	}
+	return jsonMenu.toMenu(), nil
+}
+
+func LoadFromFile(filename string) (*Menu, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, fmt.Errorf("Could not load menu from %s: %v", filename, err)
+	}
+	defer f.Close()
+
+	return Parse(f)
+}
-- 
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