bogem/nehm

// Copyright 2016 Albert Nigmatzianov. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package menu

import (
    "bufio"
    "bytes"
    "os"
    "strings"

    "github.com/bogem/nehm/logs"
)

type Menu struct {
    choices map[string]func()
    output  *bytes.Buffer
}

func (m *Menu) AddItems(items ...MenuItem) {
    if m.choices == nil {
        m.choices = make(map[string]func(), len(items))
    }
    if m.output == nil {
        m.output = new(bytes.Buffer)
    }

    for _, item := range items {
        if item.Run != nil {
            m.choices[item.Index] = item.Run
        }
        m.output.WriteString(item.String() + "\n")
    }
}

func (m *Menu) AddNewline() {
    m.AddItems(MenuItem{
        Desc: "",
    })
}

func (m *Menu) Reset() {
    m.choices = make(map[string]func())
    if m.output == nil {
        m.output = new(bytes.Buffer)
    }
    m.output.Reset()
}

func (m Menu) Show() {
    // Add quit note.
    m.output.WriteString("Ctrl-C to Quit\n")

    // Print all items.
    logs.FEEDBACK.Println(m.output.String())

    // Run choice.
    choose(m.choices)
}

func choose(choices map[string]func()) {
    logs.FEEDBACK.Print("Enter option: ")

    for {
        var index = readInput()
        var chosen = choices[index]
        if chosen != nil {
            chosen()
            break
        } else {
            logs.FEEDBACK.Print("Invalid choice. Please choose the correct option: ")
        }
    }
}

func readInput() string {
    reader := bufio.NewReader(os.Stdin)
    input, _ := reader.ReadString('\n')
    return strings.TrimSpace(input)
}