helpers.go

/*
   Copyright NetFoundry Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   https://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package runzmd

import (
	"fmt"
	"github.com/fatih/color"
	"github.com/openziti/foundation/v2/term"
	"io"
	"os"
	"os/exec"
	"strings"
)

func Exec(program string, colorStdout bool, args ...string) error {
	p := exec.Command(program, args...)

	stdErrWrapper := &WriterWrapper{
		c: color.New(color.FgRed),
		w: os.Stdout,
	}

	p.Stdin = os.Stdin

	if colorStdout {
		stdOutWrapper := &WriterWrapper{
			c: color.New(color.FgBlue),
			w: os.Stdout,
		}
		p.Stdout = stdOutWrapper
	} else {
		p.Stdout = os.Stdout
	}

	p.Stderr = stdErrWrapper
	if err := p.Run(); err != nil {
		return err
	}
	return nil
}

func Continue(prompt string, defaultValue bool) {
	resp, err := AskYesNoWithDefault(prompt, defaultValue)
	if err != nil {
		fmt.Printf("\nerror: %v. exiting\n", err)
		os.Exit(1)
	}

	if !resp {
		fmt.Print("\nok, exiting\n")
		os.Exit(0)
	}
}

func AskYesNo(prompt string) (bool, error) {
	filter := &yesNoFilter{}
	if _, err := Ask(prompt, filter.Accept); err != nil {
		return false, err
	}
	return filter.result, nil
}

func AskYesNoWithDefault(prompt string, defaultVal bool) (bool, error) {
	filter := &yesNoDefaultFilter{
		defaultVal: defaultVal,
	}
	if _, err := Ask(prompt, filter.Accept); err != nil {
		return false, err
	}
	return filter.result, nil
}

func Ask(prompt string, f func(string) bool) (string, error) {
	for {
		val, err := term.Prompt(prompt)
		if err != nil {
			return "", err
		}
		val = strings.TrimSpace(val)
		if f(val) {
			return val, nil
		}
		fmt.Printf("Invalid input: %v\n", val)
	}
}

type yesNoFilter struct {
	result bool
}

func (self *yesNoFilter) Accept(s string) bool {
	if strings.EqualFold("y", s) || strings.EqualFold("yes", s) {
		self.result = true
		return true
	}

	if strings.EqualFold("n", s) || strings.EqualFold("no", s) {
		self.result = false
		return true
	}

	return false
}

type yesNoDefaultFilter struct {
	result     bool
	defaultVal bool
}

func (self *yesNoDefaultFilter) Accept(s string) bool {
	if s == "" {
		self.result = self.defaultVal
		return true
	}

	if strings.EqualFold("y", s) || strings.EqualFold("yes", s) {
		self.result = true
		return true
	}

	if strings.EqualFold("n", s) || strings.EqualFold("no", s) {
		self.result = false
		return true
	}

	return false
}

type WriterWrapper struct {
	c *color.Color
	w io.Writer
}

func (self *WriterWrapper) Write(p []byte) (n int, err error) {
	return self.c.Fprint(self.w, string(p))
}