package utils

import "strings"

const (
	PemPrivateKHeader = "-----BEGIN RSA PRIVATE KEY-----"
	PemPrivateKFooter = "-----END RSA PRIVATE KEY-----"
)

const (
	PemPublicHeader   = "-----BEGIN PUBLIC KEY-----"
	PemPublicPuFooter = "-----END PUBLIC KEY-----"
)

type Private struct {
	pemHeader string
	pemFooter string
}

type Public struct {
	pemHeader string
	pemFooter string
}

type OptionPri func(p *Private)
type OptionPub func(p *Public)

func WithPemPriHeader(pemHeader string) OptionPri {
	return func(p *Private) {
		p.pemHeader = pemHeader
	}
}
func WithPemPriFooter(pemFooter string) OptionPri {
	return func(p *Private) {
		p.pemFooter = pemFooter
	}
}

func NewPrivate(options ...OptionPri) *Private {
	p := &Private{
		pemHeader: PemPrivateKHeader,
		pemFooter: PemPrivateKFooter,
	}
	for _, option := range options {
		option(p)
	}
	return p
}

func (p *Private) Build(keyStr string) string {
	return buildPem(p.pemHeader, p.pemFooter, keyStr)
}

func WithPemPukHeader(pemHeader string) OptionPub {
	return func(p *Public) {
		p.pemHeader = pemHeader
	}
}
func WithPemPukFooter(pemFooter string) OptionPub {
	return func(p *Public) {
		p.pemFooter = pemFooter
	}
}

func NewPublic(options ...OptionPub) *Public {
	p := &Public{
		pemHeader: PemPublicHeader,
		pemFooter: PemPublicPuFooter,
	}
	for _, option := range options {
		option(p)
	}
	return p
}

func (p *Public) Build(keyStr string) string {
	return buildPem(p.pemHeader, p.pemFooter, keyStr)
}

func buildPem(pemHeader, pemFooter, keyStr string) string {
	var lines []string
	lines = append(lines, pemHeader)
	lines = append(lines, keyStr)
	lines = append(lines, pemFooter)
	return strings.Join(lines, "\n")
}