package hmpki

import (
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/x509"
	"encoding/pem"
	"os"

	"git.handmadecities.com/HMC/shhh/pkg/pki"
	"github.com/spf13/cobra"
)

func init() {
	generateCmd.AddCommand(generateKeyCmd)
}

var generateKeyCmd = &cobra.Command{
	Use:   "key",
	Short: "Generate a private key and save it to a file",
	RunE: func(cmd *cobra.Command, args []string) error {
		priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
		if err != nil {
			return err
		}

		der, err := x509.MarshalPKCS8PrivateKey(priv)
		if err != nil {
			return err
		}

		pemBytes := pem.EncodeToMemory(&pem.Block{
			Type:  pki.PEMTypePrivateKey,
			Bytes: der,
		})

		kf, err := os.OpenFile(
			Output,
			// Write only, and fail if it alreay exists.
			os.O_WRONLY|os.O_CREATE|os.O_EXCL,
			pki.PrivateKeyFilePerms,
		)
		if err != nil {
			return err
		}
		defer kf.Close()
		if _, err = kf.Write(pemBytes); err != nil {
			return err
		}

		return nil
	},
}