package test

import (
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"fmt"
	"log"
	"math/big"
	"os"
	"time"
)

// UnsafeSelfSignedCertificates creates a pair of test certificates in the given test folder
func UnsafeSelfSignedCertificates(testfolder string) (privateKeyPath string, publicKeyPath string) {
	privateKeyPath = fmt.Sprintf("%s/cert.key", testfolder)
	publicKeyPath = fmt.Sprintf("%s/cert.pem", testfolder)

	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	if err != nil {
		log.Fatalf("Failed to generatekey: %v", err)
	}

	template := x509.Certificate{
		SerialNumber: big.NewInt(1234),
		Subject: pkix.Name{
			Organization: []string{"Gatus test"},
		},
		NotBefore:             time.Now(),
		NotAfter:              time.Now().Add(time.Hour * 24),
		KeyUsage:              x509.KeyUsageDigitalSignature,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
		BasicConstraintsValid: true,
		DNSNames:              []string{"localhost"},
	}
	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &key.PublicKey, key)
	if err != nil {
		log.Fatalf("Failed to create certificate: %v", err)
	}

	certOut, err := os.Create(publicKeyPath)
	if err != nil {
		log.Fatalf("Failed to open cert.pem for writing: %v", err)
	}
	if err := pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
		log.Fatalf("Failed to write data to cert.pem: %v", err)
	}
	if err := certOut.Close(); err != nil {
		log.Fatalf("Error closing cert.pem: %v", err)
	}

	keyOut, err := os.OpenFile(privateKeyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
	if err != nil {
		log.Fatalf("Failed to open %s for writing: %v", privateKeyPath, err)
	}
	privBytes, err := x509.MarshalPKCS8PrivateKey(key)
	if err != nil {
		log.Fatalf("Unable to marshal private key: %v", err)
	}
	if err := pem.Encode(keyOut, &pem.Block{Type: "PRIVATE KEY", Bytes: privBytes}); err != nil {
		log.Fatalf("Failed to write data to key.pem: %v", err)
	}
	if err := keyOut.Close(); err != nil {
		log.Fatalf("Error closing key.pem: %v", err)
	}
	log.Print("wrote key.pem\n")

	return
}