package crt

import (
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/x509"
	"crypto/x509/pkix"
	"database/sql"
	"fmt"
	"log"
	"math/big"
	"time"

	"github.com/jasinco/crtman/internal/cli"
	"github.com/jasinco/crtman/internal/store"
)

func IssueRoot(config cli.CA_CFG) {
	log.Printf("CA: Org: %s, FQDN: %s\n", config.Org, config.FQDN)
	rootca := x509.Certificate{
		IsCA:        true,
		Version:     1,
		KeyUsage:    x509.KeyUsageCertSign | x509.KeyUsageCRLSign | x509.KeyUsageDigitalSignature,
		ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageOCSPSigning},
		Subject: pkix.Name{
			Country:      []string{"Taiwan"},
			Organization: []string{config.Org},
			CommonName:   config.FQDN,
		},
		NotBefore:             time.Now(),
		BasicConstraintsValid: true,
		SerialNumber:          big.NewInt(0),
	}
	privkey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	if err != nil {
		log.Fatal(err)
	}

	crt, err := x509.CreateCertificate(rand.Reader, &rootca, &rootca, &privkey.PublicKey, privkey)
	if err != nil {
		log.Fatal("can't create x509 ca, ", err)
	}
	// privkey_bytes, err := x509.MarshalECPrivateKey(privkey)
	// if err != nil {
	// 	log.Fatal("can't create ecdsa key encoded, ", err)
	// }
	store.RootCA = crt
	store.RootCAKey = privkey
}

// csr is a DER csr
func IssueCert(csr []byte) sql.Null[[]byte] {
	req, err := x509.ParseCertificateRequest(csr)
	if err != nil {
		return sql.Null[[]byte]{Valid: false}
	}
	if req.CheckSignature() != nil {
		return sql.Null[[]byte]{Valid: false}
	}

	store.SerialLock.Lock()
	defer store.SerialLock.Unlock()
	cert := x509.Certificate{
		Subject:               req.Subject,
		PublicKey:             req.PublicKey,
		PublicKeyAlgorithm:    req.PublicKeyAlgorithm,
		NotBefore:             time.Now(),
		NotAfter:              time.Now().Add(time.Hour * 24 * 720),
		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
		IsCA:                  false,
		BasicConstraintsValid: true,
		DNSNames:              req.DNSNames,
		IPAddresses:           req.IPAddresses,
		SerialNumber:          &store.Serial,
		OCSPServer:            []string{fmt.Sprintf("https://%s/api/ocsp", cli.Outbound)},
	}
	ca, err := x509.ParseCertificate(store.RootCA)
	if err != nil {
		log.Println(err)
		return sql.Null[[]byte]{Valid: false}
	}
	signed, err := x509.CreateCertificate(rand.Reader, &cert, ca, req.PublicKey, store.RootCAKey)
	if err != nil {
		log.Println(err)
		return sql.Null[[]byte]{Valid: false}
	}
	store.Serial.Add(&store.Serial, big.NewInt(1))

	return sql.Null[[]byte]{Valid: true, V: signed}
}