package server

import (
	"context"
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/tls"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"io"
	"math/big"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

// TestHTTPSAndPlainOnOnePort serves a certificate file: the same port
// answers HTTPS, and plain HTTP from loopback.
func TestHTTPSAndPlainOnOnePort(t *testing.T) {
	dir := t.TempDir()
	key, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	tmpl := &x509.Certificate{SerialNumber: big.NewInt(1), Subject: pkix.Name{CommonName: "dhcp.test"}, DNSNames: []string{"dhcp.test"},
		NotBefore: time.Now().Add(-time.Hour), NotAfter: time.Now().Add(time.Hour)}
	der, _ := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &key.PublicKey, key)
	kd, _ := x509.MarshalPKCS8PrivateKey(key)
	os.WriteFile(filepath.Join(dir, "c.pem"), pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der}), 0o600)
	os.WriteFile(filepath.Join(dir, "k.pem"), pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: kd}), 0o600)
	ln, _ := net.Listen("tcp", "127.0.0.1:0")
	addr := ln.Addr().String()
	ln.Close()
	e := newEnv(t)
	e.srv.cfg.Listen, e.srv.cfg.TLSCertFile, e.srv.cfg.TLSKeyFile = []string{addr}, filepath.Join(dir, "c.pem"), filepath.Join(dir, "k.pem")
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	ready := make(chan struct{})
	go e.srv.Serve(ctx, func() { close(ready) })
	<-ready
	pool := x509.NewCertPool()
	pool.AddCert(func() *x509.Certificate { c, _ := x509.ParseCertificate(der); return c }())
	hc := &http.Client{Timeout: 5 * time.Second, Transport: &http.Transport{TLSClientConfig: &tls.Config{RootCAs: pool, ServerName: "dhcp.test"}}}
	for _, url := range []string{"https://" + addr + "/healthz", "http://" + addr + "/healthz"} {
		resp, err := hc.Get(url)
		if err != nil {
			t.Fatalf("%s: %v", url, err)
		}
		b, _ := io.ReadAll(resp.Body)
		resp.Body.Close()
		if resp.StatusCode != 200 || !strings.Contains(string(b), `"ok":true`) {
			t.Errorf("%s: %d %s", url, resp.StatusCode, b)
		}
	}
}