package ssh

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"os"
	"path/filepath"
	"testing"
)

func TestAuthMethodsPreferAgentBeforeKeyFile(t *testing.T) {
	keyFile := writePrivateKey(t)
	methods, cleanup, err := authMethodsWithAgent("/tmp/ssh-agent.sock", nil, keyFile)
	if err != nil {
		t.Fatalf("authMethodsWithAgent() error = %v", err)
	}
	defer cleanup()
	if got, want := len(methods), 2; got != want {
		t.Fatalf("auth method count = %d, want %d", got, want)
	}
}

func TestAuthMethodsLoadsKeyFile(t *testing.T) {
	keyFile := writePrivateKey(t)
	methods, cleanup, err := authMethodsWithAgent("", nil, keyFile)
	if err != nil {
		t.Fatalf("authMethodsWithAgent() error = %v", err)
	}
	defer cleanup()
	if got, want := len(methods), 1; got != want {
		t.Fatalf("auth method count = %d, want %d", got, want)
	}
}

func TestAuthMethodsRejectsMissingAuth(t *testing.T) {
	_, _, err := authMethodsWithAgent("", nil, "")
	if err == nil {
		t.Fatal("authMethodsWithAgent() error = nil, want error")
	}
}

func writePrivateKey(t *testing.T) string {
	t.Helper()
	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		t.Fatalf("generate key: %v", err)
	}
	data := pem.EncodeToMemory(&pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(privateKey),
	})
	path := filepath.Join(t.TempDir(), "id_rsa")
	if err := os.WriteFile(path, data, 0o600); err != nil {
		t.Fatalf("write private key: %v", err)
	}
	return path
}