package pgwire

import (
	"bytes"
	"encoding/binary"
	"errors"
	"io"
	"net"
	"testing"
	"time"
)

func TestStartupMessageReadsDatabase(t *testing.T) {
	raw := startupBytes("analytics", "ruckstack")
	message, err := ReadStartupMessage(bytes.NewReader(raw))
	if err != nil {
		t.Fatal(err)
	}
	if message.Database != "analytics" {
		t.Fatalf("Database = %q", message.Database)
	}
}

func TestReadStartupMessageRejectsMissingDatabase(t *testing.T) {
	_, err := ReadStartupMessage(bytes.NewReader(startupBytes("", "ruckstack")))
	if !errors.Is(err, ErrMissingDatabase) {
		t.Errorf("ReadStartupMessage() error = %v, want ErrMissingDatabase", err)
	}
}

func TestReplayForwardsStartupAndUnderlyingStream(t *testing.T) {
	reader, writer := io.Pipe()
	defer reader.Close()
	go func() {
		_, _ = writer.Write([]byte("tail"))
		_ = writer.Close()
	}()
	connection := &readOnlyConn{Reader: reader}
	replayed := Replay(connection, []byte("startup"))
	got, err := io.ReadAll(replayed)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "startuptail" {
		t.Errorf("Replay() = %q", got)
	}
}

func startupBytes(database, user string) []byte {
	body := make([]byte, 4)
	binary.BigEndian.PutUint32(body, startupProtocolVersion)
	if database != "" {
		body = append(body, "database"...)
		body = append(body, 0)
		body = append(body, database...)
		body = append(body, 0)
	}
	body = append(body, "user"...)
	body = append(body, 0)
	body = append(body, user...)
	body = append(body, 0, 0)
	message := make([]byte, 4, 4+len(body))
	message = append(message, body...)
	binary.BigEndian.PutUint32(message, uint32(len(message)))
	return message
}

type readOnlyConn struct{ io.Reader }

func (c *readOnlyConn) Write([]byte) (int, error)        { return 0, io.ErrClosedPipe }
func (c *readOnlyConn) Close() error                     { return nil }
func (c *readOnlyConn) LocalAddr() net.Addr              { return nil }
func (c *readOnlyConn) RemoteAddr() net.Addr             { return nil }
func (c *readOnlyConn) SetDeadline(time.Time) error      { return nil }
func (c *readOnlyConn) SetReadDeadline(time.Time) error  { return nil }
func (c *readOnlyConn) SetWriteDeadline(time.Time) error { return nil }