pull request, response, handlers out of the gemini package

9 files changed, 150 insertions, 385 deletions

diff --git a/gemini/client.go b/gemini/client.go
index 0e8dd07..4f99078 100644
--- a/gemini/client.go
+++ b/gemini/client.go
@@ -6,6 +6,8 @@ import (
 	"errors"
 	"io"
 	"net"
+
+	"tildegit.org/tjp/gus"
 )
 
 // Client is used for sending gemini requests and parsing gemini responses.
@@ -31,7 +33,7 @@ func NewClient(tlsConf *tls.Config) Client {
 //
 // This method will not automatically follow redirects or cache permanent failures or
 // redirects.
-func (client Client) RoundTrip(request *Request) (*Response, error) {
+func (client Client) RoundTrip(request *gus.Request) (*gus.Response, error) {
 	if request.Scheme != "gemini" && request.Scheme != "" {
 		return nil, errors.New("non-gemini protocols not supported")
 	}
diff --git a/gemini/handler.go b/gemini/handler.go
deleted file mode 100644
index 0f48e62..0000000
--- a/gemini/handler.go
+++ /dev/null
@@ -1,54 +0,0 @@
-package gemini
-
-import "context"
-
-// Handler is a function which can turn a gemini request into a gemini response.
-//
-// A Handler MUST NOT return a nil response. Errors should be returned in the form
-// of error responses (4x, 5x, 6x response status). If the Handler should not be
-// responsible for the requested resource it can return a 51 response.
-type Handler func(context.Context, *Request) *Response
-
-// Middleware is a handle decorator.
-//
-// It returns a handler which may call the passed-in handler or not, or may
-// transform the request or response in some way.
-type Middleware func(Handler) Handler
-
-// FallthroughHandler builds a handler which tries multiple child handlers.
-//
-// The returned handler will invoke each of the passed child handlers in order,
-// stopping when it receives a response with status other than 51.
-func FallthroughHandler(handlers ...Handler) Handler {
-	return func(ctx context.Context, req *Request) *Response {
-		for _, handler := range handlers {
-			response := handler(ctx, req)
-			if response.Status != StatusNotFound {
-				return response
-			}
-		}
-
-		return NotFound("Resource does not exist.")
-	}
-}
-
-// Filter wraps a handler with a predicate which determines whether to run the handler.
-//
-// When the predicate function returns false, the Filter returns the provided failure
-// response. The failure argument may be nil, in which case a "51 Resource does not exist."
-// response will be used.
-func Filter(
-	predicate func(context.Context, *Request) bool,
-	handler Handler,
-	failure *Response,
-) Handler {
-	if failure == nil {
-		failure = NotFound("Resource does not exist.")
-	}
-	return func(ctx context.Context, req *Request) *Response {
-		if !predicate(ctx, req) {
-			return failure
-		}
-		return handler(ctx, req)
-	}
-}
diff --git a/gemini/handler_test.go b/gemini/handler_test.go
deleted file mode 100644
index c83df65..0000000
--- a/gemini/handler_test.go
+++ /dev/null
@@ -1,117 +0,0 @@
-package gemini_test
-
-import (
-	"bytes"
-	"context"
-	"io"
-	"net/url"
-	"strings"
-	"testing"
-
-	"tildegit.org/tjp/gus/gemini"
-)
-
-func TestFallthrough(t *testing.T) {
-	h1 := func(ctx context.Context, req *gemini.Request) *gemini.Response {
-		if req.Path == "/one" {
-			return gemini.Success("text/gemini", bytes.NewBufferString("one"))
-		}
-		return gemini.NotFound("nope")
-	}
-
-	h2 := func(ctx context.Context, req *gemini.Request) *gemini.Response {
-		if req.Path == "/two" {
-			return gemini.Success("text/gemini", bytes.NewBufferString("two"))
-		}
-		return gemini.NotFound("no way")
-	}
-
-	fth := gemini.FallthroughHandler(h1, h2)
-
-	u, err := url.Parse("gemini://test.local/one")
-	if err != nil {
-		t.Fatalf("url.Parse: %s", err.Error())
-	}
-
-	resp := fth(context.Background(), &gemini.Request{URL: u})
-
-	if resp.Status != gemini.StatusSuccess {
-		t.Errorf("expected status %d, got %d", gemini.StatusSuccess, resp.Status)
-	}
-
-	if resp.Meta != "text/gemini" {
-		t.Errorf(`expected meta "text/gemini", got %q`, resp.Meta)
-	}
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		t.Errorf("Read: %s", err.Error())
-	}
-	if string(body) != "one" {
-		t.Errorf(`expected body "one", got %q`, string(body))
-	}
-
-	u, err = url.Parse("gemini://test.local/two")
-	if err != nil {
-		t.Fatalf("url.Parse: %s", err.Error())
-	}
-
-	resp = fth(context.Background(), &gemini.Request{URL: u})
-
-	if resp.Status != gemini.StatusSuccess {
-		t.Errorf("expected status %d, got %d", gemini.StatusSuccess, resp.Status)
-	}
-
-	if resp.Meta != "text/gemini" {
-		t.Errorf(`expected meta "text/gemini", got %q`, resp.Meta)
-	}
-
-	body, err = io.ReadAll(resp.Body)
-	if err != nil {
-		t.Errorf("Read: %s", err.Error())
-	}
-	if string(body) != "two" {
-		t.Errorf(`expected body "two", got %q`, string(body))
-	}
-
-	u, err = url.Parse("gemini://test.local/three")
-	if err != nil {
-		t.Fatalf("url.Parse: %s", err.Error())
-	}
-
-	resp = fth(context.Background(), &gemini.Request{URL: u})
-
-	if resp.Status != gemini.StatusNotFound {
-		t.Errorf("expected status %d, got %d", gemini.StatusNotFound, resp.Status)
-	}
-}
-
-func TestFilter(t *testing.T) {
-	pred := func(ctx context.Context, req *gemini.Request) bool {
-		return strings.HasPrefix(req.Path, "/allow")
-	}
-	base := func(ctx context.Context, req *gemini.Request) *gemini.Response {
-		return gemini.Success("text/gemini", bytes.NewBufferString("allowed!"))
-	}
-	handler := gemini.Filter(pred, base, nil)
-
-	u, err := url.Parse("gemini://test.local/allow/please")
-	if err != nil {
-		t.Fatalf("url.Parse: %s", err.Error())
-	}
-
-	resp := handler(context.Background(), &gemini.Request{URL: u})
-	if resp.Status != gemini.StatusSuccess {
-		t.Errorf("expected status %d, got %d", gemini.StatusSuccess, resp.Status)
-	}
-
-	u, err = url.Parse("gemini://test.local/disallow/please")
-	if err != nil {
-		t.Fatalf("url.Parse: %s", err.Error())
-	}
-
-	resp = handler(context.Background(), &gemini.Request{URL: u})
-	if resp.Status != gemini.StatusNotFound {
-		t.Errorf("expected status %d, got %d", gemini.StatusNotFound, resp.Status)
-	}
-}
diff --git a/gemini/request.go b/gemini/request.go
index 933281b..ced7d0b 100644
--- a/gemini/request.go
+++ b/gemini/request.go
@@ -2,43 +2,18 @@ package gemini
 
 import (
 	"bufio"
-	"crypto/tls"
 	"errors"
 	"io"
-	"net"
 	"net/url"
+
+	"tildegit.org/tjp/gus"
 )
 
 // InvalidRequestLineEnding indicates that a gemini request didn't end with "\r\n".
 var InvalidRequestLineEnding = errors.New("invalid request line ending")
 
-// Request represents a request over the gemini protocol.
-type Request struct {
-	// URL is the specific URL being fetched by the request.
-	*url.URL
-
-	// Server is the server which received the request.
-	//
-	// This is only populated in gemini servers.
-	// It is unused on the client end.
-	Server     *Server
-
-	// RemoteAddr is the address of the other side of the connection.
-	//
-	// This will be the server address for clients, or the connecting
-	// client's address in servers.
-	//
-	// Be aware though that proxies (and reverse proxies) can confuse this.
-	RemoteAddr net.Addr
-
-	// TLSState contains information about the TLS encryption over the connection.
-	//
-	// This includes peer certificates and version information.
-	TLSState   *tls.ConnectionState
-}
-
 // ParseRequest parses a single gemini request from a reader.
-func ParseRequest(rdr io.Reader) (*Request, error) {
+func ParseRequest(rdr io.Reader) (*gus.Request, error) {
 	line, err := bufio.NewReader(rdr).ReadString('\n')
 	if err != io.EOF && err != nil {
 		return nil, err
@@ -57,13 +32,5 @@ func ParseRequest(rdr io.Reader) (*Request, error) {
 		u.Scheme = "gemini"
 	}
 
-	return &Request{URL: u}, nil
-}
-
-// UnescapedQuery performs %XX unescaping on the URL query segment.
-//
-// Like URL.Query(), it silently drops malformed %-encoded sequences.
-func (req Request) UnescapedQuery() string {
-	unescaped, _ := url.QueryUnescape(req.RawQuery)
-	return unescaped
+	return &gus.Request{URL: u}, nil
 }
diff --git a/gemini/request_test.go b/gemini/request_test.go
index c23d54b..1da24f7 100644
--- a/gemini/request_test.go
+++ b/gemini/request_test.go
@@ -3,7 +3,6 @@ package gemini_test
 import (
 	"bytes"
 	"testing"
-	"net/url"
 
 	"tildegit.org/tjp/gus/gemini"
 )
@@ -85,19 +84,3 @@ func TestParseRequest(t *testing.T) {
 		})
 	}
 }
-
-func TestUnescapedQuery(t *testing.T) {
-	table := []string{
-		"foo bar",
-	}
-
-	for _, test := range table {
-		t.Run(test, func(t *testing.T) {
-			u, _ := url.Parse("gemini://domain.com/path?" + url.QueryEscape(test))
-			result := gemini.Request{ URL: u }.UnescapedQuery()
-			if result != test {
-				t.Errorf("expected %q, got %q", test, result)
-			}
-		})
-	}
-}
diff --git a/gemini/response.go b/gemini/response.go
index 5b5ced4..0452462 100644
--- a/gemini/response.go
+++ b/gemini/response.go
@@ -6,65 +6,68 @@ import (
 	"errors"
 	"io"
 	"strconv"
+
+	"tildegit.org/tjp/gus"
 )
 
-// StatusCategory represents the various types of responses.
-type StatusCategory int
+// ResponseCategory represents the various types of gemini responses.
+type ResponseCategory int
 
 const (
-	// StatusCategoryInput is for responses which request additional input.
+	// ResponseCategoryInput is for responses which request additional input.
 	//
 	// The META line will be the prompt to display to the user.
-	StatusCategoryInput StatusCategory = iota*10 + 10
-	// StatusCategorySuccess is for successful responses.
+	ResponseCategoryInput ResponseCategory = iota*10 + 10
+	// ResponseCategorySuccess is for successful responses.
 	//
 	// The META line will be the resource's mime type.
 	// This is the only response status which indicates the presence of a response body,
 	// and it will contain the resource itself.
-	StatusCategorySuccess
-	// StatusCategoryRedirect is for responses which direct the client to an alternative URL.
+	ResponseCategorySuccess
+	// ResponseCategoryRedirect is for responses which direct the client to an alternative URL.
 	//
 	// The META line will contain the new URL the client should try.
-	StatusCategoryRedirect
-	// StatusCategoryTemporaryFailure is for responses which indicate a transient server-side failure.
+	ResponseCategoryRedirect
+	// ResponseCategoryTemporaryFailure is for responses which indicate a transient server-side failure.
 	//
 	// The META line may contain a line with more information about the error.
-	StatusCategoryTemporaryFailure
-	// StatusCategoryPermanentFailure is for permanent failure responses.
+	ResponseCategoryTemporaryFailure
+	// ResponseCategoryPermanentFailure is for permanent failure responses.
 	//
 	// The META line may contain a line with more information about the error.
-	StatusCategoryPermanentFailure
-	// StatusCategoryCertificateRequired indicates client certificate related issues.
+	ResponseCategoryPermanentFailure
+	// ResponseCategoryCertificateRequired indicates client certificate related issues.
 	//
 	// The META line may contain a line with more information about the error.
-	StatusCategoryCertificateRequired
+	ResponseCategoryCertificateRequired
 )
 
-// Status is the integer status code of a gemini response.
-type Status int
+func ResponseCategoryForStatus(status gus.Status) ResponseCategory {
+	return ResponseCategory(status / 10)
+}
 
 const (
 	// StatusInput indicates a required query parameter at the requested URL.
-	StatusInput Status = Status(StatusCategoryInput) + iota
+	StatusInput gus.Status = gus.Status(ResponseCategoryInput) + iota
 	// StatusSensitiveInput indicates a sensitive query parameter is required.
 	StatusSensitiveInput
 )
 
 const (
 	// StatusSuccess is a successful response.
-	StatusSuccess = Status(StatusCategorySuccess) + iota
+	StatusSuccess = gus.Status(ResponseCategorySuccess) + iota
 )
 
 const (
 	// StatusTemporaryRedirect indicates a temporary redirect to another URL.
-	StatusTemporaryRedirect = Status(StatusCategoryRedirect) + iota
+	StatusTemporaryRedirect = gus.Status(ResponseCategoryRedirect) + iota
 	// StatusPermanentRedirect indicates that the resource should always be requested at the new URL.
 	StatusPermanentRedirect
 )
 
 const (
 	// StatusTemporaryFailure indicates that the request failed and there is no response body.
-	StatusTemporaryFailure = Status(StatusCategoryTemporaryFailure) + iota
+	StatusTemporaryFailure = gus.Status(ResponseCategoryTemporaryFailure) + iota
 	// StatusServerUnavailable occurs when the server is unavailable due to overload or maintenance.
 	StatusServerUnavailable
 	// StatusCGIError is the result of a failure of a CGI script.
@@ -80,7 +83,7 @@ const (
 
 const (
 	// StatusPermanentFailure is a server failure which should be expected to continue indefinitely.
-	StatusPermanentFailure = Status(StatusCategoryPermanentFailure) + iota
+	StatusPermanentFailure = gus.Status(ResponseCategoryPermanentFailure) + iota
 	// StatusNotFound means the resource doesn't exist but it may in the future.
 	StatusNotFound
 	// StatusGone occurs when a resource will not be available any longer.
@@ -88,58 +91,37 @@ const (
 	// StatusProxyRequestRefused means the server is unwilling to act as a proxy for the resource.
 	StatusProxyRequestRefused
 	// StatusBadRequest indicates that the request was malformed somehow.
-	StatusBadRequest = Status(StatusCategoryPermanentFailure) + 9
+	StatusBadRequest = gus.Status(ResponseCategoryPermanentFailure) + 9
 )
 
 const (
 	// StatusClientCertificateRequired is returned when a certificate was required but not provided.
-	StatusClientCertificateRequired = Status(StatusCategoryCertificateRequired) + iota
+	StatusClientCertificateRequired = gus.Status(ResponseCategoryCertificateRequired) + iota
 	// StatusCertificateNotAuthorized means the certificate doesn't grant access to the requested resource.
 	StatusCertificateNotAuthorized
 	// StatusCertificateNotValid means the provided client certificate is invalid.
 	StatusCertificateNotValid
 )
 
-// StatusCategory returns the category a specific status belongs to.
-func (s Status) Category() StatusCategory {
-	return StatusCategory(s / 10)
-}
-
-// Response contains everything in a gemini protocol response.
-type Response struct {
-	// Status is the status code of the response.
-	Status Status
-
-	// Meta is the status-specific line of additional information.
-	Meta string
-
-	// Body is the response body, if any.
-	//
-	// It is not guaranteed to be readable more than once.
-	Body io.Reader
-
-	reader io.Reader
-}
-
 // Input builds an input-prompting response.
-func Input(prompt string) *Response {
-	return &Response{
+func Input(prompt string) *gus.Response {
+	return &gus.Response{
 		Status: StatusInput,
 		Meta:   prompt,
 	}
 }
 
 // SensitiveInput builds a password-prompting response.
-func SensitiveInput(prompt string) *Response {
-	return &Response{
+func SensitiveInput(prompt string) *gus.Response {
+	return &gus.Response{
 		Status: StatusSensitiveInput,
 		Meta:   prompt,
 	}
 }
 
 // Success builds a success response with resource body.
-func Success(mediatype string, body io.Reader) *Response {
-	return &Response{
+func Success(mediatype string, body io.Reader) *gus.Response {
+	return &gus.Response{
 		Status: StatusSuccess,
 		Meta:   mediatype,
 		Body:   body,
@@ -147,120 +129,120 @@ func Success(mediatype string, body io.Reader) *Response {
 }
 
 // Redirect builds a redirect response.
-func Redirect(url string) *Response {
-	return &Response{
+func Redirect(url string) *gus.Response {
+	return &gus.Response{
 		Status: StatusTemporaryRedirect,
 		Meta:   url,
 	}
 }
 
 // PermanentRedirect builds a response with a permanent redirect.
-func PermanentRedirect(url string) *Response {
-	return &Response{
+func PermanentRedirect(url string) *gus.Response {
+	return &gus.Response{
 		Status: StatusPermanentRedirect,
 		Meta:   url,
 	}
 }
 
 // Failure builds a temporary failure response from an error.
-func Failure(err error) *Response {
-	return &Response{
+func Failure(err error) *gus.Response {
+	return &gus.Response{
 		Status: StatusTemporaryFailure,
 		Meta:   err.Error(),
 	}
 }
 
 // Unavailable build a "server unavailable" response.
-func Unavailable(msg string) *Response {
-	return &Response{
+func Unavailable(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusServerUnavailable,
 		Meta:   msg,
 	}
 }
 
 // CGIError builds a "cgi error" response.
-func CGIError(err string) *Response {
-	return &Response{
+func CGIError(err string) *gus.Response {
+	return &gus.Response{
 		Status: StatusCGIError,
 		Meta:   err,
 	}
 }
 
 // ProxyError builds a proxy error response.
-func ProxyError(msg string) *Response {
-	return &Response{
+func ProxyError(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusProxyError,
 		Meta:   msg,
 	}
 }
 
 // SlowDown builds a "slow down" response with the number of seconds until the resource is available.
-func SlowDown(seconds int) *Response {
-	return &Response{
+func SlowDown(seconds int) *gus.Response {
+	return &gus.Response{
 		Status: StatusSlowDown,
 		Meta:   strconv.Itoa(seconds),
 	}
 }
 
 // PermanentFailure builds a "permanent failure" from an error.
-func PermanentFailure(err error) *Response {
-	return &Response{
+func PermanentFailure(err error) *gus.Response {
+	return &gus.Response{
 		Status: StatusPermanentFailure,
 		Meta:   err.Error(),
 	}
 }
 
 // NotFound builds a "resource not found" response.
-func NotFound(msg string) *Response {
-	return &Response{
+func NotFound(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusNotFound,
 		Meta:   msg,
 	}
 }
 
 // Gone builds a "resource gone" response.
-func Gone(msg string) *Response {
-	return &Response{
+func Gone(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusGone,
 		Meta:   msg,
 	}
 }
 
 // RefuseProxy builds a "proxy request refused" response.
-func RefuseProxy(msg string) *Response {
-	return &Response{
+func RefuseProxy(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusProxyRequestRefused,
 		Meta:   msg,
 	}
 }
 
 // BadRequest builds a "bad request" response.
-func BadRequest(msg string) *Response {
-	return &Response{
+func BadRequest(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusBadRequest,
 		Meta:   msg,
 	}
 }
 
 // RequireCert builds a "client certificate required" response.
-func RequireCert(msg string) *Response {
-	return &Response{
+func RequireCert(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusClientCertificateRequired,
 		Meta:   msg,
 	}
 }
 
 // CertAuthFailure builds a "certificate not authorized" response.
-func CertAuthFailure(msg string) *Response {
-	return &Response{
+func CertAuthFailure(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusCertificateNotAuthorized,
 		Meta:   msg,
 	}
 }
 
 // CertInvalid builds a "client certificate not valid" response.
-func CertInvalid(msg string) *Response {
-	return &Response{
+func CertInvalid(msg string) *gus.Response {
+	return &gus.Response{
 		Status: StatusCertificateNotValid,
 		Meta:   msg,
 	}
@@ -275,7 +257,7 @@ var InvalidResponseHeaderLine = errors.New("Invalid response header line.")
 // ParseResponse parses a complete gemini response from a reader.
 //
 // The reader must contain only one gemini response.
-func ParseResponse(rdr io.Reader) (*Response, error) {
+func ParseResponse(rdr io.Reader) (*gus.Response, error) {
 	bufrdr := bufio.NewReader(rdr)
 
 	hdrLine, err := bufrdr.ReadBytes('\n')
@@ -295,53 +277,57 @@ func ParseResponse(rdr io.Reader) (*Response, error) {
 		return nil, InvalidResponseHeaderLine
 	}
 
-	return &Response{
-		Status: Status(status),
+	return &gus.Response{
+		Status: gus.Status(status),
 		Meta:   string(hdrLine[3:]),
 		Body:   bufrdr,
 	}, nil
 }
 
-// Read implements io.Reader for Response.
-func (r *Response) Read(b []byte) (int, error) {
-	r.ensureReader()
-	return r.reader.Read(b)
+type ResponseReader interface {
+	io.Reader
+	io.WriterTo
+	io.Closer
 }
 
-// WriteTo implements io.WriterTo for Response.
-func (r *Response) WriteTo(dst io.Writer) (int64, error) {
-	r.ensureReader()
-	return r.reader.(io.WriterTo).WriteTo(dst)
+func NewResponseReader(response *gus.Response) ResponseReader {
+	return &responseReader{ Response: response }
 }
 
-// Close implements io.Closer and ensures the body gets closed.
-func (r *Response) Close() error {
-	if r != nil {
-		if cl, ok := r.Body.(io.Closer); ok {
-			return cl.Close()
-		}
-	}
-	return nil
+type responseReader struct {
+	*gus.Response
+	reader io.Reader
+}
+
+func (rdr *responseReader) Read(b []byte) (int, error) {
+	rdr.ensureReader()
+	return rdr.reader.Read(b)
+}
+
+func (rdr *responseReader) WriteTo(dst io.Writer) (int64, error) {
+	rdr.ensureReader()
+	return rdr.reader.(io.WriterTo).WriteTo(dst)
 }
 
-func (r *Response) ensureReader() {
-	if r.reader != nil {
+func (rdr *responseReader) ensureReader() {
+	if rdr.reader != nil {
 		return
 	}
 
-	hdr := bytes.NewBuffer(r.headerLine())
-	if r.Body != nil {
-		r.reader = io.MultiReader(hdr, r.Body)
+	hdr := bytes.NewBuffer(rdr.headerLine())
+	if rdr.Body != nil {
+		rdr.reader = io.MultiReader(hdr, rdr.Body)
 	} else {
-		r.reader = hdr
+		rdr.reader = hdr
 	}
 }
 
-func (r Response) headerLine() []byte {
-	buf := make([]byte, len(r.Meta)+5)
-	_ = strconv.AppendInt(buf[:0], int64(r.Status), 10)
+func (rdr responseReader) headerLine() []byte {
+	meta := rdr.Meta.(string)
+	buf := make([]byte, len(meta)+5)
+	_ = strconv.AppendInt(buf[:0], int64(rdr.Status), 10)
 	buf[2] = ' '
-	copy(buf[3:], r.Meta)
+	copy(buf[3:], meta)
 	buf[len(buf)-2] = '\r'
 	buf[len(buf)-1] = '\n'
 	return buf
diff --git a/gemini/response_test.go b/gemini/response_test.go
index 616fac4..9287d71 100644
--- a/gemini/response_test.go
+++ b/gemini/response_test.go
@@ -6,14 +6,15 @@ import (
 	"io"
 	"testing"
 
+	"tildegit.org/tjp/gus"
 	"tildegit.org/tjp/gus/gemini"
 )
 
 func TestBuildResponses(t *testing.T) {
 	table := []struct {
 		name     string
-		response *gemini.Response
-		status   gemini.Status
+		response *gus.Response
+		status   gus.Status
 		meta     string
 		body     string
 	}{
@@ -137,7 +138,7 @@ func TestBuildResponses(t *testing.T) {
 				t.Errorf("expected meta %q, got %q", test.meta, test.response.Meta)
 			}
 
-			responseBytes, err := io.ReadAll(test.response)
+			responseBytes, err := io.ReadAll(gemini.NewResponseReader(test.response))
 			if err != nil {
 				t.Fatalf("error reading response body: %q", err.Error())
 			}
@@ -153,7 +154,7 @@ func TestBuildResponses(t *testing.T) {
 func TestParseResponses(t *testing.T) {
 	table := []struct {
 		input  string
-		status gemini.Status
+		status gus.Status
 		meta   string
 		body   string
 		err    error
@@ -232,7 +233,7 @@ func TestParseResponses(t *testing.T) {
 
 func TestResponseClose(t *testing.T) {
 	body := &rdCloser{Buffer: bytes.NewBufferString("the body here")}
-	resp := &gemini.Response{
+	resp := &gus.Response{
 		Status: gemini.StatusSuccess,
 		Meta:   "text/gemini",
 		Body:   body,
@@ -246,7 +247,7 @@ func TestResponseClose(t *testing.T) {
 		t.Error("response body was not closed by response.Close()")
 	}
 
-	resp = &gemini.Response{
+	resp = &gus.Response{
 		Status: gemini.StatusInput,
 		Meta:   "give me more",
 	}
@@ -269,8 +270,8 @@ func (rc *rdCloser) Close() error {
 func TestResponseWriteTo(t *testing.T) {
 	// invariant under test: WriteTo() sends the same bytes as Read()
 
-	clone := func(resp *gemini.Response) *gemini.Response {
-		other := &gemini.Response{
+	clone := func(resp *gus.Response) *gus.Response {
+		other := &gus.Response{
 			Status: resp.Status,
 			Meta:   resp.Meta,
 		}
@@ -296,7 +297,7 @@ func TestResponseWriteTo(t *testing.T) {
 
 	table := []struct {
 		name     string
-		response *gemini.Response
+		response *gus.Response
 	}{
 		{
 			name: "simple success",
@@ -316,13 +317,13 @@ func TestResponseWriteTo(t *testing.T) {
 			r1 := test.response
 			r2 := clone(test.response)
 
-			rdbuf, err := io.ReadAll(r1)
+			rdbuf, err := io.ReadAll(gemini.NewResponseReader(r1))
 			if err != nil {
 				t.Fatalf("response.Read(): %s", err.Error())
 			}
 
 			wtbuf := &bytes.Buffer{}
-			if _, err := r2.WriteTo(wtbuf); err != nil {
+			if _, err := gemini.NewResponseReader(r2).WriteTo(wtbuf); err != nil {
 				t.Fatalf("response.WriteTo(): %s", err.Error())
 			}
 
diff --git a/gemini/roundtrip_test.go b/gemini/roundtrip_test.go
index 5dd61f1..326ffbc 100644
--- a/gemini/roundtrip_test.go
+++ b/gemini/roundtrip_test.go
@@ -9,6 +9,7 @@ import (
 	"net/url"
 	"testing"
 
+	"tildegit.org/tjp/gus"
 	"tildegit.org/tjp/gus/gemini"
 )
 
@@ -18,7 +19,7 @@ func TestRoundTrip(t *testing.T) {
 		t.Fatalf("FileTLS(): %s", err.Error())
 	}
 
-	handler := func(ctx context.Context, req *gemini.Request) *gemini.Response {
+	handler := func(ctx context.Context, req *gus.Request) *gus.Response {
 		return gemini.Success("text/gemini", bytes.NewBufferString("you've found my page"))
 	}
 
@@ -36,7 +37,7 @@ func TestRoundTrip(t *testing.T) {
 	}
 
 	cli := gemini.NewClient(testClientTLS())
-	response, err := cli.RoundTrip(&gemini.Request{URL: u})
+	response, err := cli.RoundTrip(&gus.Request{URL: u})
 	if err != nil {
 		t.Fatalf("RoundTrip(): %s", err.Error())
 	}
diff --git a/gemini/serve.go b/gemini/serve.go
index bc13531..c148558 100644
--- a/gemini/serve.go
+++ b/gemini/serve.go
@@ -6,27 +6,28 @@ import (
 	"io"
 	"net"
 	"sync"
+
+	"tildegit.org/tjp/gus"
 )
 
-// Server listens on a network and serves the gemini protocol.
-type Server struct {
+type server struct {
 	ctx      context.Context
 	network  string
 	address  string
 	cancel   context.CancelFunc
 	wg       *sync.WaitGroup
 	listener net.Listener
-	handler  Handler
+	handler  gus.Handler
 }
 
-// NewServer builds a server.
+// NewServer builds a gemini server.
 func NewServer(
 	ctx context.Context,
 	tlsConfig *tls.Config,
 	network string,
 	address string,
-	handler Handler,
-) (*Server, error) {
+	handler gus.Handler,
+) (gus.Server, error) {
 	listener, err := net.Listen(network, address)
 	if err != nil {
 		return nil, err
@@ -34,7 +35,7 @@ func NewServer(
 
 	addr := listener.Addr()
 
-	s := &Server{
+	s := &server{
 		ctx:      ctx,
 		network:  addr.Network(),
 		address:  addr.String(),
@@ -54,7 +55,7 @@ func NewServer(
 // It will respect cancellation of the context the server was created with,
 // but be aware that Close() must still be called in that case to avoid
 // dangling goroutines.
-func (s *Server) Serve() error {
+func (s *server) Serve() error {
 	s.wg.Add(1)
 	defer s.wg.Done()
 
@@ -66,7 +67,7 @@ func (s *Server) Serve() error {
 	for {
 		conn, err := s.listener.Accept()
 		if err != nil {
-			if s.closed() {
+			if s.Closed() {
 				err = nil
 			}
 			return err
@@ -77,62 +78,57 @@ func (s *Server) Serve() error {
 	}
 }
 
-// Close begins a graceful shutdown of the server.
-//
-// It cancels the server's context which interrupts all concurrently running
-// request handlers, if they support it. It then blocks until all resources
-// have been cleaned up and all request handlers have completed.
-func (s *Server) Close() {
+func (s *server) Close() {
 	s.cancel()
 	s.wg.Wait()
 }
 
-// Network returns the network type on which the server is running.
-func (s *Server) Network() string {
+func (s *server) Network() string {
 	return s.network
 }
 
-// Address returns the address on which the server is listening.
-func (s *Server) Address() string {
+func (s *server) Address() string {
 	return s.address
 }
 
-// Hostname returns just the hostname portion of the listen address.
-func (s *Server) Hostname() string {
+func (s *server) Hostname() string {
 	host, _, _ := net.SplitHostPort(s.address)
 	return host
 }
 
-// Port returns the port on which the server is listening.
-func (s *Server) Port() string {
+func (s *server) Port() string {
 	_, portStr, _ := net.SplitHostPort(s.address)
 	return portStr
 }
 
-func (s *Server) handleConn(conn net.Conn) {
+func (s *server) handleConn(conn net.Conn) {
 	defer s.wg.Done()
 	defer conn.Close()
 
+	var response *gus.Response
 	req, err := ParseRequest(conn)
 	if err != nil {
-		_, _ = io.Copy(conn, BadRequest(err.Error()))
+		response = BadRequest(err.Error())
 		return
-	}
+	} else {
+		req.Server = s
+		req.RemoteAddr = conn.RemoteAddr()
+		if tlsconn, ok := conn.(*tls.Conn); req != nil && ok {
+			state := tlsconn.ConnectionState()
+			req.TLSState = &state
+		}
 
-	req.Server = s
-	req.RemoteAddr = conn.RemoteAddr()
-	if tlsconn, ok := conn.(*tls.Conn); req != nil && ok {
-		state := tlsconn.ConnectionState()
-		req.TLSState = &state
+		response = s.handler(s.ctx, req)
+		if response == nil {
+			response = NotFound("Resource does not exist.")
+		}
+		defer response.Close()
 	}
 
-	resp := s.handler(s.ctx, req)
-	defer resp.Close()
-
-	_, _ = io.Copy(conn, resp)
+	_, _ = io.Copy(conn, NewResponseReader(response))
 }
 
-func (s *Server) propagateCancel() {
+func (s *server) propagateCancel() {
 	go func() {
 		defer s.wg.Done()
 
@@ -141,7 +137,7 @@ func (s *Server) propagateCancel() {
 	}()
 }
 
-func (s *Server) closed() bool {
+func (s *server) Closed() bool {
 	select {
 	case <-s.ctx.Done():
 		return true