spartan =: prompt line support in gemtext

gemini/gemtext/parse_line.go

@@ -10,10 +10,16 @@ func ParseLine(line []byte) Line {
 
 	switch line[0] {
 	case '=':
-		if len(line) == 1 || line[1] != '>' {
+		if len(line) == 1 {
 			break
 		}
-		return parseLinkLine(line)
+		if line[1] == '>' {
+			return parseLinkLine(line)
+		}
+		if line[1] == ':' {
+			return parsePromptLine(line)
+		}
+		break
 	case '`':
 		if len(line) < 3 || line[1] != '`' || line[2] != '`' {
 			break
@@ -73,6 +79,39 @@ func parseLinkLine(raw []byte) LinkLine {
 	return line
 }
 
+func parsePromptLine(raw []byte) PromptLine {
+	line := PromptLine{raw: raw}
+
+	// move past =:[<whitespace>]
+	raw = bytes.TrimLeft(raw[2:], " \t")
+
+	// find the next space or tab
+	spIdx := bytes.IndexByte(raw, ' ')
+	tbIdx := bytes.IndexByte(raw, '\t')
+	idx := spIdx
+	if idx == -1 {
+		idx = tbIdx
+	}
+	if tbIdx >= 0 && tbIdx < idx {
+		idx = tbIdx
+	}
+
+	if idx < 0 {
+		line.url = bytes.TrimRight(raw, "\r\n")
+		return line
+	}
+
+	line.url = raw[:idx]
+	raw = raw[idx+1:]
+
+	label := bytes.TrimRight(bytes.TrimLeft(raw, " \t"), "\r\n")
+	if len(label) > 0 {
+		line.label = label
+	}
+
+	return line
+}
+
 func parsePreformatToggleLine(raw []byte) PreformatToggleLine {
 	line := PreformatToggleLine{raw: raw}
 

gemini/gemtext/parse_line_test.go

@@ -57,6 +57,57 @@ func TestParseLinkLine(t *testing.T) {
 	}
 }
 
+func TestParsePromptLine(t *testing.T) {
+	tests := []struct {
+		input string
+		url   string
+		label string
+	}{
+		{
+			input: "=: gemini.ctrl-c.club/~tjp/ home page\r\n",
+			url:   "gemini.ctrl-c.club/~tjp/",
+			label: "home page",
+		},
+		{
+			input: "=: gemi.dev/\n",
+			url:   "gemi.dev/",
+		},
+		{
+			input: "=: /gemlog/foobar 2023-01-13 - Foo Bar\n",
+			url:   "/gemlog/foobar",
+			label: "2023-01-13 - Foo Bar",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.input, func(t *testing.T) {
+			line := gemtext.ParseLine([]byte(test.input))
+			if line == nil {
+				t.Fatal("ParseLine() returned nil line")
+			}
+			if string(line.Raw()) != string(test.input) {
+				t.Error("Raw() does not match input")
+			}
+
+			if line.Type() != gemtext.LineTypePrompt{
+				t.Errorf("expected LineTypePrompt, got %d", line.Type())
+			}
+			link, ok := line.(gemtext.PromptLine)
+			if !ok {
+				t.Fatalf("expected a PromptLine, got %T", line)
+			}
+
+			if link.URL() != test.url {
+				t.Errorf("expected url %q, got %q", test.url, link.URL())
+			}
+
+			if link.Label() != test.label {
+				t.Errorf("expected label %q, got %q", test.label, link.Label())
+			}
+		})
+	}
+}
+
 func TestParsePreformatToggleLine(t *testing.T) {
 	tests := []struct {
 		input   string

gemini/gemtext/parse_test.go

@@ -24,6 +24,8 @@ This is some non-blank regular text.
 
 => gemini://google.com/ as if
 
+=: spartan://foo.bar/baz this should be a spartan prompt
+
 > this is a quote
 > -tjp
 
@@ -37,7 +39,7 @@ This is some non-blank regular text.
 	doc, err := gemtext.Parse(bytes.NewBuffer(docBytes))
 	require.Nil(t, err)
 
-	require.Equal(t, 18, len(doc))
+	require.Equal(t, 20, len(doc))
 
 	assert.Equal(t, gemtext.LineTypeHeading1, doc[0].Type())
 	assert.Equal(t, "# top-level header line\n", string(doc[0].Raw()))
@@ -74,26 +76,33 @@ This is some non-blank regular text.
 
 	assertEmptyLine(t, doc[11])
 
-	assert.Equal(t, gemtext.LineTypeQuote, doc[12].Type())
-	assert.Equal(t, "> this is a quote\n", string(doc[12].Raw()))
-	assert.Equal(t, " this is a quote", doc[12].(gemtext.QuoteLine).Body())
+	assert.Equal(t, gemtext.LineTypePrompt, doc[12].Type())
+	assert.Equal(t, "=: spartan://foo.bar/baz this should be a spartan prompt\n", string(doc[12].Raw()))
+	assert.Equal(t, "spartan://foo.bar/baz", doc[12].(gemtext.PromptLine).URL())
+	assert.Equal(t, "this should be a spartan prompt", doc[12].(gemtext.PromptLine).Label())
 
-	assert.Equal(t, gemtext.LineTypeQuote, doc[13].Type())
-	assert.Equal(t, "> -tjp\n", string(doc[13].Raw()))
-	assert.Equal(t, " -tjp", doc[13].(gemtext.QuoteLine).Body())
+	assertEmptyLine(t, doc[13])
 
-	assertEmptyLine(t, doc[14])
+	assert.Equal(t, gemtext.LineTypeQuote, doc[14].Type())
+	assert.Equal(t, "> this is a quote\n", string(doc[14].Raw()))
+	assert.Equal(t, " this is a quote", doc[14].(gemtext.QuoteLine).Body())
 
-	assert.Equal(t, gemtext.LineTypePreformatToggle, doc[15].Type())
-	assert.Equal(t, "```pre-formatted code\n", string(doc[15].Raw()))
-	assert.Equal(t, "pre-formatted code", doc[15].(gemtext.PreformatToggleLine).AltText())
+	assert.Equal(t, gemtext.LineTypeQuote, doc[15].Type())
+	assert.Equal(t, "> -tjp\n", string(doc[15].Raw()))
+	assert.Equal(t, " -tjp", doc[15].(gemtext.QuoteLine).Body())
 
-	assert.Equal(t, gemtext.LineTypePreformattedText, doc[16].Type())
-	assert.Equal(t, "doc := gemtext.Parse(req.Body)\n", string(doc[16].Raw()))
+	assertEmptyLine(t, doc[16])
 
 	assert.Equal(t, gemtext.LineTypePreformatToggle, doc[17].Type())
-	assert.Equal(t, "```ignored closing alt-text\n", string(doc[17].Raw()))
-	assert.Equal(t, "", doc[17].(gemtext.PreformatToggleLine).AltText())
+	assert.Equal(t, "```pre-formatted code\n", string(doc[17].Raw()))
+	assert.Equal(t, "pre-formatted code", doc[17].(gemtext.PreformatToggleLine).AltText())
+
+	assert.Equal(t, gemtext.LineTypePreformattedText, doc[18].Type())
+	assert.Equal(t, "doc := gemtext.Parse(req.Body)\n", string(doc[18].Raw()))
+
+	assert.Equal(t, gemtext.LineTypePreformatToggle, doc[19].Type())
+	assert.Equal(t, "```ignored closing alt-text\n", string(doc[19].Raw()))
+	assert.Equal(t, "", doc[19].(gemtext.PreformatToggleLine).AltText())
 
 	// ensure we can rebuild the original doc from all the line.Raw()s
 	buf := &bytes.Buffer{}

gemini/gemtext/types.go

@@ -16,6 +16,13 @@ const (
 	// The line is a LinkLine.
 	LineTypeLink
 
+	// LineTypePrompt is a spartan =: prompt line.
+	//
+	// =:[<ws>]<url>[<ws><label>][\r]\n
+	//
+	// The line is a PromptLine.
+	LineTypePrompt
+
 	// LineTypePreformatToggle switches the document between pre-formatted text or not.
 	//
 	// ```[<alt-text>][\r]\n
@@ -111,6 +118,25 @@ func (ll LinkLine) URL() string { return string(ll.url) }
 // Label returns the label portion of the line.
 func (ll LinkLine) Label() string { return string(ll.label) }
 
+// PromptLine is a Spartan =: prompt line.
+type PromptLine struct {
+	raw   []byte
+	url   []byte
+	label []byte
+}
+
+func (pl PromptLine) Type() LineType { return LineTypePrompt }
+func (pl PromptLine) Raw() []byte    { return pl.raw }
+func (pl PromptLine) String() string { return string(pl.raw) }
+
+// URL returns the original url portion of the line.
+//
+// It is not guaranteed to be a valid URL.
+func (pl PromptLine) URL() string { return string(pl.url) }
+
+// Label retrns the label portion of the line.
+func (pl PromptLine) Label() string { return string(pl.label) }
+
 // PreformatToggleLine is a preformatted text toggle line.
 type PreformatToggleLine struct {
 	raw     []byte

spartan/client.go

@@ -0,0 +1,70 @@
+package spartan
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+
+	"tildegit.org/tjp/gus"
+)
+
+// Client is used for sending spartan requests and receiving responses.
+//
+// It carries no state and is reusable simultaneously by multiple goroutines.
+//
+// The zero value is immediately usabble.
+type Client struct{}
+
+// RoundTrip sends a single spartan request and returns its response.
+func (c Client) RoundTrip(request *gus.Request, body io.Reader) (*gus.Response, error) {
+	if request.Scheme != "spartan" && request.Scheme != "" {
+		return nil, errors.New("non-spartan protocols not supported")
+	}
+
+	host, port, _ := net.SplitHostPort(request.Host)
+	if port == "" {
+		host = request.Host
+		port = "300"
+	}
+	addr := net.JoinHostPort(host, port)
+
+	conn, err := net.Dial("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	request.RemoteAddr = conn.RemoteAddr()
+
+	var bodyBytes []byte = nil
+	if body != nil {
+		bodyBytes, err = io.ReadAll(body)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	requestLine := host + " " + request.EscapedPath() + " " + strconv.Itoa(len(bodyBytes)) + "\r\n"
+
+	if _, err := conn.Write([]byte(requestLine)); err != nil {
+		return nil, err
+	}
+	if _, err := conn.Write(bodyBytes); err != nil {
+		return nil, err
+	}
+
+	response, err := ParseResponse(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	bodybuf, err := io.ReadAll(response.Body)
+	if err != nil {
+		return nil, err
+	}
+	response.Body = bytes.NewBuffer(bodybuf)
+
+	return response, nil
+}

spartan/request.go

@@ -37,7 +37,7 @@ func ParseRequest(rdr io.Reader) (*gus.Request, int, error) {
 	if !ok {
 		return nil, 0, InvalidRequestLine
 	}
-	path, rest, ok := strings.Cut(line, " ")
+	path, rest, ok := strings.Cut(rest, " ")
 	if !ok {
 		return nil, 0, InvalidRequestLine
 	}
@@ -46,7 +46,7 @@ func ParseRequest(rdr io.Reader) (*gus.Request, int, error) {
 		return nil, 0, InvalidRequestLineEnding
 	}
 
-	contentlen, err := strconv.Atoi(line[:len(line)-2])
+	contentlen, err := strconv.Atoi(rest[:len(rest)-2])
 	if err != nil {
 		return nil, 0, err
 	}

spartan/request_test.go

@@ -0,0 +1,45 @@
+package spartan_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"tildegit.org/tjp/gus/spartan"
+)
+
+func TestParseRequest(t *testing.T) {
+	tests := []struct {
+		requestLine string
+		host        string
+		path        string
+		clen        int
+	}{
+		{
+			requestLine: "foobar.ninja /baz/quux 0\r\n",
+			host:        "foobar.ninja",
+			path:        "/baz/quux",
+			clen:        0,
+		},
+		{
+			requestLine: "foo.bar / 12\r\n",
+			host:        "foo.bar",
+			path:        "/",
+			clen:        12,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.requestLine, func(t *testing.T) {
+			request, clen, err := spartan.ParseRequest(bytes.NewBufferString(test.requestLine))
+			require.Nil(t, err)
+
+			assert.Equal(t, test.host, request.Host)
+			assert.Equal(t, test.path, request.Path)
+			assert.Equal(t, test.path, request.RawPath)
+			assert.Equal(t, test.clen, clen)
+		})
+	}
+}

spartan/response.go

@@ -1,8 +1,11 @@
 package spartan
 
 import (
+	"bufio"
 	"bytes"
+	"errors"
 	"io"
+	"strconv"
 	"sync"
 
 	"tildegit.org/tjp/gus"
@@ -37,7 +40,7 @@ func Redirect(url string) *gus.Response {
 func ClientError(err error) *gus.Response {
 	return &gus.Response{
 		Status: StatusClientError,
-		Meta: err.Error(),
+		Meta:   err.Error(),
 	}
 }
 
@@ -45,10 +48,39 @@ func ClientError(err error) *gus.Response {
 func ServerError(err error) *gus.Response {
 	return &gus.Response{
 		Status: StatusServerError,
-		Meta: err.Error(),
+		Meta:   err.Error(),
 	}
 }
 
+// InvalidResponseHeaderLine indicates a malformed spartan response line.
+var InvalidResponseHeaderLine = errors.New("Invalid response header line.")
+
+// InvalidResponseLineEnding indicates that a spartan response header didn't end with "\r\n".
+var InvalidResponseLineEnding = errors.New("Invalid response line ending.")
+
+func ParseResponse(rdr io.Reader) (*gus.Response, error) {
+	bufrdr := bufio.NewReader(rdr)
+
+	hdrLine, err := bufrdr.ReadString('\n')
+	if err != nil {
+		return nil, InvalidResponseLineEnding
+	}
+	if len(hdrLine) < 2 {
+		return nil, InvalidResponseHeaderLine
+	}
+
+	status, err := strconv.Atoi(string(hdrLine[0]))
+	if err != nil || hdrLine[1] != ' ' || hdrLine[len(hdrLine)-2:] != "\r\n" {
+		return nil, InvalidResponseHeaderLine
+	}
+
+	return &gus.Response{
+		Status: gus.Status(status),
+		Meta:   hdrLine[2 : len(hdrLine)-2],
+		Body:   bufrdr,
+	}, nil
+}
+
 // NewResponseReader builds a reader for a response.
 func NewResponseReader(response *gus.Response) gus.ResponseReader {
 	return &responseReader{