1 files changed, 72 insertions, 0 deletions
diff --git a/gopher/request.go b/gopher/request.go
new file mode 100644
index 0000000..6c708c0
--- /dev/null
+++ b/gopher/request.go
@@ -0,0 +1,72 @@
+package gopher
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"net/url"
+	"path"
+	"strings"
+
+	"tildegit.org/tjp/gus"
+)
+
+// ParseRequest parses a gopher protocol request into a gus.Request object.
+func ParseRequest(rdr io.Reader) (*gus.Request, error) {
+	selector, search, err := readFullRequest(rdr)
+	if err != nil {
+		return nil, err
+	}
+
+	if !strings.HasPrefix(selector, "/") {
+		selector = "/" + selector
+	}
+
+	return &gus.Request{
+		URL: &url.URL{
+			Scheme:   "gopher",
+			Path:     path.Clean(strings.TrimRight(selector, "\r\n")),
+			OmitHost: true, //nolint:typecheck
+			// (for some reason typecheck on drone-ci doesn't realize OmitHost is a field in url.URL)
+			RawQuery: url.QueryEscape(strings.TrimRight(search, "\r\n")),
+		},
+	}, nil
+}
+
+func readFullRequest(rdr io.Reader) (string, string, error) {
+	// The vast majority of requests will fit in this size:
+	// the specified 255 byte max for selector, then CRLF.
+	buf := make([]byte, 257)
+
+	n, err := rdr.Read(buf)
+	if err != nil && !errors.Is(err, io.EOF) {
+		return "", "", err
+	}
+	buf = buf[:n]
+
+	// Full-text search transactions are the exception, they
+	// may be longer because there is an additional search string
+	if n == 257 && buf[256] != '\n' {
+		intake := buf[n:cap(buf)]
+		total := n
+		for {
+			intake = append(intake, 0)
+			intake = intake[:cap(intake)]
+
+			n, err = rdr.Read(intake)
+			if err != nil && err != io.EOF {
+				return "", "", err
+			}
+			total += n
+
+			if n < cap(intake) || intake[cap(intake)-1] == '\n' {
+				break
+			}
+			intake = intake[n:]
+		}
+		buf = buf[:total]
+	}
+
+	selector, search, _ := bytes.Cut(buf, []byte{'\t'})
+	return string(selector), string(search), nil
+}