add nex protocol support

1 files changed, 61 insertions, 0 deletions

diff --git a/nex/client.go b/nex/client.go
new file mode 100644
index 0000000..5f53746
--- /dev/null
+++ b/nex/client.go
@@ -0,0 +1,61 @@
+package nex
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"net"
+	neturl "net/url"
+
+	"tildegit.org/tjp/sliderule/internal/types"
+)
+
+// Client is used for sending nex requests and reading responses.
+//
+// It carries no state and is reusable simultaneously by multiple goroutines.
+//
+// The zero value is immediately usable.
+type Client struct{}
+
+// RoundTrip sends a single nex request and returns its response.
+func (c Client) RoundTrip(request *types.Request) (*types.Response, error) {
+	if request.Scheme != "nex" && request.Scheme != "" {
+		return nil, errors.New("non-nex protocols not supported")
+	}
+
+	host := request.Host
+	if _, port, _ := net.SplitHostPort(host); port == "" {
+		host = net.JoinHostPort(host, "1900")
+	}
+
+	conn, err := net.Dial("tcp", host)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	request.RemoteAddr = conn.RemoteAddr()
+	request.TLSState = nil
+
+	if _, err := conn.Write([]byte(request.Path + "\n")); err != nil {
+		return nil, err
+	}
+
+	response, err := io.ReadAll(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	return &types.Response{Body: bytes.NewBuffer(response)}, nil
+}
+
+// Fetch builds and sends a nex request, and returns the response.
+func (c Client) Fetch(url string) (*types.Response, error) {
+	u, err := neturl.Parse(url)
+	if err != nil {
+		return nil, err
+	}
+	return c.RoundTrip(&types.Request{URL: u})
+}
+
+func (c Client) IsRedirect(response *types.Response) bool { return false }