chore: release v0.26.0

internal/integrations/udp/wsjtfreetext.go

@@ -0,0 +1,78 @@
+package udp
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"strings"
+
+	"hamlog/internal/applog"
+)
+
+// WSJT-X Free Text (message type 9) — "put this in the free-text box, and send".
+//
+//	Free Text  type 9
+//	  id    utf8  the target application's own id
+//	  text  utf8  the message
+//	  send  bool  true = transmit it now, false = only fill the box
+//
+// What this is FOR, and what it is not:
+//
+// It is the one "transmit this now" primitive that behaves the same on WSJT-X,
+// WSJT-Z, JTDX, JTDX-Improved and MSHV, because it needs no decode to match
+// against — unlike Reply, which the receiving application will only action if it
+// can find the exact decode being answered.
+//
+// It is NOT a way to call a station. FT8 free text is 13 characters, so a
+// standard "<DX> <ME> <GRID>" does not fit, and more importantly the text goes
+// out AS free text without setting the DX Call — so the sequencer never takes
+// over, and no report, RR73 or logging prompt follows. Use it for a 73, a short
+// note or a CQ; use Reply to start a QSO.
+const wsjtMsgFreeText = 9
+
+// EncodeFreeText builds the datagram. send=false fills the box without keying.
+func EncodeFreeText(programID, text string, send bool) []byte {
+	var b bytes.Buffer
+	_ = binary.Write(&b, binary.BigEndian, uint32(wsjtMagic))
+	_ = binary.Write(&b, binary.BigEndian, uint32(2)) // schema 2 — what every current sender speaks
+	_ = binary.Write(&b, binary.BigEndian, uint32(wsjtMsgFreeText))
+	writeQString(&b, programID)
+	writeQString(&b, text)
+	var s uint8
+	if send {
+		s = 1
+	}
+	_ = binary.Write(&b, binary.BigEndian, s)
+	return b.Bytes()
+}
+
+// SendFreeText hands a free-text message to one decoding application.
+//
+// Routed by program id to the address that instance's packets arrive from, for
+// the same reason as SendReply and SendHaltTx: two receivers can share one
+// multicast group, and transmitting from the wrong one is worse than not
+// transmitting at all.
+func (m *Manager) SendFreeText(programID, text string, send bool) error {
+	if strings.TrimSpace(programID) == "" {
+		return fmt.Errorf("no application id — cannot tell which receiver to send with")
+	}
+	m.mu.Lock()
+	servers := make([]*Server, 0, len(m.inbound))
+	for _, s := range m.inbound {
+		servers = append(servers, s)
+	}
+	m.mu.Unlock()
+
+	for _, s := range servers {
+		conn, addr := s.replyTarget(programID)
+		if conn == nil || addr == nil {
+			continue
+		}
+		if _, err := conn.WriteToUDP(EncodeFreeText(programID, text, send), addr); err != nil {
+			return fmt.Errorf("send free text to %s at %s: %w", programID, addr, err)
+		}
+		applog.Printf("udp: free text sent to %s at %s — %q (send=%v)", programID, addr, text, send)
+		return nil
+	}
+	return fmt.Errorf("no packet has arrived from %q yet — nothing to send to", programID)
+}