feat(skychat): voice audio backend (PulseAudio) + terminal spectrogram demo

.gitignore

@@ -136,3 +136,4 @@ skysocks-client
 
 
 !cmd/wasm-visor/cacert.pem
+/skywire-cli

cmd/skywire-cli/commands/skychat/voice_answer.go

@@ -0,0 +1,74 @@
+// Package cliskychat cmd/skywire-cli/commands/skychat/voice_answer.go c4-vis-cli
+//
+// Explicit-answer controls for inbound voice calls. When a visor runs with real
+// audio (SKYWIRE_VOICE_AUDIO=mic|monitor) incoming calls RING instead of
+// auto-answering, so the microphone is never streamed without an explicit
+// answer. `voice incoming` lists ringing calls; `voice answer`/`voice decline`
+// act on one by id.
+package cliskychat
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"github.com/skycoin/skywire/cmd/skywire-cli/cliutil"
+	clirpc "github.com/skycoin/skywire/cmd/skywire-cli/commands/rpc"
+)
+
+func init() {
+	voiceCmd.AddCommand(voiceIncomingCmd, voiceAnswerCmd, voiceDeclineCmd)
+}
+
+var voiceIncomingCmd = &cobra.Command{
+	Use:   "incoming",
+	Short: "List ringing inbound calls awaiting an answer",
+	Run: func(cmd *cobra.Command, _ []string) {
+		rpcClient, err := clirpc.Client(cmd.Flags())
+		if err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		ids, err := rpcClient.VoiceIncoming()
+		if err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		out := "no ringing calls\n"
+		if len(ids) > 0 {
+			out = "ringing calls:\n  " + strings.Join(ids, "\n  ") + "\n"
+		}
+		cliutil.PrintOutput(cmd.Flags(), ids, out)
+	},
+}
+
+var voiceAnswerCmd = &cobra.Command{
+	Use:   "answer <call-id>",
+	Short: "Accept a ringing inbound call",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		rpcClient, err := clirpc.Client(cmd.Flags())
+		if err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		if err := rpcClient.VoiceAnswer(args[0]); err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		cliutil.PrintOutput(cmd.Flags(), args[0], fmt.Sprintf("answered: %s\n", args[0]))
+	},
+}
+
+var voiceDeclineCmd = &cobra.Command{
+	Use:   "decline <call-id>",
+	Short: "Reject a ringing inbound call",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		rpcClient, err := clirpc.Client(cmd.Flags())
+		if err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		if err := rpcClient.VoiceDecline(args[0]); err != nil {
+			cliutil.PrintFatalError(cmd.Flags(), err)
+		}
+		cliutil.PrintOutput(cmd.Flags(), args[0], fmt.Sprintf("declined: %s\n", args[0]))
+	},
+}