init

internal/backend/status.go

@@ -0,0 +1,103 @@
+package backend
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+const protonInterface = "proton0"
+
+var ErrNmcliNotFound = errors.New("nmcli: binary not found in PATH")
+
+type ConnectionStatus struct {
+	Connected bool
+	Server    string
+	Location  string
+	Load      int
+	Protocol  string
+}
+
+func Status() (ConnectionStatus, error) {
+	connected, err := isConnectedViaNetworkManager()
+	if err != nil {
+		return ConnectionStatus{}, err
+	}
+	if !connected {
+		return ConnectionStatus{Connected: false}, nil
+	}
+
+	res, err := Run(context.Background(), "status")
+	if err != nil {
+		return ConnectionStatus{}, err
+	}
+
+	status := parseStatus(res.Stdout)
+	status.Connected = true
+	return status, nil
+}
+
+func IsConnected() (bool, error) {
+	return isConnectedViaNetworkManager()
+}
+
+func isConnectedViaNetworkManager() (bool, error) {
+	if _, err := exec.LookPath("nmcli"); err != nil {
+		return false, ErrNmcliNotFound
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), DefaultTimeout)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, "nmcli", "-t", "-f", "DEVICE", "connection", "show", "--active")
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		return false, fmt.Errorf("nmcli: %w (stderr: %q)", err, strings.TrimSpace(stderr.String()))
+	}
+
+	for device := range strings.SplitSeq(strings.TrimSpace(stdout.String()), "\n") {
+		if device == protonInterface {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func parseStatus(output string) ConnectionStatus {
+	var status ConnectionStatus
+
+	for line := range strings.SplitSeq(output, "\n") {
+		key, value, found := strings.Cut(strings.TrimSpace(line), ": ")
+		if !found {
+			continue
+		}
+
+		switch key {
+		case "Status":
+			status.Connected = value == "Connected"
+		case "Server":
+			if server, location, ok := strings.Cut(value, " in "); ok {
+				status.Server = server
+				status.Location = location
+			} else {
+				status.Server = value
+			}
+		case "Load":
+			if load, err := strconv.Atoi(strings.TrimSuffix(value, "%")); err == nil {
+				status.Load = load
+			}
+		case "Protocol":
+			status.Protocol = value
+		}
+	}
+
+	return status
+}