feat:KCP协议

cmd/kcppeer/interactive.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+)
+
+const (
+	kcpInteractiveCommandHelp = "help"
+	kcpInteractiveCommandQuit = "quit"
+	kcpInteractiveCommandText = "text"
+	kcpInteractiveCommandFile = "file"
+)
+
+var errKCPEmptyInteractiveCommand = errors.New("interactive command is empty")
+
+type kcpInteractiveCommand struct {
+	name  string
+	to    string
+	value string
+}
+
+func parseKCPInteractiveCommand(line string) (kcpInteractiveCommand, error) {
+	commandName, rest, ok := cutKCPInteractiveField(strings.TrimSpace(line))
+	if !ok {
+		return kcpInteractiveCommand{}, errKCPEmptyInteractiveCommand
+	}
+
+	switch strings.ToLower(commandName) {
+	case "help", "h", "?":
+		return kcpInteractiveCommand{name: kcpInteractiveCommandHelp}, nil
+	case "quit", "exit":
+		return kcpInteractiveCommand{name: kcpInteractiveCommandQuit}, nil
+	case kcpInteractiveCommandText:
+		to, body, err := parseKCPInteractiveTargetValue(rest, kcpInteractiveCommandText)
+		if err != nil {
+			return kcpInteractiveCommand{}, err
+		}
+		return kcpInteractiveCommand{name: kcpInteractiveCommandText, to: to, value: body}, nil
+	case kcpInteractiveCommandFile:
+		to, path, err := parseKCPInteractiveTargetValue(rest, kcpInteractiveCommandFile)
+		if err != nil {
+			return kcpInteractiveCommand{}, err
+		}
+		return kcpInteractiveCommand{name: kcpInteractiveCommandFile, to: to, value: path}, nil
+	default:
+		return kcpInteractiveCommand{}, fmt.Errorf("unknown command %q; type help for usage", commandName)
+	}
+}
+
+func parseKCPInteractiveTargetValue(rest, commandName string) (string, string, error) {
+	to, value, ok := cutKCPInteractiveField(strings.TrimSpace(rest))
+	if !ok {
+		return "", "", fmt.Errorf("%s command requires a target peer and payload", commandName)
+	}
+	if strings.TrimSpace(value) == "" {
+		return "", "", fmt.Errorf("%s command requires a non-empty payload", commandName)
+	}
+
+	return to, strings.TrimSpace(value), nil
+}
+
+func cutKCPInteractiveField(input string) (string, string, bool) {
+	trimmed := strings.TrimSpace(input)
+	if trimmed == "" {
+		return "", "", false
+	}
+
+	for i, r := range trimmed {
+		if r == ' ' || r == '\t' {
+			return trimmed[:i], strings.TrimSpace(trimmed[i+1:]), true
+		}
+	}
+
+	return trimmed, "", true
+}
+
+func printKCPInteractiveHelp(w io.Writer) {
+	_, _ = fmt.Fprintln(w, "interactive mode commands (KCP):")
+	_, _ = fmt.Fprintln(w, "  help                    show this help")
+	_, _ = fmt.Fprintln(w, "  text <peer> <message>   send one text message over the existing KCP session")
+	_, _ = fmt.Fprintln(w, "  file <peer> <path>      send one file over the existing KCP session")
+	_, _ = fmt.Fprintln(w, "  quit                    exit this peer process")
+}