feat: add TS3 command encoding/decoding with escape handling

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ts-protocol/commands.ts

@@ -0,0 +1,77 @@
+const ESCAPE_MAP: [string, string][] = [
+  ["\\", "\\\\"],
+  ["/", "\\/"],
+  [" ", "\\s"],
+  ["|", "\\p"],
+  ["\n", "\\n"],
+  ["\r", "\\r"],
+  ["\t", "\\t"],
+  ["\x07", "\\a"],
+  ["\x08", "\\b"],
+  ["\x0C", "\\f"],
+  ["\x0B", "\\v"],
+];
+
+const UNESCAPE_MAP: [string, string][] = ESCAPE_MAP.map(
+  ([plain, escaped]) => [escaped, plain] as [string, string]
+).reverse();
+
+export function escapeValue(value: string): string {
+  let result = value;
+  for (const [plain, escaped] of ESCAPE_MAP) {
+    result = result.replaceAll(plain, escaped);
+  }
+  return result;
+}
+
+export function unescapeValue(value: string): string {
+  let result = value;
+  for (const [escaped, plain] of UNESCAPE_MAP) {
+    result = result.replaceAll(escaped, plain);
+  }
+  return result;
+}
+
+export function encodeCommand(
+  command: string,
+  params: Record<string, string | number>
+): string {
+  const parts = [command];
+  for (const [key, value] of Object.entries(params)) {
+    parts.push(`${key}=${escapeValue(String(value))}`);
+  }
+  return parts.join(" ") + "\n";
+}
+
+export function decodeResponse(raw: string): Record<string, string>[] {
+  const entries = raw.split("|");
+  return entries.map((entry) => {
+    const result: Record<string, string> = {};
+    const pairs = entry.trim().split(" ");
+    for (const pair of pairs) {
+      const eqIndex = pair.indexOf("=");
+      if (eqIndex === -1) {
+        result[pair] = "";
+      } else {
+        const key = pair.substring(0, eqIndex);
+        const value = unescapeValue(pair.substring(eqIndex + 1));
+        result[key] = value;
+      }
+    }
+    return result;
+  });
+}
+
+export interface TS3Response {
+  errorId: number;
+  errorMessage: string;
+  data: Record<string, string>[];
+}
+
+export function parseErrorLine(line: string): { id: number; msg: string } {
+  const decoded = decodeResponse(line.replace(/^error\s+/, ""))[0];
+  return {
+    id: parseInt(decoded.id ?? "0", 10),
+    msg: decoded.msg ?? "ok",
+  };
+}