export type VoiceChatCommand =
  | { kind: "set_voice"; voiceName: string }
  | { kind: "speak_on" }
  | { kind: "speak_off" };

const SET_VOICE_PATTERNS = [
  /^(?:\/stimme|\/voice)\s+(.+)$/i,
  /^(?:ändere|aendere|wechsel|nimm)\s+(?:deine\s+)?stimme\s+(?:zu|auf|in)\s+(.+)$/i,
  /^(?:change|switch|use)\s+(?:your\s+)?voice\s+(?:to\s+)?(.+)$/i,
  /^sprich\s+(?:mit\s+)?(?:der\s+)?stimme\s+(.+)$/i,
  /^(?:nutze|verwende|nimm)\s+(?:die\s+)?stimme\s+(.+)$/i,
] as const;

const SPEAK_ON_PATTERNS = [
  /^(?:\/sprechen|\/speak)$/i,
  /^(?:kann\s+wieder\s+)?sprechen$/i,
  /^(?:lies|lese)\s+(?:antworten\s+)?(?:wieder\s+)?(?:laut\s+)?vor$/i,
  /^(?:turn\s+)?speak(?:ing)?\s+on$/i,
  /^read\s+(?:replies\s+)?aloud$/i,
] as const;

const SPEAK_OFF_PATTERNS = [
  /^(?:\/schweigen|\/mute)$/i,
  /^(?:sprich\s+)?(?:nicht\s+mehr|nicht\s+wieder)$/i,
  /^sprich\s+nicht$/i,
  /^(?:turn\s+)?speak(?:ing)?\s+off$/i,
  /^stop\s+speaking$/i,
  /^schweig(?:e)?$/i,
] as const;

function firstCapture(patterns: readonly RegExp[], text: string): string | undefined {
  for (const pattern of patterns) {
    const match = pattern.exec(text.trim());
    const captured = match?.[1]?.trim();
    if (captured) return captured;
  }
  return undefined;
}

function matchesAny(patterns: readonly RegExp[], text: string): boolean {
  const trimmed = text.trim();
  return patterns.some((pattern) => pattern.test(trimmed));
}

/** Parse a chat message for local voice control before sending to the agent. */
export function parseVoiceChatCommand(text: string): VoiceChatCommand | null {
  const trimmed = text.trim();
  if (!trimmed) return null;

  if (matchesAny(SPEAK_OFF_PATTERNS, trimmed)) return { kind: "speak_off" };
  if (matchesAny(SPEAK_ON_PATTERNS, trimmed)) return { kind: "speak_on" };

  const voiceName = firstCapture(SET_VOICE_PATTERNS, trimmed);
  if (voiceName) return { kind: "set_voice", voiceName };

  return null;
}