export function tokenizeArgs(input: string): string[] {
  const tokens: string[] = [];
  let current = "";
  let quote: '"' | "'" | undefined;
  let escaped = false;

  for (const char of input) {
    if (escaped) {
      current += char;
      escaped = false;
      continue;
    }

    if (char === "\\") {
      escaped = true;
      continue;
    }

    if (quote) {
      if (char === quote) quote = undefined;
      else current += char;
      continue;
    }

    if (char === '"' || char === "'") {
      quote = char;
      continue;
    }

    if (/\s/.test(char)) {
      if (current) {
        tokens.push(current);
        current = "";
      }
      continue;
    }

    current += char;
  }

  if (escaped) current += "\\";
  if (quote) throw new Error(`Unclosed ${quote} quote`);
  if (current) tokens.push(current);
  return tokens;
}

export function takeValue(tokens: string[], index: number, flag: string): string {
  const value = tokens[index + 1];
  if (!value || value.startsWith("--")) throw new Error(`${flag} requires a value`);
  return value;
}

export function takeOptionalValue(tokens: string[], index: number): string | undefined {
  const value = tokens[index + 1];
  return value && !value.startsWith("--") ? value : undefined;
}