// Terminal escapes: colours and cursor moves (CSI), titles and links (OSC), and the short ones.
const ESCAPES = /\x1b(?:\[[0-?]*[ -/]*[@-~]|\][^\x07\x1b]*(?:\x07|\x1b\\)|[@-Z\\-_])/g;

/**
 * A step's output as plain lines, the way a terminal would end up showing them: escapes removed and
 * carriage-return redraws (progress bars) collapsed to what was drawn last. Keeps the last `max` lines.
 */
export function logTail(text: string, max = 2000) {
  const lines = text
    .replace(ESCAPES, "")
    .replace(/\r+\n/g, "\n")
    .split("\n")
    .map((line) => line.slice(line.lastIndexOf("\r") + 1));
  if (lines.at(-1) === "") lines.pop();
  const omitted = Math.max(0, lines.length - max);
  return { lines: lines.slice(omitted), omitted };
}