import type { Theme } from "@earendil-works/pi-coding-agent";
import { truncateToWidth, visibleWidth } from "@earendil-works/pi-tui";

/** pi-core keybinding-hint convention: dim key + muted description. */
export function hintLine(th: Theme, pairs: Array<[string, string]>): string {
  return " " + pairs.map(([k, d]) => th.fg("dim", k) + th.fg("muted", ` ${d}`)).join("  ");
}

/**
 * Render highest-priority hints that fit, without letting navigation displace
 * the primary action or cancel. pi-tui measures display cells after stripping
 * ANSI sequences, so CJK and themed hints remain width-safe.
 */
export function prioritizedHintLine(th: Theme, pairs: Array<[string, string]>, width: number, ellipsis: string): string {
  const full = hintLine(th, pairs);
  if (visibleWidth(full) <= width) return full;

  let prefix = "";
  for (const pair of pairs) {
    const hint = hintLine(th, [pair]);
    const candidate = prefix ? `${prefix}  ${hint.trimStart()}` : hint;
    // Reserve the truncation marker before accepting each complete hint. Once
    // a higher-priority hint cannot fit, no lower-priority hint may replace it.
    if (visibleWidth(`${candidate}  ${ellipsis}`) > width) break;
    prefix = candidate;
  }
  return prefix ? `${prefix}  ${ellipsis}` : truncateToWidth(ellipsis, width, "");
}