gemini-cli/packages/cli/src/ui/utils/textUtils.ts

/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * Calculates the maximum width of a multi-line ASCII art string.
 * @param asciiArt The ASCII art string.
 * @returns The length of the longest line in the ASCII art.
 */
export const getAsciiArtWidth = (asciiArt: string): number => {
  if (!asciiArt) {
    return 0;
  }
  const lines = asciiArt.split('\n');
  return Math.max(...lines.map((line) => line.length));
};

/*
 * -------------------------------------------------------------------------
 *  Unicode‑aware helpers (work at the code‑point level rather than UTF‑16
 *  code units so that surrogate‑pair emoji count as one "column".)
 * ---------------------------------------------------------------------- */

export function toCodePoints(str: string): string[] {
  // [...str] or Array.from both iterate by UTF‑32 code point, handling
  // surrogate pairs correctly.
  return Array.from(str);
}

export function cpLen(str: string): number {
  return toCodePoints(str).length;
}

export function cpSlice(str: string, start: number, end?: number): string {
  // Slice by code‑point indices and re‑join.
  const arr = toCodePoints(str).slice(start, end);
  return arr.join('');
}