string_width

import { toList } from './gleam.mjs'

const ANSI_RE = /(?:\x1b[a-zA-Z])|(?:(?:\x1b\[|\x9b)[\x20-\x3f]*?[\x40-\x7e])|(?:[\x1b\x0d].*?(?:\x07|\x1b\\|\x9c))/mg
const ASCII_RE = /[\x20-\x7e]+/g;
const SEGMENTER = new Intl.Segmenter();

export function prepare_measure(options, str) {
  if (!options.count_ansi_codes) {
    str = str.replaceAll(ANSI_RE, '')
  }
  const ascii_ranges = scan_poslen(ASCII_RE, str)
  return [str, ascii_ranges, 1]
}

export function table_lookup(table, value) {
  let hi = value >> 8; // $int.bitwise_shift_right(value, 8);
  let md = (value & 0xff) >> 3; // $int.bitwise_shift_right($int.bitwise_and(value, 0xff), 3);
  let lo = value & 7; // $int.bitwise_and(value, 7);
  // return (remainderInt(
  //   $int.bitwise_shift_right(at(table, at(table, hi) * 32 + md), lo),
  //   2
  // )) !== 0;
  return ((table.byteAt(table.byteAt(hi) * 32 + md) >> lo) & 1) > 0;
}

export function match_ansi(str) {
  return scan_poslen(ANSI_RE, str)
}

export function strip_ansi(str) {
  return str.replaceAll(ANSI_RE, '')
}

export function unsafe_split(str, at) {
  return [str.slice(0, at), str.slice(at)]
}

export function fold_codepoints(str, state, fun) {
  for (const codePoint of str) {
    state = fun(state, codePoint.codePointAt(0))
  }
  return state
}

export function fold_graphemes(str, state, fun) {
  for(const { segment } of SEGMENTER.segment(str)) {
    state = fun(state, segment)
  }
  return state
}

export function utf_codepoint_to_string(cp) {
  return String.fromCodePoint(cp)
}

function scan_poslen(re, str) {
  let match
  let matches = []

  re.lastIndex = 0
  while (null !== (match = re.exec(str))) {
    matches.push([match.index, re.lastIndex-match.index])
  }

  return toList(matches)
}