export function bytesToAscii(bytes: number[]): string {
	let s = ''
	for (let i = 0; i < bytes.length; i++) s += String.fromCharCode(bytes[i] & 0xFF)
	return s
}

export function asciiToBytes(s: string): Array<number> {
 const out = [] as Array<number>
  for (let i = 0; i < s.length; i++) {
    const c = s.charCodeAt(i)
    out.push(c == null ? 0 : c)
  }
  return out
}

export function bytesToHex(bytes: number[]): string {
	let s = ''
	for (let i = 0; i < bytes.length; i++) {
		const v = bytes[i] & 0xFF
		s += (v < 16 ? '0' : '') + v.toString(16)
	}
	return s
}

// "4D 00 00 01 01"  => 0x4d 0x00 0x00 0x01 0x01
export function parseHexBytes(input: string): Array<number> | null {
  let s = input.trim()
  if (s.length == 0) return [] as Array<number>

  // 逗号、换行、制表符 全部变空格（全局）
  s = s.replace(/[,\n\t]/g, " ")

  // 去掉 0x / 0X（全局）
  s = s.replace(/0x/ig, "")

  const parts = s.split(" ")
  const out = [] as Array<number>

  for (let i = 0; i < parts.length; i++) {
    const p = parts[i].trim()
    if (p.length == 0) continue

    const token = (p.length == 1) ? ("0" + p) : p
    const v = parseInt(token, 16)
    if (isNaN(v) || v < 0 || v > 255) return null
    out.push(v)
  }
  return out
}