type Sequence = number[] | Buffer | Uint8Array

/**
 * Check whether two sequences (e.g. Arrays of numbers) are equal.
 *
 * @param arr1 - One of the arrays to compare.
 * @param arr2 - The other array to compare.
 */
export function seqEqual(arr1: Sequence, arr2: Sequence): boolean {
  if (arr1.length !== arr2.length) {
    return false
  }

  for (let i = 0; i < arr1.length; i++) {
    if (arr1[i] !== arr2[i]) {
      return false
    }
  }
  return true
}

/**
 * Check whether a value is a sequence (e.g. Array of numbers).
 *
 * @param val - The value to check.
 */
function isSequence(val: Sequence | number): val is Sequence {
  return typeof val !== 'number'
}

/**
 * Concatenate all `arguments` into a single array. Each argument can be either
 * a single element or a sequence, which has a `length` property and supports
 * element retrieval via sequence[ix].
 *
 * > concatArgs(1, [2, 3], Buffer.from([4,5]), new Uint8Array([6, 7]));
 * [1,2,3,4,5,6,7]
 *
 * @param args - Concatenate of these args into a single array.
 * @returns Array of concatenated arguments
 */
export function concatArgs(...args: Array<number | Sequence>): number[] {
  const ret: number[] = []

  args.forEach((arg) => {
    if (isSequence(arg)) {
      for (const j of arg) {
        ret.push(j)
      }
    } else {
      ret.push(arg)
    }
  })
  return ret
}