/**

* @module

* Encode utility.

*/

export const decodeBase64Url = (str: string): Uint8Array<ArrayBuffer> => {

return decodeBase64(str.replace(/_|-/g, (m) => ({ _: '/', '-': '+' })[m] ?? m))

}

export const encodeBase64Url = (buf: ArrayBufferLike): string =>

encodeBase64(buf).replace(/\/|\+/g, (m) => ({ '/': '_', '+': '-' })[m] ?? m)

// This approach is written in MDN.

// btoa does not support utf-8 characters. So we need a little bit hack.

export const encodeBase64 = (buf: ArrayBufferLike): string => {

let binary = ''

const bytes = new Uint8Array(buf)

for (let i = 0, len = bytes.length; i < len; i++) {

binary += String.fromCharCode(bytes[i])

}

return btoa(binary)

}

// atob does not support utf-8 characters. So we need a little bit hack.

export const decodeBase64 = (str: string): Uint8Array<ArrayBuffer> => {

const binary = atob(str)

const bytes = new Uint8Array<ArrayBuffer>(new ArrayBuffer(binary.length))

const half = binary.length / 2

for (let i = 0, j = binary.length - 1; i <= half; i++, j--) {

bytes[i] = binary.charCodeAt(i)

bytes[j] = binary.charCodeAt(j)

}

return bytes

}