//See: https://github.com/ethereum/wiki/wiki/RLP

import { getBytes } from "./data.js";

import type { RlpStructuredDataish } from "./rlp.js";

function arrayifyInteger(value: number): Array<number> {

const result: Array<number> = [];

while (value) {

result.unshift(value & 0xff);

value >>= 8;

}

return result;

}

function _encode(object: Array<any> | string | Uint8Array): Array<number> {

if (Array.isArray(object)) {

let payload: Array<number> = [];

object.forEach(function(child) {

payload = payload.concat(_encode(child));

});

if (payload.length <= 55) {

payload.unshift(0xc0 + payload.length)

return payload;

}

const length = arrayifyInteger(payload.length);

length.unshift(0xf7 + length.length);

return length.concat(payload);

}

const data: Array<number> = Array.prototype.slice.call(getBytes(object, "object"));

if (data.length === 1 && data[0] <= 0x7f) {

return data;

} else if (data.length <= 55) {

data.unshift(0x80 + data.length);

return data;

}

const length = arrayifyInteger(data.length);

length.unshift(0xb7 + length.length);

return length.concat(data);

}

const nibbles = "0123456789abcdef";

/**

* Encodes %%object%% as an RLP-encoded [[DataHexString]].

*/

export function encodeRlp(object: RlpStructuredDataish): string {

let result = "0x";

for (const v of _encode(object)) {

result += nibbles[v >> 4];

result += nibbles[v & 0xf];

}

return result;

}