import {createHmac, randomBytes} from 'crypto';

import {formatISO} from 'date-fns';

import {Effect} from 'effect';

import {ApiKeyError, DefaultError} from '../errors/defaultError';

enum AuthenticateType {

API_KEY,

}

export type AuthenticationParameter = {

apiKey: string;

apiSecret: string;

};

/**

* 특정 사이즈의 텍스트를 생성합니다.

* @param alphabet 지정할 알파벳/숫자 문자열

* @param size 지정할 문자 길이

*/

function genCustomText(alphabet: string, size: number): string {

const bytes = randomBytes(size);

let genRandomText = '';

for (let i = 0; i < size; i++) {

genRandomText += alphabet[bytes[i] % alphabet.length];

}

return genRandomText;

}

/**

* Get Authenticate Information for SOLAPI Requests

* @param authenticationParameter

* @param authType

* @return Effect<string, ApiKeyError> Authorization value

*/

export default function getAuthInfo(

authenticationParameter: AuthenticationParameter,

authType: AuthenticateType = AuthenticateType.API_KEY,

): Effect.Effect<string, ApiKeyError | DefaultError> {

const {apiKey, apiSecret} = authenticationParameter;

switch (authType) {

case AuthenticateType.API_KEY:

default:

if (!apiKey || !apiSecret) {

return Effect.fail(

new ApiKeyError({message: 'API Key와 API Secret은 필수입니다.'}),

);

}

return Effect.try({

try: () => {

const salt = genCustomText(

'1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',

32,

);

const date = formatISO(new Date());

const hmacData = date + salt;

const genHmac = createHmac('sha256', apiSecret);

genHmac.update(hmacData);

const signature = genHmac.digest('hex');

return `HMAC-SHA256 apiKey=${apiKey}, date=${date}, salt=${salt}, signature=${signature}`;

},

catch: e =>

new DefaultError({

errorCode: 'AuthError',

errorMessage: e instanceof Error ? e.message : String(e),

}),

});

}

}