import { EncryptionType } from '../../enums/encryptionType';

import { Utils } from '../../misc/utils';

export class SymmetricCryptoKey {
    key: ArrayBuffer;
    encKey?: ArrayBuffer;
    macKey?: ArrayBuffer;
    encType: EncryptionType;

    keyB64: string;
    encKeyB64: string;
    macKeyB64: string;

    meta: any;

    constructor(key: ArrayBuffer, encType?: EncryptionType) {
        if (key == null) {
            throw new Error('Must provide key');
        }

        if (encType == null) {
            if (key.byteLength === 32) {
                encType = EncryptionType.AesCbc256_B64;
            } else if (key.byteLength === 64) {
                encType = EncryptionType.AesCbc256_HmacSha256_B64;
            } else {
                throw new Error('Unable to determine encType.');
            }
        }

        this.key = key;
        this.encType = encType;

        if (encType === EncryptionType.AesCbc256_B64 && key.byteLength === 32) {
            this.encKey = key;
            this.macKey = null;
        } else if (encType === EncryptionType.AesCbc128_HmacSha256_B64 && key.byteLength === 32) {
            this.encKey = key.slice(0, 16);
            this.macKey = key.slice(16, 32);
        } else if (encType === EncryptionType.AesCbc256_HmacSha256_B64 && key.byteLength === 64) {
            this.encKey = key.slice(0, 32);
            this.macKey = key.slice(32, 64);
        } else {
            throw new Error('Unsupported encType/key length.');
        }

        if (this.key != null) {
            this.keyB64 = Utils.fromBufferToB64(this.key);
        }
        if (this.encKey != null) {
            this.encKeyB64 = Utils.fromBufferToB64(this.encKey);
        }
        if (this.macKey != null) {
            this.macKeyB64 = Utils.fromBufferToB64(this.macKey);
        }
    }
}