import stream from "stream";
import { StringDecoder as StringDecoder$0 } from "string_decoder";
import { inherits as inherits$0 } from "util";
var Transform = stream.Transform;
var StringDecoder = { StringDecoder: StringDecoder$0 }.StringDecoder;
var inherits = { inherits: inherits$0 }.inherits;
function CipherBase(hashMode) {
    Transform.call(this);
    this.hashMode = typeof hashMode === 'string';
    if (this.hashMode) {
        this[hashMode] = this._finalOrDigest;
    }
    else {
        this.final = this._finalOrDigest;
    }
    if (this._final) {
        this.__final = this._final;
        this._final = null;
    }
    this._decoder = null;
    this._encoding = null;
}
inherits(CipherBase, Transform);
CipherBase.prototype.update = function (data, inputEnc, outputEnc) {
    if (typeof data === 'string') {
        data = Buffer.from(data, inputEnc);
    }
    var outData = this._update(data);
    if (this.hashMode)
        return this;
    if (outputEnc) {
        outData = this._toString(outData, outputEnc);
    }
    return outData;
};
CipherBase.prototype.setAutoPadding = function () { };
CipherBase.prototype.getAuthTag = function () {
    throw new Error('trying to get auth tag in unsupported state');
};
CipherBase.prototype.setAuthTag = function () {
    throw new Error('trying to set auth tag in unsupported state');
};
CipherBase.prototype.setAAD = function () {
    throw new Error('trying to set aad in unsupported state');
};
CipherBase.prototype._transform = function (data, _, next) {
    var err;
    try {
        if (this.hashMode) {
            this._update(data);
        }
        else {
            this.push(this._update(data));
        }
    }
    catch (e) {
        err = e;
    }
    finally {
        next(err);
    }
};
CipherBase.prototype._flush = function (done) {
    var err;
    try {
        this.push(this.__final());
    }
    catch (e) {
        err = e;
    }
    done(err);
};
CipherBase.prototype._finalOrDigest = function (outputEnc) {
    var outData = this.__final() || Buffer.alloc(0);
    if (outputEnc) {
        outData = this._toString(outData, outputEnc, true);
    }
    return outData;
};
CipherBase.prototype._toString = function (value, enc, fin) {
    if (!this._decoder) {
        this._decoder = new StringDecoder(enc);
        this._encoding = enc;
    }
    if (this._encoding !== enc)
        throw new Error('can\'t switch encodings');
    var out = this._decoder.write(value);
    if (fin) {
        out += this._decoder.end();
    }
    return out;
};
export default CipherBase;