import Utils from "../Utils.js";
import {toBase64} from "../lib/Base64";
import {toHexFast} from "../lib/Hex";
import CryptoJS from "crypto-js";
import forge from "imports-loader?jQuery=>null!node-forge/dist/forge.min.js";
import {blowfish as Blowfish} from "sladex-blowfish";
import BigNumber from "bignumber.js";


/**
 * Cipher operations.
 *
 * @author n1474335 [n1474335@gmail.com]
 * @copyright Crown Copyright 2016
 * @license Apache-2.0
 *
 * @namespace
 */
const Cipher = {

    /**
     * @constant
     * @default
     */
    IO_FORMAT1: ["Hex", "UTF8", "Latin1", "Base64"],
    /**
    * @constant
    * @default
    */
    IO_FORMAT2: ["UTF8", "Latin1", "Hex", "Base64"],
    /**
    * @constant
    * @default
    */
    IO_FORMAT3: ["Raw", "Hex"],
    /**
    * @constant
    * @default
    */
    IO_FORMAT4: ["Hex", "Raw"],
    /**
     * @constant
     * @default
     */
    AES_MODES: ["CBC", "CFB", "OFB", "CTR", "GCM", "ECB"],

    /**
     * AES Encrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runAesEnc: function (input, args) {
        const key = Utils.convertToByteArray(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if ([16, 24, 32].indexOf(key.length) < 0) {
            return `Invalid key length: ${key.length} bytes

The following algorithms will be used based on the size of the key:
  16 bytes = AES-128
  24 bytes = AES-192
  32 bytes = AES-256`;
        }

        input = Utils.convertToByteString(input, inputType);

        const cipher = forge.cipher.createCipher("AES-" + mode, key);
        cipher.start({iv: iv});
        cipher.update(forge.util.createBuffer(input));
        cipher.finish();

        if (outputType === "Hex") {
            if (mode === "GCM") {
                return cipher.output.toHex() + "\n\n" +
                    "Tag: " + cipher.mode.tag.toHex();
            }
            return cipher.output.toHex();
        } else {
            if (mode === "GCM") {
                return cipher.output.getBytes() + "\n\n" +
                    "Tag: " + cipher.mode.tag.getBytes();
            }
            return cipher.output.getBytes();
        }
    },


    /**
     * AES Decrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runAesDec: function (input, args) {
        const key = Utils.convertToByteArray(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4],
            gcmTag = Utils.convertToByteString(args[5].string, args[5].option);

        if ([16, 24, 32].indexOf(key.length) < 0) {
            return `Invalid key length: ${key.length} bytes

The following algorithms will be used based on the size of the key:
  16 bytes = AES-128
  24 bytes = AES-192
  32 bytes = AES-256`;
        }

        input = Utils.convertToByteString(input, inputType);

        const decipher = forge.cipher.createDecipher("AES-" + mode, key);
        decipher.start({
            iv: iv,
            tag: gcmTag
        });
        decipher.update(forge.util.createBuffer(input));
        const result = decipher.finish();

        if (result) {
            return outputType === "Hex" ? decipher.output.toHex() : decipher.output.getBytes();
        } else {
            return "Unable to decrypt input with these parameters.";
        }
    },


    /**
     * @constant
     * @default
     */
    DES_MODES: ["CBC", "CFB", "OFB", "CTR", "ECB"],

    /**
     * DES Encrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runDesEnc: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length !== 8) {
            return `Invalid key length: ${key.length} bytes

DES uses a key length of 8 bytes (64 bits).
Triple DES uses a key length of 24 bytes (192 bits).`;
        }

        input = Utils.convertToByteString(input, inputType);

        const cipher = forge.cipher.createCipher("DES-" + mode, key);
        cipher.start({iv: iv});
        cipher.update(forge.util.createBuffer(input));
        cipher.finish();

        return outputType === "Hex" ? cipher.output.toHex() : cipher.output.getBytes();
    },


    /**
     * DES Decrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runDesDec: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length !== 8) {
            return `Invalid key length: ${key.length} bytes

DES uses a key length of 8 bytes (64 bits).
Triple DES uses a key length of 24 bytes (192 bits).`;
        }

        input = Utils.convertToByteString(input, inputType);

        const decipher = forge.cipher.createDecipher("DES-" + mode, key);
        decipher.start({iv: iv});
        decipher.update(forge.util.createBuffer(input));
        const result = decipher.finish();

        if (result) {
            return outputType === "Hex" ? decipher.output.toHex() : decipher.output.getBytes();
        } else {
            return "Unable to decrypt input with these parameters.";
        }
    },


    /**
     * Triple DES Encrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runTripleDesEnc: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length !== 24) {
            return `Invalid key length: ${key.length} bytes

Triple DES uses a key length of 24 bytes (192 bits).
DES uses a key length of 8 bytes (64 bits).`;
        }

        input = Utils.convertToByteString(input, inputType);

        const cipher = forge.cipher.createCipher("3DES-" + mode, key);
        cipher.start({iv: iv});
        cipher.update(forge.util.createBuffer(input));
        cipher.finish();

        return outputType === "Hex" ? cipher.output.toHex() : cipher.output.getBytes();
    },


    /**
     * Triple DES Decrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runTripleDesDec: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length !== 24) {
            return `Invalid key length: ${key.length} bytes

Triple DES uses a key length of 24 bytes (192 bits).
DES uses a key length of 8 bytes (64 bits).`;
        }

        input = Utils.convertToByteString(input, inputType);

        const decipher = forge.cipher.createDecipher("3DES-" + mode, key);
        decipher.start({iv: iv});
        decipher.update(forge.util.createBuffer(input));
        const result = decipher.finish();

        if (result) {
            return outputType === "Hex" ? decipher.output.toHex() : decipher.output.getBytes();
        } else {
            return "Unable to decrypt input with these parameters.";
        }
    },


    /**
     * RC2 Encrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runRc2Enc: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteString(args[1].string, args[1].option),
            inputType = args[2],
            outputType = args[3],
            cipher = forge.rc2.createEncryptionCipher(key);

        input = Utils.convertToByteString(input, inputType);

        cipher.start(iv || null);
        cipher.update(forge.util.createBuffer(input));
        cipher.finish();

        return outputType === "Hex" ? cipher.output.toHex() : cipher.output.getBytes();
    },


    /**
     * RC2 Decrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runRc2Dec: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteString(args[1].string, args[1].option),
            inputType = args[2],
            outputType = args[3],
            decipher = forge.rc2.createDecryptionCipher(key);

        input = Utils.convertToByteString(input, inputType);

        decipher.start(iv || null);
        decipher.update(forge.util.createBuffer(input));
        decipher.finish();

        return outputType === "Hex" ? decipher.output.toHex() : decipher.output.getBytes();
    },


    /**
     * @constant
     * @default
     */
    BLOWFISH_MODES: ["CBC", "PCBC", "CFB", "OFB", "CTR", "ECB"],
    /**
     * @constant
     * @default
     */
    BLOWFISH_OUTPUT_TYPES: ["Hex", "Base64", "Raw"],

    /**
     * Lookup table for Blowfish output types.
     *
     * @private
     */
    _BLOWFISH_OUTPUT_TYPE_LOOKUP: {
        Base64: 0, Hex: 1, String: 2, Raw: 3
    },
    /**
     * Lookup table for Blowfish modes.
     *
     * @private
     */
    _BLOWFISH_MODE_LOOKUP: {
        ECB: 0, CBC: 1, PCBC: 2, CFB: 3, OFB: 4, CTR: 5
    },

    /**
     * Blowfish Encrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runBlowfishEnc: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length === 0) return "Enter a key";

        input = Utils.convertToByteString(input, inputType);

        Blowfish.setIV(toBase64(iv), 0);

        const enc = Blowfish.encrypt(input, key, {
            outputType: Cipher._BLOWFISH_OUTPUT_TYPE_LOOKUP[outputType],
            cipherMode: Cipher._BLOWFISH_MODE_LOOKUP[mode]
        });

        return outputType === "Raw" ? Utils.byteArrayToChars(enc) : enc   ;
    },


    /**
     * Blowfish Decrypt operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runBlowfishDec: function (input, args) {
        const key = Utils.convertToByteString(args[0].string, args[0].option),
            iv = Utils.convertToByteArray(args[1].string, args[1].option),
            mode = args[2],
            inputType = args[3],
            outputType = args[4];

        if (key.length === 0) return "Enter a key";

        input = inputType === "Raw" ? Utils.strToByteArray(input) : input;

        Blowfish.setIV(toBase64(iv), 0);

        const result = Blowfish.decrypt(input, key, {
            outputType: Cipher._BLOWFISH_OUTPUT_TYPE_LOOKUP[inputType], // This actually means inputType. The library is weird.
            cipherMode: Cipher._BLOWFISH_MODE_LOOKUP[mode]
        });

        return outputType === "Hex" ? toHexFast(Utils.strToByteArray(result)) : result;
    },


    /**
     * @constant
     * @default
     */
    KDF_KEY_SIZE: 128,
    /**
     * @constant
     * @default
     */
    KDF_ITERATIONS: 1,
    /**
     * @constant
     * @default
     */
    HASHERS: ["SHA1", "SHA256", "SHA384", "SHA512", "MD5"],

    /**
     * Derive PBKDF2 key operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runPbkdf2: function (input, args) {
        const passphrase = Utils.convertToByteString(args[0].string, args[0].option),
            keySize = args[1],
            iterations = args[2],
            hasher = args[3],
            salt = Utils.convertToByteString(args[4].string, args[4].option) ||
                forge.random.getBytesSync(keySize),
            derivedKey = forge.pkcs5.pbkdf2(passphrase, salt, iterations, keySize / 8, hasher.toLowerCase());

        return forge.util.bytesToHex(derivedKey);
    },


    /**
     * @constant
     * @default
     */
    PRNG_BYTES: 32,
    /**
     * @constant
     * @default
     */
    PRNG_OUTPUT: ["Hex", "Integer", "Byte array", "Raw"],

    /**
     * Pseudo-Random Number Generator operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runPRNG: function(input, args) {
        const numBytes = args[0],
            outputAs = args[1];

        let bytes;

        if (ENVIRONMENT_IS_WORKER() && self.crypto) {
            bytes = self.crypto.getRandomValues(new Uint8Array(numBytes));
            bytes = Utils.arrayBufferToStr(bytes.buffer);
        } else {
            bytes = forge.random.getBytesSync(numBytes);
        }

        let value = new BigNumber(0),
            i;

        switch (outputAs) {
            case "Hex":
                return forge.util.bytesToHex(bytes);
            case "Integer":
                for (i = bytes.length - 1; i >= 0; i--) {
                    value = value.times(256).plus(bytes.charCodeAt(i));
                }
                return value.toFixed();
            case "Byte array":
                return JSON.stringify(Utils.strToCharcode(bytes));
            case "Raw":
            default:
                return bytes;
        }
    },

};

export default Cipher;