// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// Copyright Joyent, Inc. and Node.js contributors. All rights reserved. MIT license.

// TODO(petamoriken): enable prefer-primordials for node polyfills
// deno-lint-ignore-file prefer-primordials

import { notImplemented } from "ext:deno_node/_utils.ts";
import { Buffer } from "node:buffer";
import {
  ERR_INVALID_ARG_TYPE,
  hideStackFrames,
} from "ext:deno_node/internal/errors.ts";
import {
  isAnyArrayBuffer,
  isArrayBufferView,
} from "ext:deno_node/internal/util/types.ts";
import { crypto as constants } from "ext:deno_node/internal_binding/constants.ts";
import {
  kHandle,
  kKeyObject,
} from "ext:deno_node/internal/crypto/constants.ts";

export type EllipticCurve = {
  name: string;
  ephemeral: boolean;
  privateKeySize: number;
  publicKeySize: number;
  publicKeySizeCompressed: number;
  sharedSecretSize: number;
};

export const ellipticCurves: Array<EllipticCurve> = [
  {
    name: "secp256k1",
    privateKeySize: 32,
    publicKeySize: 65,
    publicKeySizeCompressed: 33,
    sharedSecretSize: 32,
  }, // Weierstrass-class EC used by Bitcoin
  {
    name: "prime256v1",
    privateKeySize: 32,
    publicKeySize: 65,
    publicKeySizeCompressed: 33,
    sharedSecretSize: 32,
  }, // NIST P-256 EC
  {
    name: "secp256r1",
    privateKeySize: 32,
    publicKeySize: 65,
    publicKeySizeCompressed: 33,
    sharedSecretSize: 32,
  }, // NIST P-256 EC (same as above)
  {
    name: "secp384r1",
    privateKeySize: 48,
    publicKeySize: 97,
    publicKeySizeCompressed: 49,
    sharedSecretSize: 48,
  }, // NIST P-384 EC
  {
    name: "secp224r1",
    privateKeySize: 28,
    publicKeySize: 57,
    publicKeySizeCompressed: 29,
    sharedSecretSize: 28,
  }, // NIST P-224 EC
];

// deno-fmt-ignore
const supportedCiphers = [
  "aes-128-ecb",  "aes-192-ecb",
  "aes-256-ecb",  "aes-128-cbc",
  "aes-192-cbc",  "aes-256-cbc",
  "aes128",       "aes192",
  "aes256",       "aes-128-cfb",
  "aes-192-cfb",  "aes-256-cfb",
  "aes-128-cfb8", "aes-192-cfb8",
  "aes-256-cfb8", "aes-128-cfb1",
  "aes-192-cfb1", "aes-256-cfb1",
  "aes-128-ofb",  "aes-192-ofb",
  "aes-256-ofb",  "aes-128-ctr",
  "aes-192-ctr",  "aes-256-ctr",
  "aes-128-gcm",  "aes-192-gcm",
  "aes-256-gcm"
];

export function getCiphers(): string[] {
  return supportedCiphers;
}

export function getCipherInfo(
  nameOrNid: string | number,
  options?: { keyLength?: number; ivLength?: number },
) {
  if (typeof nameOrNid !== "string" && typeof nameOrNid !== "number") {
    throw new ERR_INVALID_ARG_TYPE(
      "nameOrNid",
      ["string", "number"],
      nameOrNid,
    );
  }

  if (typeof nameOrNid === "number") {
    validateInt32(nameOrNid, "nameOrNid");
  }

  let keyLength, ivLength;

  if (options !== undefined) {
    validateObject(options, "options");

    ({ keyLength, ivLength } = options);

    if (keyLength !== undefined) {
      validateInt32(keyLength, "options.keyLength");
    }

    if (ivLength !== undefined) {
      validateInt32(ivLength, "options.ivLength");
    }
  }

  // This API is heavily based on OpenSSL's EVP_get_cipherbyname(3) and
  // EVP_get_cipherbynid(3) functions.
  //
  // TODO(@littledivy): write proper cipher info utility in Rust
  // in future refactors
  const cipher = supportedCiphers.find((c) => c === nameOrNid);
  if (cipher === undefined) {
    return undefined;
  }

  const match = cipher.match(/^(aes)-(\d+)-(\w+)$/);
  if (match) {
    const [, name, keyLength, mode] = match;
    return {
      name: `${name}-${keyLength}-${mode}`,
      keyLength: parseInt(keyLength) / 8,
      mode,
      ivLength: 16,
    };
  }

  if (cipher === "aes128") {
    return {
      name: "aes-128-cbc",
      keyLength: 16,
      mode: "cbc",
      ivLength: 16,
    };
  }

  if (cipher === "aes192") {
    return {
      name: "aes-192-cbc",
      keyLength: 24,
      mode: "cbc",
      ivLength: 16,
    };
  }

  if (cipher === "aes256") {
    return {
      name: "aes-256-cbc",
      keyLength: 32,
      mode: "cbc",
      ivLength: 16,
    };
  }

  return undefined;
}

let defaultEncoding = "buffer";

export function setDefaultEncoding(val: string) {
  defaultEncoding = val;
}

export function getDefaultEncoding(): string {
  return defaultEncoding;
}

// This is here because many functions accepted binary strings without
// any explicit encoding in older versions of node, and we don't want
// to break them unnecessarily.
export function toBuf(val: string | Buffer, encoding?: string): Buffer {
  if (typeof val === "string") {
    if (encoding === "buffer") {
      encoding = "utf8";
    }

    return Buffer.from(val, encoding);
  }

  return val;
}

export const validateByteSource = hideStackFrames((val, name) => {
  val = toBuf(val);

  if (isAnyArrayBuffer(val) || isArrayBufferView(val)) {
    return;
  }

  throw new ERR_INVALID_ARG_TYPE(
    name,
    ["string", "ArrayBuffer", "TypedArray", "DataView", "Buffer"],
    val,
  );
});

const curveNames = ellipticCurves.map((x) => x.name);
export function getCurves(): readonly string[] {
  return curveNames;
}

export interface SecureHeapUsage {
  total: number;
  min: number;
  used: number;
  utilization: number;
}

export function secureHeapUsed(): SecureHeapUsage {
  notImplemented("crypto.secureHeapUsed");
}

export function setEngine(_engine: string, _flags: typeof constants) {
  notImplemented("crypto.setEngine");
}

const kAesKeyLengths = [128, 192, 256];

export { kAesKeyLengths, kHandle, kKeyObject };

export default {
  getDefaultEncoding,
  setDefaultEncoding,
  getCiphers,
  getCipherInfo,
  getCurves,
  secureHeapUsed,
  setEngine,
  validateByteSource,
  toBuf,
  kHandle,
  kKeyObject,
  kAesKeyLengths,
};