// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
// Copyright 2017 Fedor Indutny. All rights reserved. MIT license.

import { Buffer } from "internal:deno_node/polyfills/buffer.ts";
import { Node } from "internal:deno_node/polyfills/_crypto/crypto_browserify/asn1.js/base/node.js";

// Import DER constants
import * as der from "internal:deno_node/polyfills/_crypto/crypto_browserify/asn1.js/constants/der.js";

export function DEREncoder(entity) {
  this.enc = "der";
  this.name = entity.name;
  this.entity = entity;

  // Construct base tree
  this.tree = new DERNode();
  this.tree._init(entity.body);
}

DEREncoder.prototype.encode = function encode(data, reporter) {
  return this.tree._encode(data, reporter).join();
};

// Tree methods

function DERNode(parent) {
  Node.call(this, "der", parent);
}
// inherits(DERNode, Node);
DERNode.prototype = Object.create(Node.prototype, {
  constructor: {
    value: DERNode,
    enumerable: false,
    writable: true,
    configurable: true,
  },
});

DERNode.prototype._encodeComposite = function encodeComposite(
  tag,
  primitive,
  cls,
  content,
) {
  const encodedTag = encodeTag(tag, primitive, cls, this.reporter);

  // Short form
  if (content.length < 0x80) {
    const header = Buffer.alloc(2);
    header[0] = encodedTag;
    header[1] = content.length;
    return this._createEncoderBuffer([header, content]);
  }

  // Long form
  // Count octets required to store length
  let lenOctets = 1;
  for (let i = content.length; i >= 0x100; i >>= 8) {
    lenOctets++;
  }

  const header = Buffer.alloc(1 + 1 + lenOctets);
  header[0] = encodedTag;
  header[1] = 0x80 | lenOctets;

  for (let i = 1 + lenOctets, j = content.length; j > 0; i--, j >>= 8) {
    header[i] = j & 0xff;
  }

  return this._createEncoderBuffer([header, content]);
};

DERNode.prototype._encodeStr = function encodeStr(str, tag) {
  if (tag === "bitstr") {
    return this._createEncoderBuffer([str.unused | 0, str.data]);
  } else if (tag === "bmpstr") {
    const buf = Buffer.alloc(str.length * 2);
    for (let i = 0; i < str.length; i++) {
      buf.writeUInt16BE(str.charCodeAt(i), i * 2);
    }
    return this._createEncoderBuffer(buf);
  } else if (tag === "numstr") {
    if (!this._isNumstr(str)) {
      return this.reporter.error(
        "Encoding of string type: numstr supports " +
          "only digits and space",
      );
    }
    return this._createEncoderBuffer(str);
  } else if (tag === "printstr") {
    if (!this._isPrintstr(str)) {
      return this.reporter.error(
        "Encoding of string type: printstr supports " +
          "only latin upper and lower case letters, " +
          "digits, space, apostrophe, left and rigth " +
          "parenthesis, plus sign, comma, hyphen, " +
          "dot, slash, colon, equal sign, " +
          "question mark",
      );
    }
    return this._createEncoderBuffer(str);
  } else if (/str$/.test(tag)) {
    return this._createEncoderBuffer(str);
  } else if (tag === "objDesc") {
    return this._createEncoderBuffer(str);
  } else {
    return this.reporter.error(
      "Encoding of string type: " + tag +
        " unsupported",
    );
  }
};

DERNode.prototype._encodeObjid = function encodeObjid(id, values, relative) {
  if (typeof id === "string") {
    if (!values) {
      return this.reporter.error("string objid given, but no values map found");
    }
    // deno-lint-ignore no-prototype-builtins
    if (!values.hasOwnProperty(id)) {
      return this.reporter.error("objid not found in values map");
    }
    id = values[id].split(/[\s.]+/g);
    for (let i = 0; i < id.length; i++) {
      id[i] |= 0;
    }
  } else if (Array.isArray(id)) {
    id = id.slice();
    for (let i = 0; i < id.length; i++) {
      id[i] |= 0;
    }
  }

  if (!Array.isArray(id)) {
    return this.reporter.error(
      "objid() should be either array or string, " +
        "got: " + JSON.stringify(id),
    );
  }

  if (!relative) {
    if (id[1] >= 40) {
      return this.reporter.error("Second objid identifier OOB");
    }
    id.splice(0, 2, id[0] * 40 + id[1]);
  }

  // Count number of octets
  let size = 0;
  for (let i = 0; i < id.length; i++) {
    let ident = id[i];
    for (size++; ident >= 0x80; ident >>= 7) {
      size++;
    }
  }

  const objid = Buffer.alloc(size);
  let offset = objid.length - 1;
  for (let i = id.length - 1; i >= 0; i--) {
    let ident = id[i];
    objid[offset--] = ident & 0x7f;
    while ((ident >>= 7) > 0) {
      objid[offset--] = 0x80 | (ident & 0x7f);
    }
  }

  return this._createEncoderBuffer(objid);
};

function two(num) {
  if (num < 10) {
    return "0" + num;
  } else {
    return num;
  }
}

DERNode.prototype._encodeTime = function encodeTime(time, tag) {
  let str;
  const date = new Date(time);

  if (tag === "gentime") {
    str = [
      two(date.getUTCFullYear()),
      two(date.getUTCMonth() + 1),
      two(date.getUTCDate()),
      two(date.getUTCHours()),
      two(date.getUTCMinutes()),
      two(date.getUTCSeconds()),
      "Z",
    ].join("");
  } else if (tag === "utctime") {
    str = [
      two(date.getUTCFullYear() % 100),
      two(date.getUTCMonth() + 1),
      two(date.getUTCDate()),
      two(date.getUTCHours()),
      two(date.getUTCMinutes()),
      two(date.getUTCSeconds()),
      "Z",
    ].join("");
  } else {
    this.reporter.error("Encoding " + tag + " time is not supported yet");
  }

  return this._encodeStr(str, "octstr");
};

DERNode.prototype._encodeNull = function encodeNull() {
  return this._createEncoderBuffer("");
};

DERNode.prototype._encodeInt = function encodeInt(num, values) {
  if (typeof num === "string") {
    if (!values) {
      return this.reporter.error("String int or enum given, but no values map");
    }
    // deno-lint-ignore no-prototype-builtins
    if (!values.hasOwnProperty(num)) {
      return this.reporter.error(
        "Values map doesn't contain: " +
          JSON.stringify(num),
      );
    }
    num = values[num];
  }

  // Bignum, assume big endian
  if (typeof num !== "number" && !Buffer.isBuffer(num)) {
    const numArray = num.toArray();
    if (!num.sign && numArray[0] & 0x80) {
      numArray.unshift(0);
    }
    num = Buffer.from(numArray);
  }

  if (Buffer.isBuffer(num)) {
    let size = num.length;
    if (num.length === 0) {
      size++;
    }

    const out = Buffer.alloc(size);
    num.copy(out);
    if (num.length === 0) {
      out[0] = 0;
    }
    return this._createEncoderBuffer(out);
  }

  if (num < 0x80) {
    return this._createEncoderBuffer(num);
  }

  if (num < 0x100) {
    return this._createEncoderBuffer([0, num]);
  }

  let size = 1;
  for (let i = num; i >= 0x100; i >>= 8) {
    size++;
  }

  const out = new Array(size);
  for (let i = out.length - 1; i >= 0; i--) {
    out[i] = num & 0xff;
    num >>= 8;
  }
  if (out[0] & 0x80) {
    out.unshift(0);
  }

  return this._createEncoderBuffer(Buffer.from(out));
};

DERNode.prototype._encodeBool = function encodeBool(value) {
  return this._createEncoderBuffer(value ? 0xff : 0);
};

DERNode.prototype._use = function use(entity, obj) {
  if (typeof entity === "function") {
    entity = entity(obj);
  }
  return entity._getEncoder("der").tree;
};

DERNode.prototype._skipDefault = function skipDefault(
  dataBuffer,
  reporter,
  parent,
) {
  const state = this._baseState;
  let i;
  if (state["default"] === null) {
    return false;
  }

  const data = dataBuffer.join();
  if (state.defaultBuffer === undefined) {
    state.defaultBuffer = this._encodeValue(state["default"], reporter, parent)
      .join();
  }

  if (data.length !== state.defaultBuffer.length) {
    return false;
  }

  for (i = 0; i < data.length; i++) {
    if (data[i] !== state.defaultBuffer[i]) {
      return false;
    }
  }

  return true;
};

// Utility methods

function encodeTag(tag, primitive, cls, reporter) {
  let res;

  if (tag === "seqof") {
    tag = "seq";
  } else if (tag === "setof") {
    tag = "set";
  }

  // deno-lint-ignore no-prototype-builtins
  if (der.tagByName.hasOwnProperty(tag)) {
    res = der.tagByName[tag];
  } else if (typeof tag === "number" && (tag | 0) === tag) {
    res = tag;
  } else {
    return reporter.error("Unknown tag: " + tag);
  }

  if (res >= 0x1f) {
    return reporter.error("Multi-octet tag encoding unsupported");
  }

  if (!primitive) {
    res |= 0x20;
  }

  res |= der.tagClassByName[cls || "universal"] << 6;

  return res;
}