Refactor serialization logic in BookService, VisitorService, and WorkerService

- Simplified the serialization of book, visitor, and worker objects by removing unnecessary asynchronous calls to serializeTxtRow.
- Updated the writeLines method to directly use the synchronous map function for improved performance.
- Removed unused key-manager, crypto, lzss, and offset-encryption utility files to clean up the codebase.

src/book/book.service.ts

@@ -34,7 +34,7 @@ export class BookService {
       status: BookStatus.AVAILABLE,
     };
     const lines = await this.file.readLines();
-    lines.push(await serializeTxtRow(newBook));
+    lines.push(serializeTxtRow(newBook));
     await this.file.writeLines(lines);
     return newBook;
   }
@@ -44,9 +44,7 @@ export class BookService {
     const index = books.findIndex((b) => b.id === id);
     if (index === -1) return null;
     books[index] = { ...books[index], ...dto };
-    await this.file.writeLines(
-      await Promise.all(books.map((book) => serializeTxtRow(book))),
-    );
+    await this.file.writeLines(books.map(serializeTxtRow));
     return books[index];
   }
 
@@ -55,9 +53,7 @@ export class BookService {
     const index = books.findIndex((b) => b.id === id);
     if (index === -1) return false;
     books.splice(index, 1);
-    await this.file.writeLines(
-      await Promise.all(books.map((book) => serializeTxtRow(book))),
-    );
+    await this.file.writeLines(books.map(serializeTxtRow));
     return true;
   }
 
@@ -81,9 +77,7 @@ export class BookService {
       borrowed.push(book);
     }
 
-    await this.file.writeLines(
-      await Promise.all(books.map((book) => serializeTxtRow(book))),
-    );
+    await this.file.writeLines(books.map(serializeTxtRow));
     return borrowed;
   }
 
@@ -115,9 +109,7 @@ export class BookService {
       returned.push(book);
     }
 
-    await this.file.writeLines(
-      await Promise.all(books.map((book) => serializeTxtRow(book))),
-    );
+    await this.file.writeLines(books.map(serializeTxtRow));
     return returned;
   }
 }

src/common/key-manager.ts

@@ -1,51 +0,0 @@
-import { promises as fs } from 'fs';
-import path from 'path';
-import {
-  decryptWithAlphabet,
-  encryptWithAlphabet,
-} from 'src/utils/offset-encryption.util';
-
-const dataDir = path.join(process.cwd(), 'src/data/encrypted/');
-const keyFile = path.join(dataDir, '.encryption_key');
-
-const MASTER_KEY = process.env.MASTER_KEY || 'RSIOT_SECRET_KEY_VARIAHT1';
-
-export async function ensureDataDir(): Promise<void> {
-  try {
-    await fs.access(dataDir);
-  } catch {
-    await fs.mkdir(dataDir, { recursive: true });
-  }
-}
-
-export async function getOrCreateKey(): Promise<string> {
-  await ensureDataDir();
-
-  try {
-    const encryptedKey = await fs.readFile(keyFile, 'utf-8');
-    return decryptWithAlphabet(encryptedKey, MASTER_KEY);
-  } catch (err: unknown) {
-    if (err instanceof Error && err.message.includes('ENOENT')) {
-      const newKey = generateRandomKey(16);
-      await saveKey(newKey);
-      return newKey;
-    }
-    throw err;
-  }
-}
-
-export async function saveKey(key: string): Promise<void> {
-  await ensureDataDir();
-  const encryptedKey = encryptWithAlphabet(key, MASTER_KEY);
-  await fs.writeFile(keyFile, encryptedKey, 'utf-8');
-}
-
-export function generateRandomKey(length: number): string {
-  const chars =
-    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*';
-  let key = '';
-  for (let i = 0; i < length; i++) {
-    key += chars.charAt(Math.floor(Math.random() * chars.length));
-  }
-  return key;
-}

src/utils/crypto.utils.ts

@@ -1,23 +0,0 @@
-import { lzssEncode, lzssDecode } from './lzss.util';
-import {
-  encryptWithAlphabet,
-  decryptWithAlphabet,
-} from './offset-encryption.util';
-import { getOrCreateKey } from 'src/common/key-manager';
-
-export async function encryptData(data: string): Promise<string> {
-  const compressed = lzssEncode(data);
-  const key = await getOrCreateKey();
-  const encrypted = encryptWithAlphabet(compressed, key);
-
-  return encrypted;
-}
-
-export async function decryptData(encrypted: string): Promise<string> {
-  const key = await getOrCreateKey();
-  const decrypted = decryptWithAlphabet(encrypted, key);
-  const decompressed = lzssDecode(decrypted);
-  console.log('decompressed', decompressed);
-
-  return decompressed;
-}

src/utils/file.utils.ts

@@ -1,13 +1,11 @@
 /* eslint-disable @typescript-eslint/no-unsafe-member-access */
 import { Link } from '../common/Link';
-import { decryptData, encryptData } from './crypto.utils';
-
 function isLinkString(value: string | undefined) {
   if (!value) return false;
   return /^[a-zA-Z]+:[^:]+$/.test(value);
 }
 
-function parseTxtRowInternal(row: string): any {
+export function parseTxtRow(row: string): any {
   if (typeof row !== 'string') {
     throw new Error('parseTxtRow: row is not string: ' + JSON.stringify(row));
   }
@@ -53,7 +51,7 @@ function parseTxtRowInternal(row: string): any {
   return obj;
 }
 
-function serializeTxtRowInternal(obj: any): string {
+export function serializeTxtRow(obj: any): string {
   return Object.entries(obj)
     .map(([key, value]) => {
       if (value instanceof Link) {
@@ -76,13 +74,3 @@ function serializeTxtRowInternal(obj: any): string {
     })
     .join(';');
 }
-
-export async function parseTxtRow(encryptedRow: string): Promise<any> {
-  const decrypted = await decryptData(encryptedRow);
-  return parseTxtRowInternal(decrypted);
-}
-
-export async function serializeTxtRow(obj: any): Promise<string> {
-  const serialized = serializeTxtRowInternal(obj);
-  return await encryptData(serialized);
-}

src/utils/lzss.util.ts

@@ -1,165 +0,0 @@
-export interface LZSSMatch {
-  offset: number;
-  length: number;
-}
-
-export interface LZSSToken {
-  type: 'literal' | 'match';
-  value: string | LZSSMatch;
-}
-
-// Параметры LZSS
-const WINDOW_SIZE = 4096; // Размер окна поиска (12 бит)
-const LOOKAHEAD_SIZE = 18; // Размер буфера упреждения
-const MIN_MATCH_LENGTH = 3; // Минимальная длина совпадения
-
-export function lzssEncode(text: string): string {
-  if (!text) return '';
-
-  const tokens: LZSSToken[] = [];
-  let pos = 0;
-
-  while (pos < text.length) {
-    let bestMatch: LZSSMatch | null = null;
-    let bestLength = 0;
-
-    // Определяем начало окна поиска
-    const windowStart = Math.max(0, pos - WINDOW_SIZE);
-    const lookaheadEnd = Math.min(text.length, pos + LOOKAHEAD_SIZE);
-
-    // Ищем самое длинное совпадение в окне
-    for (let i = windowStart; i < pos; i++) {
-      let matchLength = 0;
-
-      // Считаем длину совпадения
-      while (
-        pos + matchLength < lookaheadEnd &&
-        text[i + matchLength] === text[pos + matchLength]
-      ) {
-        matchLength++;
-      }
-
-      // Если найдено лучшее совпадение
-      if (matchLength >= MIN_MATCH_LENGTH && matchLength > bestLength) {
-        bestLength = matchLength;
-        bestMatch = {
-          offset: pos - i,
-          length: matchLength,
-        };
-      }
-    }
-
-    if (bestMatch) {
-      tokens.push({
-        type: 'match',
-        value: bestMatch,
-      });
-      pos += bestMatch.length;
-    } else {
-      tokens.push({
-        type: 'literal',
-        value: text[pos],
-      });
-      pos++;
-    }
-  }
-
-  // Кодируем токены в бинарную строку
-  return encodeTokens(tokens);
-}
-
-function encodeTokens(tokens: LZSSToken[]): string {
-  let result = '';
-
-  for (const token of tokens) {
-    if (token.type === 'literal') {
-      // Флаг 1 означает литерал, затем 8 бит символа
-      result += '1';
-      const char = token.value as string;
-      const charCode = char.charCodeAt(0);
-      result += charCode.toString(2).padStart(16, '0'); // 16 бит для Unicode
-    } else {
-      // Флаг 0 означает совпадение
-      result += '0';
-      const match = token.value as LZSSMatch;
-      // 12 бит для смещения, 6 бит для длины (максимум 18+3=21)
-      result += match.offset.toString(2).padStart(12, '0');
-      result += (match.length - MIN_MATCH_LENGTH).toString(2).padStart(6, '0');
-    }
-  }
-
-  return result;
-}
-
-export function lzssDecode(encoded: string): string {
-  if (!encoded) return '';
-
-  let result = '';
-  let pos = 0;
-
-  while (pos < encoded.length) {
-    const flag = encoded[pos];
-    pos++;
-
-    if (flag === '1') {
-      // Литерал: читаем 16 бит
-      if (pos + 16 > encoded.length) {
-        console.error('Неполный литерал на позиции', pos);
-        break;
-      }
-      const charCode = parseInt(encoded.substring(pos, pos + 16), 2);
-      result += String.fromCharCode(charCode);
-      pos += 16;
-    } else if (flag === '0') {
-      // Совпадение: читаем 12 бит смещения и 6 бит длины
-      if (pos + 18 > encoded.length) {
-        console.error('Неполное совпадение на позиции', pos);
-        break;
-      }
-
-      const offset = parseInt(encoded.substring(pos, pos + 12), 2);
-      pos += 12;
-      const length =
-        parseInt(encoded.substring(pos, pos + 6), 2) + MIN_MATCH_LENGTH;
-      pos += 6;
-
-      // Копируем из уже декодированной части
-      const startPos = result.length - offset;
-
-      if (startPos < 0) {
-        console.error(
-          `Некорректное смещение: ${offset} на позиции результата ${result.length}`,
-        );
-        break;
-      }
-
-      for (let i = 0; i < length; i++) {
-        result += result[startPos + i];
-      }
-    } else {
-      console.error('Неизвестный флаг:', flag);
-      break;
-    }
-  }
-
-  return result;
-}
-
-// Функция для статистики сжатия
-export function getLZSSStats(
-  original: string,
-  encoded: string,
-): {
-  originalSize: number;
-  compressedSize: number;
-  compressionRatio: number;
-} {
-  const originalSize = original.length * 16; // 16 бит на символ (UTF-16)
-  const compressedSize = encoded.length;
-
-  return {
-    originalSize,
-    compressedSize,
-    compressionRatio: compressedSize / originalSize,
-  };
-}

src/utils/offset-encryption.util.ts

@@ -1,55 +0,0 @@
-export const CUSTOM_ALPHABET =
-  'abcdefghijklmnopqrstuvwxyz' +
-  'ABCDEFGHIJKLMNOPQRSTUVWXYZ' +
-  '0123456789' +
-  '.,;:=|!?()[]{}"\'-_/\\@#$%^&* ';
-
-const alphabetMap = new Map<string, number>();
-
-for (let i = 0; i < CUSTOM_ALPHABET.length; i++) {
-  alphabetMap.set(CUSTOM_ALPHABET[i], i + 1);
-}
-
-function getPos(char: string): number {
-  const pos = alphabetMap.get(char);
-  if (!pos) throw new Error(`Character "${char}" is missing in the alphabet`);
-  return pos;
-}
-
-function getChar(pos: number): string {
-  return CUSTOM_ALPHABET[pos - 1];
-}
-
-export function encryptWithAlphabet(text: string, key: string): string {
-  let result = '';
-  const N = CUSTOM_ALPHABET.length;
-
-  for (let i = 0; i < text.length; i++) {
-    const tPos = getPos(text[i]);
-    const kPos = getPos(key[i % key.length]);
-
-    let encPos = tPos + kPos;
-    if (encPos > N) encPos -= N;
-
-    result += getChar(encPos);
-  }
-
-  return result;
-}
-
-export function decryptWithAlphabet(encrypted: string, key: string): string {
-  let result = '';
-  const N = CUSTOM_ALPHABET.length;
-
-  for (let i = 0; i < encrypted.length; i++) {
-    const ePos = getPos(encrypted[i]);
-    const kPos = getPos(key[i % key.length]);
-
-    let decPos = ePos - kPos;
-    if (decPos <= 0) decPos += N;
-
-    result += getChar(decPos);
-  }
-
-  return result;
-}

src/visitor/visitor.service.ts

@@ -46,7 +46,7 @@ export class VisitorService {
     };
 
     const lines = await this.file.readLines();
-    lines.push(await serializeTxtRow(newVisitor));
+    lines.push(serializeTxtRow(newVisitor));
     await this.file.writeLines(lines);
 
     return newVisitor;
@@ -59,9 +59,7 @@ export class VisitorService {
       throw new NotFoundException(`Visitor with id ${id} not found`);
 
     visitors[index] = { ...visitors[index], ...dto };
-    await this.file.writeLines(
-      await Promise.all(visitors.map((visitor) => serializeTxtRow(visitor))),
-    );
+    await this.file.writeLines(visitors.map(serializeTxtRow));
     return visitors[index];
   }
 
@@ -78,9 +76,7 @@ export class VisitorService {
     }
 
     visitors.splice(index, 1);
-    await this.file.writeLines(
-      await Promise.all(visitors.map((visitor) => serializeTxtRow(visitor))),
-    );
+    await this.file.writeLines(visitors.map(serializeTxtRow));
   }
 
   async addCurrentBooks(visitorId: string, books: Book[]): Promise<void> {
@@ -94,9 +90,7 @@ export class VisitorService {
     visitors[visitorIndex].currentBooks.push(
       ...books.map((b) => bookLinkManager.toLink(b.id)),
     );
-    await this.file.writeLines(
-      await Promise.all(visitors.map((visitor) => serializeTxtRow(visitor))),
-    );
+    await this.file.writeLines(visitors.map(serializeTxtRow));
   }
 
   async moveToHistory(visitorId: string, books: Book[]): Promise<void> {
@@ -124,9 +118,7 @@ export class VisitorService {
       visitor.history.push(removedBook);
     }
 
-    await this.file.writeLines(
-      await Promise.all(visitors.map((visitor) => serializeTxtRow(visitor))),
-    );
+    await this.file.writeLines(visitors.map(serializeTxtRow));
   }
 
   async hasBook(visitorId: string, bookId: string): Promise<boolean> {

src/worker/worker.service.ts

@@ -74,9 +74,7 @@ export class WorkerService {
     };
 
     workers.push(newWorker);
-    await this.file.writeLines(
-      await Promise.all(workers.map((worker) => serializeTxtRow(worker))),
-    );
+    await this.file.writeLines(workers.map(serializeTxtRow));
 
     return newWorker;
   }
@@ -94,9 +92,7 @@ export class WorkerService {
       ...workers[index],
       ...dto,
     };
-    await this.file.writeLines(
-      await Promise.all(workers.map((worker) => serializeTxtRow(worker))),
-    );
+    await this.file.writeLines(workers.map(serializeTxtRow));
     return workers[index];
   }
 
@@ -107,9 +103,7 @@ export class WorkerService {
     if (index === -1) return false;
 
     workers.splice(index, 1);
-    await this.file.writeLines(
-      await Promise.all(workers.map((worker) => serializeTxtRow(worker))),
-    );
+    await this.file.writeLines(workers.map(serializeTxtRow));
 
     return true;
   }
@@ -135,8 +129,6 @@ export class WorkerService {
 
     workers[index] = target;
 
-    await this.file.writeLines(
-      await Promise.all(workers.map((worker) => serializeTxtRow(worker))),
-    );
+    await this.file.writeLines(workers.map(serializeTxtRow));
   }
 }