/*******************************************************************************
    * Copyhacked (H) 2012-2025.
    * This program and the accompanying materials
    * are made available under no term at all, use it like
    * you want, but share and discuss it
    * every time possible with every body.
    * 
    * Contributors:
    *      ron190 at ymail dot com - initial implementation
   ******************************************************************************/
  package com.jsql.util;
  
  import com.jsql.util.bruter.Base16;
  import com.jsql.util.bruter.Base58;
  import org.apache.commons.codec.binary.Base32;
  import org.apache.commons.lang3.ArrayUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.text.StringEscapeUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mozilla.universalchardet.UniversalDetector;
  
  import java.awt.*;
  import java.io.*;
  import java.net.URLDecoder;
  import java.net.URLEncoder;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Base64;
  import java.util.List;
  import java.util.Objects;
  import java.util.zip.DeflaterOutputStream;
  import java.util.zip.InflaterOutputStream;
  
  /**
   * Utility class adding String operations like join() which are not
   * part of standard JVM.
   */
  public final class StringUtil {
      
      private static final Logger LOGGER = LogManager.getRootLogger();
      
      // Define the schema of conversion to html entities
      private static final CharEncoder DECIMAL_HTML_ENCODER = new CharEncoder("&#", ";", 10);
      public static final String GET = "GET";
      public static final String POST = "POST";
      public static final String INFORMATION_SCHEMA = "information_schema";
      public static final String APP_NAME = "jSQL Injection";
  
      /**
       * This utility class defines a schema used to encode a text into a specialized
       * representation
       */
      private static class CharEncoder {
          
          private final String prefix;
          private final String suffix;
          private final int radix;
          
          public CharEncoder(String prefix, String suffix, int radix) {
              this.prefix = prefix;
              this.suffix = suffix;
              this.radix = radix;
          }
          
          protected void encode(char c, StringBuilder buff) {
              buff
              .append(this.prefix)
              .append(Integer.toString(c, this.radix))
              .append(this.suffix);
          }
      }
  
      private StringUtil() {
          // Utility class
      }
      
      /**
       * Convert special characters like Chinese and Arabic letters to the corresponding html entities.
       * @param text string to encode
       * @return string encoded in html entities
       */
      public static String toHtmlDecimal(String text) {
          return StringUtil.encode(text);
      }
      
      /**
       * Non-trivial methods to convert unicode characters to html entities.
       * @param text string to encode
       * @return string representation using the encoder schema
       */
      private static String encode(String text) {
          var buff = new StringBuilder();
          for (var i = 0 ; i < text.length() ; i++) {
              if (text.charAt(i) > 128) {
                  StringUtil.DECIMAL_HTML_ENCODER.encode(text.charAt(i), buff);
              } else {
                  buff.append(text.charAt(i));
              }
         }
         return buff.toString();
     }
 
     /**
      * Convert a hexadecimal String to String.
      * @param hex Hexadecimal String to convert
      * @return The string converted from hex
      */
     public static String hexstr(String hex) {
         var bytes = new byte[hex.length() / 2];
         for (var i = 0 ; i < bytes.length ; i++) {
             bytes[i] = (byte) Integer.parseInt(hex.substring(2 * i, 2 * i + 2), 16);
         }
         return new String(bytes, StandardCharsets.UTF_8);
     }
     
     public static boolean isUtf8(String text) {
         if (text == null) {
             return false;
         }
         
         var detector = new UniversalDetector(null);
         detector.handleData(text.getBytes(StandardCharsets.UTF_8), 0, text.length() - 1);
         detector.dataEnd();
         String encoding = detector.getDetectedCharset();
         return encoding != null;
     }
     
     public static String detectUtf8(String text) {
         if (text == null) {
             return StringUtils.EMPTY;
         }
         
         String encoding = null;
         
         // ArrayIndexOutOfBoundsException on handleData()
         try {
             var detector = new UniversalDetector(null);
             detector.handleData(text.getBytes(StandardCharsets.UTF_8), 0, text.length() - 1);
             detector.dataEnd();
             encoding = detector.getDetectedCharset();
             
         } catch (ArrayIndexOutOfBoundsException e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         }
         
         String result = text;
         if (encoding != null) {
             result = new String(text.getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8);
         }
         return result;
     }
     
     public static String base32Encode(String s) {
         var base32 = new Base32();
         return base32.encodeToString(StringUtil.getBytesUtf8(s));
     }
     
     public static String base32Decode(String s) {
         var base32 = new Base32();
         return StringUtil.newStringUtf8(base32.decode(s));
     }
     
     public static String base58Encode(String s) {
         return Base58.encode(StringUtil.getBytesUtf8(s));
     }
     
     public static String base58Decode(String s) {
         return StringUtil.newStringUtf8(Base58.decode(s));
     }
     
     public static String base16Encode(String s) {
         var base16 = new Base16();
         return base16.encodeToString(StringUtil.getBytesUtf8(s));
     }
     
     public static String base16Decode(String s) {
         var base16 = new Base16();
         return StringUtil.newStringUtf8(base16.decode(s));
     }
 
     public static String base64Decode(String s) {
         return StringUtil.newStringUtf8(Base64.getDecoder().decode(s));
     }
 
     public static String base64Encode(String s) {
         return Base64.getEncoder().encodeToString(StringUtil.getBytesUtf8(s));
     }
 
     public static String toHex(String text) {
         return StringUtil.encodeHexString(text.getBytes(StandardCharsets.UTF_8));
     }
     
     public static String fromHex(String text) {
         byte[] hex = StringUtil.decodeHexString(text);
         return new String(hex, StandardCharsets.UTF_8);
     }
     
     public static String toHexZip(String text) throws IOException {
         byte[] zip = StringUtil.compress(text);
         return StringUtil.encodeHexString(zip);
     }
 
     public static String fromHexZip(String text) throws IOException {
         return new String(StringUtil.decompress(StringUtil.decodeHexString(text)), StandardCharsets.UTF_8);
     }
     
     public static String toBase64Zip(String text) throws IOException {
         return new String(Base64.getEncoder().encode(StringUtil.compress(text)));
     }
     
     public static String fromBase64Zip(String text) throws IOException {
         byte[] decompressedBArray = StringUtil.decompress(Base64.getDecoder().decode(text));
         return new String(decompressedBArray, StandardCharsets.UTF_8);
     }
     
     public static String toHtml(String text) {
         return StringEscapeUtils.escapeHtml4(text);
     }
     
     public static String fromHtml(String text) {
         return StringEscapeUtils.unescapeHtml4(text);
     }
     
     public static String toUrl(String text) {
         return URLEncoder.encode(text, StandardCharsets.UTF_8);
     }
     
     public static String fromUrl(String text) {
         return URLDecoder.decode(text, StandardCharsets.UTF_8);
     }
     
     public static String cleanSql(String query) {
         return StringUtil.removeSqlComment(query)
             .replaceAll("(?s)([^\\s\\w])(\\s+)", "$1")  // Remove spaces after a word
             .replaceAll("(?s)(\\s+)([^\\s\\w])", "$2")  // Remove spaces before a word
             .replaceAll("(?s)\\s+", " ")  // Replace spaces
             .trim();
     }
 
     /**
      * Remove SQL comments except tamper /**\/ /*!...*\/
      * Negative lookahead: don't match tamper empty comment /**\/ or version comment /*!...*\/
      * JavaScript: (?!\/\*!.*\*\/|\/\*\*\/)\/\*.*\*\/
      */
     public static String removeSqlComment(String query) {
         return query.replaceAll(
             "(?s)(?!/\\*\\*/|/\\*!.*\\*/)/\\*.*?\\*/",
             StringUtils.EMPTY
         );
     }
 
     public static String formatReport(Color color, String text) {
         return String.format(
             "<span style=color:rgb(%s,%s,%s)>%s</span>",
             color.getRed(),
             color.getGreen(),
             color.getBlue(),
             text
         );
     }
 
 
     // Utils
 
     private static byte[] compress(String text) throws IOException {
         ByteArrayOutputStream os = new ByteArrayOutputStream();
         try (DeflaterOutputStream dos = new DeflaterOutputStream(os)) {
             dos.write(text.getBytes());
         }
         return os.toByteArray();
     }
 
     private static byte[] decompress(byte[] compressedTxt) throws IOException {
         ByteArrayOutputStream os = new ByteArrayOutputStream();
         try (OutputStream ios = new InflaterOutputStream(os)) {
             ios.write(compressedTxt);
         }
         return os.toByteArray();
     }
 
     private static byte hexToByte(String hexString) {
         int firstDigit = StringUtil.toDigit(hexString.charAt(0));
         int secondDigit = StringUtil.toDigit(hexString.charAt(1));
         return (byte) ((firstDigit << 4) + secondDigit);
     }
 
     private static int toDigit(char hexChar) {
         int digit = Character.digit(hexChar, 16);
         if (digit == -1) {
             throw new IllegalArgumentException("Invalid Hexadecimal Character: "+ hexChar);
         }
         return digit;
     }
 
     private static String byteToHex(byte num) {
         char[] hexDigits = new char[2];
         hexDigits[0] = Character.forDigit((num >> 4) & 0xF, 16);
         hexDigits[1] = Character.forDigit(num & 0xF, 16);
         return new String(hexDigits);
     }
 
     private static String encodeHexString(byte[] byteArray) {
         StringBuilder hexStringBuffer = new StringBuilder();
         for (byte b : byteArray) {
             hexStringBuffer.append(StringUtil.byteToHex(b));
         }
         return hexStringBuffer.toString();
     }
 
     private static byte[] decodeHexString(String hexString) {
         if (hexString.length() % 2 == 1) {
             throw new IllegalArgumentException("Invalid hexadecimal String supplied.");
         }
         byte[] bytes = new byte[hexString.length() / 2];
         for (int i = 0 ; i < hexString.length() ; i += 2) {
             bytes[i / 2] = StringUtil.hexToByte(hexString.substring(i, i + 2));
         }
         return bytes;
     }
 
     private static byte[] getBytesUtf8(String string) {
         return string == null ? null : string.getBytes(StandardCharsets.UTF_8);
     }
 
     private static String newStringUtf8(byte[] bytes) {
         return bytes == null ? null : new String(bytes, StandardCharsets.UTF_8);
     }
 
     public static byte[] xor(byte[] plaintext, int key) {
         var ciphertext = new byte[plaintext.length];
         for (var i = 0 ; i < plaintext.length ; i++) {
             ciphertext[i] = (byte) (plaintext[i] ^ (key >>> (8 * (i % 4))));
         }
         return ciphertext;
     }
 
     public static List<String> toHexChunks(byte[] fileData) {
         StringBuilder hexString = new StringBuilder();
         for (byte b : fileData) {
             hexString.append(String.format("%02X", b));
         }
         int chunkSize = 900; // 450 bytes = 900 hex characters
         List<String> chunks = new ArrayList<>();
         for (int i = 0 ; i < hexString.length() ; i += chunkSize) {
             int endIndex = Math.min(i + chunkSize, hexString.length());
             chunks.add(hexString.substring(i, endIndex));
         }
         return chunks;
     }
 
     public static String getFile(String path) {
         var content = new StringBuilder();
         try (
             var inputStream = PreferencesUtil.class.getClassLoader().getResourceAsStream(path);
             var inputStreamReader = new InputStreamReader(Objects.requireNonNull(inputStream), StandardCharsets.UTF_8);
             var reader = new BufferedReader(inputStreamReader)
         ) {
             String line;
             while ((line = reader.readLine()) != null) {
                 content.append(line).append("\n");  // required to prevent \n<text>\r on edit
             }
         } catch (IOException e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         }
         return content.toString();
     }
 
     public static byte[] uncloak(byte[] fileData) {
         fileData = StringUtil.xor(fileData, 353837730);
         ArrayUtils.reverse(fileData);
         return fileData;
     }
 }