feat: support BaiduPinyin backup binary format

Co-authored-by: stevenlele <15964380+stevenlele@users.noreply.github.com>

src/ImeWlConverterCore/ConstantString.cs

@@ -29,6 +29,7 @@ public class ConstantString
         public const string BAIDU_BDICT = "百度分类词库bdict";
         public const string BAIDU_BCD = "百度手机词库bcd";
         public const string BAIDU_PINYIN = "百度拼音";
+        public const string BAIDU_PINYIN_BACKUP = "百度拼音备份词库bin";
         public const string QQ_PINYIN_ENG = "QQ拼音英文";
         public const string QQ_SHOUJI = "QQ手机";
         public const string QQ_WUBI = "QQ五笔";
@@ -81,6 +82,8 @@ public class ConstantString
         public const string BAIDU_SHOUJI_ENG_C = "bdsje";
         public const string BAIDU_BDICT_C = "bdict";
         public const string BAIDU_BCD_C = "bcd";
+        public const string BAIDU_PINYIN_C = "bdpy";
+        public const string BAIDU_PINYIN_BACKUP_C = "bdpybin";
         public const string QQ_SHOUJI_C = "qqsj";
         public const string QQ_WUBI_C = "qqwb";
         public const string TOUCH_PAL_C = "cbsj";
@@ -114,7 +117,6 @@ public class ConstantString
         public const string RIME_USERDB_C = "rimedb";
         public const string BING_PINYIN_C = "bing";
         public const string LINGOES_LD2_C = "ld2";
-        public const string BAIDU_PINYIN_C = "bdpy";
         public const string QQ_PINYIN_ENG_C = "qqpye";
         public const string XIAOYA_WUBI_C = "xywb";
         public const string CANGJIE_PLATFORM_C = "cjpt";

src/ImeWlConverterCore/IME/BaiduPinyinBackup.cs

@@ -0,0 +1,169 @@
+/*!
+ * This work contains codes translated from the original work 
+ * by stevenlele (https://github.com/studyzy/imewlconverter/issues/204#issuecomment-2011007855)
+ * translate to csharp by nopdan
+ */
+
+using Studyzy.IMEWLConverter.Entities;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace Studyzy.IMEWLConverter.IME
+{
+    /// <summary>
+    ///     百度拼音备份词库
+    /// </summary>
+    [ComboBoxShow(ConstantString.BAIDU_PINYIN_BACKUP, ConstantString.BAIDU_PINYIN_BACKUP_C, 20)]
+    public class BaiduPinyinBackup : BaseImport, IWordLibraryImport
+    {
+        #region IWordLibraryImport 成员
+
+        public WordLibraryList Import(string path)
+        {
+            var wordLibraryList = new WordLibraryList();
+            var fs = new FileStream(path, FileMode.Open, FileAccess.Read);
+            // FF FE
+            fs.Seek(2, SeekOrigin.Begin);
+            // 不清楚 <cnword> 是否在 <enword> 前面，所以标记一下
+            var cnFlag = false;
+            while (fs.Position < fs.Length - 4)
+            {
+                // 每次读取两字节
+                var lineBytes = new List<byte>();
+                var bytes = new byte[2];
+                do
+                {
+                    fs.Read(bytes, 0, 2);
+                    // 遇到换行符结束读取
+                    if (bytes[0] == 0x0A && bytes[1] == 0x00) break;
+                    lineBytes.AddRange(bytes);
+                } while (true);
+                var line = Decode(lineBytes.ToArray());
+                var theLine = Encoding.Unicode.GetString(line);
+                // 忽略英文单词
+                if (cnFlag && (theLine == "<enword>" || theLine == "<sysusrword>")) break;
+                if (theLine == "<cnword>") { cnFlag = true; continue; }
+                // 每一行的格式
+                // 百度输入法(bai|du|shu|ru|fa) 2 24 1703756731 N N
+                var array = theLine.Split(" ");
+                if (array.Length < 2) continue;
+                var rank = Convert.ToInt32(array[1]);
+                // 用正则分离词组和拼音
+                var pattern = @"([^\(]+)\((.+)\)";
+                var match = Regex.Match(array[0], pattern);
+                if (match.Groups.Count != 3) continue;
+                var word = match.Groups[1].Value;
+                var py = match.Groups[2].Value;
+                var pinyin = py.Split("|");
+
+                wordLibraryList.Add(new WordLibrary
+                {
+                    Rank = rank,
+                    Word = word,
+                    PinYin = pinyin
+                });
+            }
+            return wordLibraryList;
+        }
+
+        #endregion
+
+        #region 解码算法
+
+        private const uint MASK = 0x2D382324;
+        private static readonly byte[] TABLE = Encoding.ASCII.GetBytes("qogjOuCRNkfil5p4SQ3LAmxGKZTdesvB6z_YPahMI9t80rJyHW1DEwFbc7nUVX2-");
+        private static byte[] DECODE_TABLE;
+
+        public BaiduPinyinBackup()
+        {
+            DECODE_TABLE = new byte[256];
+            for (var i = 0; i < 256; i++)
+            {
+                DECODE_TABLE[i] = (byte)i;
+            }
+            for (var i = 0; i < TABLE.Length; i++)
+            {
+                DECODE_TABLE[TABLE[i]] = (byte)i;
+            }
+        }
+
+        public static byte[] Decode(byte[] data)
+        {
+            if (data.Length % 4 != 2)
+                throw new ArgumentException("Invalid data length");
+
+            byte base64Remainder = (byte)(data[data.Length - 2] - 65);
+            if (base64Remainder < 0 || base64Remainder > 2 || data[data.Length - 1] != 0)
+                throw new ArgumentException("Invalid padding");
+
+            byte[] newData = new byte[data.Length - 2];
+            for (int i = 0; i < data.Length - 2; i++)
+            {
+                newData[i] = DECODE_TABLE[data[i]];
+            }
+
+            var transformed = new List<byte>();
+            for (int i = 0; i < newData.Length - 2; i += 4)
+            {
+                byte highBits = newData[i + 3];
+                transformed.Add((byte)(newData[i] | (highBits & 0b110000) << 2));
+                transformed.Add((byte)(newData[i + 1] | (highBits & 0b1100) << 4));
+                transformed.Add((byte)(newData[i + 2] | (highBits & 0b11) << 6));
+            }
+
+            if (base64Remainder > 0)
+            {
+                for (int i = 0; i < 3 - base64Remainder; i++)
+                {
+                    if (transformed[transformed.Count - 1] != 0)
+                        throw new ArgumentException("Invalid padding");
+                    transformed.RemoveAt(transformed.Count - 1);
+                }
+            }
+            var result = transformed.ToArray();
+
+
+            List<byte> finalResult = new List<byte>();
+            for (int i = 0; i < result.Length / 4 * 4; i += 4)
+            {
+                uint chunk = MASK ^ BitConverter.ToUInt32(result, i);
+                chunk = (chunk & 0x1FFFFFFF) << 3 | chunk >> 29;
+                finalResult.AddRange(BitConverter.GetBytes(chunk));
+            }
+
+            if (result.Length % 4 != 0)
+            {
+                byte[] bytes = result.Skip(result.Length / 4 * 4).ToArray();
+                int num = 0;
+                for (int i = 0; i < bytes.Length; i++)
+                {
+                    num |= bytes[i] << (i * 8);
+                }
+                uint chunk = MASK ^ (uint)num;
+                finalResult.AddRange(BitConverter.GetBytes(chunk).Take(result.Length % 4));
+            }
+
+            return finalResult.ToArray();
+        }
+
+        #endregion
+
+        #region IWordLibraryImport Members
+
+        public override bool IsText
+        {
+            get { return false; }
+        }
+
+        #endregion
+
+        public WordLibraryList ImportLine(string line)
+        {
+            throw new Exception("百度输入法备份格式是二进制文件，不支持流转换");
+        }
+    }
+}