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QWERTYkez.ExcelProcessor/Editors/CellAddressHelper.cs

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+namespace QWERTYkez.ExcelProcessor.Editors;
+
+internal static class CellAddressHelper
+{
+    private const string letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    private static readonly uint[] _powers = [1, 26, 676];
+
+    public static uint ColumnLetterToIndex(string col)
+    {
+        uint index = 0;
+        foreach (char ch in col)
+        {
+            char c = char.ToUpperInvariant(ch);
+            if (c < 'A' || c > 'Z') return 0;
+            index = index * 26 + (uint)(c - 'A' + 1);
+        }
+        return index;
+    }
+
+    public static string ColumnIndexToLetter(uint col)
+    {
+        if (col == 0) return "";
+        uint n = col;
+        char[] buf = new char[3];
+        int idx = 0;
+        while (n > 0)
+        {
+            n--;
+            buf[idx++] = (char)('A' + (n % 26));
+            n /= 26;
+        }
+        return new string(buf, 0, idx);
+    }
+
+    public static bool TryParseCellReference(string reference, out uint row, out uint col)
+    {
+        row = 0; col = 0;
+        if (string.IsNullOrEmpty(reference)) return false;
+        int i = 0;
+        while (i < reference.Length && char.IsLetter(reference[i])) i++;
+        if (i == 0) return false;
+        string colPart = reference.Substring(0, i);
+        string rowPart = reference.Substring(i);
+        if (!uint.TryParse(rowPart, out row)) return false;
+        col = CellAddressHelper.ColumnLetterToIndex(colPart);
+        return true;
+    }
+}