benscode-StitcherApi/Services/Utilities/CoordinateParser.cs

using System.Text.RegularExpressions;

namespace StitcherApi.Services.Utilities;

public static class CoordinateParser
{
    private static readonly Regex CoordRegex = new(
        @"([A-Z]+)(\d+)",
        RegexOptions.Compiled | RegexOptions.IgnoreCase
    );

    public static (int MinRow, int MinCol, int MaxRow, int MaxCol) ParseCanvasRect(string rect)
    {
        if (string.IsNullOrEmpty(rect))
        {
            throw new ArgumentException("canvas_rect cannot be null or empty.");
        }

        string[] parts = rect.Split(':');
        if (parts.Length != 2)
        {
            throw new ArgumentException("Invalid canvas_rect format.");
        }

        (int row1, int col1) = ParseSingleCoordinate(parts[0]);
        (int row2, int col2) = ParseSingleCoordinate(parts[1]);

        return (
            Math.Min(row1, row2),
            Math.Min(col1, col2),
            Math.Max(row1, row2),
            Math.Max(col1, col2)
        );
    }

    private static (int Row, int Col) ParseSingleCoordinate(string coord)
    {
        Match match = CoordRegex.Match(coord);
        if (!match.Success)
        {
            throw new ArgumentException($"Invalid coordinate format: {coord}");
        }

        string rowStr = match.Groups[1].Value.ToUpper();
        string colStr = match.Groups[2].Value;

        int row = rowStr.Length == 1 ? rowStr[0] - 'A' : 26 + (rowStr[1] - 'A');
        int col = int.Parse(colStr) - 1;

        return (row, col);
    }
}