Kavita/API/Extensions/StringExtensions.cs

using System;
using System.Globalization;
using System.Text.RegularExpressions;

namespace API.Extensions;
#nullable enable

public static class StringExtensions
{
    private static readonly Regex SentenceCaseRegex = new(@"(^[a-z])|\.\s+(.)",
        RegexOptions.ExplicitCapture | RegexOptions.Compiled,
        Services.Tasks.Scanner.Parser.Parser.RegexTimeout);

    public static string Sanitize(this string input)
    {
        if (string.IsNullOrEmpty(input))
            return string.Empty;

        // Remove all newline and control characters
        var sanitized = input
            .Replace(Environment.NewLine, string.Empty)
            .Replace("\n", string.Empty)
            .Replace("\r", string.Empty);

        // Optionally remove other potentially unwanted characters
        sanitized = Regex.Replace(sanitized, @"[^\u0020-\u007E]", string.Empty); // Removes non-printable ASCII

        return sanitized.Trim(); // Trim any leading/trailing whitespace
    }

    public static string SentenceCase(this string value)
    {
        return SentenceCaseRegex.Replace(value.ToLower(), s => s.Value.ToUpper());
    }

    /// <summary>
    /// Apply normalization on the String
    /// </summary>
    /// <param name="value"></param>
    /// <returns></returns>
    public static string ToNormalized(this string? value)
    {
        return string.IsNullOrEmpty(value) ? string.Empty : Services.Tasks.Scanner.Parser.Parser.Normalize(value);
    }

    public static float AsFloat(this string? value, float defaultValue = 0.0f)
    {
        return string.IsNullOrEmpty(value) ? defaultValue : float.Parse(value, CultureInfo.InvariantCulture);
    }

    public static double AsDouble(this string? value, double defaultValue = 0.0f)
    {
        return string.IsNullOrEmpty(value) ? defaultValue : double.Parse(value, CultureInfo.InvariantCulture);
    }
}