EnvelopeGenerator/EnvelopeGenerator.Infrastructure.Notification/ReplacePlaceholderExtensions.cs

using System.Collections.Concurrent;
using System.Reflection;
using System.Text.RegularExpressions;

namespace EnvelopeGenerator.Infrastructure.Notification;

public static class ReplacePlaceholderExtensions
{
    private sealed record PlaceholderProperty(string Placeholder, PropertyInfo Property);

    private static readonly ConcurrentDictionary<Type, PlaceholderProperty[]> PropertyCache = new();

    public static string ReplacePlaceholders(this string template, object data)
    {
        var properties = PropertyCache.GetOrAdd(data.GetType(), CreatePlaceholderProperties);

        foreach (var item in properties)
        {
            var value = item.Property.GetValue(data)?.ToString() ?? string.Empty;
            template = template.Replace(
                item.Placeholder,
                value,
                StringComparison.Ordinal);
        }

        return template;
    }

    private static PlaceholderProperty[] CreatePlaceholderProperties(
        Type type)
    {
        return [.. type
            .GetProperties(BindingFlags.Public | BindingFlags.Instance)
            .Where(p => p.CanRead && p.GetIndexParameters().Length == 0)
            .Select(p => new PlaceholderProperty(
                $"[{ToCapitalSnakeCase(p.Name)}]",
                p))];
    }

    private static string ToCapitalSnakeCase(string name)
    {
        return Regex.Replace(
            Regex.Replace(name, @"([A-Z]+)([A-Z][a-z])", "$1_$2"),
            @"([a-z0-9])([A-Z])",
            "$1_$2").ToUpperInvariant();
    }
}