BepInEx/BepInEx.NetLauncher/Utility.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;

namespace BepInEx.NetLauncher;

/// <summary>
///     Generic helper properties and methods.
/// </summary>
public static class LocalUtility
{
    /// <summary>
    ///     Try to resolve and load the given assembly DLL.
    /// </summary>
    /// <param name="assemblyName">Name of the assembly, of the type <see cref="AssemblyName" />.</param>
    /// <param name="directory">Directory to search the assembly from.</param>
    /// <param name="assembly">The loaded assembly.</param>
    /// <returns>True, if the assembly was found and loaded. Otherwise, false.</returns>
    private static bool TryResolveDllAssembly<T>(AssemblyName assemblyName,
                                                 string directory,
                                                 Func<string, T> loader,
                                                 out T assembly) where T : class
    {
        assembly = null;

        if (!Directory.Exists(directory))
            return false;

        var potentialDirectories = new List<string> { directory };

        potentialDirectories.AddRange(Directory.GetDirectories(directory, "*", SearchOption.AllDirectories));

        foreach (var subDirectory in potentialDirectories)
        {
            var path = Path.Combine(subDirectory, $"{assemblyName.Name}.dll");

            if (!File.Exists(path))
                continue;

            try
            {
                assembly = loader(path);
            }
            catch (Exception)
            {
                continue;
            }

            return true;
        }

        return false;
    }

    /// <summary>
    ///     Try to resolve and load the given assembly DLL.
    /// </summary>
    /// <param name="assemblyName">Name of the assembly, of the type <see cref="AssemblyName" />.</param>
    /// <param name="directory">Directory to search the assembly from.</param>
    /// <param name="assembly">The loaded assembly.</param>
    /// <returns>True, if the assembly was found and loaded. Otherwise, false.</returns>
    public static bool TryResolveDllAssembly(AssemblyName assemblyName, string directory, out Assembly assembly) =>
        TryResolveDllAssembly(assemblyName, directory, Assembly.LoadFile, out assembly);
}