Unreal.cs

using System;
using System.Linq;
using System.IO;
using System.Collections.Generic;
using Nuke.Common.IO;
using System.Runtime.InteropServices;
using Nuke.Common.Tooling;
using Newtonsoft.Json;
using Serilog;
using System.Text;
using Nuke.Unreal.Tools;
using Nuke.Cola.Tooling;
using Nuke.Common;
using Nuke.Common.Utilities;
using Newtonsoft.Json.Converters;
 
namespace Nuke.Unreal;
 
/// <summary>
/// A collection of utilities around basic functions regarding the environment of the Engine
/// we're working with.
/// </summary>
public static class Unreal
{
    /// <summary>
    /// Frankly this is not really relevant anymore
    /// </summary>
    public static readonly HashSet<AbsolutePath>? EngineSearchPaths;
 
    /// <summary>
    /// Once the Engine location is found for the current session, it ain't gonna move around,
    /// so we cache it.
    /// </summary>
    public static AbsolutePath? EnginePathCache = null;
 
    static Unreal()
    {
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
        {
            // Use UnrealLocator
            return;
        }
 
        // TODO: Use UnrealLocator on other platforms as well
        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
        {
            EngineSearchPaths = new()
            {
                (AbsolutePath) @"/Users/Shared/Epic Games",
            };
            return;
        }
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
        {
            // TODO: build and use UnrealLocator on linux
            EngineSearchPaths = new()
            {
                (AbsolutePath) @"/Users/Shared/Epic Games",
            };
            return;
        }
 
        throw new Exception("Attempting to build on an unsupported platform");
    }
 
    /// <summary>
    /// Common `JsonSerializerSettings` for Unreal conventions of JSON format
    /// </summary>
    public static readonly JsonSerializerSettings JsonReadSettings = new()
    {
        MissingMemberHandling = MissingMemberHandling.Ignore,
        DefaultValueHandling = DefaultValueHandling.Populate,
        NullValueHandling = NullValueHandling.Include,
        Converters = {
            new StringEnumConverter(false)
        }
    };
 
    /// <summary>
    /// Write data in JSON with Unreal conventions of JSON format
    /// </summary>
    public static void WriteJson(object input, AbsolutePath path)
    {
        var sb = new StringBuilder();
        var sw = new StringWriter(sb);
 
        using var jtw = new JsonTextWriter(sw)
        {
            Formatting = Formatting.Indented,
            Indentation = 1,
            IndentChar = '\t'
        };
 
        var serializer = new JsonSerializer()
        {
            NullValueHandling = NullValueHandling.Ignore,
            Formatting = Formatting.Indented,
            Converters = {
                new StringEnumConverter(false)
            }
        };
        serializer.Serialize(jtw, input);
        File.WriteAllText(path, sb.ToString());
    }
 
    /// <summary>
    /// In the rare and unlikely case that the Engine location may have changed during one
    /// session
    /// </summary>
    public static void InvalidateEnginePathCache() => EnginePathCache = null;
 
    /// <summary>
    /// Get the Unreal Engine path based on an input association text.
    /// (version, GUID or absolute path)
    /// </summary>
    public static AbsolutePath GetEnginePath(string engineAssociation, bool ignoreCache = false)
    {
        if (!ignoreCache && EnginePathCache != null) return EnginePathCache;
 
        IUnrealLocator locator = UnrealLocator.Make();
 
        Log.Debug("Looking for Unreal Engine installation {0}", engineAssociation);
 
        EnginePathCache = locator.GetEngine(engineAssociation);
        Assert.NotNull(EnginePathCache, "Couldn't find Unreal Engine with that association");
 
        Log.Debug("Found at: {0}", EnginePathCache!);
        return EnginePathCache!;
    }
 
    /// <summary>
    /// Get high-level version of currently used Engine
    /// </summary>
    public static EngineVersion Version(IUnrealBuild build) => build.GetEngineVersionFromProject();
 
    /// <summary>
    /// Create a compatibility flag mask which indicates that a feature is available un-broken
    /// in given and the following versions of Unreal Engine
    /// </summary>
    public static UnrealCompatibility AndLater(this UnrealCompatibility compatibility)
        => ~(compatibility - 1);
 
    /// <summary>
    /// Are we working with UE4
    /// </summary>
    public static bool Is4(IUnrealBuild build) => Version(build).SemanticalVersion.Major == 4;
 
    /// <summary>
    /// Are we working with UE5
    /// </summary>
    public static bool Is5(IUnrealBuild build) => Version(build).SemanticalVersion.Major == 5;
 
    /// <summary>
    /// Is given path a vanilla engine most probably installed via the Marketplace?
    /// </summary>
    public static bool IsInstalled(AbsolutePath enginePath)
        => (enginePath / "Engine" / "Build" / "InstalledBuild.txt").FileExists();
 
    /// <summary>
    /// Gets the parsed content of Build.version file of an engine instance
    /// </summary>
    public static UnrealBuildVersion GetBuildVersion(AbsolutePath enginePath)
    {
        var buildVersionPath = enginePath / "Engine" / "Build" / "Build.version";
        Assert.FileExists(buildVersionPath, $"Specified path was not an Unreal Engine instance ({buildVersionPath})");
        return buildVersionPath.ReadJson<UnrealBuildVersion>(JsonReadSettings);
    }
 
    /// <summary>
    /// Are we working with a vanilla engine most probably installed via the Marketplace?
    /// </summary>
    public static bool IsInstalled(EngineVersion ofVersion)
        => IsInstalled(ofVersion.EnginePath);
 
    /// <summary>
    /// Are we working with a vanilla engine most probably installed via the Marketplace?
    /// </summary>
    public static bool IsInstalled(IUnrealBuild build)
        => IsInstalled(GetEnginePath(build));
 
    /// <summary>
    /// Is given path an engine built from source?
    /// </summary>
    public static bool IsSource(AbsolutePath enginePath)
        => !IsInstalled(enginePath);
 
    /// <summary>
    /// Are we working with an engine built from source?
    /// </summary>
    public static bool IsSource(EngineVersion ofVersion)
        => IsSource(ofVersion.EnginePath);
 
    /// <summary>
    /// Are we working with an engine built from source?
    /// </summary>
    public static bool IsSource(IUnrealBuild build)
        => IsSource(GetEnginePath(build));
 
    public static AbsolutePath GetEnginePath(IUnrealBuild build)
        => Version(build).EnginePath;
 
    /// <summary>
    /// Get the current development platform flag Nuke.Unreal is ran on.
    /// </summary>
    public static UnrealPlatformFlag GetHostPlatformFlag()
    {
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            return UnrealPlatformFlag.Win64;
 
        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            return UnrealPlatformFlag.Mac;
 
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
            return UnrealPlatformFlag.Linux;
 
        throw new Exception("Attempting to build on an unsupported platform");
    }
 
    /// <summary>
    /// Get the current development platform Nuke.Unreal is ran on.
    /// </summary>
    public static UnrealPlatform GetHostPlatform() => UnrealPlatform.FromFlag(GetHostPlatformFlag());
 
    /// <summary>
    /// On Mac many Unreal tools need the Mono bootstrap.
    /// </summary>
    public static AbsolutePath MacRunMono(EngineVersion ofVersion) =>
        ofVersion.EnginePath / "Engine" / "Build" / "BatchFiles" / "Mac" / "RunMono.sh";
 
    /// <summary>
    /// Exit handler which throws an exception on error which doesn't include the entire process output, which tends
    /// to be biblical amount in case of Unreal
    /// </summary>
    public static Action<IProcess> UnrealToolExitHandler(bool repeatErrorsOnFailure = false)
        => p => p.AssertZeroExitCodeNoLog(repeatErrorsOnFailure);
 
    /// <summary>Prepare invocation for UBT</summary>
    /// <returns>A Tool delegate for UBT</returns>
    public static ToolEx BuildTool(EngineVersion ofVersion)
    {
        var ubtPath = ofVersion.SemanticalVersion.Major >= 5
            ? ofVersion.EnginePath / "Engine" / "Binaries" / "DotNET" / "UnrealBuildTool" / "UnrealBuildTool.exe"
            : ofVersion.EnginePath / "Engine" / "Binaries" / "DotNET" / "UnrealBuildTool.exe";
 
        return ToolExResolver.GetTool(ubtPath)
            .WithSemanticLogging()
            .With(exitHandler: UnrealToolExitHandler())
        ;
 
        // TODO: MacOS: "sh", $"\"{MacRunMono(ofVersion)}\" \"{ubtPath}\" " + arguments
        // TODO: Linux: "mono", $"\"{ubtPath}\" " + arguments
    }
 
    /// <summary>
    /// Prepare invocation for UBT with extra fluent-API configuration
    /// </summary>
    /// <param name="ofVersion"></param>
    /// <param name="config">
    /// Auto-generated Configuration facilities mirroring UBT arguments
    /// </param>
    /// <returns>A Tool delegate for UBT</returns>
    public static ToolEx BuildTool(EngineVersion ofVersion, Action<UbtConfig> config)
    {
        var toolConfig = new UbtConfig();
        config.Invoke(toolConfig);
        return BuildTool(ofVersion).With(
            arguments: toolConfig.Gather(ofVersion),
            workingDirectory: ofVersion.EnginePath / "Engine" / "Source",
            logInvocation: true
        );
    }
 
    /// <summary>Prepare invocation for UBT</summary>
    /// <returns>A Tool delegate for UBT</returns>
    public static ToolEx BuildTool(IUnrealBuild build) => BuildTool(Version(build));
 
    /// <summary>
    /// Prepare invocation for UBT with extra fluent-API configuration
    /// </summary>
    /// <param name="build"></param>
    /// <param name="config">
    /// Auto-generated Configuration facilities mirroring UBT arguments
    /// </param>
    /// <returns>A Tool delegate for UBT</returns>
    public static ToolEx BuildTool(IUnrealBuild build, Action<UbtConfig> config) => BuildTool(Version(build), config);
 
    /// <summary>Prepare invocation for UAT</summary>
    /// <returns>A Tool delegate for UAT</returns>
    public static ToolEx AutomationTool(EngineVersion ofVersion)
    {
        var scriptExt = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? "bat" : "sh";
        return ToolExResolver.GetTool(ofVersion.EnginePath / "Engine" / "Build" / "BatchFiles" / $"RunUAT.{scriptExt}")
            .WithSemanticLogging(filter: l =>
                !(l.Contains("Reading chunk manifest") && l.Contains("which contains 0 entries"))
            )
            .With(exitHandler: UnrealToolExitHandler())
        ;
    }
 
    /// <summary>
    /// Prepare invocation for UAT with extra fluent-API configuration
    /// </summary>
    /// <param name="ofVersion"></param>
    /// <param name="config">
    /// Auto-generated Configuration facilities mirroring UAT arguments
    /// </param>
    /// <returns>A Tool delegate for UAT</returns>
    public static ToolEx AutomationTool(EngineVersion ofVersion, Action<UatConfig> config)
    {
        var toolConfig = new UatConfig();
        config?.Invoke(toolConfig);
        return AutomationTool(ofVersion).With(
            arguments: $"{toolConfig.Gather(ofVersion):nq}",
            workingDirectory: ofVersion.EnginePath / "Engine" / "Source",
            logInvocation: true
        );
    }
 
    /// <summary>Prepare invocation for UAT</summary>
    /// <returns>A Tool delegate for UAT</returns>
    public static ToolEx AutomationTool(IUnrealBuild build) => AutomationTool(Version(build));
 
    /// <summary>
    /// Prepare invocation for UAT with extra fluent-API configuration
    /// </summary>
    /// <param name="build"></param>
    /// <param name="config">
    /// Auto-generated Configuration facilities mirroring UAT arguments
    /// </param>
    /// <returns>A Tool delegate for UAT</returns>
    public static ToolEx AutomationTool(IUnrealBuild build, Action<UatConfig> config) => AutomationTool(Version(build), config);
 
    /// <summary>
    /// Clear intermediate folders of Unreal from a given folder
    /// </summary>
    public static void ClearFolder(AbsolutePath folder)
    {
        (folder / "Intermediate").ExistingDirectory()?.DeleteDirectory();
        (folder / "Binaries").ExistingDirectory()?.DeleteDirectory();
        (folder / "DerivedDataCache").ExistingDirectory()?.DeleteDirectory();
    }
 
    /// <summary>
    /// Read copyright info from the project's `DefaultGame.ini`
    /// </summary>
    public static string ReadCopyrightFromProject(AbsolutePath projectFolder)
    {
        var configPath = projectFolder / "Config" / "DefaultGame.ini";
        if (!File.Exists(configPath)) return "Fill in Copyright info...";
 
        var crLine = File.ReadAllLines(configPath)
            .FirstOrDefault(l => l.StartsWith("CopyrightNotice="));
 
        if (string.IsNullOrWhiteSpace(crLine)) return "Fill in Copyright info...";
 
        var crEntry = crLine.Split('=', 2, StringSplitOptions.TrimEntries);
        if (crEntry.Length < 2) return "Fill in Copyright info...";
 
        return crEntry[1];
    }
 
    /// <summary>
    /// Get a native binary tool from `Engine/Binaries` folder. Unreal tools written in C# or
    /// stored in other folders/sub-folders are not supported. You can omit the `Unreal` part
    /// of the tool name.
    /// </summary>
    /// <param name="build"></param>
    /// <param name="name">You can omit the `Unreal` part of the tool name.</param>
    /// <returns>A Tool delegate for selected Unreal tool</returns>
    public static ToolEx GetTool(IUnrealBuild build, string name)
    {
        var binaries = GetEnginePath(build) / "Engine" / "Binaries" / GetHostPlatformFlag().ToString();
        var ext = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? ".exe" : "";
        var path = binaries / (name + ext);
 
        if (!path.FileExists())
            path = binaries / ("Unreal" + name + ext);
 
        Assert.FileExists(path, $"Requested tool {name} doesn't exist.");
        return ToolExResolver.GetTool(path)
            .With(exitHandler: UnrealToolExitHandler())
        ;
    }
}