// Copyright Epic Games, Inc. All Rights Reserved.

/*=============================================================================
DiffPackagesCommandlet.cpp: Commandlet used for comparing two packages.

=============================================================================*/

#include "Commandlets/DiffFilesCommandlet.h"
#include "HAL/FileManager.h"
#include "Misc/Paths.h"
#include "Misc/ConfigCacheIni.h"
#include "Modules/ModuleManager.h"
#include "AssetRegistryModule.h"

DEFINE_LOG_CATEGORY_STATIC(LogDiffFilesCommandlet, Log, All);

UDiffFilesCommandlet::UDiffFilesCommandlet(const FObjectInitializer& ObjectInitializer)
    : Super(ObjectInitializer)
{
}

bool UDiffFilesCommandlet::Initialize(const TCHAR* Parms)
{
    bool bResult = false;

    // parse the command line into tokens and switches
    TArray<FString> Tokens, Switches;
    ParseCommandLine(Parms, Tokens, Switches);

    uint32 PackageCounter = 0;

    // find the package files that should be diffed - doesn't need to be a valid package path (i.e. can be a package located in a tmp directory or something)
    for (int32 TokenIndex = 0; TokenIndex < Tokens.Num(); TokenIndex++)
    {
        TArray<FString> FilesInPath;

        bool bMergePackage = false, bAncestorPackage = false, bFirstPackage = false, bSecondPackage = false;
        FString PackageWildcard = Tokens[TokenIndex];
        /*if (PackageWildcard.Contains(TEXT("=")))
        {
                FString ParsedFilename;
                if (FParse::Value(*PackageWildcard, TEXT("MERGE="), ParsedFilename))
                {
                bMergePackage = true;
                }
                // look for a common ancestor setting
                else if (FParse::Value(*PackageWildcard, TEXT("ANCESTOR="), ParsedFilename))
                {
                bAncestorPackage = true;
                }
                PackageWildcard = ParsedFilename;
        }*/

        if (PackageWildcard.Len() == 0)
        {
            SET_WARN_COLOR(COLOR_RED);
            UE_LOG(LogDiffFilesCommandlet, Error, TEXT("No package specified for parameter %i: %s.  Use 'help DiffFilesCommandlet' to view correct usage syntax for this commandlet."),
                   TokenIndex, *Tokens[TokenIndex]);

            CLEAR_WARN_COLOR();
            bResult = false;
            break;
        }

        IFileManager::Get().FindFiles((TArray<FString>&)FilesInPath, *PackageWildcard, true, false);
        if (FilesInPath.Num() == 0)
        {
            // if no files were found in the script directory, search all valid package paths
            TArray<FString> Paths;
            if (GConfig->GetArray(TEXT("Core.System"), TEXT("Paths"), Paths, GEngineIni) > 0)
            {
                for (int32 i = 0; i < Paths.Num(); i++)
                {
                    TArray<FString> Temp;
                    IFileManager::Get().FindFiles(Temp, *(Paths[i] / PackageWildcard), 1, 0);
                    FString Path = FPaths::GetPath(Paths[i] / PackageWildcard);
                    for (const auto& T: Temp)
                    {
                        FilesInPath.Add(Path / T);
                    }
                }
            }
        }
        else
        {
            // re-add the path information so that GetPackageLinker finds the correct version of the file.
            FString WildcardPath = PackageWildcard;
            for (int32 FileIndex = 0; FileIndex < FilesInPath.Num(); FileIndex++)
            {
                FilesInPath[FileIndex] = FPaths::GetPath(WildcardPath) / FilesInPath[FileIndex];
            }
        }

        for (const auto& FileInPath: FilesInPath)
        {
            FPackageInfo PackageInfo;
            PackageInfo.FullPath     = FileInPath;

            PackageInfo.FriendlyName = FString::Printf(TEXT("%s(%d)"), *FPaths::GetBaseFilename(PackageInfo.FullPath), PackageCounter++);
            PackageInfos.Add(PackageInfo);
            bResult = true;
        }
    }

    if (PackageInfos.Num() < 2)
    {
        SET_WARN_COLOR(COLOR_RED);
        UE_LOG(LogDiffFilesCommandlet, Error, TEXT("You must specify two packages to use this commandlet.  Use 'help DiffFilesCommandlet' to view correct usage syntax for this commandlet."));

        CLEAR_WARN_COLOR();
        bResult = false;
    }

    return bResult;
}

int32 UDiffFilesCommandlet::Main(const FString& Params)
{
    if (!Initialize(*Params))
    {
        // Initialize fails if the command-line parameters were invalid.
        return 1;
    }

    LoadAndDiff();

    return 0;
}

void UDiffFilesCommandlet::LoadAndDiff()
{
    // load the first package and use our super diff archiver

    check(PackageInfos.Num() >= 2);

    UPackage* Package = CreatePackage(TEXT("Package_(0)"));

    Package           = LoadPackage(Package, *FString::Printf(TEXT("%s;%s"), *PackageInfos[0].FullPath, *PackageInfos[1].FullPath), LOAD_ForDiff | LOAD_ForFileDiff);

    if (Package->LinkerLoad->IsTextFormat())
    {
        UE_LOG(LogDiffFilesCommandlet, Warning, TEXT("FileDiffs are not currently supported for text based assets"));
    }
    else
    {
        FAssetRegistryModule& AssetRegistryModule = FModuleManager::LoadModuleChecked<FAssetRegistryModule>(TEXT("AssetRegistry"));
        IAssetRegistry& AssetRegistry             = AssetRegistryModule.Get();
        TArray<FAssetData*> AssetData;
        AssetRegistry.LoadPackageRegistryData(*Package->LinkerLoad->GetLoader_Unsafe(), AssetData);
    }
}