// Copyright (c), Firelight Technologies Pty, Ltd. 2012-2023.

#include "FMODBankUpdateNotifier.h"
#include "FMODSettings.h"
#include "HAL/FileManager.h"

#include "FMODStudioEditorPrivatePCH.h"

FFMODBankUpdateNotifier::FFMODBankUpdateNotifier()
    : bUpdateEnabled(true)
    , NextRefreshTime(FDateTime::MinValue())
    , FileTime(FDateTime::MinValue())
    , Countdown(0.0f)
{
}

void FFMODBankUpdateNotifier::SetFilePath(const FString &InPath)
{
    FilePath = InPath;
    NextRefreshTime = FDateTime::MinValue();
    FileTime = MostRecentFileTime();
}

void FFMODBankUpdateNotifier::Update(float DeltaTime)
{
    if (bUpdateEnabled)
    {
        FDateTime CurTime = FDateTime::UtcNow();

        if (CurTime >= NextRefreshTime)
        {
            Refresh();
            NextRefreshTime = CurTime + FTimespan(0, 0, 1);
        }

        if (Countdown > 0.0f)
        {
            Countdown -= DeltaTime;

            if (Countdown <= 0.0f)
            {
                BanksUpdatedEvent.Broadcast();
            }
        }
    }
}

void FFMODBankUpdateNotifier::EnableUpdate(bool bEnable)
{
    bUpdateEnabled = bEnable;

    if (bEnable)
    {
        // Refreshing right after update is enabled is not desirable
        NextRefreshTime = FDateTime::UtcNow() + FTimespan(0, 0, 1);

        // Cancel any pending countdown
        Countdown = 0.0f;
    }
}

void FFMODBankUpdateNotifier::Refresh()
{
    if (!FilePath.IsEmpty())
    {
        FDateTime NewFileTime = MostRecentFileTime();

        if (NewFileTime != FileTime)
        {
            const UFMODSettings &Settings = *GetDefault<UFMODSettings>();
            Countdown = (float)Settings.ReloadBanksDelay;
            FileTime = NewFileTime;
        }
    }
}

FDateTime FFMODBankUpdateNotifier::MostRecentFileTime()
{
    // Get the most recent modified timestamp of all the bank files in the directory we are watching.
    FDateTime MostRecent = FDateTime::MinValue();

    TArray<FString> BankPaths;
    IFileManager::Get().FindFilesRecursive(BankPaths, *FilePath, TEXT("*.bank"), true, false, false);

    for (const auto& Path : BankPaths)
    {
        FDateTime ModifiedTime = IFileManager::Get().GetTimeStamp(*Path);

        if (ModifiedTime > MostRecent)
        {
            MostRecent = ModifiedTime;
        }
    }

    return MostRecent;
}