--require("Script.Common.UGCLog");
--require("Script.Common.TableHelper");

LevelStreamUtil = LevelStreamUtil or
{
    LevelLoadCounter = 0;
    LoadDelegate = nil;
    LoadCompletedCallback = nil;
    IsAsyncLoad = false;

    LevelUnloadCounter = 0;
    UnLoadDelegate = nil;
    UnloadCompletedCallback = nil;
    IsAsyncUnload = false;

    LoadedLevels = {};
};

---@class CallbackStruct
---@field Object Object
---@field Func fun()



---@param LevelNameList string[]字符串关卡名列表
---@param CompletedCallback CallbackStruct 加载完成时的回调函静态函数
---@param bShouldBlockOnLoad bool 是否等待处理完成
--- LoadStreamLevel fun(WorldContextObject:UObject,LevelName:FName,bMakeVisibleAfterLoad:bool,bShouldBlockOnLoad:bool,LatentInfo:FLatentActionInfo)
function LevelStreamUtil.LoadStreamLevels(LevelNameList, CompletedCallback, bShouldBlockOnLoad)

    --UGCLogSystem.Log("[Level] 加载关卡数量：%d CompletedCallback:%s", LevelNameList:Num(), UE.ToTable(CompletedCallback));
        
    LevelStreamUtil.LevelLoadCounter = LevelStreamUtil.LevelLoadCounter + #LevelNameList;
    LevelStreamUtil.LoadCompletedCallback = CompletedCallback;
    LevelStreamUtil.IsAsyncLoad = not bShouldBlockOnLoad;
    
    --UGCLogSystem.Log("[Level] 加载关卡 LoadCompletedCallback:%s", UE.ToTable(LevelStreamUtil.LoadCompletedCallback));

    for k, v in pairs(LevelNameList) do
        UGCLogSystem.Log("[Level] 加载关卡:%s", v);
        table.insert(LevelStreamUtil.LoadedLevels, v);

        LevelStreamUtil.LoadDelegate = ObjectExtend.CreateDelegate(UGCGameSystem.GameState, LevelStreamUtil.OnLoadCompleted, LevelStreamUtil);

        GameplayStatics.LoadStreamLevel(UGCGameSystem.GameState, v, true, bShouldBlockOnLoad,
            ObjectExtend.CreateLatentAction(LevelStreamUtil.LoadDelegate));

        -- 强制加载完成
        if bShouldBlockOnLoad then
            GameplayStatics.FlushLevelStreaming(UGCGameSystem.GameState);
        end
    end

    if bShouldBlockOnLoad then
        UGCLogSystem.Log("[Level] 完成同步加载关卡");
        -- LevelStreamUtil.LoadCompletedCallback();
        LevelStreamUtil.LoadCompletedCallback.Func(LevelStreamUtil.LoadCompletedCallback.Object);
    end
end


--- 加载结束异步回调
function LevelStreamUtil:OnLoadCompleted()
    if not LevelStreamUtil.IsAsyncLoad then
        return;
    end

    LevelStreamUtil.LevelLoadCounter = LevelStreamUtil.LevelLoadCounter - 1;
    UGCLogSystem.Log("[Level] 加载关卡完成 剩余等待计数:[%d]", LevelStreamUtil.LevelLoadCounter);

    if LevelStreamUtil.LevelLoadCounter == 0 then
        ObjectExtend.DestroyDelegate(LevelStreamUtil.LoadDelegate);
        LevelStreamUtil.LoadDelegate = nil;

        UGCLogSystem.Log("[Level] 加载关卡完成 LoadCompletedCallback:%s", UE.ToTable(LevelStreamUtil.LoadCompletedCallback));
        if LevelStreamUtil.LoadCompletedCallback ~= nil then
            UGCLogSystem.Log("[Level] 完成异步加载关卡");
            -- LevelStreamUtil.CompletedCallback();
            
            -- 必须缓存用，不然会被加载子关卡的调用冲掉
            local Callback = LevelStreamUtil.LoadCompletedCallback;
            LevelStreamUtil.LoadCompletedCallback = nil;
            Callback.Func(Callback.Object);
            
        end
    end
end

--- 根据传入的列表销毁相应的关卡
---@param LevelNameList string[]字符串关卡名列表
---@param UnloadCompletedCallback CallbackStruct 销毁完成时的回调函静态函数
---@param bShouldBlockOnLoad bool 是否等待处理完成
---UnloadStreamLevel fun(WorldContextObject:UObject,LevelName:FName,LatentInfo:FLatentActionInfo)
function LevelStreamUtil.UnLoadStreamLevels(LevelNameList, UnloadCompletedCallback, bShouldBlockOnLoad)
    
    LevelStreamUtil.UnloadCompletedCallback = UnloadCompletedCallback;
    LevelStreamUtil.LevelUnloadCounter = LevelStreamUtil.LevelUnloadCounter + #LevelNameList;
    LevelStreamUtil.IsAsyncUnload = not bShouldBlockOnLoad;

    for k, v in pairs(LevelNameList) do
        UGCLogSystem.Log("[Level] 销毁关卡:%s", v);

        -- TableHelper.RemoveByValue(LevelStreamUtil.LoadedLevels, v);
        table.removeValue(LevelStreamUtil.LoadedLevels, v, true)

        LevelStreamUtil.UnLoadDelegate = ObjectExtend.CreateDelegate(UGCGameSystem.GameState, LevelStreamUtil.UnLoadCompleted, LevelStreamUtil);
        GameplayStatics.UnloadStreamLevel(UGCGameSystem.GameState, v, 
            ObjectExtend.CreateLatentAction(LevelStreamUtil.UnLoadDelegate));
        
        -- 强制销毁完成
        if bShouldBlockOnLoad then
            GameplayStatics.FlushLevelStreaming(UGCGameSystem.GameState);
        end
    end

    if bShouldBlockOnLoad then
        UGCLogSystem.Log("[Level] 完成同步销毁关卡");
        LevelStreamUtil.UnloadCompletedCallback.Func(LevelStreamUtil.UnloadCompletedCallback.Object);
    end
end


--- 销毁结束异步回调
function LevelStreamUtil:UnLoadCompleted()
    if not LevelStreamUtil.IsAsyncUnload then
        return;
    end

    UGCLogSystem.Log("[Level] 销毁关卡完成[%d]", LevelStreamUtil.LevelUnloadCounter);
    LevelStreamUtil.LevelUnloadCounter = LevelStreamUtil.LevelUnloadCounter - 1;
    
    if LevelStreamUtil.LevelUnloadCounter == 0 then
        ObjectExtend.DestroyDelegate(LevelStreamUtil.UnLoadDelegate);
        LevelStreamUtil.UnLoadDelegate = nil;

        if LevelStreamUtil.UnloadCompletedCallback ~= nil then
            UGCLogSystem.Log("[Level] 完成异步销毁关卡");
            -- LevelStreamUtil.UnloadCompletedCallback();
            LevelStreamUtil.UnloadCompletedCallback.Func(LevelStreamUtil.UnloadCompletedCallback.Object);
            LevelStreamUtil.UnloadCompletedCallback = nil;
        end
    end
end