local CoreGui = game:GetService("CoreGui")
local GuiRoot = CoreGui:FindFirstChild("RobloxGui")
local Modules = GuiRoot:FindFirstChild("Modules")
local ShellModules = Modules:FindFirstChild("Shell")
local GuiService = game:GetService('GuiService')

local Strings = require(ShellModules:FindFirstChild('LocalizedStrings'))
local Utility = require(ShellModules:FindFirstChild('Utility'))

local SortsData = require(ShellModules:FindFirstChild('SortsData'))
local FFlagXboxUseCuratedGameSort = SortsData.FFlagXboxNewGameSortsEndpoint

local ScrollingGrid = require(ShellModules:FindFirstChild('ScrollingGrid'))
local GameCarouselItem = require(ShellModules:FindFirstChild('GameCarouselItem'))
local GlobalSettings = require(ShellModules:FindFirstChild('GlobalSettings'))
local EventHub = require(ShellModules:FindFirstChild('EventHub'))
local LockedGameCarouselView = require(ShellModules:FindFirstChild('LockedGameCarouselView'))
local AchievementManager = require(ShellModules:FindFirstChild('AchievementManager'))

local createGamesView = function(viewGridConfig, onNewGameSelected)

	local viewGridContainer = ScrollingGrid(viewGridConfig)
	viewGridContainer.Container.Visible = false
	local this = {}

	local carouselItems = {}
	--The local savedCarouselItems which will always hold all the carouselItems even
	--there is no games in it
	local savedCarouselItems = {}

	local selectedCoreObjectChangedCn = nil
	local setLoadDebounce = false
	local inFocus = false
	local lastLoadTime = nil
	local sortCategories = nil
	local savedSelectedCarouselItem = nil

	local staticSelectionImage = Utility.Create'ImageLabel'
	{
		-- Values pulled from GuiService.cpp; see constructor
		-- these numbers will need to be updated if positions/sizes change
		Name = "StaticSelectionImage";
		Size = UDim2.new(0, 232 + 14, 0, 232 + 14);
		BackgroundTransparency = 1;
		ScaleType = Enum.ScaleType.Slice;
		SliceCenter = Rect.new(19, 19, 43, 43);
		Image = "rbxasset://textures/ui/SelectionBox.png";
		Selectable = false;
		ZIndex = 3;
	}

	local lockView = LockedGameCarouselView()
	lockView:SetSelectionImageObject(
		Utility.Create'ImageLabel'
		{
			BackgroundTransparency = 1;
		}
	)

	lockView:SetParent(nil)
	lockView:SetZIndex(2)

	local function GetSelectionRectangleFromFirstItem(firstItemContainer)
		return UDim2.new(
				firstItemContainer.Position.X.Scale, firstItemContainer.Position.X.Offset - 7,
				firstItemContainer.Position.Y.Scale, firstItemContainer.Position.Y.Offset + 50 - 7)
	end

	local function showStaticSelectionImage()
		local firstSortItem = #carouselItems > 0 and carouselItems[1] or nil
		if firstSortItem then
			local firstItemContainer = firstSortItem:GetContainer()
			local pos = GetSelectionRectangleFromFirstItem(firstItemContainer)
			staticSelectionImage.Position = pos
			staticSelectionImage.Size = UDim2.new(0, 232 + 14, 0, 232 + 14);
			staticSelectionImage.Parent = viewGridContainer.Container.Parent
		end
		lockView:SetParent(nil)
	end

	local function enterNormalSelectionMode()
		lockView:SetParent(nil)
		local firstSortItem = #carouselItems > 0 and carouselItems[1] or nil
		if firstSortItem then
			local firstItemContainer = firstSortItem:GetContainer()
			local pos = GetSelectionRectangleFromFirstItem(firstItemContainer)
			staticSelectionImage.Position = pos
			staticSelectionImage.Size = UDim2.new(0, 232 + 14, 0, 232 + 14);
		end
	end

	local function enterLockedRowSelectionMode()
		local firstSortItem = #carouselItems > 0 and carouselItems[1] or nil
		if firstSortItem then
			local firstItemView = firstSortItem:GetCarouselView()
			if firstItemView then
				local viewContainerSize = firstItemView:GetContainer().Size

				-- scaling comes from GameCarouselItem
				local lockViewSize = UDim2.new(0, viewContainerSize.X.Offset, 0, viewContainerSize.Y.Offset * 0.84)
				lockView:SetSize(lockViewSize)
				lockView:SetPosition(UDim2.new(0, 8, 0, 8))

				staticSelectionImage.Size = lockViewSize + UDim2.new(0, 16, 0, 16)

				local viewContainerPos = firstItemView:GetContainer().Position
				staticSelectionImage.Position = UDim2.new(
					viewContainerPos.X.Scale,
					viewContainerPos.X.Offset - 118,
					viewContainerPos.Y.Scale,
					viewContainerPos.Y.Offset + 10
				)
			end
		end
		lockView:SetParent(staticSelectionImage)
	end

	local function removeStaticSelectionImage()
		staticSelectionImage.Parent = nil
	end

	local fadableObjets = {}

	local function getItemByIndex(i)
		local item = carouselItems[i]
		return item and item:GetContainer()
	end

	local function getIndexByItem(item)
		for i = 1, #carouselItems do
			if item == carouselItems[i] then
				return i
			end
		end

		return 0
	end

	local function getMappedIndex(item)
		for i = 1, #savedCarouselItems do
			if item == savedCarouselItems[i] then
				return i
			end
		end

		return 0
	end

	local lastSelectedRow = 0
	local function GetSelectedRow()
		for i = 1, #carouselItems do
			local item = carouselItems[i]
			if item:IsSelected() then
				return i
			end
		end
		return 0
	end

	local function GetSelectedItem()
		for i = 1, #carouselItems do
			local item = carouselItems[i]
			if item:IsSelected() then
				return item
			end
		end
		return nil
	end

	local function onSelectedCoreObjectChanged()
		if setLoadDebounce then return end
		local currentSelectedRow = GetSelectedRow()
		lastSelectedRow = currentSelectedRow
		local selectedItem = nil

		if currentSelectedRow == 0 then
			for i = 1, #carouselItems do
				local item = carouselItems[i]
				item:RemoveFocus()
				item:SetTransparency(0, 0, 0.5)
			end
		else
			for i = 1, #carouselItems do
				local item = carouselItems[i]
				local imageTransparency = 0
				local textTransparency = 0
				if item:IsSelected() then
					item:Focus()
					showStaticSelectionImage()
					selectedItem = item
				else
					if i < currentSelectedRow then
						-- Making these bigger than one causes the fadeout to happen before the carousel
						-- overlaps with the game info and preview-image above.  It looks better.
						imageTransparency = 4
						textTransparency = 4
					elseif i == currentSelectedRow then
						imageTransparency = 0
						textTransparency = 0
					else
						imageTransparency = 0.5
						textTransparency = 0.5
					end
					item:RemoveFocus()
				end

				item:SetTransparency(imageTransparency, textTransparency, nil)
			end
			if selectedItem then
				if selectedItem:IsLocked() then
					enterLockedRowSelectionMode()
				else
					enterNormalSelectionMode()
				end
			end
		end
	end

	local function UpdateTransparency()
		local currentSelectedRow = GetSelectedRow()
		if currentSelectedRow > 0 then
			for i = 1, #carouselItems do
				local item = carouselItems[i]
				local imageTransparency = 0
				local textTransparency = 0
				if i < currentSelectedRow then
					imageTransparency = 4
					textTransparency = 4
				elseif i == currentSelectedRow then
					imageTransparency = 0
					textTransparency = 0
				else
					imageTransparency = 0.5
					textTransparency = 0.5
				end

				item:SetTransparency(imageTransparency, textTransparency, 0, true)
			end
		end
	end


	local function carouselItemsResultsUpdate(item)
		if not item then return end
		local lastItemIndex = getIndexByItem(item)
		if item:HasResults() then
			--Add a new row
			if lastItemIndex == 0 then
				local prevSelectedRow = GetSelectedRow()
				local Inserted = false
				for i = 1, #carouselItems do
					if getMappedIndex(item) < getMappedIndex(carouselItems[i]) then
						table.insert(carouselItems, i, item)
						Inserted = true
						break
					end
				end
				if not Inserted then
					table.insert(carouselItems, item)
				end
				--Recalc when carouselItems changes
				viewGridContainer:RecalcLayout(#carouselItems + 1)
				--Try to select the same row after insertion happened
				carouselItems[prevSelectedRow]:Focus()
			end
		else
			--Remove a row
			if lastItemIndex > 0 then
				local wasSelected = item:IsSelected()
				item:RemoveFocus()
				--If was in the carouselItems, remove
				table.remove(carouselItems, lastItemIndex)
				viewGridContainer:RecalcLayout(#carouselItems + 1)

				--The selected row get removed, select the same selected row or first row if doesn't exist
				if inFocus and wasSelected then
					if lastItemIndex > 0 and lastItemIndex <= #carouselItems then
						carouselItems[lastItemIndex]:Focus()
					else
						viewGridContainer:BackToInitial()
						if #carouselItems > 0  then
							carouselItems[1]:Focus()
						end
					end
				end
				lastSelectedRow = GetSelectedRow()
			end
		end

		UpdateTransparency()
	end

	local function createCarouselItem(name, getGameCollection)
		local item = GameCarouselItem(UDim2.new(0, 1900, 0, 250), name, getGameCollection, onNewGameSelected, carouselItemsResultsUpdate)
		table.insert(carouselItems, item)
		table.insert(savedCarouselItems, item)
		return item
	end

	local function createCarouselItems(sortCategories)
		local featuredSortId = 3
		for i = 1, #sortCategories do
			local sort = sortCategories[i]
			local item = createCarouselItem(sort["Name"], function() return sort end)
			if not sort["userId"] then  --If the sort is not related to user
				if not FFlagXboxUseCuratedGameSort then
					if item and sort["Id"] ~= featuredSortId then
						item:SetLockInPUP(true)
					end
				else
					local sortGameSetTargetId = sort["GameSetTargetId"] or 0
					if item and not (sort["Id"] == featuredSortId and sortGameSetTargetId == 0) then
						item:SetLockInPUP(true)
					end
				end
			end
		end

		viewGridContainer:SetItemCallback(getItemByIndex)
		viewGridContainer:RecalcLayout(#carouselItems + 1)

		for i = 1, #savedCarouselItems do
			if not AchievementManager:AllGamesUnlocked() and savedCarouselItems[i]:GetLockInPUP() then
				savedCarouselItems[i]:Lock()
			else
				savedCarouselItems[i]:Unlock()
			end
		end

		for i = 1, #savedCarouselItems do
			savedCarouselItems[i]:Init()
		end
	end

	--Load function for SortsData
	local sortsDataVersion = nil
	local function LoadGameSorts()
		if setLoadDebounce then return end
		setLoadDebounce = true

		local needUpdate = false
		local sortsData = nil
		if SortsData:HasSorts() then  --Sync Call
			sortsData = SortsData:GetSorts()
			if not sortsDataVersion or sortsData.Version ~= sortsDataVersion then
				needUpdate = true
			end
		else
			needUpdate = true
		end

		if needUpdate then
			viewGridContainer.Container.Visible = false
			spawn(function()
				local maxRetry = 2
				while maxRetry > 0 and not sortsData do
					sortsData = SortsData:GetSorts()
					maxRetry = maxRetry - 1
				end

				if sortsData then
					if #savedCarouselItems > 0 then
						--Remove all
						for i = 1, #savedCarouselItems do
							savedCarouselItems[i]:Destroy()
						end
					end

					--Reset all data
					carouselItems = {}
					savedCarouselItems = {}
					savedSelectedCarouselItem = nil
					onNewGameSelected(nil)
					viewGridContainer:RecalcLayout(0)
					viewGridContainer:BackToInitial()
					lastSelectedRow = 0

					--Create new CarouselItems
					createCarouselItems(sortsData.Data)
					sortsDataVersion = sortsData.Version
				end

				viewGridContainer.Container.Visible = true
				if inFocus then
					if #carouselItems > 0  then
						carouselItems[1]:Focus()
						showStaticSelectionImage()
						UpdateTransparency()
					end
				end
				setLoadDebounce = false
			end)
		else
			setLoadDebounce = false
		end
	end

	local function onGridViewFocused()
		--Focus on viewGridContainer and the selected row
		viewGridContainer:Focus()
		if not setLoadDebounce then
			local selectedRow = 0
			if savedSelectedCarouselItem then
				selectedRow = getIndexByItem(savedSelectedCarouselItem)
				savedSelectedCarouselItem = nil
			else
				selectedRow = GetSelectedRow()
			end

			if selectedRow > 0 and selectedRow <= #carouselItems then
				carouselItems[selectedRow]:Focus()
			else
				viewGridContainer:BackToInitial()
				if #carouselItems > 0  then
					carouselItems[1]:Focus()
				end
			end
			UpdateTransparency()
		end
	end

	local function onGridViewFocusRemoved(fromAppHub)
		savedSelectedCarouselItem = GetSelectedItem()
		lastSelectedRow = 0

		--If the bumper/button B caused the removing focus, reset to the top of viewGridContainer
		if fromAppHub then
			viewGridContainer:BackToInitial(GlobalSettings.TabDockTweenDuration)
			savedSelectedCarouselItem = nil
		end
		--Remove image and the focus on all inside elements
		removeStaticSelectionImage()
		viewGridContainer:RemoveFocus()
		for i = 1, #carouselItems do
			local item = carouselItems[i]
			item:RemoveFocus()
			item:SetTransparency(0, 0, 0.5)
		end
	end

	function this:GetDefaultFocusItem()
		return nil
	end

	function this:SetParent(parent)
		viewGridContainer:SetParent(parent)
	end

	function this:Load()
		LoadGameSorts()
	end

	function this:Focus()
		inFocus = true
		Utility.DisconnectEvent(selectedCoreObjectChangedCn)
		selectedCoreObjectChangedCn = GuiService:GetPropertyChangedSignal('SelectedCoreObject'):connect(function()
			onSelectedCoreObjectChanged()
		end)
		onGridViewFocused()
	end

	function this:RemoveFocus(fromAppHub)
		inFocus = false
		Utility.DisconnectEvent(selectedCoreObjectChangedCn)
		onGridViewFocusRemoved(fromAppHub)
	end


	EventHub:removeEventListener(EventHub.Notifications["PlayedGamesChanged"], "GamesPaneRecentlyPlayedUpdate")
	EventHub:removeEventListener(EventHub.Notifications["FavoriteToggle"], "GamesPaneFavoritesUpdate")
	EventHub:removeEventListener(EventHub.Notifications["UnlockedUGC"], "GamesPaneUnlockedUGC")

	--Add listener to PlayedGamesChanged and FavoriteToggle to reload these two types timely
	EventHub:addEventListener(EventHub.Notifications["PlayedGamesChanged"], "GamesPaneRecentlyPlayedUpdate",
	function()
		spawn(function()
			local updateItemName = Strings:LocalizedString("RecentlyPlayedSortTitle")
			for i = 1, #savedCarouselItems do
				if updateItemName == savedCarouselItems[i]:GetSortName() then
					savedCarouselItems[i]:Refresh()
					break
				end
			end
		end)
	end)

	EventHub:addEventListener(EventHub.Notifications["FavoriteToggle"], "GamesPaneFavoritesUpdate",
	function(success)
		if success then
			spawn(function()
				local updateItemName = Strings:LocalizedString("FavoritesSortTitle")
				for i = 1, #savedCarouselItems do
					if updateItemName == savedCarouselItems[i]:GetSortName() then
						savedCarouselItems[i]:Refresh()
						break
					end
				end
			end)
		end
	end)

	if not AchievementManager:AllGamesUnlocked() then
		EventHub:addEventListener(EventHub.Notifications["UnlockedUGC"], "GamesPaneUnlockedUGC",
		function()
			spawn(function()
				for i = 1, #savedCarouselItems do
					if savedCarouselItems[i]:IsLocked() then
						savedCarouselItems[i]:Unlock()
					end
				end
			end)
		end)
	end

	--[[ Initialize - Don't Block ]]--
	spawn(function()
		LoadGameSorts()
	end)

	return this
end

return createGamesView