-- 智能滚动界面
--[[	
	initCount ? : number,  // 初始加载initCount个UIItem
	loadCount ? : number,  // 滚动到增长边界时则加载loadCount个item
	initIndex ? : number,  // 初始化索引位置，从1开始
	isPlayAnime ? : boolean,  // 是否在第一次更新数据时播放动画
	isWheelStyle ? : boolean,  // 是否滚轮风格
	focusPercent ? : number,  // 从0到1，表示从下到上，从左到右，聚焦的百分比位置
	radiusRate ? : number,  // 滚轮效果显著程度参数，越大越不明显
	coverRate ? : number,  // ui条目覆盖效果，越大覆盖越明显
	autoScrollToFocus ? : boolean,  // 自动将最近的ui回滚到焦点
	scrollDisScale ? : number,  //
--]]
local SmartScrollView = class("SmartScrollView");

function SmartScrollView:ctor(scrollView, param)
	self.initCount = (param and param.initCount) or 8;
	self.loadCount = (param and param.loadCount) or 3;
	self.initIndex = (param and param.initIndex) or 1;
	self.isPlayAnime = param and param.isPlayAnime;
	self.isWheelStyle = param and param.isWheelStyle;
	self.focusPercent = (param and param.focusPercent) or 0.5;
	self.radiusRate = (param and param.radiusRate) or app.config.Rule.SCROLL_VIEW_WHEEL_RADIUS_RATE.value;
	self.coverRate = (param and param.coverRate) or app.config.Rule.SCROLL_VIEW_WHEEL_COVER_RATE.value;
	self.autoScrollToFocus = param and param.autoScrollToFocus;
	self.scrollDisScale = (param and param.scrollDisScale) or 1;
	self.FocusRadius = 5;  -- 焦点范围误差距离
	self.orderArray = {};  -- 数据必须连续有效，且每个数据皆可创建有效ui
	self.scrollItems = {};  -- Map<number , {layoutNode : cc.Widget , showObj : any}>(); 所有UIItem Map
	self.headDataIdx = 0;
	self.tailDataIdx = 1;
	self.dataChangeOnce = true;
    self.playAnimeOnce = true;

	self.scrollView = scrollView

	self:init();
end

-- 数据数组
function SmartScrollView:getOrderArray()
	return self.orderArray;
end

-- 赋值触发初始化
function SmartScrollView:setOrderArray(arr)
	-- 初始化数据获取方法，若数据变化，则UI重新加载
	local me = self
	me.orderArray = arr;
	if me.dataChangeOnce then
		me.dataChangeOnce = false;
		if not me.scrollView or tolua.isnull(me.scrollView) then
			print("SmartScrollView wasn't assigned UIScrollView！");
			return
		end
		me.scrollView:runDelay(0, function()
			me.dataChangeOnce = true;
			me:onDataChanged();
		end);
	end
end

function SmartScrollView:init()
	local me = self;
	local innerContainer = me.scrollView:getInnerContainer();
	innerContainer:setAutoSize(true);
--	me.scrollView:setScrollDisScale(me.scrollDisScale);
	-- 隐藏进度条
	me.scrollView:getHBar():setVisible(false);
	me.scrollView:getVBar():setVisible(false);

	-- 滚轮风格初始化
	if me.isWheelStyle then
		local oldDoLayout = innerContainer.doLayout;
		innerContainer.doLayout = function()
			for k,v in ipairs(me.scrollItems) do
				v.layoutNode.LocalZOrder = k;
			end
			oldDoLayout(innerContainer);
			me.onScrollWheel();
		end
		-- 解决分辨率变化等导致的界面混乱问题
		me.scrollView:setWidgetEventListener(function(node, eventType)
			if eventType == cc.WidgetEvent.SIZE_CHANGED then
				me.scrollView.runDelay(0 , function()
					me.doLayout();
				end);
			end
		end);
	end

	-- 监听滚到顶部和底部(LocalZOrder大的，布局时排在下面)
	me.scrollView:addEventListener(function(target , eventType)
		if eventType == cc.ScrollviewEventType.scrollToTop or eventType == cc.ScrollviewEventType.scrollToLeft then
			if me.headDataIdx < 1 then
				return;
			end
			for i = 1 , me.loadCount do
				me:addItem(true);
			end
			if me.headDataIdx < 1 and me.isWheelStyle and #me.scrollItems > 0 then
				me:fillStart();
			end
			if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
				if not cc.pEqual(innerContainer:getAnchorPoint() , cc.p(1 , 0)) then
					innerContainer:setPositionX(innerContainer:getPositionX() + (1 - innerContainer:getAnchorPoint().x) * innerContainer:getSize().width);
					innerContainer:setPositionY(innerContainer:getPositionY() - innerContainer:getAnchorPoint().y * innerContainer:getSize().height);
					innerContainer:setAnchorPoint(cc.p(1 , 0));
				end
			else
				if not cc.pEqual(innerContainer:getAnchorPoint() , cc.p(0 , 0)) then
					innerContainer:setPositionX(innerContainer:getPositionX() - innerContainer:getAnchorPoint().x * innerContainer:getSize().width);
					innerContainer:setPositionY(innerContainer:getPositionY() - innerContainer:getAnchorPoint().y * innerContainer:getSize().height);
					innerContainer:setAnchorPoint(cc.p(0 , 0));
				end
			end
			me:doLayout();
		elseif eventType == cc.ScrollviewEventType.scrollToBottom or eventType == cc.ScrollviewEventType.scrollToRight then
			if me.tailDataIdx > #me.orderArray then
				return;
			end
			for i = 1 , me.loadCount do
				me:addItem(false);
			end
			if me.tailDataIdx > #me.orderArray and me.isWheelStyle and #me.scrollItems > 0 then
				me:fillEnd();
			end
			if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
				if not cc.pEqual(innerContainer:getAnchorPoint() , cc.p(0 , 0)) then
					innerContainer:setPositionX(innerContainer:getPositionX() - innerContainer:getAnchorPoint().x * innerContainer:getSize().width);
					innerContainer:setPositionY(innerContainer:getPositionY() - innerContainer:getAnchorPoint().y * innerContainer:getSize().height);
					innerContainer:setAnchorPoint(cc.p(0 , 0));
				end
			else
				if not cc.pEqual(innerContainer:getAnchorPoint() , cc.p(0 , 1)) then
					innerContainer:setPositionX(innerContainer:getPositionX() - innerContainer:getAnchorPoint().x * innerContainer:getSize().width);
					innerContainer:setPositionY(innerContainer:getPositionY() + (1 - innerContainer:getAnchorPoint().y) * innerContainer:getSize().height);
					innerContainer:setAnchorPoint(cc.p(0 , 1));
				end
			end
			me:doLayout();
		end
		if eventType == cc.ScrollviewEventType.scrolling then
			if me.isWheelStyle then
				me:onScrollWheel();
			end
--[[		elseif eventType == cc.ScrollviewEventType.scrollingEnded then
			-- 自动回滚
			if me.isWheelStyle and me.autoScrollToFocus then
				local minDis;
				local minOffset
				for i,v in ipairs(me.scrollItems) do
					local node = v.layoutNode;
					local pos = me.scrollView:convertToNodeSpace2D(node:getWorldPosition());
					-- ui相对于scrollView的center坐标
					local center;
					local offset;
					local dis = 0;
					if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
						center = pos.x + node:getContentSize().width * (0.5 - node:getAnchorPoint().x);
						if center > me.scrollView:getSize().width or center < 0 then
							return;
						end
						offset = center - me.scrollView:getSize().width * me.focusPercent;
						dis = math.abs(offset);
					else
						center = pos.y + node:getContentSize().height * (0.5 - node:getAnchorPoint().y);
						if center > me.scrollView:getSize().height or center < 0 then
							return;
						end
						offset = center - me.scrollView:getSize().height * me.focusPercent;
						dis = math.abs(offset);
					end
					if not minDis then
						minDis = dis;
						minOffset = offset;
						return;
					end
					if dis < minDis then
						minDis = dis;
						minOffset = offset;
					end
				end;
				if #me.scrollItems > 0 and minDis > me.FocusRadius then
					local vec2 = cc.p(0 , 0);
					if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
						vec2.x = -minOffset / me.scrollDisScale;
					else
						vec2.y = -minOffset / me.scrollDisScale;
					end
					me.scrollView:scrollBy(vec2 , 0.5 / me.scrollDisScale , true);
					me:onScrollWheel();
				end
			end
--]]		
		end
	end);
end

function SmartScrollView:doLayout()
	self.scrollView:getInnerContainer():requestDoLayout();
	self.scrollView:getInnerContainer():doLayout();
end

function SmartScrollView:removeAllChildren()
	self.scrollView:removeAllChildren();
	self.scrollItems = {};
end

-- @param index 对应数组下标，从1开始
function SmartScrollView:getUIItem(index)
	return self.scrollItems[index].showObj;
end

-- 将index 对应的ui 节点滚动到focus处，从1开始
function SmartScrollView:scrollToIndex(index , onEnd)
	local me = self;
	if index < 1 or index > #me.orderArray then
		return;
	end
	if #me.scrollItems <= 0 then
		return;
	end
	while index <= me.headDataIdx or index >= me.tailDataIdx do
		me:addItem(index <= me.headDataIdx);
	end
	me:doLayout();
	local item = me.scrollItems[index].layoutNode;
	if not item then
		return;
	end
	local pos = me.scrollView:convertToNodeSpace2D(item:getWorldPosition());
	local center;
	local offset;
	local speed = 1800;
	if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
		center = pos.x + item:getContentSize().width * (0.5 - item:getAnchorPoint().x);
		offset = center - me.scrollView:getSize().width * me.focusPercent;
		me.scrollView:scrollBy(cc.p(-offset , 0) , math.max(offset / speed , 0.5) , true);
	else
		center = pos.y + item:getContentSize().height * (0.5 - item:getAnchorPoint().y);
		offset = center - me.scrollView:getSize().height * me.focusPercent;
		me.scrollView:scrollBy(cc.p(0 , -offset) , math.max(offset / speed , 0.5) , true);
	end
	if onEnd then
		me.scrollView:runDelay(math.max(offset / speed , 0.5) , onEnd);
	end
end

-- index从1开始
function SmartScrollView:jumpToIndex(index)
	local me = self;
	local innerContainer = me.scrollView:getInnerContainer();
	if index < 1 and index > #me.orderArray then
		return;
	end
	if #me.scrollItems <= 0 then
		return;
	end
	while index <= me.headDataIdx or index >= me.tailDataIdx do
		me:addItem(index <= me.headDataIdx);
	end
	me:doLayout();
	local item = me.scrollItems[index].layoutNode;
	if not item or not item:isVisible() then
		me.scrollView:jumpToTop();
		return;
	end
	local pos = me.scrollView:convertToNodeSpace2D(item:getWorldPosition());
	local center;
	local offset;
	if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
		center = pos.x + item:getContentSize().width * (0.5 - item:getAnchorPoint().x);
		offset = center - me.scrollView:getSize().width * me.focusPercent;
		local finalPosX = innerContainer:getPositionX() - offset;
		innerContainer:setPositionX(finalPosX);
		local finalRightX = finalPosX + (1 - innerContainer:getAnchorPoint().x) * innerContainer:getSize().width;
		local finalLeftX = finalPosX - innerContainer:getAnchorPoint().x * innerContainer:getSize().width;
		if finalRightX < me.scrollView:getSize().width then
			innerContainer:setPositionX(finalPosX + me.scrollView:getSize().width - finalRightX);
		end
		if finalLeftX > 0 then
			innerContainer:setPositionX(finalPosX - finalLeftX);
		end
	else
		center = pos.y + item:getContentSize().height * (0.5 - item:getAnchorPoint().y);
		offset = center - me.scrollView:getSize().height * me.focusPercent;
		local finalPosY = innerContainer:getPositionY() - offset;
		innerContainer:setPositionY(finalPosY);
		local finalTopY = finalPosY + (1 - innerContainer:getAnchorPoint().y) * innerContainer:getSize().height;
		local finalBottomY = finalPosY - innerContainer:getAnchorPoint().y * innerContainer:getSize().height;
		if finalBottomY > 0 then
			innerContainer:setPositionY(finalPosY - finalBottomY);
		end
		if finalTopY < me.scrollView:getSize().height then
			innerContainer:setPositionY(finalPosY + me.scrollView:getSize().height - finalTopY);
		end
	end
end


-- orderArray更新后调用
function SmartScrollView:onDataChanged()
	local me = self;
	me:removeAllChildren();
	-- 修正initIndex
	if me.initIndex < 1 then
		me.initIndex = 1;
	end
	if me.initIndex > #me.orderArray then
		me.initIndex = #me.orderArray;
	end

	-- 修正headDataIdx 的初始位置
	me.headDataIdx = me.initIndex + math.floor(me.initCount / 2);
	if me.headDataIdx < 1 then
		me.headDataIdx = 1;
	end
	if me.headDataIdx > #me.orderArray then
		me.headDataIdx = #me.orderArray;
	end
	local count = #me.orderArray > me.initCount and me.initCount or #me.orderArray;
	for i = 1 , count do
		me:addItem(true);
	end
	me.tailDataIdx = me.headDataIdx + #me.scrollItems + 1;
	if me.isWheelStyle and me.headDataIdx < 1 and #me.scrollItems > 0 then
		me:fillStart();
	end
	if me.isWheelStyle and me.tailDataIdx > #me.orderArray and #me.scrollItems > 0 then
		me:fillEnd();
	end
	me:doLayout();
	-- 第一次更新数据，播放动画
	if me.isPlayAnime and me.playAnimeOnce then
		me.playAnimeOnce = false;
		local delayTime = 0.5 --app.config.Rule.get("SCROLL_VIEW_ANI_DELAY_TIME").value;
		local playTime = 0.5 --app.config.Rule.get("SCROLL_VIEW_ANI_PLAY_TIME").value;
		local time = 0;
		for i = me.headDataIdx + 1 , me.tailDataIdx - 1 do
			local node = me.scrollItems[i].layoutNode;
			if node and node:isVisible() then
				time = time + delayTime;
				local offset = node:getContentSize().width;
				for ii,vv in pairs(node:getChildren()) do
					if vv:isVisible() then
						vv:setPositionX(vv:getPositionX() - offset);
						vv:runAction(cc.Sequence.create(cc.DelayTime:create(time)
							, cc.MoveBy:create(playTime , cc.vec3(offset,0,0))
						));
					end
				end
			end
		end
	end
	me:jumpToIndex(me.initIndex);
	if me.isWheelStyle then
		me:onScrollWheel();
	end
end

-- 在开头填空
function SmartScrollView:fillStart()
	local me = self;
	local node = me.scrollItems[1].layoutNode;
	local startNullNode = cc.Widget.create();
	startNullNode:setAutoSize(false);
	if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
		startNullNode:setSize(cc.size(me.scrollView:getSize().width * me.focusPercent - node:getContentSize().width / 2
			, node:getContentSize().height
		));
	else
		startNullNode:setSize(cc.size(node:getContentSize().width
			, me.scrollView:getSize().height * (1 - me.focusPercent) - node:getContentSize().height / 2
		));
	end
	startNullNode:setAutoSize(true);
	me.scrollView:addChild(startNullNode , -100);
end

-- 在结尾填空
function SmartScrollView:fillEnd()
	local me = self;
	local node = me.scrollItems[#me.orderArray].layoutNode;
	local endNullNode = cc.Widget.create();
	endNullNode:setAutoSize(false);
	if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
		endNullNode:setSize(cc.size(
			me.scrollView:getSize().width * (1 - me.focusPercent) - node:getContentSize().width / 2 ,
			node:getContentSize().height
		));
	else
		endNullNode:setSize(cc.size(
			node:getContentSize().width ,
			me.scrollView:getSize().height * me.focusPercent - node:getContentSize().height / 2
		));
	end
	endNullNode:setAutoSize(true);
	me.scrollView:addChild(endNullNode , #me.orderArray + 100);
end

-- 滚轮效果
function SmartScrollView:onScrollWheel()
	local me = self;
	for i,v in pairs(me.scrollItems) do
		local node = v.layoutNode;
		local pos = me.scrollView:convertToNodeSpace2D(node:getWorldPosition());
		-- ui相对于scrollView的center坐标
		local center;
		local dis;
		local range;
		if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
			center = pos.x + node:getContentSize().width * (0.5 - node:getAnchorPoint().x);
			local a = center > me.scrollView:getSize().width + node:getContentSize().width * 2;
			local b = center < -node:getContentSize().width * 2;
			if a or b then
				return;
			end
			dis = math.abs(center - me.scrollView:getSize().width * me.focusPercent);
			range = (me.scrollView:getSize().width + node:getContentSize().width) / 2 * me.radiusRate;
		else
			center = pos.y + node:getContentSize().height * (0.5 - node:getAnchorPoint().y);
			local a = center > me.scrollView:getSize().height + node:getContentSize().height * 2;
			local b = center < -node:getContentSize().height * 2;
			if a or b then
				return;
			end
			dis = math.abs(center - me.scrollView:getSize().height * me.focusPercent);
			range = (me.scrollView:getSize().height / 2 + node:getContentSize().height / 2) * me.radiusRate;
		end
		-- 可视范围内的
		local item = node:getChildren()[0];
		local percent = (range - dis) / range;
		if percent < 0.001 then
			percent = 0.001;
		end
		-- 置透明度
		item:setOpacity(255 * percent);
		-- 置缩放大小
		item:setScale(percent);
		-- 置渲染秩序
		node:setLocalZOrder(range - dis);
	end
end

function SmartScrollView:nextDataIdx(isAddToHead)
	local me = self;
	if isAddToHead then
		me.headDataIdx = me.headDataIdx - 1;
	else
		me.tailDataIdx = me.tailDataIdx + 1;
	end
end

-- @param isAddToHead 是否向数组小端取数据
function SmartScrollView:addItem(isAddToHead)
	local me = self;
	local curDataIdx = isAddToHead and me.headDataIdx or me.tailDataIdx;
	if not me.orderArray[curDataIdx] then
		if curDataIdx >= 1 and curDataIdx <= #me.orderArray then
			me:nextDataIdx(isAddToHead);
		end
		return false;
	end

	assert(me.createUI , "SmartScrollView wasn't assigned ui create function!");
	local item = me:createUI(me.orderArray[curDataIdx], curDataIdx);
	if not item then
		me:nextDataIdx(isAddToHead);
		return false;
	end
	local ui = item.ui or item;
	local node = cc.Widget:create();
	node:setAutoSize(false);
	if me.scrollView:getDirection() == cc.ScrollViewDir.horizontal then
		node:setSize(cc.size(ui:getSize().width - me.coverRate , ui:getSize().height));
		ui:setPositionX(ui:getAnchorPoint().x * ui:getSize().width - me.coverRate / 2);
		ui:setPositionY(ui:getAnchorPoint().y * ui:getSize().height);
	else
		node:setSize(cc.size(ui:getSize().width , ui:getSize().height - me.coverRate));
		ui:setPositionX(ui:getAnchorPoint().x * ui:getSize().width);
		ui:setPositionY(ui:getAnchorPoint().y * ui:getSize().height - me.coverRate / 2);
	end
	-- 节点可见性
	local oldValue = ui:isVisible();
	ui:setVisible(true);
	ui.setVisible = function(this , flag)
		node:setVisible(flag);
	end
	ui.isVisible = function()
		return node:isVisible();
	end
	node:addChild(ui);
	node:setAutoSize(true);
	node:setVisible(oldValue);
	me.scrollView:addChild(node , curDataIdx);
	me.scrollItems[curDataIdx] = {layoutNode = node , showObj = item};
	me:nextDataIdx(isAddToHead);
	return true;
end

return SmartScrollView;