-- 用来实现自动倒计时，并可以做数据绑定，具体用法参考VT_RemainTime.lua
local RemainTime = class("RemainTime");

function RemainTime:ctor()
	-- 当前剩余秒数，每秒更新一次，可绑定
	self.Value = 0;
	-- 总剩余时间（单位秒，外部设置），可绑定
	self.RemainTime = 0;
	-- 上次更新的本地时间
	self.LastTime = 0
	-- 总共流失了多少时间
	self.TotalElapse = 0
	-- 开始倒计时的时间（os.time()获取）
	self.StartTime = 0;
	-- 计时到0后，回调OnTimeOver(self)
	self.OnTimeOver = nil;
	-- 数据绑定列表，key是变量名（Value或RemainTime），value是Binder表
	self.BindsByName = {}
	-- 根据索引排序的绑定列表，key是BindIndex，value是Binder表
	self.BindsByIndex = {}
	-- 绑定索引
	self.BindIndex = 0;
	-- 每隔多久触发一次
	self.Interval = 1;
	-- 定时器速度
	self.Speed = 1;
	-- 暂停状态
	self.Pause = false;
end

function RemainTime:setInterval(interval)
	if self.Interval ~= interval then
		self.Interval = interval;
		if self.TimerID then
			self:stopTimer();
			self:startTimer();
		end
	end
end

-- 设置加速速度
function RemainTime:setSpeed(speed)
	self.Speed = speed
end

-- 设置剩余秒数多少
function RemainTime:setRemainTime(seconds)
	--print("设置倒计时" , seconds);
	if type(seconds) == "table" then
		seconds = seconds:getRemainTime();
	end

	self.RemainTime = seconds;
	self.Value = seconds;
	self.StartTime = os.time()
	self.LastTime = self.StartTime
	self.TotalElapse = 0
	self:triggerBinder("RemainTime");
	self:triggerBinder("Value");

	-- 开始计时
	if self.Value > 0 and next(self.BindsByIndex) ~= nil and self.Pause == false then
		self:startTimer();
	end
end

function RemainTime:getRemainTime()
	return self.RemainTime;
end

function RemainTime:updateTo(target)
	target.Value = self.Value;
	target.RemainTime = self.RemainTime;
	target.StartTime = self.StartTime;
	target.LastTime = self.LastTime
	target.TotalElapse = self.TotalElapse
	target.Speed = self.Speed
	if target.startTimer and target.Value > 0 and next(target.BindsByIndex) ~= nil and target.Pause == false then
		target:startTimer()
	end
	
	return target;
end;

-- 获取一个绑定实例
function RemainTime:getBinder(valueName)
	local bindTable = self.BindsByName[valueName];
	-- 根据名字创建绑定表，一个名字可以绑定多次
	if bindTable == nil then
		bindTable = {};
		self.BindsByName[valueName] = bindTable;
	end

	self.BindIndex = self.BindIndex + 1
	-- 创建单个绑定实例
	local binder = 
	{
		TargetNode = nil;
		ValueName = valueName;
		BindIndex = self.BindIndex;
		OnPropChanged = nil
	};

	self.BindsByIndex[binder.BindIndex] = binder;
	
	bindTable[binder.BindIndex] = binder;

	return binder;
end

-- 每秒回调一次
function RemainTime:onTimer()
	local now = os.time()
	local elapse = (now - self.LastTime) * self.Speed;
	self.TotalElapse = self.TotalElapse + elapse
	self.LastTime = now
	-- 计算剩余时间
	self.Value = self.RemainTime - self.TotalElapse;
	if self.Value <= 0 then
		self.Value = 0;
	end
	--print("计算剩余时间：" , self.Value , self.RemainTime , seconds , now , self.StartTime);
	-- 触发数据修改通知
	self:triggerBinder("Value");

	-- 倒计时结束
	if self.Value <= 0 then
		--print("倒计时结束" , self.Value);
		self:stopTimer();
		if self.OnTimeOver then 
			self.OnTimeOver(self); 
		end;
	end;			
end

-- 触发数据修改通知
function RemainTime:triggerBinder(valueName)
	local value = self[valueName];
	--print("值改变：" , valueName , value);
	local binders = self.BindsByName[valueName];
	if binders then
		for i , v in pairs(binders) do
			v.OnPropChanged(valueName , value);
		end
	end
end

-- 开始计时器
function RemainTime:startTimer()
	if self.Pause then
		return
	end
	
	if self.TimerID == nil then
		self.TimerID = cc.Director:getInstance():getScheduler():scheduleScriptFunc(function()self:onTimer()end, self.Interval, false);
	end
end

-- 停止计时器
function RemainTime:stopTimer()
	if self.TimerID then
		cc.Director:getInstance():getScheduler():unscheduleScriptEntry(self.TimerID);
		self.TimerID = nil;
	end
end

-- 暂停计时器（计时器就不走了）
function RemainTime:pause()
	if self.Pause then
		return
	end
	
	self:stopTimer()
	-- 执行一次时间
	self:onTimer()
	self.Pause = true
end

-- 恢复计时器
function RemainTime:resume()
	if not self.Pause then
		return
	end
	
	self.Pause = false
	-- 如果时间完了就不能开始了
	if self.Value <= 0 then
		print("计时器时间已经流失完了，恢复失败")
		return
	end
	
	-- 重新设置下时间
	self:setRemainTime(self.Value)
end

-- 实现自动绑定数据的函数
-- @valueName 需要绑定哪个变量名  
-- @propertyNameOrFunc , 当添加事件发生时的回调或设置什么属性，回调格式是func(key , value);
-- @return 返回绑定索引
function RemainTime:bind(valueName , propertyNameOrFunc , targetNode)
	local onPropChange;
	local typeP = type(propertyNameOrFunc);

	if typeP == "function" then
		onPropChange = function(key , value)
			propertyNameOrFunc(self , value);
		end
	elseif typeP == "string" then
		local function onChange(key , value)
			self[propertyNameOrFunc](self , value);
		end
		onPropChange = onChange
	else
		error("绑定数据" .. tostring(valueName) .. "时第三个参数错误，必须是属性名或函数" .. tostring(propertyNameOrFunc))
		return;
	end

	local binder = self:getBinder(valueName);
	binder.TargetNode = targetNode;
	binder.OnPropChanged = onPropChange;

	-- 开始计时
	if self.Value > 0 then
		self:startTimer();
	end
	self:triggerBinder(valueName);
	return binder.BindIndex;
end

-- 解除绑定
function RemainTime:unbind(bindIndex)
	local binder = self.BindsByIndex[bindIndex];
	if binder == nil then
		print("找不到绑定索引" .. tostring(bindIndex));
		return;
	end
	self.BindsByName[binder.ValueName][bindIndex] = nil;
	self.BindsByIndex[bindIndex] = nil;
	
	-- 没人绑定了，就停止计时器
	if next(self.BindsByIndex) == nil then
		self:stopTimer();
	end
end

return RemainTime;