-- 是否是瑞年
function isLeapYear(year)
	if year % 100 == 0 then
		return year % 400 == 0;
	else
		return year % 4 == 0;
	end
end

-- UTC时间转换成北京时间
function UTCToBeijingTime(second)
	return second + 8 * 60 * 60
end

-- 格式:yyyyMMdd返回年月日
function timeToDate(time)
	local year;
	local month;
	local day;
	
	year = math.floor(time / 10000);
	local monthDay = time % 10000;
	month = math.floor(monthDay / 100);
	day = monthDay % 100;

	return year, month, day
end

-- 支持ServerTest的公用函数
BeijingTime = 
{
	convert2Zone = 8;
	oldDateFunc = os.date;
	oldTimeFunc = os.time;
	dateFunc = nil;
	timeFunc = nil;
	
	monthTable1 = 
	{
		0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
	};
	
	monthTable2 = 
	{
		0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335
	};
	
	yearTable = nil;
};

function BeijingTime:initYearTable()
	local yearTable = {};
	
	yearTable[1970] = 0; 
	local dayCount = 0;
	for i = 1971, 2100 do
		local tmpDay;
		if isLeapYear(i - 1) then
			tmpDay = 366;
		else
			tmpDay = 365;
		end
		dayCount = dayCount + tmpDay;
		yearTable[i] = dayCount;
	end;
	
	self.yearTable = yearTable;
end;

function BeijingTime:reload()
	
	if not self.yearTable then
		self:initYearTable();
	end;
	
	BeijingTime.dateFunc = function(time)
		time = time or self.oldTimeFunc();
		time = time + self.convert2Zone * 3600;
		local year, month, day, hour, min, sec, weekDay = self:second2Date(time);
		return {year = year, month = month, day = day, hour = hour, min = min, sec = sec, week = weekDay};
	end
	
	BeijingTime.timeFunc = function(t)
		if not t then
			return self.oldTimeFunc();
		else
			local time = self:date2Second(t.year, t.month, t.day, t.hour, t.min, t.sec);
			return time - self.convert2Zone * 3600;
		end
	end
end;


function BeijingTime:date(formatStr, time)
	if not self.dateFunc then
		self:reload();
	end
	
	return self.dateFunc(formatStr, time);
end

function BeijingTime:second2Date(sec)
	local yearTable = self.yearTable;
	local monthTable1 = self.monthTable1;
	local monthTable2 = self.monthTable2;


	local weekDay = 0;
	local dayCount = 0;
	local year = 0;
	for i = 1971, 2100 do
		dayCount = yearTable[i];
		if dayCount * 86400 > sec then
			year = i - 1;
			dayCount = yearTable[year];
			break;
		end
	end
	
	sec = sec - dayCount * 86400;
	weekDay = dayCount;
	
	local month = 0;
	if isLeapYear(year) then
		for i = 1, 12 do
			month = i;
			dayCount = monthTable2[i];
			if sec >= monthTable2[i] * 86400 
				and monthTable2[i + 1]
				and sec <  monthTable2[i + 1] * 86400 then
				break;
			end
		end
	else
		for i = 1, 12 do
			month = i;
			dayCount = monthTable1[i];
			if sec >= monthTable1[i] * 86400 
				and monthTable1[i + 1]
				and sec <  monthTable1[i + 1] * 86400 then
				break;
			end
		end
	end
	
	weekDay = dayCount + weekDay;
	
	sec = sec - dayCount * 86400;
	
	local day = math.floor(sec / 86400) + 1;
	sec = sec % 86400;
	local hour  = math.floor(sec / 3600);
	sec = sec % 3600;
	local min = math.floor(sec / 60);
	sec = sec % 60;

	-- 1970年1月1日是星期4
	weekDay = weekDay + day - 1 + 4;
	weekDay = weekDay % 7;
	-- 如果是0， 则改为7
	if weekDay == 0 then
	   weekDay = 7;
	end
	
	return year, month, day, hour, min, sec, weekDay;
end;


function BeijingTime:date2Second(year, month, day, hour, min, sec)
	local yearTable = self.yearTable;
	local monthTable1 = self.monthTable1;
	local monthTable2 = self.monthTable2;

	local dayCount = 0;
	if isLeapYear(year) then
		dayCount = yearTable[year] + monthTable2[month] + day - 1;
	else
		dayCount = yearTable[year] + monthTable1[month] + day - 1;
	end
	
	local ret = dayCount * 86400;
	hour = hour or 12;
	min = min or 0;
	sec = sec or 0;
	ret = ret + hour * 3600 + min * 60 + sec;
	
	return ret;
end;	

BeijingTime:reload();