//贷款计算器

/// 根据属性PayWay（还款方式）计算还款表
/// <param name="PlayList">还款表</param>
function GetPlayList(oDocument)
{
var LastSum=oDocument.all.edLastSum.value;
var BeginYear=0;
var LoanTimes=parseInt(oDocument.all.edTimes.value);
var Rate=parseFloat(oDocument.all.edRate.value)/100;
var PayWay=oDocument.all.ddlPayWay.value;
if (oDocument.all.rbPayFreq_0.checked)
PayFreq=1;
else
{
if (oDocument.all.rbPayFreq_1.checked)
PayFreq=3;
else
PayFreq=1;
}

var result=0;
var LoanTimesTemp=0;
LoanTimesTemp=LoanTimes/PayFreq;
PlayList=new Array();
var nowdate=new Date();
var addnowdate=new Date();

addnowdate.setMonth(addnowdate.getMonth()+LoanTimes)
switch (PayWay)
{
case "1"://等额还款
result=CalcLoanPay(document.all.xmldso.XMLDocument, LastSum,nowdate,LoanTimesTemp,Rate,PayFreq);
break;
case "2"://等本还款
result=ECorpus(document.all.xmldso.XMLDocument, LastSum,nowdate,LoanTimesTemp,Rate,PayFreq);
break;
case "3"://一次性还本付息
result=CalcPayOnce(document.all.xmldso.XMLDocument, LastSum,nowdate,addnowdate,Rate);
break;
}
//return result;
}

//---------------------公用部分-----------------------------------------
/// 等额付款的现金支出（还款计划）数据生成
/// <param name="oXMLDoc">还款表</param>
/// <param name="LastSum">债务本金（贷款总额）</param>
/// <param name="BeginYear">债务开始年份（贷款日期）</param>
/// <param name="times">债务的期限（贷款期限（月份数））</param>
/// <param name="Rate">债务的年利率</param>
/// <param name="Freq">债务的偿还频率</param>
function CalcLoanPay(oXMLDoc, LastSum,BeginYear,times,Rate,Freq)
{
var root = oXMLDoc.documentElement;
var elem;
var node;
var i, m;
var fTotalInterest = new Number(0), fTotalSum = new Number(0);
//清空xml中的数据
m = root.childNodes.length;
for (i=0;i<m;i++)
{
node = root.childNodes.item(0);
root.removeChild(node);
}

i=0;
var r,M,Inter,C,dtemp;
r=Rate*Freq/12;
dtemp=Math.pow((1+r),times);
if (dtemp!=1)
M=(LastSum*r*dtemp/(dtemp-1));
else
M=LastSum/times;
for (i=0;i<times;i++)
{
Inter=LastSum*r;
C=M-Inter;
mRecTimes=i+1;
mRecYear=new Date(BeginYear.getYear(), BeginYear.getMonth() + 1, BeginYear.getDate());
mRecYear.setMonth(mRecYear.getMonth()+(i*Freq));
LastSum=LastSum-C;
mRecCorpus=C;
mRecRateSum=Inter;
mRecLeavCorpus=LastSum;

//-----绑定数据到表格-----
// 还款期次Times
// 还款时间Year
// 偿还的本金Corpus
// 偿还的 利息RateSum
// 剩余的本金LeavCorpus
elem = oXMLDoc.createElement("Items");
root.appendChild(elem);
node = root.lastChild;

elem = oXMLDoc.createElement("Times");
node.appendChild(elem);
node.lastChild.text = mRecTimes;

elem = oXMLDoc.createElement("Year");
node.appendChild(elem);
node.lastChild.text = mRecYear.getYear() + "-" + (mRecYear.getMonth() + 1) + "-" + mRecYear.getDate();

elem = oXMLDoc.createElement("RateSum");
node.appendChild(elem);
node.lastChild.text = (Math.round(mRecRateSum * 100) / 100).toString();
fTotalInterest += mRecRateSum;//new Number(node.lastChild.text);

elem = oXMLDoc.createElement("Corpus");
node.appendChild(elem);
node.lastChild.text = Math.round(mRecCorpus * 100) / 100;
fTotalSum += mRecCorpus;//new Number(node.lastChild.text);

elem = oXMLDoc.createElement("CorpusRate");
node.appendChild(elem);
node.lastChild.text = Math.round((mRecRateSum + mRecCorpus) * 100) / 100;

elem = oXMLDoc.createElement("LeavCorpus");
node.appendChild(elem);
node.lastChild.text = Math.round(mRecLeavCorpus * 100) / 100;
}
elem = oXMLDoc.createElement("Items");
root.appendChild(elem);
node = root.lastChild;

elem = oXMLDoc.createElement("Times");
node.appendChild(elem);
node.lastChild.text = "合计";

elem = oXMLDoc.createElement("Year");
node.appendChild(elem);

elem = oXMLDoc.createElement("RateSum");
node.appendChild(elem);
node.lastChild.text = (Math.round(fTotalInterest * 100) / 100).toString();

elem = oXMLDoc.createElement("Corpus");
node.appendChild(elem);
node.lastChild.text = Math.round(fTotalSum * 100) / 100;

elem = oXMLDoc.createElement("CorpusRate");
node.appendChild(elem);
node.lastChild.text = Math.round((fTotalInterest + fTotalSum) * 100) / 100;

elem = oXMLDoc.createElement("LeavCorpus");
node.appendChild(elem);
}

/// 等本付款的现金支出（还款计划）数据生成（本金还款法）
/// <param name="oXMLDoc">还款表</param>
/// <param name="LastSum">债务本金（贷款总额）</param>
/// <param name="BeginYear">债务开始年份（贷款日期）</param>
/// <param name="times">债务的期限（贷款期限（月份数））</param>
/// <param name="Rate">债务的年利率</param>
/// <param name="Freq">债务的偿还频率</param>
function ECorpus(oXMLDoc,LastSum,BeginYear,times,Rate,Freq)
{
var r,Inter,c;
var i=0,result=0;
var TotalLoan=LastSum;

var root = oXMLDoc.documentElement;
var elem;
var node;
var i, m;
var fTotalInterest = new Number(0), fTotalSum = new Number(0);
//清空xml中的数据
m = root.childNodes.length;
for (i=0;i<m;i++)
{
node = root.childNodes.item(0);
root.removeChild(node);
}

r=Rate*Freq/12;
if (times!=0)
c=LastSum/times;
else
c=0;
for (i=0;i<times;i++)
{
RecTimes=i+1;
//RecYear=BeginYear;
//RecYear.setMonth(BeginYear.getMonth()+(i*Freq));
RecYear=new Date(BeginYear.getYear(), BeginYear.getMonth() + 1, BeginYear.getDate());
RecYear.setMonth(RecYear.getMonth()+(i*Freq));
Inter=LastSum*r;
LastSum=LastSum-c;
RecCorpus=c;
RecRateSum=Inter;
RecLeavCorpus=LastSum;

//-----绑定数据到表格-----
// 还款期次Times
// 还款时间Year
// 偿还的本金Corpus
// 偿还的 利息RateSum
// 剩余的本金LeavCorpus
elem = oXMLDoc.createElement("Items");
root.appendChild(elem);
node = root.lastChild;

elem = oXMLDoc.createElement("Times");
node.appendChild(elem);
node.lastChild.text = RecTimes;

elem = oXMLDoc.createElement("Year");
node.appendChild(elem);
node.lastChild.text = RecYear.getYear() + "-" + (RecYear.getMonth() + 1) + "-" + RecYear.getDate();

elem = oXMLDoc.createElement("RateSum");
node.appendChild(elem);
node.lastChild.text = (Math.round(RecRateSum * 100) / 100).toString();
fTotalInterest += RecRateSum;//new Number(node.lastChild.text);

elem = oXMLDoc.createElement("Corpus");
node.appendChild(elem);

node.lastChild.text = Math.round(RecCorpus * 100) / 100;
fTotalSum += RecCorpus;//new Number(node.lastChild.text);

elem = oXMLDoc.createElement("CorpusRate");
node.appendChild(elem);
node.lastChild.text = Math.round((RecRateSum + RecCorpus) * 100) / 100;

elem = oXMLDoc.createElement("LeavCorpus");
node.appendChild(elem);
node.lastChild.text = Math.round(RecLeavCorpus * 100) / 100;
}
elem = oXMLDoc.createElement("Items");
root.appendChild(elem);
node = root.lastChild;

elem = oXMLDoc.createElement("Times");
node.appendChild(elem);
node.lastChild.text = "合计";

elem = oXMLDoc.createElement("Year");
node.appendChild(elem);

elem = oXMLDoc.createElement("RateSum");
node.appendChild(elem);
node.lastChild.text = (Math.round(fTotalInterest * 100) / 100).toString();

elem = oXMLDoc.createElement("Corpus");
node.appendChild(elem);
node.lastChild.text = Math.round(fTotalSum * 100) / 100;

elem = oXMLDoc.createElement("CorpusRate");
node.appendChild(elem);
node.lastChild.text = Math.round((fTotalInterest + fTotalSum) * 100) / 100;

elem = oXMLDoc.createElement("LeavCorpus");
node.appendChild(elem);
}

///一次性还本付息的现金支出（还款计划）数据生成
/// <param name="oXMLDoc">还款表</param>
/// <param name="LastSum">债务本金（贷款总额）</param>
/// <param name="BeginYear"> 债务开始年份（贷款日期）</param>
/// <param name="EndYear">债务结束年份（贷款日期）</param>
/// <param name="Rate">债务的年利率</param>
function CalcPayOnce(oXMLDoc,LastSum,BeginYear,EndYear,Rate)
{
var result=0;
var r;
var days;

var root = oXMLDoc.documentElement;
var elem;
var node;
var i, m;
//清空xml中的数据
m = root.childNodes.length;
for (i=0;i<m;i++)
{
node = root.childNodes.item(0);
root.removeChild(node);
}

r=Rate;
days=GetDayLen(EndYear,BeginYear);//计算债务期限（天数）
RecYear=EndYear;
RecTimes =1;
RecCorpus=new Number(LastSum);
RecRateSum=RecCorpus*r/360*days;
RecLeavCorpus=0;

//-----绑定数据到表格-----
// 还款期次Times
// 还款时间Year
// 偿还的本金Corpus
// 偿还的 利息RateSum
// 剩余的本金LeavCorpus

elem = oXMLDoc.createElement("Items");
root.appendChild(elem);
node = root.lastChild;

elem = oXMLDoc.createElement("Times");
node.appendChild(elem);
node.lastChild.text = RecTimes;

elem = oXMLDoc.createElement("Year");
node.appendChild(elem);
node.lastChild.text = RecYear.getYear() + "-" + (RecYear.getMonth() + 1) + "-" + RecYear.getDate();

elem = oXMLDoc.createElement("RateSum");
node.appendChild(elem);
node.lastChild.text = (Math.round(RecRateSum * 100) / 100).toString();

elem = oXMLDoc.createElement("Corpus");
node.appendChild(elem);
node.lastChild.text = Math.round(RecCorpus * 100) / 100;

elem = oXMLDoc.createElement("CorpusRate");
node.appendChild(elem);
node.lastChild.text = Math.round((RecRateSum + RecCorpus) * 100) / 100;

elem = oXMLDoc.createElement("LeavCorpus");
node.appendChild(elem);
node.lastChild.text = Math.round(RecLeavCorpus * 100) / 100;
}

/// 计算段后计息天数
/// <param name="StartDate">债务结束日期</param>
/// <param name="StandDate">债务开始日期或者标准日期（1999年11月1日）</param>
/// <returns></returns>
function GetDayLen(StartDate,StandDate)
{
//以每月30天算一月，一年为360天
return (StartDate.getYear()-StandDate.getYear())*360+(StartDate.getMonth()-StandDate.getMonth())*30+(StartDate.getDate()-StandDate.getDate());
}