public static GoalMonthInfo CalculateGoalMonthInfo(Goal goal, DateTime month, List <Transaction> transactions)
{
var info = new GoalMonthInfo();
CalculateIdeal(transactions, goal, month, info);
CalculateActual(transactions, month, info);
CalculateStatus(goal, month, info);
return(info);
}
private static void CalculateStatus(Goal goal, DateTime month, GoalMonthInfo info)
{
var marginLimit = goal.Limit - (info.InitialAmount - goal.Limit) * 0.1; // 10% fail margin 10%
if (DateTime.Now.Date > month.LastDayOfMonth()) // old month
{
info.Status = info.CurrentAmount >= goal.Limit ? GoalStatus.Success: (info.CurrentAmount < marginLimit ? GoalStatus.Failed : GoalStatus.OffTrack);
}
else // current month
{
info.Status =
info.CurrentAmount < marginLimit ? GoalStatus.Failed :
info.CurrentAmount < goal.Limit ? GoalStatus.OffTrack :
info.CurrentAmount < info.CurrentIdealAmount ? GoalStatus.OffTrack
: GoalStatus.OnTrack;
}
}
private static void CalculateActual(List <Transaction> transactions, DateTime month, GoalMonthInfo info)
{
var points = new List <DateAmountPoint>();
var date = month.FirstDayOfMonth();
var lastDate = (DateTime.Now.Date < month.LastDayOfMonth()) ? DateTime.Now.Date : month.LastDayOfMonth();
var cumulativeAmount = 0d;
while (date <= lastDate)
{
var dayAmount = transactions.Where(x => x.Date.Date == date).Select(x => x.Amount).Sum();
cumulativeAmount += dayAmount;
points.Add(new DateAmountPoint(date, cumulativeAmount));
date = date.AddDays(1);
}
info.CurrentAmount = cumulativeAmount;
info.ActualPoints = points;
}
private static void CalculateIdeal(List <Transaction> transactions, Goal goal, DateTime month, GoalMonthInfo info)
{
info.InitialAmount = transactions.Where(x => x.Recurring || x.Category.CategoryType == CategoryType.Recurring).Select(x => x.Amount).Sum();
var endAmount = goal.Limit;
var startDate = month.FirstDayOfMonth();
var endDate = month.LastDayOfMonth();
var slope = (endAmount - info.InitialAmount) / (endDate.Subtract(startDate).Days + 1);
// +1: initialAmount applies at start of day 1 (so actually at day 0)
var points = new List <DateAmountPoint>
{
new DateAmountPoint(startDate, info.InitialAmount + slope),
new DateAmountPoint(endDate, endAmount)
};
var currentDate = DateTime.Now.Date;
if (currentDate < endDate && currentDate > startDate)
{
var currentAmount = info.InitialAmount + (currentDate.Subtract(startDate).Days + 1) * slope;
points.Add(new DateAmountPoint(currentDate, currentAmount));
info.CurrentIdealAmount = currentAmount;
}
else
{
info.CurrentIdealAmount = endAmount;
}
info.IdealPoints = points;
}