public static void Validate(BookItemStatus itemStatus, BookItemStatus newStatus)
{
switch (itemStatus)
{
case BookItemStatus.Read:
if (newStatus == BookItemStatus.Read)
{
break;
}
throw new CannotChangeStatusException(itemStatus, newStatus);
case BookItemStatus.Reading:
case BookItemStatus.StartedButPostponed:
if (newStatus == BookItemStatus.ToReading)
{
throw new CannotChangeStatusException(itemStatus, newStatus);
}
break;
case BookItemStatus.ToReading:
if (newStatus == BookItemStatus.Read || newStatus == BookItemStatus.StartedButPostponed)
{
throw new CannotChangeStatusException(itemStatus, newStatus);
}
break;
default:
throw new ArgumentOutOfRangeException(nameof(itemStatus), itemStatus.ToString("G"), null);
}
}
public static int Calculate(int previousTime, BookItemStatus previousStatus, DateTimeOffset previousDate,
BookItemStatus newStatus)
{
var diff = default(int);
if (previousStatus == newStatus)
{
return(previousTime + diff);
}
switch (newStatus)
{
case BookItemStatus.StartedButPostponed:
case BookItemStatus.Read:
diff = Convert.ToInt32(Math.Round((DateTime.UtcNow - previousDate).TotalSeconds,
MidpointRounding.AwayFromZero));
break;
case BookItemStatus.ToReading:
case BookItemStatus.Reading:
break;
default:
throw new ArgumentOutOfRangeException(nameof(newStatus), newStatus, null);
}
return(previousTime + diff);
}
public static void Update(this PrivateBookListItem item, Dictionary <string, object> source,
BookItemStatus newStatus)
{
var newReadingTime = ReadingTimeCalculator.Calculate(item.ReadingTimeInSeconds, item.Status,
item.LastStatusUpdateDate, newStatus);
source.Add(nameof(PrivateBookListItem.ReadingTimeInSeconds), newReadingTime);
ObjectUpdater <PrivateBookListItem> .Update(item, source);
}
public CannotChangeStatusException(BookItemStatus from, BookItemStatus to)
: base(string.Format(ExceptionMessages.CannotChangeStatusFromTo, from.ToStringFromDescription(),
to.ToStringFromDescription()))
{
}
