// groups items into lines based on the IsIdenticalItem() test, and sums up quantities for the groups accordingly
public IEnumerable <PackingListItem> BuildPackingList(IEnumerable <PackingListItem> dataResult)
{
var resultGroups = new List <PackingListItem>();
var packingListItems = dataResult as PackingListItem[] ?? dataResult.ToArray();
var qtyOfIdenticalItems = 0m;
var prevWasIdentical = false;
var minBox = 1;
var maxBox = 1;
for (var i = 0; i < packingListItems.Length; i++)
{
var current = packingListItems.ElementAt(i);
if (string.IsNullOrEmpty(current.ContentsDescription))
{
// don't add blank lines that sometimes appear in the query result
continue;
}
// the first item we see, so add it to a new group unless it is the <<__ End of Input __> delimiter returned by the query
if (i == 0)
{
if (current.ContentsDescription != "<<__ End of input __>>")
{
resultGroups.Add(
new PackingListItem(
current.Pallet,
current.Box,
current.ContentsDescription,
current.Quantity)
{
Count = current.Box, To = current.Box
});
qtyOfIdenticalItems += current.Quantity;
}
continue;
}
var prev = packingListItems.ElementAt(i - 1);
// no box information, so add item since it needs to be on its own line with a count of 1
if (current.Box == null && current.ContentsDescription != "<<__ End of input __>>")
{
var group = new PackingListItem(
current.Pallet,
current.Box,
current.ContentsDescription,
current.Quantity)
{
Count = 1
};
resultGroups.Add(group);
continue;
}
// we've come to the end of a group of 'identical' items (or the end of the list), so update the description for the previous group
if ((prevWasIdentical && !IsIdenticalItem(prev, current)) ||
current.ContentsDescription == "<<__ End of input __>>")
{
var group = resultGroups.Last();
// descriptions with commas in them are already totalised
if (!group.ContentsDescription.Contains(","))
{
var desc = group.ContentsDescription;
// remove the individual item quantity from the string
var item = desc.Remove(0, desc.IndexOf(' ') + 1);
// and replace it with the counted up total
group.ContentsDescription = $"{qtyOfIdenticalItems} {item}";
}
// the box the group starts on
group.Box = minBox;
// the box the group ends on
group.To = maxBox;
// count is the range from max -> min, inclusive
group.Count = maxBox - minBox + 1;
// reset counters for the next group
qtyOfIdenticalItems = 0;
minBox = 0;
maxBox = 0;
}
// the first time we see a new item that isn't 'identical' to the previous one, hence add it as a new group
if (!IsIdenticalItem(prev, current) && current.ContentsDescription != "<<__ End of input __>>")
{
qtyOfIdenticalItems = 0;
minBox = current.Box ?? 0;
maxBox = current.Box ?? 0;
var group = new PackingListItem(
current.Pallet,
current.Box,
current.ContentsDescription,
current.Quantity)
{
Box = current.Box
};
group.To = current.Box;
group.Count = 1;
resultGroups.Add(group);
qtyOfIdenticalItems += current.Quantity;
}
else
{
// else we've seen an item 'identical' to this before, so just count it up
qtyOfIdenticalItems += current.Quantity;
if (current.Box != null && current.Box >= maxBox)
{
maxBox = (int)current.Box;
}
}
// keep track of whether the previous item was 'identical' to the one before it
prevWasIdentical = IsIdenticalItem(prev, current);
}
return(resultGroups);
}
private static bool IsIdenticalItem(PackingListItem prev, PackingListItem current)
{
return((current.ContentsDescription == prev.ContentsDescription || current.Box == prev.Box) &&
(current.Pallet == prev.Pallet || current.Pallet == null));
}