Building a multi-record flat file - linq

Question

I'm struggling to find a proper solution for generating a flat file.
Here are some criteria I need to take care of:
The file has a header with summary of its following records
there could be multiple Collection Header Records with multiple Batch Header Records which contain multiple records of different types.
All records within a Batch have a checksum which has to be added to a batch checksum. This one has to be added to the collection Header checksum and that again to the file checksum. Also each entry in the file has a counter value.
So my plan was to create a class for each record. but what now? I have the records and the "summary records", the next step would be to bring them all in order, count the sums and then set the counters.
How should I proceed from here, should I put everything in a big SortedList? If so, how do I know where to add the latest record (It has to be added to its representing batch summary)?
My first idea was to do something like this:
SortedList<HeaderSummary, SortedList<BatchSummary, SortedList<string, object>>>();
But it is hard to navigate through the HeaderSummaries and BatchSummaries to add a object in the inner Sorted list, bearing in mind that I may have to create and add a HeaderSummary / BachtSummary.
Having several different ArrayLists like one for Header, one for Batch and one for the rest gives me problems when combining them to a flat file because of the order and the - yet to set - counters, while keeping the order etc.
Do you have any clever solution for such a flat file?

Answer 1

Consider using classes to represent levels of your tree structure.
interface iBatch {
public int checksum { get; set; }
}
class BatchSummary {
int batchChecksum;
List<iBatch> records;
public void WriteBatch() {
WriteBatchHeader();
foreach (var record in records)
batch.WriteRecord();
}
public void Add(iBatch rec) {
records.Add(rec); // or however you find the appropriate batch
}
}
class CollectionSummary {
int collectionChecksum;
List<BatchSummary> batches;
public void WriteCollection() {
WriteCollectionHeader();
foreach (var batch in batches)
batch.WriteBatch();
}
public void Add(int WhichBatch, iBatch rec) {
batches[whichBatch].Add(rec); // or however you find the appropriate batch
}
}
class FileSummary {
// ... file summary info
int fileChecksum;
List<CollectionSummary> collections;
public void WriteFile() {
WriteFileHeader();
foreach (var collection in collections)
collection.WriteCollection();
}
public void Add(int whichCollection, int WhichBatch, iBatch rec) {
collections[whichCollection].Add(whichBatch, rec); // or however you find the appropriate collection
}
}
Of course, you could use a common Summary class to be more DRY, if not necessarily more clear.