Dialogs

gistfile1.cs

public class DialogueEntry
{
    public string ConversationID;
    public string ConversationTitle;
    public string DialogueEntryID;
    public string DialogueEntryTitle;
}

class InvalidConversationTitle : Exception
{
    public readonly DialogueEntry entry;
    public InvalidConversationTitle(DialogueEntry _entry)
    {
        entry = _entry;
    }
}

class DuplicatedDialogueEntryID : Exception
{
    public readonly DialogueEntry entry;
    public DuplicatedDialogueEntryID(DialogueEntry _entry)
    {
        entry = _entry;
    }
}
class DuplicatedDialogueEntryTitle : Exception
{
    public readonly DialogueEntry entry;
    public DuplicatedDialogueEntryTitle(DialogueEntry _entry)
    {
        entry = _entry;
    }
}

class Program
{

    static void Main(string[] args)
    {
    }
    private void Validate(IEnumerable<DialogueEntry> enumerable)
    {
        foreach(var conversation in enumerable.GroupBy(x => x.ConversationID)) {
            var titlesOfConversation = conversation.GroupBy(x => x.ConversationTitle).ToList();
            if(titlesOfConversation.Count() > 1) {
                var titleWithMinimalOccurences = titlesOfConversation.Aggregate((min, x) => (min == null || x.Count() < min.Count() ? x : min));
                throw new InvalidConversationTitle(titleWithMinimalOccurences.First());
            }

            var entryIdDuplicates = conversation.GroupBy(x => x.DialogueEntryID).FirstOrDefault(x => x.Count() > 1);
            if(entryIdDuplicates != null) {
                throw new DuplicatedDialogueEntryID(entryIdDuplicates.Last());
            }

            var entryTitleDuplicates = conversation.GroupBy(x => x.DialogueEntryTitle).FirstOrDefault(x => x.Count() > 1);
            if (entryIdDuplicates != null)
            {
                throw new DuplicatedDialogueEntryTitle(entryIdDuplicates.Last());
            }
        }
    }

}