static void Main(string[] args)
{
// Parse and validate command line args.
ArgValidator argValidator = new ArgValidator();
bool? validatedArgs = argValidator.Validate(args);
if (validatedArgs != true)
{
// If there are parse errors display syntax help.
if (validatedArgs == false)
{
ShowHelp();
}
else
{
// User input a filename to save the data and the file already exists.
// when prompted to overwrite the file, the user said no.
Console.WriteLine("\n\n** Query cancelled.\n");
}
Environment.Exit(0);
}
// Query the remote site.
TweetDataClient tdc = new TweetDataClient();
IEnumerable <Tweet> queryResult = null;
try
{
queryResult = tdc.GetItemsFromUrl(argValidator.Url, argValidator.StartDate, argValidator.EndDate,
argValidator.Verbose);
}
catch
{
Console.WriteLine("\n**Query Error - Cannot query the remote host\n");
}
int recsSaved = 0;
if (queryResult != null && queryResult.Count() > 0 && !argValidator.NoList)
{
ShowPaginatedList(queryResult, argValidator);
if (argValidator.Filename != String.Empty)
{
recsSaved = SaveToFile(argValidator.Filename, queryResult);
}
}
// Show results summary.
if (argValidator.PageSize == 0 || !string.IsNullOrEmpty(argValidator.Filename) || argValidator.NoList)
{
int recsFound = queryResult?.Count() ?? 0;
Console.WriteLine("\n============================================================");
Console.WriteLine($"Query from: {argValidator.StartDate} to {argValidator.EndDate}");
Console.WriteLine($"Records Found: {recsFound}");
if (!string.IsNullOrEmpty(argValidator.Filename))
{
Console.WriteLine($"Records Saved: {recsSaved}");
}
Console.WriteLine("============================================================");
}
}
private static void ShowPaginatedList(IEnumerable <Tweet> queryResult, ArgValidator argValidator)
{
List <Tweet> results = queryResult.ToList();
// Set start index for page.
int startIndex = -1;
int endIndex = 0;
// Show page
PageKey key = PageKey.Home;
do
{
string keyNext = " next - >";
string keyPrvious = "< - previous ";
bool updateScreen = false;
switch (key)
{
// Jump to end.
case PageKey.End:
if (endIndex != results.Count)
{
endIndex = results.Count;
startIndex = endIndex - argValidator.PageSize;
if (startIndex < 0)
{
startIndex = 0;
}
keyNext = "";
updateScreen = true;
}
break;
// Next page.
case PageKey.Next:
if (endIndex != results.Count)
{
if (startIndex + argValidator.PageSize < results.Count)
{
startIndex += argValidator.PageSize;
endIndex += argValidator.PageSize;
if (endIndex > results.Count)
{
keyNext = "";
}
updateScreen = true;
}
}
break;
// Jump to beginning.
case PageKey.Home:
if (startIndex != 0)
{
Console.Clear();
startIndex = 0;
endIndex = startIndex +
((argValidator.PageSize == 0) ? results.Count : argValidator.PageSize);
updateScreen = true;
keyPrvious = "";
}
break;
// Previou page.
case PageKey.Previous:
if (startIndex != 0)
{
startIndex -= argValidator.PageSize;
if (startIndex <= 0)
{
startIndex = 0;
keyPrvious = "";
}
endIndex = startIndex + argValidator.PageSize;
updateScreen = true;
}
break;
// Show key help on invalid keystrokes.
default:
Console.WriteLine("*** Valid keys:");
Console.WriteLine("N-next P-previous HOME-begin END-end Q-quit\n");
updateScreen = false;
break;
}
for (int i = startIndex; i < endIndex && i < results.Count() && updateScreen; i++)
{
Console.WriteLine($"{results[i].Id} {results[i].Stamp}\n{results[i].Text}");
Console.WriteLine("------------------------------------------------------------");
}
// Display page number information
if (argValidator.PageSize != 0)
{
if (updateScreen)
{
Console.WriteLine($"\nQuery from: {argValidator.StartDate} to {argValidator.EndDate}");
int endNum = (endIndex > results.Count) ? results.Count : endIndex;
Console.WriteLine(
$"Records {startIndex + 1} - {endNum} of {results.Count} {keyPrvious}{keyNext}\n");
}
key = CheckKey(Console.ReadKey());
}
else
{
key = PageKey.Quit;
}
} while (key != PageKey.Quit);
}