// Get the distance between two airports
public int GetDistance(string from, string to, DbFace dbface)
{
lock (dbface)
{
// Try to get the distance from the database
int? distance = dbface.GetValue<int>(string.Format("select km from distances where origin = '{0}' and destination = '{1}'", from, to));
if (distance.HasValue)
return distance.Value;
if (from == "NYC")
from = "JFK";
if (from == "LON")
from = "LHR";
// Otherwise, query www.world-airport.codes.com
CookieContainer cookies = new CookieContainer();
string output = WebUtilities.GetPage("http://www.world-airport-codes.com/dist/?a1=" + from + "&a2=" + to, ref cookies);
int kiloi = output.IndexOf("kilometres");
if (kiloi < 0)
return 0; // error!
string kilostr = output.Substring(kiloi - 13, 13);
int? value = GetNum(kilostr, true);
if (!value.HasValue)
{
status.Add(string.Format("Could not find distance from {0} to {1}", from, to));
return 0;
}
dbface.Execute(string.Format("insert into distances (origin, destination, km) values ('{0}', '{1}', {2})", from, to, value.Value), false);
return value.Value;
}
}
