/// <summary>
/// Constructor
/// </summary>
/// <param name="zipcodeCitiesSetting">allows to configure the path to the zuordnung_plz_ort.csv</param>
/// <exception cref="ArgumentNullException">when zipcodeCitiesSetting == null</exception>
/// <exception cref="ArgumentException">when IsNullOrWhiteSpace(zipcodeCitiesSetting.Path)</exception>
public ZipcodeToCities(ZipcodeToCitiesSetting zipcodeCitiesSetting)
{
if (zipcodeCitiesSetting == null)
{
throw new ArgumentNullException(nameof(zipcodeCitiesSetting));
}
if (string.IsNullOrWhiteSpace(zipcodeCitiesSetting.Path))
{
throw new ArgumentException("Path must not be nullOrWhitespace");
}
Dictionary = ReadZipcodeCitiesFromCsv(zipcodeCitiesSetting);
}
private static Dictionary <int, IEnumerable <string> > ReadZipcodeCitiesFromCsv(
ZipcodeToCitiesSetting settings)
{
const int zipcodeIndex = 2;
const int cityIndex = 1;
string path = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
settings.Path);
return(File.ReadAllText(path)
.Split(Environment.NewLine)
.Skip(1) // Skip Header
.Where(line => line != "") // Skip empty lines
.Select(csvLine => // Select zipcode and city
{
var column = csvLine.Split(",");
return new KeyValuePair <int, string>(int.Parse(column[zipcodeIndex]), column[cityIndex]);
})
.GroupBy(k => k.Key)
.ToDictionary(k => k.Key, k => k.Select(g => g.Value)));
}
