/// <summary>
/// Load the Stations for the <paramref name="lineName"/> into the <paramref name="subway"/> from the <paramref name="textReader"/>.
/// </summary>
/// <param name="subway">The Subway to load the line into.</param>
/// <param name="textReader">THe stream to read the lines from.</param>
/// <param name="lineName">The name of the Subway line.</param>
private void LoadLine(Subway subway, TextReader textReader, string lineName)
{
if (subway == null)
{
throw new ArgumentNullException(nameof(subway));
}
if (textReader == null)
{
throw new ArgumentNullException(nameof(textReader));
}
if (string.IsNullOrWhiteSpace(lineName))
{
throw new ArgumentNullException(nameof(lineName));
}
string station1Name = textReader.ReadLine();
if (string.IsNullOrWhiteSpace(station1Name))
{
throw new IOException("Expected station name but found an empty line.");
}
string station2Name;
while (!string.IsNullOrWhiteSpace(station2Name = textReader.ReadLine()))
{
subway.AddConnection(station1Name, station2Name, lineName);
station1Name = station2Name;
}
}
/// <summary>
/// Load the list of Station names from the <paramref name="textReader"/> into the <paramref name="subway"/>.
/// </summary>
/// <param name="subway">The Subway to load the Station names into.</param>
/// <param name="textReader">The strean to read the Station names from.</param>
private void LoadStations(Subway subway, TextReader textReader)
{
if (subway == null)
{
throw new ArgumentNullException(nameof(subway));
}
if (textReader == null)
{
throw new ArgumentNullException(nameof(textReader));
}
string currentLine;
while (!string.IsNullOrWhiteSpace(currentLine = textReader.ReadLine()))
{
subway.AddStation(currentLine);
}
}
/// <summary>
/// Load the Subway line from <paramref name="textReader"/>.
/// </summary>
/// <param name="textReader">The input stream to read the Subway line from.</param>
/// <returns>A Subway with the given line loaded.</returns>
public Subway Load(TextReader textReader)
{
if (textReader == null)
{
throw new ArgumentNullException(nameof(textReader));
}
Subway subway = new Subway();
LoadStations(subway, textReader);
string lineName;
while (!string.IsNullOrWhiteSpace(lineName = textReader.ReadLine()))
{
LoadLine(subway, textReader, lineName);
}
return(subway);
}
