// RoadNetwork.java
/** Road network simulator (or it will become one once it's done)
 *  @author Douglas W. Jones
 *  @version Feb. 12, 2021
 */

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.Collection;

class Road {
    Intersection source;      // road from here
    Intersection destination; // road to there
    double travelTime;	// time in seconds

    public Road( Scanner in ) {
        // BUG: need detail!
    }

    // BUG: need to add behavior for roads
}

class Intersection {
    // BUG: is collection the right class?  Should I pick a subclass?
    Collection <Road> incoming; // the roads leading here
    Collection <Road> outgoing; // the roads that come from here

    public Intersection( Scanner in ) {
        // BUG: need detail!
    }

    // BUG: need to add behavior for roads
}

public class RoadNetwork {

    /** build a road network model by scanning an input file
     *  @param in -- the scanner used to read the file
     *  Input file contains keywords road and intersection,
     *  details beyond that are handled by the appropriate classes
     */
    private static void buildModel( Scanner in ) {
	while (in.hasNext()) {
	    String keyword = in.next();
	    if ("intersection".equals( keyword )) {
		new Intersection( in );
	    } else if ("road".equals( keyword )) {
		new Road( in );
	    } else {
	        System.err.println( "not a keyword in the input: " + keyword );
	    }
	}
    } 

    /** main method mostly concerned with command line arguments
     *  @param args -- the command line arguments
     *  Want just one argument, the file name for model description
     */
    public static void main( String[] args ) {
	// arg[0] should be the name of a file describing a road network
	if (args.length < 1) {
	    System.err.println( "missing command line argument, a file name" );
	} else if (args.length > 1) {
	    System.err.println( "extra command line argument: " + args[1] );
	} else {
	    try {
		buildModel( new Scanner( new File( args[0] ) ) );
		// BUG: simulate the network that was built
 	    } catch ( FileNotFoundException e ) {
	        System.err.println( "could not open file: " + args[0] );
	    }
	}
    }
}