LogParser

package dailyprogrammer.medium.averagespeedcameras;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.time.LocalTime;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class LogParser {

    private List<CameraLog> cameras;

    private double limit;

    Set<String> cars;

    private DistMeasure distMeasure;

    LogParser() {
        this.cameras = new ArrayList<>();
        this.cars    = new HashSet<>();
    }

    public List<CameraLog> parseLog(File logFile) throws Exception {
        try (BufferedReader reader = new BufferedReader(new FileReader(logFile))) {
            readSpeedLimit(reader);
            readCameras(reader);
            readCameraLogs(reader);
        }
        return cameras;
    }

    private void readSpeedLimit(BufferedReader reader) throws Exception {
        String line     = reader.readLine();
        String[] tokens = line.split(" ");
        limit           = Double.parseDouble(tokens[3]);
        distMeasure     = tokens[4].equals("mph.") ? DistMeasure.MP : DistMeasure.KM;
    }

    private void readCameras(BufferedReader reader) throws Exception {
        for (;;) {
            reader.mark(50);
            String line = reader.readLine();
            if (line.matches("Speed camera number [\\d]+ is [\\d]+ metres down the motorway.")) {
                int dist = Integer.parseInt(line.split(" ")[5]);
                cameras.add(new CameraLog(dist));
            } else {
                reader.reset();
                break;
            }
        }
    }

    private void readCameraLogs(BufferedReader reader) throws Exception {
        CameraLog camera = cameras.get(0);
        String line;
        while ((line = reader.readLine()) != null) {
            if (line.matches("Start of log for camera [\\d]+.")) {
                int index = Integer.parseInt(line.split("[ \\.]")[5]);
                camera = cameras.get(--index);
            } else {
                String[] tokens = line.split(" ");
                String carNum = tokens[1] + " " + tokens[2];
                cars.add(carNum);
                LocalTime camPassed = LocalTime.parse(tokens[7]);
                camera.addToLog(carNum, camPassed);
            }
        }
    }

    public double getSpeedLimit() {
        return limit;
    }

    public Set<String> getCars() {
        return cars;
    }

    public List<CameraLog> getCameras() {
        return cameras;
    }

    public DistMeasure getDistMeasure() {
        return distMeasure;
    }

    static enum DistMeasure {
        KM,
        MP;
    }

}