.java

package aula11;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class ExerciseTwo {
    public static void main(String[] args) {
        Map<String, String> companies = new TreeMap<>();
        ArrayList<Flight> listOfFlights = new ArrayList<>();
        //delaysPerCo will contain the association between companies and an arrayList of all its delays.
        Map<String, ArrayList<String>> delaysPerCo = new HashMap<>();
        Scanner input = null;
        PrintWriter out;

        System.out.println("______________________________________________________POINT A)___________________________________________________________");
        /* ______________________________________________________POINT A)___________________________________________________________*/

        try {
            input = new Scanner(new File("aula11/companhias.txt"));
            input.nextLine();
            while(input.hasNextLine()) {
                String line = input.nextLine();
                //lineContent will return an array of all the strings in the line.
                String[] lineContent = line.split("\t");
                companies.put(lineContent[0], lineContent[1]);
            }
        } catch(FileNotFoundException e) {
            System.out.println("File not found.");
        } finally {
            if(input != null) {
                input.close();
            }
            try {
                input = new Scanner(new File("aula11/voos.txt"));
                input.nextLine();
                while(input.hasNextLine()) {
                    String line = input.nextLine();
                    //flightLine returns an array of the strings in the line.
                    String[] flightLine = line.split("\t");
                    Flight flight = new Flight();
                    String companyInitials = flightLine[1].substring(0, 2);
                    try {
                        if(companies.containsKey(companyInitials)) {
                            flight.setCompany(companies.get(companyInitials));
                        } else {
                            //In case the company is not defined, it will be "N/A" by default.
                            flight.setCompany("N/A");
                        }
                        flight.setArrivalTime(flightLine[0]); flight.setFlightNumber(flightLine[1]); flight.setOrigin(flightLine[2]); flight.setDelay(flightLine[3]);
                        listOfFlights.add(flight);

                        if(!delaysPerCo.containsKey(flight.getCompany())) {
                            delaysPerCo.put(flight.getCompany(), new ArrayList<String>());
                            delaysPerCo.get(flight.getCompany()).add(flight.getDelay());
                        } else {
                            delaysPerCo.get(flight.getCompany()).add(flight.getDelay());
                        }
                    } catch(ArrayIndexOutOfBoundsException e) {
                        flight.setDelay("");
                        listOfFlights.add(flight);
                    }
                }
            } catch(FileNotFoundException e) {
                System.out.println("File not found.");
            } finally {
                if(input != null) {
                    input.close();
                }
            }
        }

        String format = "%-6s %-10s %-25s %-30s %-10s %-1s";
        System.out.printf(String.format(format , "Hora", "Voo", "Companhia", "Origem", "Atrasos", "Obs.\n"));

        for(Flight f: listOfFlights) {
            System.out.printf(String.format(format, f.getArrivalTime(), f.getFlightNumber(), f.getCompany(), f.getOrigin(), f.getDelay(), f.delayedArrivalTime(f.getArrivalTime(), f.getDelay())) + "\n");
        }

        System.out.println();
        System.out.println("______________________________________________________POINT B)___________________________________________________________");
        /* ______________________________________________________POINT B)___________________________________________________________*/

        try {
            out = new PrintWriter(new File("aula11/Infopublico.txt"));
            String header = String.format(format , "Hora", "Voo", "Companhia", "Origem", "Atrasos", "Obs.\n");
            System.out.printf(header);
            //Write to Infopublico.txt
            out.printf(header);

            for(Flight f: listOfFlights) {
                String column= String.format(format, f.getArrivalTime(), f.getFlightNumber(), f.getCompany(), f.getOrigin(), f.getDelay(), f.delayedArrivalTime(f.getArrivalTime(), f.getDelay()));
                System.out.printf(column + "\n");
                //Write on Infopublico.txt
                out.printf(column + "\n");
            }
            //Close PrintWriter
            out.close();
        } catch (FileNotFoundException e) {
            System.out.println("Ficheiro não encontrado");
        }

        System.out.println();
        System.out.println("______________________________________________________POINT C)___________________________________________________________");
        /* ______________________________________________________POINT C)___________________________________________________________*/

        HashMap<String, String> companyDelays = new HashMap<>();

        for(String s: delaysPerCo.keySet()) {
            companyDelays.put(s,  averageDelay(delaysPerCo.get(s)));
        }

        Comparator<String> delayComparator = new DelayComparator(companyDelays);
        TreeMap<String, String> sortedCompanyDelays = new TreeMap<String, String>(delayComparator);
        sortedCompanyDelays.putAll(companyDelays);

        System.out.printf(String.format("%-18s %-6s", "Companhia", "Atraso Médio\n"));
        for(Map.Entry<String, String> f: sortedCompanyDelays.entrySet()) {
            System.out.printf(String.format("%-20s %-2s" , f.getKey(), f.getValue() + "\n"));
        }

        System.out.println();
        System.out.println("______________________________________________________POINT D)___________________________________________________________");
        /* ______________________________________________________POINT D)___________________________________________________________*/

        HashMap<String, Integer> origins = new HashMap<>();
        for(Flight f: listOfFlights) {
            if(!origins.containsKey(f.getOrigin())) {
                origins.put(f.getOrigin(), 1);
            } else {
                Integer currentCount = origins.get(f.getOrigin());
                origins.replace(f.getOrigin(), currentCount + 1);
            }
        }
        Comparator<String> comparator = new OriginComparator(origins);
        //TreeMap is a map sorted by its keys.
        //The comparator is used to sort the TreeMap by keys.
        TreeMap<String, Integer> result = new TreeMap<String, Integer>(comparator);
        result.putAll(origins);

        try {
            out = new PrintWriter(new File("aula11/Cidades.txt"));
            String header = String.format("%-20s %-2s" , "Origem", "Voos\n");
            System.out.printf(header);
            //Write to Infopublico.txt
            out.printf(header);

            for(Map.Entry<String, Integer> f: result.entrySet()) {
                String column= String.format("%-20s %-2s" , f.getKey(), f.getValue() + "\n");
                System.out.printf(column);
                //Write on Infopublico.txt
                out.printf(column);
            }
            //Close PrintWriter
            out.close();
        } catch (FileNotFoundException e) {
            System.out.println("Ficheiro não encontrado");
        }

    }


    public static String averageDelay(ArrayList<String> array) {
        int hours, minutes;
        int total = 0;
        int hoursOfDelay = 0;
        //The string will be of the type, e.g., "20:00".
        for(String s: array) {
            hours = Integer.valueOf(s.substring(0,2));
            minutes = Integer.valueOf(s.substring(3));
            total += minutes + hours*60;
        }
        int averageInMin = total/array.size();
        //These if conditions take care of the appearance of the time, never over 23 hours nor over 59 minutes.
        if(averageInMin >= 60) {
            hoursOfDelay +=1;
            averageInMin -= 60;
        }
        if(hoursOfDelay >= 24) {
            hoursOfDelay -= 24;
        }
        String stringMin = String.valueOf(averageInMin);
        String stringHr = String.valueOf(hoursOfDelay);
        //If the string is "5", for e.g., it will turn into "05".
        if(stringMin.length() == 1) {
            stringMin = "0" + stringMin;
        }
        if(stringHr.length() == 1) {
            stringHr = "0" + stringHr;
        }
        return stringHr + ":" + stringMin;
    }


    static class OriginComparator implements Comparator<String>{

        HashMap<String, Integer> map = new HashMap<String, Integer>();

        public OriginComparator(HashMap<String, Integer> map){
            this.map.putAll(map);
        }

        @Override
        public int compare(String s1, String s2) {
            if(map.get(s1) >= map.get(s2)){
                return -1;
            }else{
                return 1;
            }
        }
    }
    static class DelayComparator implements Comparator<String>{

        HashMap<String, String> map = new HashMap<String, String>();

        public DelayComparator(HashMap<String, String> map){
            this.map.putAll(map);
        }

        @Override
        public int compare(String s1, String s2) {
            //The string will be of the type, e.g., "20:00".
            int hoursS1 = Integer.valueOf(map.get(s1).substring(0,2));
            int minutesS1 = Integer.valueOf(map.get(s1).substring(3));
            int totalS1 = minutesS1 + hoursS1*60;

            int hoursS2 = Integer.valueOf(map.get(s2).substring(0,2));
            int minutesS2 = Integer.valueOf(map.get(s2).substring(3));
            int totalS2 = minutesS2 + hoursS1*60;

            if(totalS1 >= totalS2){
                return -1;
            }else{
                return 1;
            }
        }
    }
}