import java.util.ArrayList;
import java.util.List;

public class Calculations {
    // TODO: What's a better name for this method (e.g. not "calculate")?  Rename it to a better name.
    public static int calculate(int a, int b) {
        if(a > b) {
            return a;
        } else {
            return b;
        }
    }

    public static List<Integer> selectEvenNumbers(List<Integer> numbers) {
        List<Integer> result = new ArrayList<Integer>();
        for (Integer number : numbers) {
            if (number % 2 == 0) { // TODO: extract a boolean method here to check if the number is even
                result.add(number);
            }
        }
        return result;
    }
    
    public static List<Integer> squares(List<Integer> numbers) {
        List<Integer> result = new ArrayList<Integer>();
        for (Integer number : numbers) {
            result.add(number * number);
        }
        return result;
    }
    
    public static String wikiTable(List<String> wikiLines) {
        // TODO: the method is a bit too long; maybe extract wiki syntax parsing (splitting of lines) into a separate method?
        // TODO: also, consider making separate methods for e.g. creating everything between <tr> and </tr>, and the same with the 2 lines that create the <td> elements?
        // TODO: this method has nothing to do with Calculations -- move it to another class; the same for its tests
        String result = "<table>\n";
        for (String wikiLine : wikiLines) {
            result += "  <tr>\n";
            String[] parts = wikiLine.split("\\|"); // TODO: "parts" is ambiguous (what parts?).  Maybe rename it to "cells"?
            for (String part : parts) { // TODO: what would be a better name for "part"?
                if(!part.isEmpty()) {
                    String cellContents = part.trim();
                    result += "    <td>" + cellContents + "</td>\n";
                }
            }
            result += "  </tr>\n";
        }
        result += "</table>";
        return result;

        // TODO: After all these refactorings, what do you think: does the code here look more understandable now?
    }

    public static List<Integer> squaresOfEvenNumbers(List<Integer> numbers) {
        // TODO: this method duplicates some code with 2 other methods: selectEvenNumbers() and the squares() method.
        List<Integer> result = new ArrayList<Integer>();
        for (Integer number : numbers) {
            if (number % 2 == 0) {
                result.add(number * number);
            }
        }
        return result;
    }
}