/*
 ArrayExamples.java example code
 AC Chapin
 * 
 * primitive arrays
 * arrays as parameters
 * returning arrays
 * variable length parameter lists
 * random

 */
package Arrays;
import java.util.Random;

public class ArrayExamples {

    // arrays using primitives
    public static void intArrays() {
        // an int
        int x;
        x = 5;

        // an array of ints;
        int[] numList; // currently null
        numList = new int[5];
        numList[0] = x;
        numList[1] = 12;
        numList[2] = numList[0] + numList[1];

        // numList[37] = 100; // index out of bounds error
        //for loop sets array element i to be x*i
        // use numList.length for safety
        for (int i = 0; i < numList.length; i++) {
            numList[i] = x * i;
        }

        // special initialization
            // at declaration can leave out new
        int[] numList2 = {11, 22, 33, 44};
        // to do later, need new
        numList2 = new int[] {44, 33, 22, 11};
        

        // combine -- careful not to spill off end of either array
        int[] sumList = new int[numList.length];
        for (int i = 0; i < numList.length && i < numList2.length; i++) {
            sumList[i] = numList[i] + numList2[i];
        }

    }

    // arrays using objects
    public static void bunnyArrays() {
        // a Bunny
        Bunny b; // currently null
        b = new Bunny("Bugs", 5); //(name, carrotcount)

        // an array of Bunnys
        Bunny[] warren; // null
        warren = new Bunny[10]; // array exists, Bunnys in array are null

        // array elements as variables
        warren[0] = new Bunny("Hazel", 27);
        warren[2] = b;
        warren[4] = warren[0];
        warren[6] = new Bunny("Buster", 17);
        warren[7] = new Bunny("Roger", 31);
        warren[9] = new Bunny("Babs", 5);

        warren[4].setName("Bigwig"); // warren[0] is same address
        System.out.println("zeroth rabbit:" + warren[0].getName());

        // warren[1].setName("Peter Cottontail"); // null pointer error
        // pass array to method that returns Bunny with most carrots
        Bunny mostCarrots = findMostCarrots(warren);

        // print info about max Bunny
        if (mostCarrots != null) {
            System.out.println(mostCarrots.getName() + " has "
                    + mostCarrots.getCarrotCount() + " carrots");
        } else {
            System.out.println("No Bunnys");
        }
    }

    // method with array parameter
    // return Bunny from the array who has most carrots
    public static Bunny findMostCarrots(Bunny[] bunList) {
        Bunny most = null;

        for (int i = 0; i < bunList.length; i++) {
            // first Bunny we find in array is our first guess for most carrots
            if (most == null) {
                most = bunList[i];
                // when we find a bunny, compare carrot counts
                // with best we have seen so far
            } else if (bunList[i] != null) {
                // if current Bunny has more carrots than previous max
                // current Bunny becomes max
                if (bunList[i].getCarrotCount() > most.getCarrotCount()) {
                    most = bunList[i];
                }
            }
        }
        return most;
    }

    // passing and returning arrays
    // given array of ints
    // create array of strings spelling out content of int array
    public static String[] makeStringList(int[] numbers) {
        // no array passed in
        if (numbers == null) {
            return null;
        }
        // create array
        String[] strList = new String[numbers.length];
        for (int i = 0; i < strList.length; i++) {
            strList[i] = "Int Array[" + i + "] = " + numbers[i];
        }
        return strList;
    }

     // pseudorandom numbers
    public static void randoms() {
        // Math.random()
        double r = Math.random();// 0.0 to 0.9999
        double r1 = Math.random() * 10;// 0.0 to 9.9999
        double r2 = Math.random() * 10 + 5;// 5.0 to 14.9999
        int r3 = (int) (Math.random() * 100 + 1);// 1 to 100
        int r4 = (int) Math.random() * 100 + 1; // always 1 !!!
        
        // Random class, need to import
        Random rand = new Random();
        int r5 = rand.nextInt(); // any int
        int r6 = rand.nextInt(10); // 0..9
        double r7 = rand.nextDouble(); // same as Math.random()
        boolean b = rand.nextBoolean(); // 50/50
        
    }


    // main calls other methods
    public static void main(String[] args) {
        intArrays();
        bunnyArrays();

        int[] nums = {98, 87, 76, 65, 54};

        // method that returns array of strings
        // pass in array of ints -- note NO SQUARE BRACES
        String[] strs = makeStringList(nums);

        System.out.println(strs[1]);
        System.out.println(strs[3]);

        // makeStringList accepts arrays, but not lists -- compile error
        //String[] badstrs = makeStringList(1, 2, 5, 6, 9, 0);
        
        randoms();
    }
}