package eecs2030.test2;

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

/**
 * Test 2 version F.
 * 
 * @author EECS2030E Fall 2016
 *
 */
public class Test2F {
    /**
     * The size of the list required by the method Test2F.min2
     */
    public static final int MIN2_LIST_SIZE = 2;

    private Test2F() {
        // empty by design
    }
    
    /**
     * Returns true if <code>value</code> is strictly greater than
     * <code>min</code> and strictly less than <code>max</code>, and false
     * otherwise.
     * 
     * @param min
     *            a minimum value
     * @param max
     *            a maximum value
     * @param value
     *            a value to check
     * @return true if <code>value</code> is strictly greater than
     *         <code>min</code> and strictly less than <code>max</code>, and
     *         false otherwise
     * @pre min is greater than or equal to max
     */
    public static boolean isBetween(int min, int max, int value) {
        return value > min && value < max;
    }

    /**
     * Given a list containing exactly 2 integers, returns the smaller of the
     * two integers. The list <code>t</code> is not modified by this method. 
     * For example:
     * 
     * <pre>
     * t            Test2F.min2(t)
     * ---------------------------
     * [-5, 9]      -5
     * [3, 3]        3
     * [12, 6]       6
     * </pre>
     * 
     * @pre t is not null
     * 
     * @param t
     *            a list containing exactly 2 integers
     * @return
     *            the minimum of the two values in t
     * @throws IllegalArgumentException
     *             if the list does not contain exactly 2 integers
     */
    public static int min2(List<Integer> t) {
        if (t.size() != 2) {
            throw new IllegalArgumentException("list size != 2");
        }
        int t0 = t.get(0);
        int t1 = t.get(1);
        int min = Math.min(t0, t1);
        return min;
    }

    /**
     * Counts the number of elements in <code>t</code> that are greater than
     * <code>value</code>. The list <code>t</code> is not modified by this method. 
     * For example, if <code>value == 3</code> then:
     * 
     * <pre>
     * t                      Test2F.countGreaterThan(t, 3)
     * ----------------------------------------------------
     * []                     0
     * [-5]                   0
     * [3, 4]                 1
     * [12, 6, 8, 2, 2, 2]    3
     * </pre>
     * 
     * @param t
     *            a list
     * @param value
     *            a value
     * @return number of elements in t that are greater than value
     * @pre t is not null
     */
    public static int countGreaterThan(List<Integer> t, int value) {
        int count = 0;
        for (int i : t) {
            if (i > value) {
                count++;
            }
        }
        return count;
    }

    /**
     * Returns the int value equal to the value obtained by removing
     * <code>n</code> digits from the the end of <code>aNumber</code>. The
     * method will never remove all of the digits of <code>aNumber</code>. If
     * <code>n</code> is greater than the number of digits in
     * <code>aNumber</code> then the first digit of <code>aNumber</code> is
     * returned. For example:
     * 
     * <pre>
     * aNumber    n     Test2F.removeDigits(aNumber, n)
     * ------------------------------------------------ 
     *  1         0      1 
     *  2         1      2
     *  87        1      8 
     *  100353    3      100 
     * -9325256   5     -93
     * -9325256   999   -9
     * </pre>
     * 
     * @param aNumber
     *            a number
     * @param n
     *            the number of digits to remove from the end of aNumber
     * @return the number equal to removing n digits from the end of aNumber, or
     *         the first digit of aNumber if n is greater than or equal to the
     *         number of digits in aNumber
     */
    public static int removeDigits(int aNumber, int n) {

        for (int i = 0; i < n; i++) {
            int remaining = aNumber / 10;
            if (remaining == 0) {
                return aNumber;
            } else {
                aNumber /= 10;
            }
        }
        return aNumber;

    }
    
    public static void main(String[] args) {
        // isBetween
        int min = 1;
        int max = 10;
        int value = 5;
        System.out.println(
                String.format("isBetween(%d, %d, %d) : ", min, max, value) + 
                Test2F.isBetween(min, max, value));
        
        // min2
        List<Integer> t = new ArrayList<Integer>();
        t.add(3);
        t.add(5);
        System.out.println(
                String.format("min2(%s) : %s", t.toString(), Test2F.min2(t)));
        
        // countGreaterThan
        t.clear();
        t.add(4);
        t.add(5);
        t.add(6);
        t.add(7);
        t.add(8);
        value = 5;
        System.out.println(
                String.format("countGreaterThan(%s, %d) : %s", 
                        t.toString(), value, Test2F.countGreaterThan(t, value)));
        
        // removeDigits
        int aNumber = 100353;
        int n = 3;
        System.out.println(
                String.format("removeDigits(%d, %d) : %d", 
                        aNumber, n, Test2F.removeDigits(aNumber, n)));
    }
}