import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.*;
/**
 * Created by leon on 1/29/18.
 */
public class StringArrayUtils {
    /**
     * @param array array of String objects
     * @return first element of specified array
     */ // DONE
    public static String getFirstElement(String[] array) {

        return array[0];
    }

    /**
     * @param array array of String objects
     * @return second element in specified array
     * DONE
     */
    public static String getSecondElement(String[] array) {
        return array[1];
    }

    /**
     * @param array array of String objects
     * @return last element in specified array
     */ // DONE
    public static String getLastElement(String[] array) {
        return array[array.length-1];
    }

    /**
     * @param array array of String objects
     * @return second to last element in specified array
     */ // DONE
    public static String getSecondToLastElement(String[] array) {
        return array[array.length-2];
    }

    /**
     * @param array array of String objects
     * @param value value to check array for
     * @return true if the array contains the specified `value`
     */ // DONE
    public static boolean contains(String[] array, String value) {
        boolean check = false;

        for (int i = 0; i<array.length; i++){
            if (array[i] == value){
                check = true;}
        }
        return check;
    }

    /**
     * @param array of String objects
     * @return an array with identical contents in reverse order
     */ // DONE
    public static String[] reverse(String[] array) {

        for (int i = 0; i<array.length/2; i++){
            String temp = array[i];
            array[i] = array[array.length-1-i];
            array[array.length-1-i] = temp;

        }   
        return array;
    }

    /**
     * @param array array of String objects
     * @return true if the order of the array is the same backwards and forwards
     */ // DONE
    public static boolean isPalindromic(String[] array) {
        boolean check = false;
        for (int i=0; i<array.length/2; i++){
            String temp = array[i];
            array[i] = array[array.length-1-i];
            array[array.length-1-i] = temp;

            if ( temp == array[i]){
                check = true;
            }
        }
        return check;
    }

    /**
     * @param array array of String objects
     * @return true if each letter in the alphabet has been used in the array
     */ // TODO
    public static boolean isPangramic(String[] array) {
        boolean check = false;
        //Scanner reader = new Scanner();
        String string = new String();//reader.nextLine();
        Set character = new HashSet();
        Set set = new HashSet();
        for (char c:string.toUpperCase().toCharArray()){
            
            if (character.equals(c)){
                set.add(c);}
        }
        if (set.size() == 26){
            check = true;}
            else {
                check = false;}
        return check;
        
    }

    /**
     * @param array array of String objects
     * @param value value to check array for
     * @return number of occurrences the specified `value` has occurred
     */ // Done
    public static int getNumberOfOccurrences(String[] array, String value) {
        int counter = 0;
        for (int i = 0; i<array.length; i++){
            if (array[i] == array[i+1]){
                counter=counter+1;}
                
            }
        return counter;
    }

    /**
     * @param array         array of String objects
     * @param valueToRemove value to remove from array
     * @return array with identical contents excluding values of `value`
     */ // Done
    public static String[] removeValue(String[] array, String valueToRemove) {
        //sort array, create new array, compare i, add new i to new array.
        Arrays.sort(array);
        ArrayList fresh = new ArrayList();
        for (int i=0;i<array.length;i++){
            if (array[i] != valueToRemove){
                fresh.add(array[i]);
            }
            
        }
        String[] list = (String[])(fresh.toArray()); //needed to convert to a string array, not a string
        return list;
        
        //String delete = value.replaceAll (Character.toString(charToRemove), "");
       //return delete;  
        //return list.toString();
    }

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        Arrays.sort(array);
        ArrayList fresh = new ArrayList();
        for (int i=0; i<array.length; i++){
         if (array[i] != array[i-1] && array[i] != array[i+1]) {
            fresh.add(array[i]);
            }
        }
        String[] list = (String[])(fresh.toArray());
        return list;
    }

    /**
     * @param array array of chars
     * @return array of Strings with each consecutive duplicate occurrence concatenated as a single string in an array of Strings
     */ // TODO
    public static String[] packConsecutiveDuplicates(String[] array) {
        return null;
    }

}