import java.util.*;
 import java.util.ArrayList;

/**
 * Created by leon on 1/29/18.
 */
public class StringArrayUtils {
    /**
     * @param array array of String objects
     * @return first element of specified array
     */ // TODO
    public static String getFirstElement(String[] array) {
        return array[0];
    }

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

    /**
     * @param array array of String objects
     * @return last element in specified array
     */ // TODO
    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
     */ // TODO
    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`
     */ // TODO
    public static boolean contains(String[] array, String value) {
        return Arrays.asList(array).contains(value);
    }

    /**
     * @param array of String objects
     * @return an array with identical contents in reverse order
     */ // TODO
    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
     */ // TODO
    public static boolean isPalindromic(String[] array) {
        boolean isPalindromic = true;
        for(int i = 0; i < array.length/2 ; i++){
            if(array[i] != array[( array.length - 1 ) - i]){
                isPalindromic = false;
                break;
            };
        }
        return isPalindromic;
    }

    /**
     * @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) {
        ArrayList<Character> Chars = new ArrayList<Character>();
       
        for(String str: array){
            char[] chars = str.toCharArray();
            
            for(char car : chars){
                if(!Chars.contains(car)){
                    Chars.add(car);
                }
            }
            
        }
        
        return Chars.size() == 26 ? true : false;
    }
    
    

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

    /**
     * @param array         array of String objects
     * @param valueToRemove value to remove from array
     * @return array with identical contents excluding values of `value`
     */ // TODO
    public static String[] removeValue(String[] array, String valueToRemove) {
        ArrayList<String> strings = new ArrayList<String>();
        for(String str : array){
            if(!str.equals(valueToRemove)){
                strings.add(str);
            }
        }
        return strings.toArray(new String[strings.size()]);
    }

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        ArrayList<String> strings = new ArrayList<String>();
        String prevString = "";
        for(String str: array){
            if(!prevString.equals(str)){
                strings.add(str);
            }
            prevString = str;
        }
        return strings.toArray(new String[strings.size()]);
    }

    /**
     * @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) {
        ArrayList<String> strings = new ArrayList<String>();
        
        boolean isDuplicated; 
        for(String str1: array){
            isDuplicated = false;
            for(String str2: array){
                if(str1 == str2){
                    isDuplicated = true;
                }
            }
            if(!isDuplicated){
                strings.add(str1);
            }
        }
        
        return strings.toArray(new String[strings.size()]);
    }


}