import java.util.Arrays;
/**
 * 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) {
        boolean output = false;
        for (String test: array){
            if (test.equals(value)){
                output = true;
                break;
            }        
        }
        return output; 
    }

    /**
     * @param array of String objects
     * @return an array with identical contents in reverse order
     */ // TODO
    public static String[] reverse(String[] array) {
        String[] newArray = new String[array.length];
        for (int start = 0; start < array.length; start++){
            newArray[start] = array[array.length-start-1];           
        }
        return newArray;
    }

    /**
     * @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 output = false;
        String[] reverseArr = new String[array.length];
        reverseArr = reverse(array);
        if (Arrays.equals(reverseArr, array)){
            output = true;
        }
        return output;
    }

    /**
     * @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) {
        String[] arr = makeSplitStringArray(array);
        boolean isPang = containsLetter(arr);
        return isPang;
    }

    public static boolean containsLetter(String[] array){
        boolean doesContain = true;
        String[] alph = new String[]{"a", "b", "c", "d", "e", "f", "g", "h",
                "i", "j", "k", "l", "m", "n", "o", "p",
                "q", "r", "s", "t", "u", "v", "w", "x",
                "y", "z"};
        for (String check: alph){
            doesContain = contains(array, check);
            if(doesContain == false){
                break;
            }
        }
        return doesContain;
    }

    public static String[] makeSplitStringArray(String[] array){
        StringBuilder fullString = new StringBuilder();
        for(String s : array) {
            fullString.append(s);
        }
        String str = fullString.toString().toLowerCase();
        String[] individualLetters = str.split("");    
        return individualLetters;
    }

    /**
     * @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 numOfOcc = 0;
        for (String element: array){
            if (element.equals(value)){
                numOfOcc++;
            }
        }
        return numOfOcc;
    }

    /**
     * @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) {
        int howManyToDelete = getNumberOfOccurrences(array, valueToRemove);
        String[] revisedArray = new String[array.length-howManyToDelete];
        int index = 0;
        for(String element: array){
            if(element != valueToRemove){
                revisedArray[index] = element;
                index++;
            }
        }
        return revisedArray;
    }

    public static String[] sortArray(String[] array){
        String[] sorted = new String[array.length];
        Arrays.sort(sorted);
        return sorted;
    }
    
    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        int dupes = countDuplicates(array);
        String[] revisedArr = new String[array.length-dupes];
        int j = 0;
        for(int i = 0; i < array.length-1; i++){
            if (array[i]!=(array[i+1])){
                revisedArr[j] = array[i];
                j++;
            } 
        }
        revisedArr[revisedArr.length-1]=array[array.length-1];
        return revisedArr;
    }
    
    public static int countDuplicates(String[] array){
        String[] newArray = array;   
        int counter = 0;
        for(int i = 0; i < newArray.length-1; i++){
            if (newArray[i].equals(newArray[i+1])){
                counter++;   
            }
        }
        return counter;
    }
    
    /**
     * @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;
    }

}