/**
 * Created by leon on 1/29/18.
 */

import java.util.Arrays;
public class StringArrayUtils {
    /**
     * @param array array of String objects
     * @return first element of specified array
     */ // TODO
    public static String getFirstElement(String[] array) {
        String result = "";
        for(int i = 0; i < array.length; i++) {
            result += array[0]; 
            break;
        }
        return result;
    }

    /**
     * @param array array of String objects
     * @return second element in specified array
     */
    public static String getSecondElement(String[] array) {
        String result = "";
        for(int i = 0; i < array.length; i++) {
            result += array[1];
            break;
        }
        return result;
    }

    /**
     * @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 hasString = false;
        for(String s : array) {
            if(s.equals(value)) {
                hasString = true;
                break;
            }
        }
        return hasString;
    }

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

    /**
     * @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 ispalindromin = false;
        for(int i = 0; i < array.length / 2; i++) {
            if(array[i] == array[array.length -i -1]) {
                ispalindromin = true;
            }
        }
        return ispalindromin;

    }

    /**
     * @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 ispangramic = false;
        

        for(char i = 'A'; i <= 'Z'; i++) {
            if(Arrays.toString(array).indexOf(i) < 0 && (Arrays.toString(array).indexOf((char) i + 32 ) < 0)) {
                ispangramic = false;
                break;
            } else {
                ispangramic = true;
            }
        }
        return ispangramic;
    }

    /**
     * @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 count = 0;
        for(String s : array){
            if(s.equals(value)){
                count +=1;
            }
        }
        return count;
    }

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

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        int dupCount = 0;
        
        for(int i = 0; i < array.length -1; i++) {
            if(array[i].equals(array[i+1])) {
                dupCount = dupCount + 1;
            }
        }
        
        String[] str = new String[array.length - dupCount];
        
        int j = 0;
        for(int i = 0; i < array.length -1; i++) {
            if(!array[i].equals(array[i + 1])) {
                str[j++] = (array[i]);
            }
        }
        str[str.length -1] = array[array.length -1];
        return str;
    }

    /**
     * @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) {
        int dupCount = 0;
       
        for(int i = 0; i < array.length-1; i++){
            if(array[i].equals(array[i+1])){
                dupCount = dupCount + 1;
            }
        }
        
        String[] str = new String[array.length - dupCount];
        
        int j = 0;
        for(int i = 0; i < array.length-1; i++){
            if(array[i].equals(array[i+1])){
                StringBuilder sb = new StringBuilder(array[i]);
                sb.append(array[i+1]);
                
                str[j++] = (array[i]);
            }
        }
 
        return str;
    }
}