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) {
        for(String entry: array){
            if(entry.equalsIgnoreCase(value)){
                return true;
            }
        }

        return false;
    }

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

            j++;
        } 

        return reverse;
    }

    /**
     * @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) {
        String [] reverse = new String[array.length];
        reverse = reverse(array);

        if(Arrays.equals(array, reverse)){
            return true;
        }
        return false;
    }

    /**
     * @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 output = false;
        char [] alphabet = {'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'};
        int count = 0;
        for(int i =0; i< array.length; i++){
            for(int j =0; j< array[i].length(); j++){
                for( int k = 0; k<alphabet.length; k++){
                    if(array[i].toUpperCase().charAt(j) == (alphabet[k])){
                        count++;
                        continue;
                    }
                    if(count == 26){
                        output=true;
                        break;
                    }
                }
            }
        }

        return output;
    }

    /**
     * @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 entry: array){
            if(entry.equals(value)){
                count++;
            }
        }

        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 totaltodelete = getNumberOfOccurrences(array,valueToRemove);
        String[] output = new String[array.length- totaltodelete];
        int count = 0;

        for(int i =0; i< array.length; i++){
            if(array[i].equals(valueToRemove)){

            } else{
                output[count] =array[i];
                count++;
            }   
        }

        return output;
    }

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        int count = 0;
        int entry = 0;

        for(int i =0; i< array.length; i++){
            if((i-1>-1) && (array[i].equals(array[i-1]))){
                count++;
            } 
        }
        String[] output = new String[array.length - count];
        for(int i =0; i< array.length; i++){
            if((i-1>-1) && (array[i].equals(array[i-1]))){

            }else{
                output[entry] =array[i];
                entry++;
            }
        }
        return output;
    }

    /**
     * @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 count = 0;
        int entry = 0;
        int dupes = 0;

        for(int i =0; i< array.length; i++){
            if(((i+1< array.length) && (array[i].equals(array[i+1])))){

            } else{
                count++;
            }
        }

        String[] output = new String[count];
        StringBuilder consecutive = new StringBuilder("");
        for(int i =0; i< array.length; i++){
            //Is the entry equal to an adjacent entry? If so apeend to consecutive
            if((i == array.length -1) || (entry == 0) || (i+1< array.length) && (i-1>-1) && (array[i].equals(array[i-1]) || array[i].equals(array[i+1]))){
                consecutive.append(array[i]);
                entry++;
                if((i == array.length -1) || (i+1< array.length) && !(array[i].equals(array[i+1]))){
                    output[dupes] = consecutive.toString();
                    consecutive.setLength(0);
                    dupes++;
                }
            }
            //If not add it to the array
            else{
                //but make sure to add consecutive to the array first
                if(consecutive.length() > 0){
                    output[dupes] = array[i];
                }else{
                    output[dupes] = array[i];
                }
                dupes++;
            }
        }
        System.out.print(output.toString());
        return output;
    }
}