package ru.favarish;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Map;

public class Lab5 extends Lab4{

    private static final int DEBUG_MODE = 1;

    public static void main(String[] args) throws IOException {

        String strFile = readCodeFile(FILE_NAME);

        Map<String, Integer> frequencyDictionary = counterSingle(strFile);

        ArrayList<Shennon> probabilitySingle = probabilityMapCalculate(frequencyDictionary);

        // Сортируем вероятности для кодирования Шеннона
        Collections.sort(probabilitySingle);

        // Кодируем символы методом Шеннона
        shennonRecursiveStart(probabilitySingle);

        if (DEBUG_MODE == 1) {
            for (Shennon elem : probabilitySingle) {
                System.out.println(elem);
            }
            System.out.println();
        }

        String codingFile = coding(strFile, getCodeMap(probabilitySingle));

        for (int i = 1; i <= 3; i++) {
            System.out.println("Entropy for " + i + "th symbol(s) = " + (shennon(probabilityCalculate(counterUniversal(codingFile, i))) / i) + " "
                    + "Redundancy = " + (Shennon.getRedundancy(probabilitySingle) - (shennon(probabilityCalculate(counterUniversal(codingFile, i))) / i)));
            System.out.println();;

            if (DEBUG_MODE == 1) {
                System.out.println("Количество уникальных элементов: " + counterUniversal(strFile, i).size());
            }
        }

        System.out.println("Средняя длина кодового слова = " + Shennon.getRedundancy(probabilitySingle));

        if (DEBUG_MODE == 1) {
            System.out.println("GLOBAL_COUNT=" + GLOBAL_COUNT);
        }
    }

    /**
     * Метод для запуска рекурсивного кодирования Шеннона
     * @param probability
     */
    private static void shennonRecursiveStart(ArrayList<Shennon> probability) {
        double difference = Math.abs(sum(0, probability.size() - 1, probability) - sum(probability.size() - 1, probability.size(), probability));

        int tempCenter = 0;
        for (int i = 0; i < probability.size(); i++) {
            double newDifference = Math.abs(sum(0, i, probability) - sum(i + 1, probability.size(), probability));
            if (newDifference < difference) {
                tempCenter = i;
                difference = newDifference;
            }
        }

        int center1 = 0;
        for (int i = 0; i < tempCenter; i++) {
            double newDifference = Math.abs(sum(0, i, probability) - sum(i + 1, tempCenter, probability));
            if (newDifference < difference) {
                center1 = i;
                difference = newDifference;
            }
        }

        int center2 = tempCenter;
        for (int i = tempCenter; i < probability.size(); i++) {
            double newDifference = Math.abs(sum(tempCenter + 1, i, probability) - sum(i + 1, probability.size(), probability));
            if (newDifference < difference) {
                center2 = i;
                difference = newDifference;
            }
        }

        if (DEBUG_MODE == 1) {
            System.out.println("tempCenter=" + tempCenter);
            System.out.println("1 часть с " + 0 + " по " + center1 + "; 2 часть с " + (center1 + 1) + " по " + tempCenter + "; "
                    + "3 часть с " + (tempCenter + 1) + " по " + center2 + "; 4 часть с " + (center2 + 1) + " по " + probability.size());
        }

        shennonCoding(0, center1, probability, "0");
        shennonCoding(center1 + 1, tempCenter, probability, "1");
        shennonCoding(tempCenter + 1, center2, probability, "2");
        shennonCoding(center2 + 1, probability.size() - 1, probability, "3");
    }


    /**
     * Рекурсивный метод подсчета кодов Шеннона
     * @param start
     * @param finish
     * @param probability
     * @param code
     */
    public static void shennonCoding(int start, int finish, ArrayList<Shennon> probability, String code) {
        if (DEBUG_MODE == 1) {
            System.out.println("start=" + start + " finish=" + finish);
        }

        addCodeInDiapason(start, finish, probability, code);
        if (finish - start == 0) {
            addCodeInDiapason(start, finish, probability, code);
            return;
        }
        if (finish - start == 1) {
            addCodeInDiapason(start, start, probability, "0");
            addCodeInDiapason(finish, finish, probability, "1");
            return;
        }
        if (finish - start > 1) {

            double difference = Math.abs(sum(start, finish - 1, probability) - sum(finish - 1, finish, probability));

            int tempCenter = start;
            for (int i = start; i < finish; i++) {
                double newDifference = Math.abs(sum(start, i, probability) - sum(i + 1, finish, probability));
                if (newDifference < difference) {
                    tempCenter = i;
                    difference = newDifference;
                }
            }

            int center1 = start;
            for (int i = start; i < tempCenter; i++) {
                double newDifference = Math.abs(sum(start, i, probability) - sum(i + 1, tempCenter, probability));
                if (newDifference < difference) {
                    center1 = i;
                    difference = newDifference;
                }
            }

            int center2 = tempCenter;
            for (int i = tempCenter; i < finish; i++) {
                double newDifference = Math.abs(sum(tempCenter + 1, i, probability) - sum(i + 1, finish, probability));
                if (newDifference < difference) {
                    center2 = i;
                    difference = newDifference;
                }
            }

            if (DEBUG_MODE == 1) {
                System.out.println("tempCenter=" + tempCenter);
                System.out.println("1 часть с " + start + " по " + center1 + "; 2 часть с " + (center1 + 1) + " по " + tempCenter + "; "
                + "3 часть с " + (tempCenter + 1) + " по " + center2 + "; 4 часть с " + (center2 + 1) + " по " + finish);
            }

            shennonCoding(start, center1, probability, "0");
            shennonCoding(center1 + 1, tempCenter, probability, "1");
            shennonCoding(tempCenter + 1, center2, probability, "2");
            shennonCoding(center2 + 1, finish, probability, "3");
        }

    }
}