package codechicken.nei.util;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

/**
 * Backported from JustEnoughItems/Core/src/main/java/mezz/jei/core/util/TextHistory.java
 */
public class TextHistory {
    private static final int MAX_HISTORY = 100;

    public enum Direction {
        NEXT,
        PREVIOUS
    }

    private final List<String> history = new ArrayList<>();

    public boolean add(String currentText) {
        if (currentText.length() > 0) {
            history.remove(currentText);
            history.add(currentText);
            if (history.size() > MAX_HISTORY) {
                history.remove(0);
            }
            return true;
        }
        return false;
    }

    public Optional<String> get(Direction direction, String currentText) {
        if (direction == direction.NEXT) {
            return getNext(currentText);
        } else {
            return getPrevious(currentText);
        }
    }

    public Optional<String> getPrevious(String currentText) {
        int historyIndex = history.indexOf(currentText);
        if (historyIndex < 0) {
            if (add(currentText)) {
                historyIndex = history.size() - 1;
            } else {
                historyIndex = history.size();
            }
        }
        if (historyIndex <= 0) {
            return Optional.empty();
        }
        String value = history.get(historyIndex - 1);
        return Optional.of(value);
    }

    public Optional<String> getNext(String currentText) {
        int historyIndex = history.indexOf(currentText);
        if (historyIndex < 0) {
            return Optional.empty();
        }
        final String historyString;
        if (historyIndex + 1 < history.size()) {
            historyString = history.get(historyIndex + 1);
        } else {
            historyString = "";
        }
        return Optional.of(historyString);
    }
}