package danielcortes.xyz.views.components;

import javax.swing.*;
import java.awt.*;

public abstract class KeySelectionRenderer extends DefaultListCellRenderer implements JComboBox.KeySelectionManager {
    private long timeFactor;
    private long lastTime;
    private long time;
    private String prefix = "";

    public KeySelectionRenderer(JComboBox comboBox) {
        comboBox.setRenderer(this);
        comboBox.setKeySelectionManager(this);

        Long l = (Long) UIManager.get("ComboBox.timeFactor");
        timeFactor = l == null ? 1000L : l.longValue();
    }

    public abstract String getDisplayValue(Object item);


    @Override
    public Component getListCellRendererComponent(
            JList list, Object item, int index, boolean isSelected, boolean hasFocus) {
        super.getListCellRendererComponent(list, item, index, isSelected, hasFocus);

        if (item != null) {
            setText(getDisplayValue(item));
        }

        return this;
    }


    @Override
    public int selectionForKey(char aKey, ComboBoxModel model) {
        time = System.currentTimeMillis();

        //  Get the index of the currently selected item

        int size = model.getSize();
        int startIndex = -1;
        Object selectedItem = model.getSelectedItem();

        if (selectedItem != null) {
            for (int i = 0; i < size; i++) {
                if (selectedItem == model.getElementAt(i)) {
                    startIndex = i;
                    break;
                }
            }
        }


        if (time - lastTime < timeFactor) {
            if ((prefix.length() == 1) && (aKey == prefix.charAt(0))) {
                startIndex++;
            } else {
                prefix += aKey;
            }
        } else {
            startIndex++;
            prefix = "" + aKey;
        }

        lastTime = time;


        if (startIndex < 0 || startIndex >= size) {
            startIndex = 0;
        }

        int index = getNextMatch(prefix, startIndex, size, model);

        if (index < 0) {
            // wrap
            index = getNextMatch(prefix, 0, startIndex, model);
        }

        return index;
    }

    private int getNextMatch(String prefix, int start, int end, ComboBoxModel model) {
        for (int i = start; i < end; i++) {
            Object item = model.getElementAt(i);

            if (item != null) {
                String displayValue = getDisplayValue(item).toLowerCase();

                if (displayValue.startsWith(prefix)) {
                    return i;
                }
            }
        }

        return -1;
    }
}