package com.temp.client.foundation.widget.table.cell;

import java.util.List;

import com.temp.client.foundation.handler.DataClickHandler;
import com.temp.shared.utils.CollectionsUtils;
import com.temp.shared.utils.DisplayStringHandler;

import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.EventTarget;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.MouseOutEvent;
import com.google.gwt.event.dom.client.MouseOutHandler;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.user.client.ui.DecoratedPopupPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.VerticalPanel;

public class ClickableLimitedListDataCell <E, L extends List<E>> extends AbstractCell<L>{

    // full text popup variables
    private static final String LINK_STYLE = "link-button";
    private static final String POPUP_STYLE = "HoverFullTextPopup";
    private static final int POPUP_PADDING_LEFT_PX = 6;
    private static final int POPUP_PADDING_TOP_PX = 4;
    private static final int POPUP_BORDER_WIDTH_PX = 1;
    private static final int CELL_PADDING_PX = 4;

    private static final String MOUSEOVER_EVENT = "mouseover";
    private static final String CLICK_EVENT = "click";
    private static final int MAX_ELEMENTS_TO_DISPLAY = 2;

    private DataClickHandler<L> clickHandler;
	private DisplayStringHandler<E> displayStringHandler;
    private VerticalPanel fullTextPanel = new VerticalPanel();
    private L cellValue;
    private DecoratedPopupPanel popup = new DecoratedPopupPanel(true);

	public ClickableLimitedListDataCell(DataClickHandler<L> _clickHandler, DisplayStringHandler<E> _displayStringHandler) {
		super(CLICK_EVENT, MOUSEOVER_EVENT);
		clickHandler = _clickHandler;
		displayStringHandler = _displayStringHandler;
		if (displayStringHandler == null) {
			displayStringHandler = new DisplayStringHandler<E>() {
				public String getDisplayString(E value) {
					return value.toString();
				}
			};
		}
		initializePopup();
	}

	private void initializePopup() {
        popup.setGlassEnabled(false);
        popup.setWidget(fullTextPanel);
        popup.setStyleName(POPUP_STYLE);
        popup.hide();
        popup.addDomHandler(new MouseOutHandler() {
            public void onMouseOut(MouseOutEvent event) {
                popup.hide();
            }
        }, MouseOutEvent.getType());
        popup.addDomHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                if (clickHandler != null) {
                    L value = getCellValue();
                    if (value != null) {
                        clickHandler.onClick(value);
                    }
                }
            }
        }, ClickEvent.getType());
    }

    private void setCellValue(L value) {
        this.cellValue = value;
    }

    private L getCellValue() {
        return cellValue;
    }

    protected void showFullTextPopup(Element wrapper, L valueList) {
        setCellValue(valueList);
        fullTextPanel.clear();
        for (E value : valueList) {
            Label fullTextLabel = new Label(displayStringHandler.getDisplayString(value));
            fullTextLabel.setStyleName(LINK_STYLE);
            fullTextPanel.add(fullTextLabel);
        }
        int left = wrapper.getAbsoluteLeft() - (POPUP_PADDING_LEFT_PX + POPUP_BORDER_WIDTH_PX);
        int top = wrapper.getAbsoluteTop() - (POPUP_PADDING_TOP_PX + POPUP_BORDER_WIDTH_PX);
        popup.setPopupPosition(left, top);
        popup.show();
    }

    @Override
	public void render(Context context, L valueList, SafeHtmlBuilder sb) {
		if (!CollectionsUtils.isEmpty(valueList)) {
			int displayedElements = 0;
			for (E valueListElement : valueList) {
                if (displayedElements > 0) {
                    sb.appendHtmlConstant("<br/>");
                }
				if (displayedElements >= MAX_ELEMENTS_TO_DISPLAY) {
					sb.appendHtmlConstant("<span class='link-button'>...</span>");
					break;
				}
				if (clickHandler != null) {
					sb.appendHtmlConstant("<span class='link-button'>");
				} else {
					sb.appendHtmlConstant("<span>");
				}
				sb.appendEscaped(displayStringHandler.getDisplayString(valueListElement));
				sb.appendHtmlConstant("</span>");
				displayedElements++;
			}
		}
	}

	@Override
	public void onBrowserEvent(Context context, Element parent, L valueList, NativeEvent event, ValueUpdater<L> valueUpdater) {
		String eventType = event.getType();

		if (!CollectionsUtils.isEmpty(valueList) && getConsumedEvents().contains(eventType)) {
		    EventTarget eventTarget = event.getEventTarget();
		    if (Element.is(eventTarget)) {
		    	Element target = eventTarget.cast();
		    	Element container = parent;
		    	Element wrapper = container.getFirstChildElement();
		    	while (wrapper != null) {
		    		if (wrapper.isOrHasChild(target)) {
		    		    if (eventType.equals(MOUSEOVER_EVENT)) {
                            // on hover full text
                            int containerWidth = container.getAbsoluteRight() - container.getAbsoluteLeft() + CELL_PADDING_PX;
                            int textWidth = wrapper.getAbsoluteRight() - wrapper.getAbsoluteLeft();
                            if (containerWidth < textWidth) {
                                showFullTextPopup(wrapper, valueList);
                                break;
                            }
		    		    } else if (eventType.equals(CLICK_EVENT)) {
		    		        // click
		    		        if (clickHandler != null) {
	                            clickHandler.onClick(valueList);
		    		        }
		    		        break;
		    		    }
		    		}
		    		wrapper = wrapper.getNextSiblingElement();
		    	}
		    }
		}
	}
}