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

import com.google.gwt.cell.client.*;
import com.google.gwt.dom.client.*;
import com.google.gwt.event.dom.client.*;
import com.google.gwt.safehtml.shared.*;
import com.google.gwt.user.client.ui.*;
import com.temp.client.foundation.handler.*;
import com.temp.shared.utils.*;

import java.util.*;

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();
                }
            }
        }
    }
}