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.*;

public class TextDataCell<E> extends AbstractCell<E> {

    // 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 = 8;
    private static final int POPUP_PADDING_TOP_PX = 6;
    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 DataIsClickableHandler<E> isClickableHandler;
    private DisplayStringHandler<E> displayStringHandler;
    private DataClickHandler<E> clickHandler;
    private Label fullTextLabel = new Label();
    private E cellValue;
    private DecoratedPopupPanel popup = new DecoratedPopupPanel( true );

    public TextDataCell() {
        this( null, null, null );
    }

    public TextDataCell( DisplayStringHandler<E> displayStringHandler ) {
        this( displayStringHandler, null, null );
    }

    public TextDataCell(
            DisplayStringHandler<E> displayStringHandler,
            DataClickHandler<E> clickHandler ) {
        this( displayStringHandler, clickHandler, null );
    }

    public TextDataCell(
            DisplayStringHandler<E> displayStringHandler,
            DataClickHandler<E> clickHandler,
            DataIsClickableHandler<E> isClickableHandler
    ) {

        super( MOUSEOVER_EVENT, CLICK_EVENT );
        setDataDisplayStringHandler( displayStringHandler );
        setDataClickHandler( clickHandler );
        setDataIsClickableHandler( isClickableHandler );
        initializePopup();
    }

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

    private E getCellValue() {
        return cellValue;
    }

    private void setDataDisplayStringHandler( DisplayStringHandler<E> displayStringHandler ) {
        if ( displayStringHandler == null ) {
            displayStringHandler = new DisplayStringHandler<E>() {
                public String getDisplayString( E value ) {
                    if ( value != null ) {
                        return value.toString();
                    }
                    return "";
                }
            };
        }
        this.displayStringHandler = displayStringHandler;
    }

    private void setDataClickHandler( DataClickHandler<E> clickHandler ) {
        this.clickHandler = clickHandler;
    }

    private void setDataIsClickableHandler( DataIsClickableHandler<E> isClickableHandler ) {
        if ( isClickableHandler == null ) {
            isClickableHandler = new DataIsClickableHandler<E>() {
                public boolean isClickable( E elem ) {
                    return true;
                }
            };
        }
        this.isClickableHandler = isClickableHandler;
    }

    private void initializePopup() {
        popup.setGlassEnabled( false );
        popup.setWidget( fullTextLabel );
        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 ) {
                    E value = getCellValue();
                    if ( value != null ) {
                        clickHandler.onClick( value );
                    }
                }
            }
        }, ClickEvent.getType() );
    }

    protected void showFullTextPopup( Element wrapper, E value ) {
        // check if some of the text is being hidden.
        if ( isClickable( value ) ) {
            setCellValue( value );
            fullTextLabel.setStyleName( LINK_STYLE );
        } else {
            fullTextLabel.removeStyleName( LINK_STYLE );
            setCellValue( null );
        }
        fullTextLabel.setText( displayStringHandler.getDisplayString( value ) );
        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();
    }

    private boolean isClickable( E value ) {
        return clickHandler != null && isClickableHandler.isClickable( value );
    }

    @Override
    public void render( com.google.gwt.cell.client.Cell.Context context, E value, SafeHtmlBuilder sb ) {
        if ( isClickable( value ) ) {
            sb.appendHtmlConstant( "<span class='" + LINK_STYLE + "'>" );
        } else {
            sb.appendHtmlConstant( "<span>" );
        }
        sb.appendEscaped( displayStringHandler.getDisplayString( value ) );
        sb.appendHtmlConstant( "</span>" );
    }

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

        if ( value != null && 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, value );
                            }
                            break;
                        } else if ( eventType.equals( CLICK_EVENT ) ) {
                            // click
                            if ( isClickable( value ) ) {
                                clickHandler.onClick( value );
                            }
                            break;
                        }
                    }
                    wrapper = wrapper.getNextSiblingElement();
                }
            }
        }
    }
}