package org.netbeans.modules.specialcopypaste;

import java.awt.Color;
import java.awt.Toolkit;
import java.awt.datatransfer.StringSelection;
import java.io.CharConversionException;
import javax.swing.JEditorPane;
import javax.swing.text.AttributeSet;
import javax.swing.text.StyleConstants;
import org.netbeans.api.editor.mimelookup.*;
import org.netbeans.api.editor.settings.FontColorSettings;
import org.openide.cookies.EditorCookie;
import org.openide.nodes.Node;
import org.openide.util.HelpCtx;
import org.openide.util.Lookup;
import org.openide.util.NbBundle;
import org.openide.util.actions.CookieAction;
import org.netbeans.api.lexer.*;
import org.openide.util.Exceptions;
import org.openide.xml.XMLUtil;

public final class CopyAsHTMLCSS extends CookieAction
{
    protected final void performAction(final Node[] activatedNodes)
    {
        final Lookup lookup = activatedNodes[0].getLookup();
        final EditorCookie editorCookie = lookup.lookup(EditorCookie.class);
        
         
        // Bug lurking here. Surely there's a better way of getting the pane which currently has focus, but this seems to work
        for(final JEditorPane pane : editorCookie.getOpenedPanes())
            if (pane.isShowing())
                try
                {
                    StringSelection content = new StringSelection( getSelectedSourceAsHTMLCSS(pane) );
                    Toolkit.getDefaultToolkit().getSystemClipboard().setContents(content, content);
                    return;
                } 
                catch (Throwable e)
                {
                    org.openide.ErrorManager.getDefault().notify(e);
                }
    }
    
    private static final String getSelectedSourceAsHTMLCSS(final JEditorPane pane)
    {
        final MimePath mimePath = MimePath.get( pane.getContentType() );
        final Lookup lookup = MimeLookup.getLookup( mimePath );
        final FontColorSettings fontColorSettings = lookup.lookup( FontColorSettings.class );
        
        final TokenHierarchy tokenHierarchy = TokenHierarchy.get( pane.getDocument() );
        final TokenSequence tokenSeq = tokenHierarchy.tokenSequence();
        final StringBuilder stringBuilder = new StringBuilder();

        // Forward to start of selected text
        tokenSeq.move( pane.getSelectionStart() );

        // Process each token between start and end of selection
        while(tokenSeq.moveNext() && tokenSeq.offset() < pane.getSelectionEnd() )
            processToken( tokenSeq.token(), fontColorSettings, stringBuilder );
        
        // Wrap everything in a preformated tag with a font family (also add monospace as fallback) and color span
        return String.format("<pre>\n<span style=\"font-family:%s,monospace;color:%s\">\n%s\n</span>\n</pre>",
                pane.getFont().getFamily(),
                getHtmlColorString(pane.getForeground()),
                stringBuilder.toString());
    }
    
    private static final void processToken(final Token token, final FontColorSettings fontColorSettings, final StringBuilder stringBuilder)
    {
        final String tokenText = escapeHtmlContent( token.text().toString() );
        String category = token.id().name();
        AttributeSet attribs = fontColorSettings.getTokenFontColors(category);

        if (attribs == null)
        {
            category = token.id().primaryCategory();
            attribs = fontColorSettings.getTokenFontColors(category);
        }
        
        if (attribs == null || isWhiteSpace(tokenText))
            stringBuilder.append(tokenText);
        else
            styleAndEmitToken(tokenText, stringBuilder, attribs);
    }    
    
    private static final void styleAndEmitToken(final String tokenText, final StringBuilder stringBuilder, final AttributeSet attribs)
    {
        final StringBuilder styleString = new StringBuilder();
       
        final Color fg = (Color) attribs.getAttribute(StyleConstants.Foreground);
        if (fg != null)
            emit(styleString, "color:", getHtmlColorString(fg), ";");

        final Color bg = (Color) attribs.getAttribute(StyleConstants.Background);

        if (bg != null)
            emit(styleString, "background:", getHtmlColorString(bg), ";");

        Boolean b = (Boolean) attribs.getAttribute(StyleConstants.Bold);

        if ((b != null) && b.booleanValue())
            styleString.append("font-weight:bold;");

        b = (Boolean) attribs.getAttribute(StyleConstants.Italic);

        if ((b != null) && b.booleanValue())
            styleString.append("font-style:italic;");

        if (styleString.length() > 0)
            emit(stringBuilder, "<span style=\"", styleString.toString(), "\">", tokenText, "</span>");
        else
            stringBuilder.append(tokenText);        
    }
        
    /**
     * Language agnostic whitespace token detector
     * Nessesary since apparently there is no universal WHITESPACE tokenId
     * 
     * @param tokenText
     * @return
     */
    private static final boolean isWhiteSpace(String tokenText)
    {
        tokenText = tokenText.replaceAll("\\n", "");
        tokenText = tokenText.replaceAll("\\t", "");
        return (tokenText.trim().length() == 0);
    }
    
    private static final void emit(final StringBuilder stringBuilder, final String... strings)
    {
        for(String string:strings)
            stringBuilder.append(string);
    }
    
    private static final String escapeHtmlContent(final String content)
    {
        try
        {
            return XMLUtil.toElementContent(content);
        } 
        catch (CharConversionException cce)
        {
            Exceptions.printStackTrace(cce);
        }
        return content;
    }
    
    private static final String getHtmlColorString(final Color color) 
    {
        final StringBuffer result = new StringBuffer("#");
        result.append( getColorComponentAsHexString( color.getRed() ));
        result.append( getColorComponentAsHexString( color.getGreen() ));
        result.append( getColorComponentAsHexString( color.getBlue() ));
        return result.toString();
    }

    private static final String getColorComponentAsHexString(final int colorComponent)
    {
        if(colorComponent < 0x10)
            return "0" + Integer.toHexString(colorComponent);
        else
            return Integer.toHexString(colorComponent);
    }
    
    protected final int mode()
    {
        return CookieAction.MODE_EXACTLY_ONE;
    }

    public final String getName()
    {
        return NbBundle.getMessage(CopyAsHTMLCSS.class, "CTL_CopyAsHTMLCSS");
    }

    protected final Class[] cookieClasses()
    {
        return new Class[]
                {
                    EditorCookie.class
                };
    }

    @Override
    protected final void initialize()
    {
        super.initialize();
        putValue("noIconInMenu", Boolean.TRUE);
    }

    public final HelpCtx getHelpCtx()
    {
        return HelpCtx.DEFAULT_HELP;
    }

    @Override
    protected final boolean asynchronous()
    {
        return false;
    }
}