package org.simantics.scl.ui.editor2;

import java.text.CharacterIterator;

import org.eclipse.jface.action.IAction;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.resource.LocalResourceManager;
import org.eclipse.jface.resource.ResourceManager;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.link.LinkedModeModel;
import org.eclipse.jface.text.link.LinkedPosition;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ST;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorSite;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.contexts.IContextService;
import org.eclipse.ui.editors.text.TextEditor;
import org.eclipse.ui.texteditor.ITextEditorActionDefinitionIds;
import org.eclipse.ui.texteditor.IUpdate;
import org.eclipse.ui.texteditor.TextNavigationAction;
import org.simantics.scl.ui.editor.SCLSourceViewerConfigurationNew;
import org.simantics.scl.ui.editor.completion.SCLTextEditorEnvironment;
import org.simantics.scl.ui.editor2.iterator.DocumentCharacterIterator;
import org.simantics.scl.ui.editor2.iterator.JavaWordIterator;

import com.ibm.icu.text.BreakIterator;

public class SCLModuleEditor2 extends TextEditor {
    private boolean disposed = false;
    protected ResourceManager resourceManager;

    public SCLModuleEditor2() {
        super();
        resourceManager = new LocalResourceManager(JFaceResources.getResources());
        SCLSourceViewerConfigurationNew sourceViewerConfiguration = new SCLSourceViewerConfigurationNew(resourceManager);
        setDocumentProvider(new SCLModuleEditor2DocumentProvider(sourceViewerConfiguration));
        setSourceViewerConfiguration(sourceViewerConfiguration);
    }
    
    @Override
    public boolean isTabsToSpacesConversionEnabled() {
        return true;
    }
    
    @Override
    public void init(IEditorSite site, IEditorInput input)
            throws PartInitException {
        super.init(site, input);
    }

    @Override
    public void createPartControl(Composite parent) {
        super.createPartControl(parent);
        getEditorSite().getService(IContextService.class).activateContext("org.simantics.scl.ui.editor");
        updatePartName();
    }

    @Override
    protected void createNavigationActions() {
        super.createNavigationActions();
        
        // Taken from org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.createNavigationActions()
        final StyledText textWidget= getSourceViewer().getTextWidget();
        
        IAction action = new NavigatePreviousSubWordAction();
        action.setActionDefinitionId(ITextEditorActionDefinitionIds.WORD_PREVIOUS);
        setAction(ITextEditorActionDefinitionIds.WORD_PREVIOUS, action);
        textWidget.setKeyBinding(SWT.CTRL | SWT.ARROW_LEFT, SWT.NULL);

        action = new NavigateNextSubWordAction();
        action.setActionDefinitionId(ITextEditorActionDefinitionIds.WORD_NEXT);
        setAction(ITextEditorActionDefinitionIds.WORD_NEXT, action);
        textWidget.setKeyBinding(SWT.CTRL | SWT.ARROW_RIGHT, SWT.NULL);

        action = new SelectPreviousSubWordAction();
        action.setActionDefinitionId(ITextEditorActionDefinitionIds.SELECT_WORD_PREVIOUS);
        setAction(ITextEditorActionDefinitionIds.SELECT_WORD_PREVIOUS, action);
        textWidget.setKeyBinding(SWT.CTRL | SWT.SHIFT | SWT.ARROW_LEFT, SWT.NULL);

        action = new SelectNextSubWordAction();
        action.setActionDefinitionId(ITextEditorActionDefinitionIds.SELECT_WORD_NEXT);
        setAction(ITextEditorActionDefinitionIds.SELECT_WORD_NEXT, action);
        textWidget.setKeyBinding(SWT.CTRL | SWT.SHIFT | SWT.ARROW_RIGHT, SWT.NULL);
    }

    protected void updatePartName() {
        setPartName(getEditorInput().getName());
    }
    
    @Override
    public void dispose() {
        disposed = true;
        super.dispose();
        resourceManager.dispose();
    }

    public boolean isDisposed() {
        return disposed;
    }
    
    public SCLTextEditorEnvironment getSCLTextEditorEnvironment() {
        return ((SCLSourceViewerConfigurationNew)getSourceViewerConfiguration())
                .getSclTextEditorEnvironment();
    }

    public IDocument getDocument() {
        return getSourceViewer().getDocument();
    }
    
    /**
     * Text navigation action to navigate to the next sub-word.
     *
     * @since 3.0
     */
    protected abstract class NextSubWordAction extends TextNavigationAction {

        protected JavaWordIterator fIterator= new JavaWordIterator();

        /**
         * Creates a new next sub-word action.
         *
         * @param code Action code for the default operation. Must be an action code from @see org.eclipse.swt.custom.ST.
         */
        protected NextSubWordAction(int code) {
            super(getSourceViewer().getTextWidget(), code);
        }

        /*
         * @see org.eclipse.jface.action.IAction#run()
         */
        @Override
        public void run() {
            final ISourceViewer viewer= getSourceViewer();
            final IDocument document= viewer.getDocument();
            try {
                fIterator.setText((CharacterIterator)new DocumentCharacterIterator(document));
                int position= widgetOffset2ModelOffset(viewer, viewer.getTextWidget().getCaretOffset());
                if (position == -1)
                    return;

                int next= findNextPosition(position);
                if (isBlockSelectionModeEnabled() && document.getLineOfOffset(next) != document.getLineOfOffset(position)) {
                    super.run(); // may navigate into virtual white space
                } else if (next != BreakIterator.DONE) {
                    setCaretPosition(next);
                    getTextWidget().showSelection();
                    fireSelectionChanged();
                }
            } catch (BadLocationException x) {
                // ignore
            }
        }

        /**
         * Finds the next position after the given position.
         *
         * @param position the current position
         * @return the next position
         */
        protected int findNextPosition(int position) {
            ISourceViewer viewer= getSourceViewer();
            int widget= -1;
            int next= position;
            while (next != BreakIterator.DONE && widget == -1) { // XXX: optimize
                next= fIterator.following(next);
                if (next != BreakIterator.DONE)
                    widget= modelOffset2WidgetOffset(viewer, next);
            }

            IDocument document= viewer.getDocument();
            LinkedModeModel model= LinkedModeModel.getModel(document, position);
            if (model != null && next != BreakIterator.DONE) {
                LinkedPosition linkedPosition= model.findPosition(new LinkedPosition(document, position, 0));
                if (linkedPosition != null) {
                    int linkedPositionEnd= linkedPosition.getOffset() + linkedPosition.getLength();
                    if (position != linkedPositionEnd && linkedPositionEnd < next)
                        next= linkedPositionEnd;
                } else {
                    LinkedPosition nextLinkedPosition= model.findPosition(new LinkedPosition(document, next, 0));
                    if (nextLinkedPosition != null) {
                        int nextLinkedPositionOffset= nextLinkedPosition.getOffset();
                        if (position != nextLinkedPositionOffset && nextLinkedPositionOffset < next)
                            next= nextLinkedPositionOffset;
                    }
                }
            }

            return next;
        }

        /**
         * Sets the caret position to the sub-word boundary given with <code>position</code>.
         *
         * @param position Position where the action should move the caret
         */
        protected abstract void setCaretPosition(int position);
    }

    /**
     * Text navigation action to navigate to the next sub-word.
     *
     * @since 3.0
     */
    protected class NavigateNextSubWordAction extends NextSubWordAction {

        /**
         * Creates a new navigate next sub-word action.
         */
        public NavigateNextSubWordAction() {
            super(ST.WORD_NEXT);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.NextSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(final int position) {
            getTextWidget().setCaretOffset(modelOffset2WidgetOffset(getSourceViewer(), position));
        }
    }

    /**
     * Text operation action to delete the next sub-word.
     *
     * @since 3.0
     */
    protected class DeleteNextSubWordAction extends NextSubWordAction implements IUpdate {

        /**
         * Creates a new delete next sub-word action.
         */
        public DeleteNextSubWordAction() {
            super(ST.DELETE_WORD_NEXT);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.NextSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(final int position) {
            if (!validateEditorInputState())
                return;

            final ISourceViewer viewer= getSourceViewer();
            StyledText text= viewer.getTextWidget();
            Point widgetSelection= text.getSelection();
            if (isBlockSelectionModeEnabled() && widgetSelection.y != widgetSelection.x) {
                final int caret= text.getCaretOffset();
                final int offset= modelOffset2WidgetOffset(viewer, position);

                if (caret == widgetSelection.x)
                    text.setSelectionRange(widgetSelection.y, offset - widgetSelection.y);
                else
                    text.setSelectionRange(widgetSelection.x, offset - widgetSelection.x);
                text.invokeAction(ST.DELETE_NEXT);
            } else {
                Point selection= viewer.getSelectedRange();
                final int caret, length;
                if (selection.y != 0) {
                    caret= selection.x;
                    length= selection.y;
                } else {
                    caret= widgetOffset2ModelOffset(viewer, text.getCaretOffset());
                    length= position - caret;
                }

                try {
                    viewer.getDocument().replace(caret, length, ""); //$NON-NLS-1$
                } catch (BadLocationException exception) {
                    // Should not happen
                }
            }
        }

        /*
         * @see org.eclipse.ui.texteditor.IUpdate#update()
         */
        public void update() {
            setEnabled(isEditorInputModifiable());
        }
    }

    /**
     * Text operation action to select the next sub-word.
     *
     * @since 3.0
     */
    protected class SelectNextSubWordAction extends NextSubWordAction {

        /**
         * Creates a new select next sub-word action.
         */
        public SelectNextSubWordAction() {
            super(ST.SELECT_WORD_NEXT);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.NextSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(final int position) {
            final ISourceViewer viewer= getSourceViewer();

            final StyledText text= viewer.getTextWidget();
            if (text != null && !text.isDisposed()) {

                final Point selection= text.getSelection();
                final int caret= text.getCaretOffset();
                final int offset= modelOffset2WidgetOffset(viewer, position);

                if (caret == selection.x)
                    text.setSelectionRange(selection.y, offset - selection.y);
                else
                    text.setSelectionRange(selection.x, offset - selection.x);
            }
        }
    }

    /**
     * Text navigation action to navigate to the previous sub-word.
     *
     * @since 3.0
     */
    protected abstract class PreviousSubWordAction extends TextNavigationAction {

        protected JavaWordIterator fIterator= new JavaWordIterator();

        /**
         * Creates a new previous sub-word action.
         *
         * @param code Action code for the default operation. Must be an action code from @see org.eclipse.swt.custom.ST.
         */
        protected PreviousSubWordAction(final int code) {
            super(getSourceViewer().getTextWidget(), code);
        }

        /*
         * @see org.eclipse.jface.action.IAction#run()
         */
        @Override
        public void run() {
            final ISourceViewer viewer= getSourceViewer();
            final IDocument document= viewer.getDocument();
            try {
                fIterator.setText((CharacterIterator)new DocumentCharacterIterator(document));
                int position= widgetOffset2ModelOffset(viewer, viewer.getTextWidget().getCaretOffset());
                if (position == -1)
                    return;

                int previous= findPreviousPosition(position);
                if (isBlockSelectionModeEnabled() && document.getLineOfOffset(previous) != document.getLineOfOffset(position)) {
                    super.run(); // may navigate into virtual white space
                } else if (previous != BreakIterator.DONE) {
                    setCaretPosition(previous);
                    getTextWidget().showSelection();
                    fireSelectionChanged();
                }
            } catch (BadLocationException x) {
                // ignore - getLineOfOffset failed
            }

        }

        /**
         * Finds the previous position before the given position.
         *
         * @param position the current position
         * @return the previous position
         */
        protected int findPreviousPosition(int position) {
            ISourceViewer viewer= getSourceViewer();
            int widget= -1;
            int previous= position;
            while (previous != BreakIterator.DONE && widget == -1) { // XXX: optimize
                previous= fIterator.preceding(previous);
                if (previous != BreakIterator.DONE)
                    widget= modelOffset2WidgetOffset(viewer, previous);
            }

            IDocument document= viewer.getDocument();
            LinkedModeModel model= LinkedModeModel.getModel(document, position);
            if (model != null && previous != BreakIterator.DONE) {
                LinkedPosition linkedPosition= model.findPosition(new LinkedPosition(document, position, 0));
                if (linkedPosition != null) {
                    int linkedPositionOffset= linkedPosition.getOffset();
                    if (position != linkedPositionOffset && previous < linkedPositionOffset)
                        previous= linkedPositionOffset;
                } else {
                    LinkedPosition previousLinkedPosition= model.findPosition(new LinkedPosition(document, previous, 0));
                    if (previousLinkedPosition != null) {
                        int previousLinkedPositionEnd= previousLinkedPosition.getOffset() + previousLinkedPosition.getLength();
                        if (position != previousLinkedPositionEnd && previous < previousLinkedPositionEnd)
                            previous= previousLinkedPositionEnd;
                    }
                }
            }

            return previous;
        }

        /**
         * Sets the caret position to the sub-word boundary given with <code>position</code>.
         *
         * @param position Position where the action should move the caret
         */
        protected abstract void setCaretPosition(int position);
    }

    /**
     * Text navigation action to navigate to the previous sub-word.
     *
     * @since 3.0
     */
    protected class NavigatePreviousSubWordAction extends PreviousSubWordAction {

        /**
         * Creates a new navigate previous sub-word action.
         */
        public NavigatePreviousSubWordAction() {
            super(ST.WORD_PREVIOUS);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.PreviousSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(final int position) {
            getTextWidget().setCaretOffset(modelOffset2WidgetOffset(getSourceViewer(), position));
        }
    }

    /**
     * Text operation action to delete the previous sub-word.
     *
     * @since 3.0
     */
    protected class DeletePreviousSubWordAction extends PreviousSubWordAction implements IUpdate {

        /**
         * Creates a new delete previous sub-word action.
         */
        public DeletePreviousSubWordAction() {
            super(ST.DELETE_WORD_PREVIOUS);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.PreviousSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(int position) {
            if (!validateEditorInputState())
                return;

            final int length;
            final ISourceViewer viewer= getSourceViewer();
            StyledText text= viewer.getTextWidget();
            Point widgetSelection= text.getSelection();
            if (isBlockSelectionModeEnabled() && widgetSelection.y != widgetSelection.x) {
                final int caret= text.getCaretOffset();
                final int offset= modelOffset2WidgetOffset(viewer, position);

                if (caret == widgetSelection.x)
                    text.setSelectionRange(widgetSelection.y, offset - widgetSelection.y);
                else
                    text.setSelectionRange(widgetSelection.x, offset - widgetSelection.x);
                text.invokeAction(ST.DELETE_PREVIOUS);
            } else {
                Point selection= viewer.getSelectedRange();
                if (selection.y != 0) {
                    position= selection.x;
                    length= selection.y;
                } else {
                    length= widgetOffset2ModelOffset(viewer, text.getCaretOffset()) - position;
                }

                try {
                    viewer.getDocument().replace(position, length, ""); //$NON-NLS-1$
                } catch (BadLocationException exception) {
                    // Should not happen
                }
            }
        }

        /*
         * @see org.eclipse.ui.texteditor.IUpdate#update()
         */
        public void update() {
            setEnabled(isEditorInputModifiable());
        }
    }

    /**
     * Text operation action to select the previous sub-word.
     *
     * @since 3.0
     */
    protected class SelectPreviousSubWordAction extends PreviousSubWordAction {

        /**
         * Creates a new select previous sub-word action.
         */
        public SelectPreviousSubWordAction() {
            super(ST.SELECT_WORD_PREVIOUS);
        }

        /*
         * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.PreviousSubWordAction#setCaretPosition(int)
         */
        @Override
        protected void setCaretPosition(final int position) {
            final ISourceViewer viewer= getSourceViewer();

            final StyledText text= viewer.getTextWidget();
            if (text != null && !text.isDisposed()) {

                final Point selection= text.getSelection();
                final int caret= text.getCaretOffset();
                final int offset= modelOffset2WidgetOffset(viewer, position);

                if (caret == selection.x)
                    text.setSelectionRange(selection.y, offset - selection.y);
                else
                    text.setSelectionRange(selection.x, offset - selection.x);
            }
        }
    }

}