/*
 * Copyright 2005 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.drools.eclipse.flow.ruleflow.view.property.constraint;

import java.util.List;
import java.util.HashSet;
import java.util.Map;

import org.drools.eclipse.editors.DRLSourceViewerConfig;
import org.drools.eclipse.editors.scanners.DRLPartionScanner;
import org.drools.eclipse.util.ArrayUtils;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IDocumentPartitioner;
import org.eclipse.jface.text.contentassist.ContentAssistant;
import org.eclipse.jface.text.contentassist.IContentAssistant;
import org.eclipse.jface.text.reconciler.IReconciler;
import org.eclipse.jface.text.rules.FastPartitioner;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TabFolder;
import org.eclipse.swt.widgets.TabItem;
import org.eclipse.swt.widgets.Text;
import org.jbpm.workflow.core.Constraint;
import org.jbpm.workflow.core.WorkflowProcess;
import org.jbpm.workflow.core.impl.ConstraintImpl;

/**
 * Dialog for editing constraints.
 */
public class RuleFlowConstraintDialog extends Dialog {

    private static final String[] DIALECTS = new String[] { "mvel", "java" };
    private static final String[] TYPES = new String[] { "rule", "code" };

    private Constraint constraint;
    private WorkflowProcess process;
    private boolean success;
    private Button alwaysTrue;
    private Text nameText;
    private Text priorityText;
    private Combo typeCombo;
    private Combo dialectCombo;
    private TabFolder tabFolder;
    private SourceViewer constraintViewer;
    private ConstraintCompletionProcessor completionProcessor;

    public RuleFlowConstraintDialog(Shell parentShell, WorkflowProcess process) {
        super(parentShell);
        this.process = process;
        setShellStyle(getShellStyle() | SWT.RESIZE);
    }

    protected void configureShell(Shell newShell) {
        super.configureShell(newShell);
        newShell.setText("Constraint editor");
    }

    protected Point getInitialSize() {
        return new Point(600, 450);
    }

    private Control createTextualEditor(Composite parent) {
        constraintViewer = new SourceViewer(parent, null, SWT.BORDER);
        constraintViewer.configure(new DRLSourceViewerConfig(null) {
            public IReconciler getReconciler(ISourceViewer sourceViewer) {
                return null;
            }
            public IContentAssistant getContentAssistant(ISourceViewer sourceViewer) {
                ContentAssistant assistant = new ContentAssistant();
                completionProcessor = new ConstraintCompletionProcessor(process);
                assistant.setContentAssistProcessor(
                    completionProcessor, IDocument.DEFAULT_CONTENT_TYPE);
                assistant.setProposalPopupOrientation(IContentAssistant.PROPOSAL_OVERLAY);
                return assistant;
            }
        });
        IDocument document = new Document();
        constraintViewer.setDocument(document);
        IDocumentPartitioner partitioner =
            new FastPartitioner(
                new DRLPartionScanner(),
                DRLPartionScanner.LEGAL_CONTENT_TYPES);
        partitioner.connect(document);
        document.setDocumentPartitioner(partitioner);
        constraintViewer.getControl().addKeyListener(new KeyListener() {
            public void keyPressed(KeyEvent e) {
                if (e.character == ' ' && e.stateMask == SWT.CTRL) {
                    constraintViewer.doOperation(ISourceViewer.CONTENTASSIST_PROPOSALS);
                }
            }
            public void keyReleased(KeyEvent e) {
            }
        });
        return constraintViewer.getControl();
    }

    private String getConstraintText() {
        return constraintViewer.getDocument().get();
    }

    private void setConstraintText(String text) {
        constraintViewer.getDocument().set(text);
    }

    public Control createDialogArea(Composite parent) {

        GridLayout layout = new GridLayout();
        parent.setLayout(layout);
        layout.numColumns = 2;

        Composite top = new Composite(parent, SWT.NONE);
        GridData gd = new GridData();
        gd.horizontalSpan = 2;
        gd.grabExcessHorizontalSpace = true;
        top.setLayoutData(gd);

        layout = new GridLayout();
        layout.numColumns = 4;
        top.setLayout(layout);

        Label l1 = new Label(top, SWT.None);
        l1.setText("Name:");
        gd = new GridData();
        l1.setLayoutData(gd);
        nameText = new Text(top, SWT.BORDER);
        gd = new GridData();
        gd.horizontalAlignment = GridData.FILL;
        gd.widthHint = 200;
        gd.horizontalSpan = 3;
        nameText.setLayoutData(gd);

        Label l2 = new Label(top, SWT.NONE);
        gd = new GridData();
        l2.setLayoutData(gd);
        l2.setText("Priority:");
        priorityText = new Text(top, SWT.BORDER);
        gd = new GridData();
        gd.widthHint = 200;
        gd.horizontalSpan = 3;
        priorityText.setLayoutData(gd);

        alwaysTrue = new Button(top, SWT.CHECK);
        alwaysTrue.setText("Always true");
        gd = new GridData();
        gd.horizontalSpan = 2;
        alwaysTrue.setLayoutData(gd);

        Button importButton = new Button(top, SWT.PUSH);
        importButton.setText("Imports ...");
        importButton.setFont(JFaceResources.getDialogFont());
        importButton.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent event) {
                importButtonPressed();
            }
        });
        gd = new GridData();
        gd.grabExcessHorizontalSpace = true;
        gd.horizontalAlignment = GridData.END;
        importButton.setLayoutData(gd);

        Button globalButton = new Button(top, SWT.PUSH);
        globalButton.setText("Globals ...");
        globalButton.setFont(JFaceResources.getDialogFont());
        globalButton.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent event) {
                globalButtonPressed();
            }
        });
        gd = new GridData();
        gd.horizontalAlignment = GridData.END;
        globalButton.setLayoutData(gd);

        Label l3 = new Label(top, SWT.NONE);
        gd = new GridData();
        l3.setLayoutData(gd);
        l3.setText("Type:");
        typeCombo = new Combo(top, SWT.DROP_DOWN | SWT.READ_ONLY);
        typeCombo.setItems(TYPES);
        gd = new GridData();
        typeCombo.setLayoutData(gd);
        typeCombo.addSelectionListener(new SelectionListener() {
            public void widgetDefaultSelected(SelectionEvent e) {
            }
            public void widgetSelected(SelectionEvent e) {
                if (completionProcessor != null) {
                    completionProcessor.setType(typeCombo.getText());
                }
            }
        });
        typeCombo.select(0);

        Label l4 = new Label(top, SWT.NONE);
        gd = new GridData();
        l4.setLayoutData(gd);
        l4.setText("Dialect:");
        dialectCombo = new Combo(top, SWT.DROP_DOWN | SWT.READ_ONLY);
        dialectCombo.setItems(DIALECTS);
        dialectCombo.select(0);
        gd = new GridData();
        dialectCombo.setLayoutData(gd);

        tabFolder = new TabFolder(parent, SWT.NONE);
        gd = new GridData();
        gd.horizontalSpan = 4;
        gd.grabExcessHorizontalSpace = true;
        gd.grabExcessVerticalSpace = true;
        gd.verticalAlignment = GridData.FILL;
        gd.horizontalAlignment = GridData.FILL;
        tabFolder.setLayoutData(gd);
        TabItem textEditorTab = new TabItem(tabFolder, SWT.NONE);
        textEditorTab.setText("Textual Editor");

        textEditorTab.setControl(createTextualEditor(tabFolder));

        alwaysTrue.addSelectionListener(new SelectionListener() {
            public void widgetSelected(SelectionEvent e) {
                tabFolder.setVisible(!alwaysTrue.getSelection());
            }

            public void widgetDefaultSelected(SelectionEvent e) {
                widgetSelected(e);
            }
        });

        return tabFolder;
    }

    private void importButtonPressed() {
        final Runnable r = new Runnable() {
            public void run() {
                RuleFlowImportsDialog dialog =
                    new RuleFlowImportsDialog(getShell(), process);
                dialog.create();
                int code = dialog.open();
                if (code != CANCEL) {
                    List<String> imports = dialog.getImports();
                    ((org.jbpm.process.core.Process) process).setImports(new HashSet(imports));
                    completionProcessor.reset();
                }
            }
        };
        r.run();
    }

    private void globalButtonPressed() {
        final Runnable r = new Runnable() {
            public void run() {
                RuleFlowGlobalsDialog dialog =
                    new RuleFlowGlobalsDialog(getShell(), process);
                dialog.create();
                int code = dialog.open();
                if (code != CANCEL) {
                    Map<String, String> globals = dialog.getGlobals();
                    ((org.jbpm.process.core.Process) process).setGlobals(globals);
                    completionProcessor.reset();
                }
            }
        };
        r.run();
    }

    public void fixType(int index) {
        typeCombo.select(index);
        typeCombo.setEnabled(false);
    }

    public void fixDialect(int index) {
        typeCombo.select(index);
        typeCombo.setEnabled(false);
    }

    protected void okPressed() {
        int selectionIndex = tabFolder.getSelectionIndex();
        if (selectionIndex == 1) {
            updateTranslation();
        } else {
            updateConstraint();
        }
        super.okPressed();
    }

    private void updateTranslation() {
        // TODO add custom token model checker
        success = true;
        constraint = new ConstraintImpl();
        constraint.setConstraint(null);
        constraint.setConstraint(getConstraintText());
        constraint.setName(nameText.getText());
        try {
            constraint.setPriority(Integer.parseInt(priorityText.getText()));
        } catch (NumberFormatException exc) {
            constraint.setPriority(1);
        }
    }

    public boolean isSuccess() {
        return success;
    }

    public void updateConstraint() {
        constraint = new ConstraintImpl();
        if (!alwaysTrue.getSelection()) {
            constraint.setConstraint(getConstraintText());
        } else {
            if (typeCombo.getSelectionIndex() == 0) {
                constraint.setConstraint("eval(true)");
            } else {
                constraint.setConstraint("return true;");
            }
        }
        constraint.setName(nameText.getText());
        try {
            constraint.setPriority(Integer.parseInt(priorityText.getText()));
        } catch (NumberFormatException exc) {
            constraint.setPriority(1);
        }
        constraint.setType(typeCombo.getItem(typeCombo.getSelectionIndex()));
        constraint.setDialect(dialectCombo.getItem(dialectCombo.getSelectionIndex()));
    }

    public Constraint getConstraint() {
        return constraint;
    }

    public void setConstraint(Constraint constraint) {
        this.constraint = constraint;
        if (constraint != null) {
            if ("eval(true)".equals(constraint.getConstraint()) || "return true;".equals(constraint.getConstraint())) {
                alwaysTrue.setSelection(true);
            } else {
                setConstraintText(constraint.getConstraint() == null ? "" : constraint.getConstraint());
            }
            tabFolder.setVisible(!alwaysTrue.getSelection());
            nameText.setText(constraint.getName() == null ? "" : constraint
                    .getName());
            priorityText.setText(constraint.getPriority() + "");
            int index = 0;
            String type = constraint.getType();
            int found = ArrayUtils.indexOf(TYPES, type);
            if (found >= 0) {
                index = found;
            }
            typeCombo.select(index);
            index = 0;
            String dialect = constraint.getDialect();
            found = ArrayUtils.indexOf(DIALECTS, dialect);
            if (found >= 0) {
                index = found;
            }
            dialectCombo.select(index);
            completionProcessor.setType(typeCombo.getText());
            setConstraintText(constraint.getConstraint());
        } else {
            priorityText.setText("1");
            nameText.setText("constraint");
        }
    }
}
