/*******************************************************************************
 * Copyright (c) 2017 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Semantum Oy - initial API and implementation
 *******************************************************************************/
package org.simantics.modeling.ui.scl.scriptEditor;

import java.util.Arrays;
import java.util.List;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.source.Annotation;
import org.eclipse.jface.text.source.AnnotationModel;
import org.simantics.Simantics;
import org.simantics.db.procedure.Listener;
import org.simantics.scl.compiler.commands.CommandSession;
import org.simantics.scl.compiler.errors.CompilationError;
import org.simantics.scl.compiler.errors.ErrorSeverity;
import org.simantics.scl.compiler.errors.Locations;
import org.simantics.scl.compiler.module.repository.ModuleRepository;
import org.simantics.scl.runtime.reporting.AbstractSCLReportingHandler;
import org.simantics.scl.runtime.reporting.SCLReportingHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Tuukka Lehtonen
 * @since 1.31.0
 */
public class SCLScriptAnnotationModel extends AnnotationModel {

    private static final Logger LOGGER = LoggerFactory.getLogger(SCLScriptAnnotationModel.class);

    private final SCLScriptEditorInput input;
    private final ModuleRepository repository;
    private volatile boolean connected = false;

    public SCLScriptAnnotationModel(SCLScriptEditorInput input, ModuleRepository repository) {
        this.input = input;
        this.repository = repository;
    }

    private Listener<String> sourceListener = new Listener<String>() {
        @Override
        public void execute(String result) {
            if (connected && result != null)
                scheduleUpdateAnnotations(result);
        }
        @Override
        public void exception(Throwable t) {
            LOGGER.error("Failed to read SCL script source from " + input.getScriptURI(), t);
        }
        @Override
        public boolean isDisposed() {
            return !connected;
        }
    };

    private void listenToSource() {
        Simantics.getSession().asyncRequest(new ReadSCLScriptDefinition(input.getScriptURI()), sourceListener);
    }

    private static final SCLReportingHandler NOP = new AbstractSCLReportingHandler() {
        @Override
        public void print(String text) {}
    };

    private void scheduleUpdateAnnotations(String sourceText) {
        //LOGGER.debug("scheduleUpdateAnnotations:\n" + sourceText);
        Job validateJob = new Job("Validate Script") {
            @Override
            protected IStatus run(IProgressMonitor monitor) {
                updateAnnotations(sourceText);
                return Status.OK_STATUS;
            }
        };
        validateJob.setPriority(Job.BUILD);
        validateJob.setUser(false);
        validateJob.setSystem(false);
        validateJob.schedule();
    }

    private void updateAnnotations(String sourceText) {
        //LOGGER.debug("updateAnnotations:\n" + sourceText);
        CompilationError[] errors = new CommandSession(repository, NOP).validate(sourceText);
        setAnnotations(Arrays.asList(errors));
    }

    protected void setAnnotations(List<CompilationError> errors) {
        synchronized (getLockObject()) {
            removeAllAnnotations();
            for (CompilationError error : errors) {
                Annotation annotation = new Annotation(
                        error.severity == ErrorSeverity.ERROR || error.severity == ErrorSeverity.IMPORT_ERROR ?
                                "org.eclipse.ui.workbench.texteditor.error" :
                                    "org.eclipse.ui.workbench.texteditor.warning",
                                    true, error.description);
                int begin = Locations.beginOf(error.location);
                int end = Locations.endOf(error.location);
                if (begin < 0 || end < begin) {
                    begin = 0;
                    end = 1;
                }
                addAnnotation(annotation, new Position(begin, end - begin));
            }
        }
    }

    @Override
    public void connect(IDocument document) {
        //LOGGER.debug("connect(" + document + ")");
        super.connect(document);
        connected = true;
        listenToSource();
    }

    @Override
    public void disconnect(IDocument document) {
        //LOGGER.debug("disconnect(" + document + ")");
        connected = false;
        super.disconnect(document);
    }

}