/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.eclipse.datatools.connectivity.oda.openmrs.ui.impl;

import java.util.logging.Level;
import java.util.logging.Logger;

import org.eclipse.datatools.connectivity.oda.IConnection;
import org.eclipse.datatools.connectivity.oda.IParameterMetaData;
import org.eclipse.datatools.connectivity.oda.IQuery;
import org.eclipse.datatools.connectivity.oda.IResultSetMetaData;
import org.eclipse.datatools.connectivity.oda.OdaException;
import org.eclipse.datatools.connectivity.oda.design.DataSetDesign;
import org.eclipse.datatools.connectivity.oda.design.DesignFactory;
import org.eclipse.datatools.connectivity.oda.design.ResultSetColumns;
import org.eclipse.datatools.connectivity.oda.design.ResultSetDefinition;
import org.eclipse.datatools.connectivity.oda.design.ui.designsession.DesignSessionUtil;
import org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage;
import org.eclipse.datatools.connectivity.oda.design.util.DesignUtil;
import org.eclipse.datatools.connectivity.oda.openmrs.impl.QueryBuilder;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;

/**
 * This page shows the user the query that will actually be sent over the line
 * to the Logic Web Service. Right now, this is also the page where the user
 * chooses between the 3 available data styles.
 */
public class ViewQueryPage extends DataSetWizardPage {

    private static final String TOKENTAG = "TOKENTAG";

    private static final String FILTER = "FILTER";

    private static final String TOKENS = "TOKENS";

    private static final String DEFAULT_DATASTYLE = "Most Recent";

    private static final String FLAT = "flat";

    private static final String STACKED = "stacked";

    private static final String MOSTRECENT = "mostrecent";

    private static final String DATASTYLE = "DATASTYLE";

    private Logger log = Logger.getLogger(ViewQueryPage.class.getName());

    private static String QUERY_VIEW_MESSAGE = "OpenMRS Query to be Sent to Logic Service";

    private Label filterLabel;

    private Button[] radios;

    private transient Composite composite;

    /**
     * Constructor.
     * 
     * @param pageName the page name
     */
    public ViewQueryPage(String pageName) {
        super(pageName);
        setTitle(pageName);
        setMessage(QUERY_VIEW_MESSAGE);

        setPageComplete(true);
    }

    /**
     * Constructor.
     * 
     * @param pageName the page name
     * @param title the title
     * @param titleImage the title image
     */
    public ViewQueryPage(String pageName, String title,
            ImageDescriptor titleImage) {
        super(pageName, title, titleImage);
        setMessage(QUERY_VIEW_MESSAGE);
        setPageComplete(true);
    }

    /**
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#createPageCustomControl(org.eclipse.swt.widgets.Composite)
     */
    @Override
    public void createPageCustomControl(Composite parent) {
        log.setLevel(Level.INFO);

        setControl(createPageControl(parent));
        initializeControl();
    }

    /**
     * Creates custom control for user-defined query text.
     * 
     * @param parent the parent
     * 
     * @return the control
     */
    private Control createPageControl(Composite parent) {
        composite = new Composite(parent, SWT.NONE);
        composite.setSize(400, 400);
        composite.setLayout(new GridLayout(2, false));
        GridData gridData = new GridData(SWT.FILL, SWT.FILL, false, false);
        gridData.heightHint = 400;
        gridData.widthHint = 400;
        composite.setLayoutData(gridData);

        /*
         * parent.setSize(405, 405); GridData parentData = new
         * GridData(SWT.FILL, SWT.FILL, false, false); parentData.heightHint =
         * 405; parentData.widthHint = 405; parent.setLayoutData(parentData);
         */
        setupQueryViewGUI();

        setupDataStyleSelection();

        return composite;
    }

    /**
     * Sets up the Label that displays the Logic Web Service query.
     */
    private void setupQueryViewGUI() {
        filterLabel = new Label(composite, SWT.BORDER | SWT.WRAP);
        GridData gridData = new GridData(SWT.LEFT, 1, true, true);
        gridData.horizontalSpan = 2;
        gridData.heightHint = 200;
        filterLabel.setLayoutData(gridData);

        if (getQueryText() != null)
            filterLabel.setText(getQueryText());

    }

    /*
     * private String prettyPrint(String query) { String answer = ""; // extract
     * the SELECT field String select = query.substring(query.indexOf("SELECT") +
     * 7, query .indexOf("FROM") - 1); String[] toks = select.split("|"); for
     * (int i = 0; i < toks.length; i++) { answer += toks[i] + "|" + "\n"; }
     * 
     * String filter = "FROM " + QueryBuilder.getFilter(query) + "\n"; String
     * datastyle = "datastyle=" + QueryBuilder.getDataStyle(query) + "\n";
     * 
     * return "SELECT " + answer + filter + datastyle; }
     */

    /**
     * Sets up the three radio buttons for the user to choose between the three
     * different available data styles.
     */
    private void setupDataStyleSelection() {
        Composite dataStyleComposite = new Composite(composite, SWT.BORDER);
        dataStyleComposite.setLayout(new GridLayout(1, false));
        GridData styleData = new GridData(SWT.FILL, 1, true, true);
        dataStyleComposite.setLayoutData(styleData);

        Label dataStyleLabel = new Label(dataStyleComposite, SWT.NONE);
        dataStyleLabel.setText("Select the Style of Data to Generate:");

        radios = new Button[3];

        radios[0] = new Button(dataStyleComposite, SWT.RADIO | SWT.TOP);
        radios[0].setText(DEFAULT_DATASTYLE);
        radios[0].addSelectionListener(new SelectionListener() {
            public void widgetSelected(SelectionEvent e) {
                InformationHolder.setPropertyValue(DATASTYLE, MOSTRECENT);
                if (getQueryText() != null) {
                    filterLabel.setText(getQueryText());
                    composite.layout();
                }
            }

            public void widgetDefaultSelected(SelectionEvent e) {

            }
        });

        radios[1] = new Button(dataStyleComposite, SWT.RADIO | SWT.TOP);
        radios[1].setText("Stacked");
        radios[1].addSelectionListener(new SelectionListener() {
            public void widgetSelected(SelectionEvent e) {
                InformationHolder.setPropertyValue(DATASTYLE, STACKED);
                if (getQueryText() != null) {
                    filterLabel.setText(getQueryText());
                    composite.layout();
                }
            }

            public void widgetDefaultSelected(SelectionEvent e) {

            }
        });

        radios[2] = new Button(dataStyleComposite, SWT.RADIO | SWT.TOP);
        radios[2].setText("Flat");
        radios[2].addSelectionListener(new SelectionListener() {
            public void widgetSelected(SelectionEvent e) {
                InformationHolder.setPropertyValue(DATASTYLE, FLAT);
                if (getQueryText() != null) {
                    filterLabel.setText(getQueryText());
                    composite.layout();
                }
            }

            public void widgetDefaultSelected(SelectionEvent e) {

            }
        });

    }

    /**
     * Initializes the page control with the last edited data set design.
     */
    private void initializeControl() {
        /*
         * To optionally restore the designer state of the previous design
         * session, use getInitializationDesignerState();
         */

        log.info("Initializing filter page");

        // Restores the last saved data set design
        DataSetDesign dataSetDesign = getInitializationDesign();

        if (InformationHolder.hasDestroyed())
            InformationHolder.start(dataSetDesign);

        // setup the default data type if its not set
        if (InformationHolder.getPropertyValue(DATASTYLE) == null) {
            InformationHolder.setPropertyValue(DATASTYLE, MOSTRECENT);
        } else if (InformationHolder.getPropertyValue(DATASTYLE).equals(
                MOSTRECENT)) {
            radios[0].setSelection(true);
        } else if (InformationHolder.getPropertyValue(DATASTYLE)
                .equals(STACKED)) {
            radios[1].setSelection(true);
        } else if (InformationHolder.getPropertyValue(DATASTYLE).equals(FLAT)) {
            radios[2].setSelection(true);
        }

        if (dataSetDesign == null)
            return; // nothing to initialize

        composite.layout();
        // composite.getParent().layout();

    }

    /**
     * Obtains the user-defined query text of this data set from page control.
     * 
     * @return query text
     */
    private String getQueryText() {
        String queryText = QueryBuilder.getQuery(InformationHolder
                .getPropertyValue(TOKENS), InformationHolder
                .getPropertyValue(FILTER), InformationHolder
                .getPropertyValue(DATASTYLE));

        log.info(queryText);

        return queryText;
    }

    /**
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#collectDataSetDesign(org.eclipse.datatools.connectivity.oda.design.DataSetDesign)
     */
    @Override
    protected DataSetDesign collectDataSetDesign(DataSetDesign design) {
        savePage(design);
        return design;
    }

    /**
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#collectResponseState()
     */
    @Override
    protected void collectResponseState() {
        super.collectResponseState();
        /*
         * To optionally assign a custom response state, for inclusion in the
         * ODA design session response, use setResponseSessionStatus(
         * SessionStatus status ); setResponseDesignerState( DesignerState
         * customState );
         */
    }

    /**
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#canLeave()
     */
    @Override
    protected boolean canLeave() {
        return isPageComplete();
    }

    /**
     * Gets the blank page properties.
     * 
     * @return the blank page properties
     */
    private static java.util.Properties getBlankPageProperties() {
        java.util.Properties prop = new java.util.Properties();
        prop.setProperty(FILTER, "");
        prop.setProperty(TOKENTAG, "");
        prop.setProperty(TOKENS, "");
        prop.setProperty(DATASTYLE, "");

        return prop;
    }

    /**
     * Saves the user-defined value in this page, and updates the specified
     * dataSetDesign with the latest design definition.
     * 
     * @param dataSetDesign the data set design
     */
    private void savePage(DataSetDesign dataSetDesign) {
        // save user-defined query text

        if (InformationHolder.hasDestroyed())
            InformationHolder.start(dataSetDesign);

        String queryText = getQueryText();
        dataSetDesign.setQueryText(queryText);

        log.info(queryText);

        if (dataSetDesign.getPublicProperties() == null) {
            try {
                dataSetDesign.setPublicProperties(DesignSessionUtil
                        .createDataSetPublicProperties(dataSetDesign
                                .getOdaExtensionDataSourceId(), dataSetDesign
                                .getOdaExtensionDataSetId(),
                                getBlankPageProperties()));
            } catch (OdaException e) {
                // TODO need some logging here
                e.printStackTrace();
            }
        }

        if (dataSetDesign.getPublicProperties() != null) {
            if (dataSetDesign.getPublicProperties().findProperty(FILTER) != null)
                dataSetDesign.getPublicProperties().findProperty(FILTER)
                        .setNameValue(FILTER,
                                InformationHolder.getPropertyValue(FILTER));

            if (dataSetDesign.getPublicProperties().findProperty(TOKENTAG) != null)
                dataSetDesign.getPublicProperties().findProperty(TOKENTAG)
                        .setNameValue(TOKENTAG,
                                InformationHolder.getPropertyValue(TOKENTAG));

            if (dataSetDesign.getPublicProperties().findProperty(TOKENS) != null)
                dataSetDesign.getPublicProperties().findProperty(TOKENS)
                        .setNameValue(TOKENS,
                                InformationHolder.getPropertyValue(TOKENS));

            if (dataSetDesign.getPublicProperties().findProperty(DATASTYLE) != null)
                dataSetDesign.getPublicProperties().findProperty(DATASTYLE)
                        .setNameValue(DATASTYLE,
                                InformationHolder.getPropertyValue(DATASTYLE));

        }

        // obtain query's current runtime metadata, and maps it to the
        // dataSetDesign
        IConnection conn = null;
        try {
            // obtain and open a live connection
            conn = new org.eclipse.datatools.connectivity.oda.openmrs.impl.Driver()
                    .getConnection(null);
            java.util.Properties connProps = DesignUtil
                    .convertDataSourceProperties(getInitializationDesign()
                            .getDataSourceDesign());
            conn.open(connProps);

            // update the data set design with the query's current runtime
            // metadata
            updateDesign(dataSetDesign, conn, queryText);
        } catch (OdaException e) {
            // not able to get current metadata, reset previous derived metadata
            dataSetDesign.setResultSets(null);
            dataSetDesign.setParameters(null);

            e.printStackTrace();
        } finally {
            closeConnection(conn);
        }

        log.info("Done saving filter page");
    }

    /**
     * Updates the given dataSetDesign with the queryText and its derived
     * metadata obtained from the ODA runtime connection.
     * 
     * @param dataSetDesign the data set design
     * @param conn the conn
     * @param queryText the query text
     * 
     * @throws OdaException the oda exception
     */
    private void updateDesign(DataSetDesign dataSetDesign, IConnection conn,
            String queryText) throws OdaException {
        IQuery query = conn.newQuery(null);

        query.prepare(queryText);

        try {
            IResultSetMetaData md = query.getMetaData();
            updateResultSetDesign(md, dataSetDesign);
        } catch (OdaException e) {
            // no result set definition available, reset previous derived
            // metadata
            dataSetDesign.setResultSets(null);
            e.printStackTrace();
        }

        // proceed to get parameter design definition
        try {
            IParameterMetaData paramMd = query.getParameterMetaData();
            updateParameterDesign(paramMd, dataSetDesign);
        } catch (OdaException ex) {
            // no parameter definition available, reset previous derived
            // metadata
            dataSetDesign.setParameters(null);
            ex.printStackTrace();
        }

        /*
         * See DesignSessionUtil for more convenience methods to define a data
         * set design instance.
         */
    }

    /**
     * Updates the specified data set design's result set definition based on
     * the specified runtime metadata.
     * 
     * @param md runtime result set metadata instance
     * @param dataSetDesign data set design instance to update
     * 
     * @throws OdaException the oda exception
     */
    private void updateResultSetDesign(IResultSetMetaData md,
            DataSetDesign dataSetDesign) throws OdaException {

        ResultSetColumns columns = DesignSessionUtil
                .toResultSetColumnsDesign(md);

        ResultSetDefinition resultSetDefn = DesignFactory.eINSTANCE
                .createResultSetDefinition();

        // resultSetDefn.setName( value ); // result set name
        resultSetDefn.setResultSetColumns(columns);

        // no exception in conversion; go ahead and assign to specified
        // dataSetDesign
        dataSetDesign.setPrimaryResultSet(resultSetDefn);

        dataSetDesign.getResultSets().setDerivedMetaData(true);

    }

    /**
     * Updates the specified data set design's parameter definition based on the
     * specified runtime metadata. Unimplemented, as parameters are unsupported.
     * 
     * @param paramMd the param md
     * @param dataSetDesign the data set design
     * 
     * @throws OdaException the oda exception
     */
    private void updateParameterDesign(IParameterMetaData paramMd,
            DataSetDesign dataSetDesign) throws OdaException {
    }

    /**
     * Attempts to close given ODA connection.
     * 
     * @param conn the conn
     */
    private void closeConnection(IConnection conn) {
        try {
            if (conn != null && conn.isOpen())
                conn.close();
        } catch (OdaException e) {
            // TODO need some logging here
            e.printStackTrace();
        }
    }

    /**
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#refresh(org.eclipse.datatools.connectivity.oda.design.DataSetDesign)
     */
    @Override
    protected void refresh(DataSetDesign dataSetDesign) {
        if (InformationHolder.hasDestroyed())
            InformationHolder.start(dataSetDesign);

        refresh();
    }

    /**
     * Refreshes the screen so the latest Logic Web Service query is displayed
     * as the user makes changes using the other data set wizard pages.
     */
    protected void refresh() {
        // setup the default data type if its not set
        if (InformationHolder.getPropertyValue(DATASTYLE) == null) {
            InformationHolder.setPropertyValue(DATASTYLE, MOSTRECENT);
        } else if (InformationHolder.getPropertyValue(DATASTYLE).equals(
                MOSTRECENT)) {
            radios[0].setSelection(true);
        } else if (InformationHolder.getPropertyValue(DATASTYLE)
                .equals(STACKED)) {
            radios[1].setSelection(true);
        } else if (InformationHolder.getPropertyValue(DATASTYLE).equals(FLAT)) {
            radios[2].setSelection(true);
        }

        if (getQueryText() != null)
            filterLabel.setText(getQueryText());

        composite.layout();
        // composite.getParent().layout();

    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage#cleanup()
     */
    @Override
    protected void cleanup() {
        InformationHolder.destroy();
    }

}