/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package com.nokia.mj.impl.utils;

import com.nokia.mj.impl.coreui.CoreUi;

import java.util.Hashtable;

/**

 * Resource loader to get localised strings and Formatter patterns.

 * <br>

 * Usage:

 * <pre>

 *   ResourceLoader res = ResourceLoader.getInstance("javaapplicationinstaller", "txt_java_inst_");

 *   Label subjectLabel = createLabel(

 *       res.format("subject").arg(certificate.getSubject()).toString(),

 *       horizontalSpan, labelStyle);

 * </pre>

 * @see ResourceLoader

 */

class ResourceLoaderQt extends ResourceLoader

{

    /**

     * Resource string map for the resources that have been fetched

     * at least once.

     */

    private Hashtable iResourceMap = new Hashtable();

    /** Resource name passed when ResourceLoader is constructed. */

    private String iResourceName = null;

    /** Array of resource names. */

    private String[] iResourceNames = null;

    /** Resource name prefix passed when ResourceLoader is constructed. */

    private String iPrefix = null;

    /** Array of resource name prefixes. */

    private String[] iPrefixes = null;

    /** Array of handles to native translator objects. */

    private int[] iTranslators = null;

    /*** ----------------------------- PUBLIC ------------------------------ */

    /**

     * Returns a resource loader instance.

     *

     * @param avkonFileName this parameter is ignored

     * @param avkonPrefix this parameter is ignored

     * @param qtFileName name of the Qt resource file

     * @param qtPrefix prefix added before each id when retrieving

     * @return resource loader instance

     */

    public static ResourceLoader getInstance(String avkonFileName,

                                             String avkonPrefix,

                                             String qtFileName,

                                             String qtPrefix)

    {

        return getInstance(qtFileName, qtPrefix);

    }

    /**

     * Returns a resource loader instance.

     *

     * @param resourceName comma separated list of resource file names

     * @param prefix comma separated list of prefixes added before each

     * id when retrieving

     * @return resource loader instance

     */

    public static ResourceLoader getInstance(String resourceName, String prefix)

    {

        String key = resourceName + ":" + prefix;

        ResourceLoader result = (ResourceLoader)iResourceLoaders.get(key);

        if (result == null)

        {

            result = new ResourceLoaderQt(resourceName, prefix);

            iResourceLoaders.put(key, result);

        }

        return result;

    }

    /**

     * Get a string formatter of a given resource id.

     *

     * @param id comma separated list of resource ids

     * @return formatter instance

     * @see Formatter

     */

    public Formatter format(String id)

    {

        return new FormatterQt(this, id);

    }

    /**

     * Get a string formatter of a given resource id.

     *

     * @param id resource id

     * @return formatter instance

     * @see Formatter

     */

    public Formatter format(Id id)

    {

        return new FormatterQt(this, id.getString(QT));

    }

    /**

     * Formats localised text with specified parameters from an array.

     *

     * @param id comma separated list of resource ids

     * @param textParameters parameters to be filled into the text

     * @return localised text formatted with the provided parameters

     * @see Formatter

     */

    public String format(String id, Object[] textParameters)

    {

        return new FormatterQt(this, id).format(textParameters);

    }

    /**

     * Formats localised text with specified parameters from an array.

     *

     * @param id resource id

     * @param textParameters parameters to be filled into the text

     * @return localised text formatted with the provided parameters

     * @see Formatter

     */

    public String format(Id id, Object[] textParameters)

    {

        return new FormatterQt(this, id.getString(QT)).format(textParameters);

    }

    /*** ----------------------------- PACKAGE ---------------------------- */

    /**

     * Releases resources and destroys this ResourceLoader instance.

     */

    void destroy()

    {

        deleteTranslators();

    }

    /**

     * Get a plain string resource with a given resource id.

     *

     * @param id resource id, either with prefix or without

     * @param n used to identify plural forms

     * @return resource string, or the id if does not exist

     */

    synchronized String string(final String id, final int n)

    {

        String str = (String)iResourceMap.get(id+n);

        if (str == null)

        {

            str = getResourceStringByList(id, n);

            // Put to resource map with original key for quick retrieval.

            iResourceMap.put(id, str+n);

        }

        return str;

    }

    /*** ----------------------------- PRIVATE ---------------------------- */

    /**

     * Creates resource loader, using the current locale of the environment.

     *

     * @param resourceName name of the resource

     * @param aPrefix prefix added before each id when retrieving

     */

    private ResourceLoaderQt(String aResourceName, String aPrefix)

    {

        setResourceName(aResourceName);

        setPrefix(aPrefix);

        if (!loadTranslators())

        {

            throw new IllegalArgumentException(

                "Translations not found for " + aResourceName);

        }

    }

    /**

     * Initializes member variables according to given resource name.

     *

     * @param aResourceName comma separated list of resource names

     */

    private void setResourceName(String aResourceName)

    {

        iResourceName = aResourceName;

        iResourceNames = Tokenizer.split(iResourceName, SEPARATOR);

        if (iResourceNames == null)

        {

            iResourceNames = new String[0];

        }

        for (int i = 0; i < iResourceNames.length; i++)

        {

            iResourceNames[i] = iResourceNames[i].trim();

        }

    }

    /**

     * Initializes member variables according to given prefix.

     *

     * @param aPrefix comma separated list of text id prefixes

     */

    private void setPrefix(String aPrefix)

    {

        iPrefix = aPrefix;

        iPrefixes = Tokenizer.split(iPrefix, SEPARATOR);

        if (iPrefixes == null)

        {

            iPrefixes = new String[0];

        }

        for (int i = 0; i < iPrefixes.length; i++)

        {

            iPrefixes[i] = iPrefixes[i].trim();

        }

    }

    /**

     * Initializes iTranslators array from given resource files.

     *

     * @param true if operation succeeds.

     */

    private boolean loadTranslators()

    {

        if (iResourceName == null)

        {

            return false;

        }

        iTranslators = new int[iResourceNames.length];

        CoreUi.runInSyncUiThread(new Runnable() {

            public void run()

            {

                for (int i = 0; i < iResourceNames.length; i++)

                {

                    iTranslators[i] = _createTranslator(iResourceNames[i]);

                    if (iTranslators[i] < 0)

                    {

                        Logger.ILOG(Logger.EUtils,

                                    "ResourceLoaderQt: Cannot load resource file " +

                                    iResourceNames[i] + ", error: " +

                                    iTranslators[i]);

                    }

                }

            }

        });

        boolean result = false;

        for (int i = 0; i < iTranslators.length; i++)

        {

            if (iTranslators[i] > 0)

            {

                // Return true if loading succeeds for at least one translator.

                result = true;

                break;

            }

        }

        return result;

    }

    /**

     * Deletes translator from iTranslators array.

     */

    private void deleteTranslators()

    {

        CoreUi.runInSyncUiThread(new Runnable() {

            public void run()

            {

                for (int i = 0; i < iTranslators.length; i++)

                {

                    if (iTranslators[i] <= 0)

                    {

                        continue;

                    }

                    int result = _deleteTranslator(iTranslators[i]);

                    if (result < 0)

                    {

                        Logger.WLOG(Logger.EUtils,

                                    "ResourceLoaderQt: Deleting translator for resource " +

                                    iResourceNames[i] + " failed, error: " +

                                    result);

                    }

                }

            }

        });

    }

    /**

     * Get a string with a given comma separated resource id list.

     *

     * @param id comma separated resource id list, either with prefix or without

     * @param n used to identify plural forms

     * @return resource string, or the id if does not exist

     */

    private String getResourceStringByList(String id, int n)

    {

        String str = null;

        String[] ids = Tokenizer.split(id, SEPARATOR);

        String strIn = null;

        String strOut = null;

        for (int i = 0; i < ids.length && str == null; i++)

        {

            for (int j = 0; j < iTranslators.length && str == null; j++)

            {

                if (iTranslators[j] <= 0)

                {

                    // Skip invalid translator handles.

                    continue;

                }

                // Check if id already has prefix.

                if (iPrefixes != null && iPrefixes.length > j &&

                    !ids[i].startsWith(iPrefixes[j]))

                {

                    // Try with prefix and id.

                    strIn = iPrefixes[j] + ids[i];

                }

                else

                {

                    // Try with id.

                    strIn = ids[i];

                }

                strOut = _translate(iTranslators[j], strIn, n);

                if (!strIn.equals(strOut))

                {

                    // Translation was found.

                    str = strOut;

                }

            }

        }

        if (str == null)

        {

            // Not found. Use the id itself.

            str = id;

            Logger.WLOG(Logger.EUtils,

                        "ResourceLoaderQt: Cannot find resource: " + id +

                        ", prefix: " + iPrefix);

        }

        return str;

    }

    /*** ----------------------------- NATIVE ----------------------------- */

    /**

     * Creates native translator object.

     *

     * @param aResourceFilename resource filename

     * @return handle to native side translator object, or negative

     * error code

     */

    private static native int _createTranslator(String aResourceFilename);

    /**

     * Deletes native translator object.

     *

     * @param handle to native side translator object

     * @return 0 if deletion was successful, or negative error code

     */

    private static native int _deleteTranslator(int aHandle);

    /**

     * Fetches localized text for given text id.

     *

     * @param aHandle translator to be used

     * @param aId text id

     * @param aN used to identify plural forms

     * @return localized text, or aId if text is not found

     */

    private static native String _translate(int aHandle, String aId, int aN);

}