/*

* Copyright (c) 2008 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:  Locator which maps standard store names and URIs

 *

*/

// PACKAGE

package com.nokia.mj.impl.location;

// CLASS DESCRIPTION

/**

 * Locator which maps standard store names and URIs

 *

 * It is possible to map standard strings to URIs and vice versa

 */

public class Locator

{

    // Landmark database file extension

    public static final String DB_FILE_EXTENSION = ".ldb";

    // Protocol separator

    public static final String PROTOCOL_SEPARATOR = "://";

    // Default landmark database protocol

    public static final String DB_DEFAULT_PROTOCOL = "file";

    // Locator string including protocol, drive letter and file extension

    private String iLocatorString;

    // Default drive to where databases are created and expected to be in

    private static final String DEFAULT_DRIVE = "c:";

    // Minimum size of specially formatted store names

    private static final int MIN_SPECIAL_NAME_LENGTH = 5;

    /**

     * Creates a store locator from a name. Note that location API

     * cannot open other than stores which are located in the file

     * system of the device

     *

     * The name can contain a special syntax which can be used to open

     * stores from non-default drives. The syntax is as follows:

     *

     *      - <storename> (<drive letter>:)

     *

     * @param aName The name of the store

     */

    public static Locator createLocator(String aName)

    {

        StringBuffer buffer = new StringBuffer(DB_DEFAULT_PROTOCOL);

        buffer.append(PROTOCOL_SEPARATOR);

        // Create URI from the name. Note that this expects that the name

        // is not in URI format and parses the string according to that

        int length = aName.length();

        int driveStart = aName.lastIndexOf('(');

        int driveEnd = aName.indexOf(":)");

        // Parse the drive letter from the URI

        if (length >= MIN_SPECIAL_NAME_LENGTH && aName.endsWith(":)")

                && driveEnd == driveStart + DEFAULT_DRIVE.length())

        {

            // Add the drive letter and colon to the uri

            buffer.append(aName.substring(driveStart + 1, driveEnd + 1));

            // Parse the name of the store and add the default file extension

            // Remove white space from the end of the name.

            buffer.append(aName.substring(0, driveStart - 1));

        }

        // No drive letter. Add just name to the string buffer

        else

        {

            buffer.append(DEFAULT_DRIVE);

            buffer.append(aName);

        }

        // Add the default file extensions to the buffer and convert it to a string

        buffer.append(DB_FILE_EXTENSION);

        return new Locator(buffer.toString());

    }

    /**

     * Package private constructor. Creates a new Locator directly from

     * the passed string. The string must be a valid locator. Otherwise

     * the creating of the object will throw IllegalArgumentException

     *

     * @param aLocatorString The locator. Must be a valid locator

     */

    Locator(String aLocatorString)

    {

        if (aLocatorString.indexOf(PROTOCOL_SEPARATOR) == -1)

        {

            throw new IllegalArgumentException();

        }

        // Remove white spaces from the end and from the start

        iLocatorString = aLocatorString;

    }

    /**

     * Returns the store URI. null indicates the default store

     */

    public String getStoreURI()

    {

        return iLocatorString;

    }

    /**

     * Returns the name of the store. If the store is located in a non-default

     * drive, the drive letter will be added to the end of the name as a

     * special syntax.

     *

     * The default store locator (null) returns a null name

     */

    public String getName()

    {

        // Create a string buffer from the URI without the protocl and extension

        int s = getProtocol().length() + PROTOCOL_SEPARATOR.length();

        int e = getExtension().length();

        String drive = getDrive().toLowerCase();

        StringBuffer buffer = new StringBuffer(iLocatorString.substring(s

                                               + drive.length(), iLocatorString.length() - e));

        // Add the drive letter to the end of the name if the URI has it

        // and it is a non default drive letter

        if (drive.length() > 0 && !drive.equals(DEFAULT_DRIVE))

        {

            // The syntax for other than default drives is "name (<drive>:)"

            buffer.append(" (");

            buffer.append(drive);

            buffer.append(")");

        }

        return buffer.toString();

    }

    /**

     * Returns the drive of this store locator. An empty string is returned

     * if there is no drive in the the locator

     */

    private String getDrive()

    {

        // Get the last index of the colon mark. This is because the procol

        // separator has also a colon mark

        int colon = iLocatorString.lastIndexOf(':');

        return colon != -1 ? iLocatorString.substring(colon - 1, colon + 1)

               : "";

    }

    /**

     * Returns the file extensions of this store locator. An empty string is

     * returned if the locator does not have a file extension

     */

    private String getExtension()

    {

        // Find the index of the file extension

        int sep = iLocatorString.indexOf(DB_FILE_EXTENSION);

        if (sep == -1)

        {

            // Find "." separator if the database extensions is not in the URI

            // (i.e this is an external landmark store)

            sep = iLocatorString.lastIndexOf('.');

        }

        // Return an empty string if the uri does not have a protocol

        return sep != -1 ? iLocatorString.substring(sep, iLocatorString

                .length()) : "";

    }

    /**

     * Returns the protocol of this locator. An emptry string is returned

     * if the locator does not have a protocol

     */

    private String getProtocol()

    {

        // Find the index of the protocol separator

        int sep = iLocatorString.indexOf(PROTOCOL_SEPARATOR);

        // Return an empty string if the uri does not have a protocol

        return sep != -1 ? iLocatorString.substring(0, sep) : "";

    }

}

// End of file