/*

* Copyright (c) 2007 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:  String class implementation

*

*/

#ifndef USTRING_IMPL_H

#define USTRING_IMPL_H

#include <gstring.h>

#include <osn/ustring.h>

#define MAX_STR_LEN 24

namespace osncore

{

class SString;

/**

 *  Glib string wrapper.

 *  @see ustring.h for description of ustring

 *  @lib osncore.lib

 *  @since S60 5.0

 */

class UStringImpl

	{

public:

    /**

     * Default constructor.

     */

    UStringImpl();

    /**

      * Construct a string as a copy of given null terminated string.

      *

      * @since S60 5.0

      * @exception std:bad_alloc is thrown if string cannot be allocated from heap

      * @param aStr Utf-8 encoded string

      */

    explicit UStringImpl(const Utf8* aStr);

    /**

     * Construct a string as a copy of given string

     * with byte length of the source buffer.

     * Because a length is provided, source doesn't need to be null terminated.

     *

     * @since S60 5.0

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aStr Utf-8 encoded string

     * @param aByteCount Byte count of Utf-8 encoded string

     */

    explicit UStringImpl(const Utf8* aStr, int aLen);

    /**

      * Construct a string from unicode code point. If Unicode is invalid,

      * @exception std:bad_alloc is thrown if string cannot be allocated from heap

      * @since S60 5.0

      * @param aCodePoint Unicode code point

      */

    explicit UStringImpl(Unicode aCodePoint);

    /**

     * UStringImpl copy constructor

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @since S60 5.0

     * @param aUString Copy source

     */

    UStringImpl(const UStringImpl& aUStringImpl);

    // Destructor

   ~UStringImpl();

    // Utilities

   /**

    * Checks whether string is empty.

    *

    * @since S60 5.0

    * @return True if string doesn't have content.

    */

   	bool empty()const;

    /**

     * Checks whether string is null.

     *

     * @since S60 5.0

     * @return True if string is null.

     */

   	bool null()const;

    /**

     * Returns the length of the string in characters.

     *

     * @since S60 5.0

     * @return Length

     */

   	long length()const;

    /**

     * Returns the length of the string in bytes

     *

     * @since S60 5.0

     * @return Bytes

     */

   	long bytes()const;

    /**

     * Returns utf8 type string

     *

     * @since S60 5.0

     * @return utf8 type string

     */

   	const Utf8* utf8()const;

    /**

     * Compares two strings using strcmp(). Note that this is not linguistic comparison nor case insensitive.

     *

     * @since S60 5.0

     * @param aUStringImpl UStringImpl object to compare

     * @return < 0 if this compares before aRhs, 0 if they compare equal, > 0 if this compares after aRhs.

     */

    int compare(const UStringImpl& aUStringImpl)const;

    /**

     * Compares two strings using strcmp(). Note that this is not linguistic comparison nor case insensitive.

     *

     * @since S60 5.0

     * @param aStr String to compare

     * @return < 0 if this compares before aRhs, 0 if they compare equal, > 0 if this compares after aRhs.

     */

    int compare(const Utf8* aStr)const;

    /**

     * Compares two strings for ordering using the linguistically correct rules for the current locale.

     * When sorting a large number of strings, it will be significantly faster

     * to obtain collation keys with g_utf8_collate_key()from libglib and compare the keys

     * with strcmp() when sorting instead of sorting the original strings.

     *

     * @since S60 5.0

     * @param aUStringImpl UStringImpl object to compare

     * @return < 0 if this compares before aRhs, 0 if they compare equal, > 0 if this compares after aRhs.

     */

    int compareC(const UStringImpl& aUStringImpl)const;

    /**

     * Compares two strings for ordering using the linguistically correct rules for the current locale.

     * When sorting a large number of strings, it will be significantly faster

     * to obtain collation keys with g_utf8_collate_key() from libglib and compare the keys

     * with strcmp() when sorting instead of sorting the original strings.

     * If aStr is invalid utf8, UString::InvalidUtf8 exception is thrown.

     *

     *

     * @since S60 5.0

     * @param aStr String to compare

     * @return < 0 if this compares before aRhs, 0 if they compare equal, > 0 if this compares after aRhs.

     */

    int compareC(const Utf8* aStr)const;

    /**

     * Adds a string onto the end of string, expanding it if necessary.

     *

     * @since S60 5.0

     * @param aUStringImpl String object to append

     */

    void append(const UStringImpl& aUStringImpl);

    /**

     * Adds a string onto the end of string, expanding it if necessary.

     *

     * @since S60 5.0

     * @param aStr String to append

     */

    void append(const Utf8* aStr);

    /**

     * Inserts aStr into string, expanding it if necessary.

     * If aPos is -1, bytes are inserted at the end of the string.

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given position is invalid

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aPos The character position to insert the copy of the string

     * @param aStr The string to insert

     */

    void insert(long aPos, const Utf8* aStr);

    /**

     * Inserts aStr into string, expanding it if necessary. Because length is

     * provided, aStr may contain embedded nulls and need not be null terminated.

     * If aPos is -1, bytes are inserted at the end of the string.

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given position is invalid

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aPos The character position to insert the copy of the string

     * @param aStr The string to insert

     * @param aCharCount Character count.

     */

    void insert(long aPos, const Utf8* aStr, long aLength);

    /**

     * Replace a substring with a given string, expanding it if necessary

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given position is invalid

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aPos The charater position to replace the string

     * @param aStr The string to insert

     */

    void replace(long aPos, const Utf8* aStr);

    /**

     * Replace a substring with a given string, expanding it if necessary. Because length is

     * provided, aStr may contain embedded nulls and need not be null terminated.

     * If aLength is < 0, length is assumed to be aStr's length.

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given position is invalid

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aPos The character position to replace the string

     * @param aStr The string to insert

     * @param aCharCount Character count.

     */

    void replace(long aPos, const Utf8* aStr, long aLength);

    /**

     * Erase a substring

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given position is invalid

     * @param aPos The character position to start erasing from

     * @param aCharCount number of characters to erase.

     */

    void erase(long aPosOffset, long aLength);

    /**

     * Returns unicode at given position in string

     *

     * @since S60 5.0

     * @exception std:out_of_range is thrown if requested index is invalid

     * @param aPos The requested position

     */

    Unicode operator[](long aIndex);

private:

    /**

     * Initialises internal string

     * @since S60 5.0

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aStr The string used for initialising

     */

    void initialize(const Utf8* aStr);

    /**

     * Allocates memory from heap if needed for internal string, throws if allocation fail

     * @since S60 5.0

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aLength length of bytes to allocate

     */

    void checkBuffer(unsigned int aLength);

    /**

     * Implements the insertion functionality

     * @since S60 5.0

     * @exception std:bad_alloc is thrown if string cannot be allocated from heap

     * @param aIndex The character position to insert the copy of the string

     * @param aInsertChars The string to insert

     * @param aInsertLength The amount of characters to insert

     */

    void insertImpl(unsigned int aIndex, const char* aInsertChars, unsigned int aInsertLength);

    /**

     * Implements the append functionality

     * @since S60 5.0

     * @param aStr The string to append

     * @param aLength The amount of characters to append

     */

    void appendImpl(const char* aStr, unsigned int aLength);

    /**

     * Implements the erase functionality

     * @since S60 5.0

     * @exception std:out_of_range is thrown if given index is invalid

     * @param aIndex The character position to start erasing from

     * @param aLength The amount of characters to erase

     */

    void eraseImpl(unsigned int aIndex, unsigned int aLength);

private:

    /**

     * Internal buffer, allocated from heap.

     * Long strings are allocated from heap 

     */

	gchar* 	str;

    /**

     * Internal buffer, allocated from stack.

     * Short strings are allocated from stack for performance reason, 

     */

	gchar 	internalStr[MAX_STR_LEN];

    /**

     * length of string

     */

	gsize   len;    

    /**

     * length of allocated bytes

     */

	gsize   allocated_len;

    /**

     * Identifies if string is allocated from heap or not

     */

	bool    isInHeap;

	};

}	

#endif