/***************************************************************************
 *   crengine-ng                                                           *
 *   Copyright (C) 2007-2012 Vadim Lopatin <coolreader.org@gmail.com>      *
 *   Copyright (C) 2021 Aleksey Chernov <valexlin@gmail.com>               *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU General Public License           *
 *   as published by the Free Software Foundation; either version 2        *
 *   of the License, or (at your option) any later version.                *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the Free Software           *
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,            *
 *   MA 02110-1301, USA.                                                   *
 ***************************************************************************/

/**
 * \file lvarray.h
 * \brief value array template
 *
 * Implements array of values
 */

#ifndef __LVARRAY_H_INCLUDED__
#define __LVARRAY_H_INCLUDED__

#include <lvref.h>

/** \brief template which implements vector of pointer

    Automatically deletes objects when vector items are destroyed.
*/
template <typename T>
class LVArray
{
    T* _array;
    int _size;
    int _count;
public:
    /// default constructor
    LVArray()
            : _array(NULL)
            , _size(0)
            , _count(0) { }
    /// creates array of given size
    LVArray(int len, T value) {
        _size = _count = len;
        _array = new T[_size];
        for (int i = 0; i < _count; i++)
            _array[i] = value;
    }
    LVArray(const LVArray& v) {
        _size = _count = v._count;
        if (_size) {
            _array = new T[_size];
            for (int i = 0; i < _count; i++)
                _array[i] = v._array[i];
        } else {
            _array = NULL;
        }
    }
    LVArray(const T* ptr, int len) {
        _size = _count = len;
        if (_size) {
            _array = new T[_size];
            for (int i = 0; i < _count; i++)
                _array[i] = ptr[i];
        } else {
            _array = NULL;
        }
    }
    LVArray& operator=(const LVArray& v) {
        clear();
        _size = _count = v._count;
        if (_size) {
            _array = new T[_size];
            for (int i = 0; i < _count; i++)
                _array[i] = v._array[i];
        } else {
            _array = NULL;
        }
        return *this;
    }
    /// retrieves pointer to C array
    T* get() {
        return _array;
    }
    /// retrieves item from specified position
    T operator[](int pos) const {
        return _array[pos];
    }
    /// retrieves item from specified position
    T get(int pos) const {
        return _array[pos];
    }
    /// retrieves item reference from specified position
    T& operator[](int pos) {
        return _array[pos];
    }
    /// ensures that size of vector is not less than specified value
    void reserve(int size) {
        if (size > _size) {
            T* new_array = new T[size];
            if (_array) {
                for (int i = 0; i < _count; i++)
                    new_array[i] = _array[i];
                delete[] _array;
            }
            _array = new_array;
            _size = size;
        }
    }
    /// sets item by index (extends vector if necessary)
    void set(int index, T item) {
        reserve(index);
        _array[index] = item;
    }
    /// returns size of buffer
    int size() const {
        return _size;
    }
    /// returns number of items in vector
    int length() const {
        return _count;
    }
    /// returns true if there are no items in vector
    bool empty() const {
        return _count == 0;
    }
    /// clears all items, deallocates storage
    void clear() {
        if (_array) {
            delete[] _array;
            _array = NULL;
        }
        _size = 0;
        _count = 0;
    }
    /// clears all items, but unlike clear() does not deallocate storage
    void reset() {
        _count = 0;
    }
    /// copies range to beginning of array
    void trim(int pos, int count, int reserved) {
#if defined(_DEBUG) && !defined(ANDROID)
        if (pos < 0 || count <= 0 || pos + count > _count)
            throw;
#endif
        int i;
        int new_sz = count;
        if (new_sz < reserved)
            new_sz = reserved;
        T* new_array = new T[new_sz];
        if (_array) {
            for (i = 0; i < count; i++) {
                new_array[i] = _array[pos + i];
            }
            delete[] _array;
        }
        _array = new_array;
        _count = count;
        _size = new_sz;
    }
    /// removes several items from vector
    void erase(int pos, int count) {
#if defined(_DEBUG) && !defined(ANDROID)
        if (pos < 0 || count <= 0 || pos + count > _count)
            throw;
#endif
        int i;
        for (i = pos + count; i < _count; i++) {
            _array[i - count] = _array[i];
        }
        _count -= count;
    }
    T remove(int pos) {
        T item = _array[pos];
        erase(pos, 1);
        return item;
    }

    /// adds new item to end of vector
    void add(T item) {
        insert(-1, item);
    }

    /// adds new item to end of vector
    void append(const T* items, int count) {
        reserve(_count + count);
        for (int i = 0; i < count; i++)
            _array[_count + i] = items[i];
        _count += count;
    }

    /// adds new items to end of vector
    void add(const LVArray& list) {
        reserve(_count + list._count);
        for (int i = 0; i < list._count; i++)
            _array[_count + i] = list._array[i];
        _count += list._count;
    }

    /// adds new items to end of vector
    void add(const T* list, int count) {
        reserve(_count + count);
        for (int i = 0; i < count; i++)
            _array[_count + i] = list[i];
        _count += count;
    }

    T* addSpace(int count) {
        reserve(_count + count);
        T* ptr = _array + _count;
        _count += count;
        return ptr;
    }

    /// inserts new item to specified position
    void insert(int pos, T item) {
        if (pos < 0 || pos > _count)
            pos = _count;
        if (_count >= _size)
            reserve(_count * 3 / 2 + 8);
        for (int i = _count; i > pos; --i)
            _array[i] = _array[i - 1];
        _array[pos] = item;
        _count++;
    }

    /// returns index of specified value, -1 if not found
    int indexOf(int value) const {
        for (int i = 0; i < _count; i++) {
            if (_array[i] == value)
                return i;
        }
        return -1;
    }

    /// returns array pointer
    T* ptr() const {
        return _array;
    }
    /// destructor
    ~LVArray() {
        clear();
    }
};

template <typename T>
class LVArrayQueue
{
private:
    LVArray<T> m_buf;
    int inpos;
public:
    LVArrayQueue()
            : inpos(0) {
    }

    /// returns pointer to reserved space of specified size
    T* prepareWrite(int size) {
        if (m_buf.length() + size > m_buf.size()) {
            if (inpos > (m_buf.length() + size) / 2) {
                // trim
                m_buf.erase(0, inpos);
                inpos = 0;
            }
        }
        return m_buf.addSpace(size);
    }

    /// writes data to end of queue
    void write(const T* data, int size) {
        T* buf = prepareWrite(size);
        for (int i = 0; i < size; i++)
            buf[i] = data[i];
    }

    int length() {
        return m_buf.length() - inpos;
    }

    /// returns pointer to data to be read
    T* peek() {
        return m_buf.ptr() + inpos;
    }

    /// reads data from start of queue
    void read(T* data, int size) {
        if (size > length())
            size = length();
        for (int i = 0; i < size; i++)
            data[i] = m_buf[inpos + i];
        inpos += size;
    }

    /// skips data from start of queue
    void skip(int size) {
        if (size > length())
            size = length();
        inpos += size;
    }
};

typedef LVArray<lUInt8> LVByteArray;
typedef LVRef<LVByteArray> LVByteArrayRef;

#endif
