#pragma once

#include <assert.h>
#include "platform.hpp"

template< class T, class I = int >
class CUtlMemory
{
public:
    // constructor, destructor
    CUtlMemory(int nGrowSize = 0, int nInitSize = 0);
    CUtlMemory(T* pMemory, int numElements);
    CUtlMemory(const T* pMemory, int numElements);
    ~CUtlMemory();

    // Set the size by which the memory grows
    void Init(int nGrowSize = 0, int nInitSize = 0);

    class Iterator_t
    {
    public:
        Iterator_t(I i) : index(i) {}
        I index;

        bool operator==(const Iterator_t& it) const { return index == it.index; }
        bool operator!=(const Iterator_t& it) const { return index != it.index; }
    };
    Iterator_t First() const { return Iterator_t(IsIdxValid(0) ? 0 : InvalidIndex()); }
    Iterator_t Next(const Iterator_t &it) const { return Iterator_t(IsIdxValid(it.index + 1) ? it.index + 1 : InvalidIndex()); }
    I GetIndex(const Iterator_t &it) const { return it.index; }
    bool IsIdxAfter(I i, const Iterator_t &it) const { return i > it.index; }
    bool IsValidIterator(const Iterator_t &it) const { return IsIdxValid(it.index); }
    Iterator_t InvalidIterator() const { return Iterator_t(InvalidIndex()); }

    // element access
    T& operator[](I i);
    const T& operator[](I i) const;
    T& Element(I i);
    const T& Element(I i) const;

    bool IsIdxValid(I i) const;

    static const I INVALID_INDEX = (I)-1; // For use with COMPILE_TIME_ASSERT
    static I InvalidIndex() { return INVALID_INDEX; }

    T* Base();
    const T* Base() const;

    void SetExternalBuffer(T* pMemory, int numElements);
    void SetExternalBuffer(const T* pMemory, int numElements);
    void AssumeMemory(T *pMemory, int nSize);
    T* Detach();
    void *DetachMemory();

    void Swap(CUtlMemory< T, I > &mem);
    void ConvertToGrowableMemory(int nGrowSize);
    int NumAllocated() const;
    int Count() const;
    void Grow(int num = 1);
    void EnsureCapacity(int num);
    void Purge();
    void Purge(int numElements);
    bool IsExternallyAllocated() const;
    bool IsReadOnly() const;
    void SetGrowSize(int size);

protected:
    void ValidateGrowSize()
    {

    }

    enum
    {
        EXTERNAL_BUFFER_MARKER = -1,
        EXTERNAL_CONST_BUFFER_MARKER = -2,
    };

    T* m_pMemory;
    int m_nAllocationCount;
    int m_nGrowSize;
};

//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------

template< class T, class I >
CUtlMemory<T, I>::CUtlMemory(int nGrowSize, int nInitAllocationCount) : m_pMemory(0),
m_nAllocationCount(nInitAllocationCount), m_nGrowSize(nGrowSize)
{
    ValidateGrowSize();
    assert(nGrowSize >= 0);
    if(m_nAllocationCount) {
        m_pMemory = (T*)new unsigned char[m_nAllocationCount * sizeof(T)];
        //m_pMemory = (T*)malloc(m_nAllocationCount * sizeof(T));
    }
}

template< class T, class I >
CUtlMemory<T, I>::CUtlMemory(T* pMemory, int numElements) : m_pMemory(pMemory),
m_nAllocationCount(numElements)
{
    // Special marker indicating externally supplied modifyable memory
    m_nGrowSize = EXTERNAL_BUFFER_MARKER;
}

template< class T, class I >
CUtlMemory<T, I>::CUtlMemory(const T* pMemory, int numElements) : m_pMemory((T*)pMemory),
m_nAllocationCount(numElements)
{
    // Special marker indicating externally supplied modifyable memory
    m_nGrowSize = EXTERNAL_CONST_BUFFER_MARKER;
}

template< class T, class I >
CUtlMemory<T, I>::~CUtlMemory()
{
    Purge();
}

template< class T, class I >
void CUtlMemory<T, I>::Init(int nGrowSize /*= 0*/, int nInitSize /*= 0*/)
{
    Purge();

    m_nGrowSize = nGrowSize;
    m_nAllocationCount = nInitSize;
    ValidateGrowSize();
    assert(nGrowSize >= 0);
    if(m_nAllocationCount) {
        UTLMEMORY_TRACK_ALLOC();
        MEM_ALLOC_CREDIT_CLASS();
        m_pMemory = (T*)malloc(m_nAllocationCount * sizeof(T));
    }
}

//-----------------------------------------------------------------------------
// Fast swap
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlMemory<T, I>::Swap(CUtlMemory<T, I> &mem)
{
    V_swap(m_nGrowSize, mem.m_nGrowSize);
    V_swap(m_pMemory, mem.m_pMemory);
    V_swap(m_nAllocationCount, mem.m_nAllocationCount);
}


//-----------------------------------------------------------------------------
// Switches the buffer from an external memory buffer to a reallocatable buffer
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlMemory<T, I>::ConvertToGrowableMemory(int nGrowSize)
{
    if(!IsExternallyAllocated())
        return;

    m_nGrowSize = nGrowSize;
    if(m_nAllocationCount) {
        int nNumBytes = m_nAllocationCount * sizeof(T);
        T *pMemory = (T*)malloc(nNumBytes);
        memcpy(pMemory, m_pMemory, nNumBytes); //-V575
        m_pMemory = pMemory;
    } else {
        m_pMemory = NULL;
    }
}


//-----------------------------------------------------------------------------
// Attaches the buffer to external memory....
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlMemory<T, I>::SetExternalBuffer(T* pMemory, int numElements)
{
    // Blow away any existing allocated memory
    Purge();

    m_pMemory = pMemory;
    m_nAllocationCount = numElements;

    // Indicate that we don't own the memory
    m_nGrowSize = EXTERNAL_BUFFER_MARKER;
}

template< class T, class I >
void CUtlMemory<T, I>::SetExternalBuffer(const T* pMemory, int numElements)
{
    // Blow away any existing allocated memory
    Purge();

    m_pMemory = const_cast<T*>(pMemory);
    m_nAllocationCount = numElements;

    // Indicate that we don't own the memory
    m_nGrowSize = EXTERNAL_CONST_BUFFER_MARKER;
}

template< class T, class I >
void CUtlMemory<T, I>::AssumeMemory(T* pMemory, int numElements)
{
    // Blow away any existing allocated memory
    Purge();

    // Simply take the pointer but don't mark us as external
    m_pMemory = pMemory;
    m_nAllocationCount = numElements;
}

template< class T, class I >
void *CUtlMemory<T, I>::DetachMemory()
{
    if(IsExternallyAllocated())
        return NULL;

    void *pMemory = m_pMemory;
    m_pMemory = 0;
    m_nAllocationCount = 0;
    return pMemory;
}

template< class T, class I >
inline T* CUtlMemory<T, I>::Detach()
{
    return (T*)DetachMemory();
}


//-----------------------------------------------------------------------------
// element access
//-----------------------------------------------------------------------------
template< class T, class I >
inline T& CUtlMemory<T, I>::operator[](I i)
{
    assert(!IsReadOnly());
    assert(IsIdxValid(i));
    return m_pMemory[i];
}

template< class T, class I >
inline const T& CUtlMemory<T, I>::operator[](I i) const
{
    assert(IsIdxValid(i));
    return m_pMemory[i];
}

template< class T, class I >
inline T& CUtlMemory<T, I>::Element(I i)
{
    assert(!IsReadOnly());
    assert(IsIdxValid(i));
    return m_pMemory[i];
}

template< class T, class I >
inline const T& CUtlMemory<T, I>::Element(I i) const
{
    assert(IsIdxValid(i));
    return m_pMemory[i];
}


//-----------------------------------------------------------------------------
// is the memory externally allocated?
//-----------------------------------------------------------------------------
template< class T, class I >
bool CUtlMemory<T, I>::IsExternallyAllocated() const
{
    return (m_nGrowSize < 0);
}


//-----------------------------------------------------------------------------
// is the memory read only?
//-----------------------------------------------------------------------------
template< class T, class I >
bool CUtlMemory<T, I>::IsReadOnly() const
{
    return (m_nGrowSize == EXTERNAL_CONST_BUFFER_MARKER);
}


template< class T, class I >
void CUtlMemory<T, I>::SetGrowSize(int nSize)
{
    assert(!IsExternallyAllocated());
    assert(nSize >= 0);
    m_nGrowSize = nSize;
    ValidateGrowSize();
}


//-----------------------------------------------------------------------------
// Gets the base address (can change when adding elements!)
//-----------------------------------------------------------------------------
template< class T, class I >
inline T* CUtlMemory<T, I>::Base()
{
    assert(!IsReadOnly());
    return m_pMemory;
}

template< class T, class I >
inline const T *CUtlMemory<T, I>::Base() const
{
    return m_pMemory;
}


//-----------------------------------------------------------------------------
// Size
//-----------------------------------------------------------------------------
template< class T, class I >
inline int CUtlMemory<T, I>::NumAllocated() const
{
    return m_nAllocationCount;
}

template< class T, class I >
inline int CUtlMemory<T, I>::Count() const
{
    return m_nAllocationCount;
}


//-----------------------------------------------------------------------------
// Is element index valid?
//-----------------------------------------------------------------------------
template< class T, class I >
inline bool CUtlMemory<T, I>::IsIdxValid(I i) const
{
    // GCC warns if I is an unsigned type and we do a ">= 0" against it (since the comparison is always 0).
    // We Get the warning even if we cast inside the expression. It only goes away if we assign to another variable.
    long x = i;
    return (x >= 0) && (x < m_nAllocationCount);
}

//-----------------------------------------------------------------------------
// Grows the memory
//-----------------------------------------------------------------------------
inline int UtlMemory_CalcNewAllocationCount(int nAllocationCount, int nGrowSize, int nNewSize, int nBytesItem)
{
    if(nGrowSize) {
        nAllocationCount = ((1 + ((nNewSize - 1) / nGrowSize)) * nGrowSize);
    } else {
        if(!nAllocationCount) {
            // Compute an allocation which is at least as big as a cache line...
            nAllocationCount = (31 + nBytesItem) / nBytesItem;
        }

        while(nAllocationCount < nNewSize) {
#ifndef _X360
            nAllocationCount *= 2;
#else
            int nNewAllocationCount = (nAllocationCount * 9) / 8; // 12.5 %
            if(nNewAllocationCount > nAllocationCount)
                nAllocationCount = nNewAllocationCount;
            else
                nAllocationCount *= 2;
#endif
        }
    }

    return nAllocationCount;
}

template< class T, class I >
void CUtlMemory<T, I>::Grow(int num)
{
    assert(num > 0);

    if(IsExternallyAllocated()) {
        // Can't grow a buffer whose memory was externally allocated 
        assert(0);
        return;
    }


    auto oldAllocationCount = m_nAllocationCount;
    // Make sure we have at least numallocated + num allocations.
    // Use the grow rules specified for this memory (in m_nGrowSize)
    int nAllocationRequested = m_nAllocationCount + num;

    int nNewAllocationCount = UtlMemory_CalcNewAllocationCount(m_nAllocationCount, m_nGrowSize, nAllocationRequested, sizeof(T));

    // if m_nAllocationRequested wraps index type I, recalculate
    if((int)(I)nNewAllocationCount < nAllocationRequested) {
        if((int)(I)nNewAllocationCount == 0 && (int)(I)(nNewAllocationCount - 1) >= nAllocationRequested) {
            --nNewAllocationCount; // deal w/ the common case of m_nAllocationCount == MAX_USHORT + 1
        } else {
            if((int)(I)nAllocationRequested != nAllocationRequested) {
                // we've been asked to grow memory to a size s.t. the index type can't address the requested amount of memory
                assert(0);
                return;
            }
            while((int)(I)nNewAllocationCount < nAllocationRequested) {
                nNewAllocationCount = (nNewAllocationCount + nAllocationRequested) / 2;
            }
        }
    }

    m_nAllocationCount = nNewAllocationCount;

    if(m_pMemory) {
        auto ptr = new unsigned char[m_nAllocationCount * sizeof(T)];

        memcpy(ptr, m_pMemory, oldAllocationCount * sizeof(T));
        m_pMemory = (T*)ptr;
    } else {
        m_pMemory = (T*)new unsigned char[m_nAllocationCount * sizeof(T)];
    }
}


//-----------------------------------------------------------------------------
// Makes sure we've got at least this much memory
//-----------------------------------------------------------------------------
template< class T, class I >
inline void CUtlMemory<T, I>::EnsureCapacity(int num)
{
    if(m_nAllocationCount >= num)
        return;

    if(IsExternallyAllocated()) {
        // Can't grow a buffer whose memory was externally allocated 
        assert(0);
        return;
    }
    m_nAllocationCount = num;

    if(m_pMemory) {
        m_pMemory = (T*)realloc(m_pMemory, m_nAllocationCount * sizeof(T)); //-V701
    } else {
        m_pMemory = (T*)malloc(m_nAllocationCount * sizeof(T));
    }
}


//-----------------------------------------------------------------------------
// Memory deallocation
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlMemory<T, I>::Purge()
{
    if(!IsExternallyAllocated()) {
        if(m_pMemory) {
            free((void*)m_pMemory);
            m_pMemory = 0;
        }
        m_nAllocationCount = 0;
    }
}

template< class T, class I >
void CUtlMemory<T, I>::Purge(int numElements)
{
    assert(numElements >= 0);

    if(numElements > m_nAllocationCount) {
        // Ensure this isn't a grow request in disguise.
        assert(numElements <= m_nAllocationCount); //-V547
        return;
    }

    // If we have zero elements, simply do a purge:
    if(numElements == 0) {
        Purge();
        return;
    }

    if(IsExternallyAllocated()) {
        // Can't shrink a buffer whose memory was externally allocated, fail silently like purge 
        return;
    }

    // If the number of elements is the same as the allocation count, we are done.
    if(numElements == m_nAllocationCount) {
        return;
    }


    if(!m_pMemory) {
        // Allocation count is non zero, but memory is null.
        assert(m_pMemory);
        return;
    }
    m_nAllocationCount = numElements;
    m_pMemory = (T*)realloc(m_pMemory, m_nAllocationCount * sizeof(T)); //-V701
}

//-----------------------------------------------------------------------------
// The CUtlMemory class:
// A growable memory class which doubles in size by default.
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
class CUtlMemoryAligned : public CUtlMemory<T>
{
public:
    // constructor, destructor
    CUtlMemoryAligned(int nGrowSize = 0, int nInitSize = 0);
    CUtlMemoryAligned(T* pMemory, int numElements);
    CUtlMemoryAligned(const T* pMemory, int numElements);
    ~CUtlMemoryAligned();

    // Attaches the buffer to external memory....
    void SetExternalBuffer(T* pMemory, int numElements);
    void SetExternalBuffer(const T* pMemory, int numElements);

    // Grows the memory, so that at least allocated + num elements are allocated
    void Grow(int num = 1);

    // Makes sure we've got at least this much memory
    void EnsureCapacity(int num);

    // Memory deallocation
    void Purge();

    // Purge all but the given number of elements (NOT IMPLEMENTED IN CUtlMemoryAligned)
    void Purge(int numElements) { assert(0); }

private:
    void *Align(const void *pAddr);
};


//-----------------------------------------------------------------------------
// Aligns a pointer
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
void *CUtlMemoryAligned<T, nAlignment>::Align(const void *pAddr)
{
    size_t nAlignmentMask = nAlignment - 1;
    return (void*)(((size_t)pAddr + nAlignmentMask) & (~nAlignmentMask));
}


//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
CUtlMemoryAligned<T, nAlignment>::CUtlMemoryAligned(int nGrowSize, int nInitAllocationCount)
{
    CUtlMemory<T>::m_pMemory = 0;
    CUtlMemory<T>::m_nAllocationCount = nInitAllocationCount;
    CUtlMemory<T>::m_nGrowSize = nGrowSize;
    this->ValidateGrowSize();

    // Alignment must be a power of two
    COMPILE_TIME_ASSERT((nAlignment & (nAlignment - 1)) == 0);
    assert((nGrowSize >= 0) && (nGrowSize != CUtlMemory<T>::EXTERNAL_BUFFER_MARKER));
    if(CUtlMemory<T>::m_nAllocationCount) {
        UTLMEMORY_TRACK_ALLOC();
        MEM_ALLOC_CREDIT_CLASS();
        CUtlMemory<T>::m_pMemory = (T*)_aligned_malloc(nInitAllocationCount * sizeof(T), nAlignment);
    }
}

template< class T, int nAlignment >
CUtlMemoryAligned<T, nAlignment>::CUtlMemoryAligned(T* pMemory, int numElements)
{
    // Special marker indicating externally supplied memory
    CUtlMemory<T>::m_nGrowSize = CUtlMemory<T>::EXTERNAL_BUFFER_MARKER;

    CUtlMemory<T>::m_pMemory = (T*)Align(pMemory);
    CUtlMemory<T>::m_nAllocationCount = ((int)(pMemory + numElements) - (int)CUtlMemory<T>::m_pMemory) / sizeof(T);
}

template< class T, int nAlignment >
CUtlMemoryAligned<T, nAlignment>::CUtlMemoryAligned(const T* pMemory, int numElements)
{
    // Special marker indicating externally supplied memory
    CUtlMemory<T>::m_nGrowSize = CUtlMemory<T>::EXTERNAL_CONST_BUFFER_MARKER;

    CUtlMemory<T>::m_pMemory = (T*)Align(pMemory);
    CUtlMemory<T>::m_nAllocationCount = ((int)(pMemory + numElements) - (int)CUtlMemory<T>::m_pMemory) / sizeof(T);
}

template< class T, int nAlignment >
CUtlMemoryAligned<T, nAlignment>::~CUtlMemoryAligned()
{
    Purge();
}


//-----------------------------------------------------------------------------
// Attaches the buffer to external memory....
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
void CUtlMemoryAligned<T, nAlignment>::SetExternalBuffer(T* pMemory, int numElements)
{
    // Blow away any existing allocated memory
    Purge();

    CUtlMemory<T>::m_pMemory = (T*)Align(pMemory);
    CUtlMemory<T>::m_nAllocationCount = ((int)(pMemory + numElements) - (int)CUtlMemory<T>::m_pMemory) / sizeof(T);

    // Indicate that we don't own the memory
    CUtlMemory<T>::m_nGrowSize = CUtlMemory<T>::EXTERNAL_BUFFER_MARKER;
}

template< class T, int nAlignment >
void CUtlMemoryAligned<T, nAlignment>::SetExternalBuffer(const T* pMemory, int numElements)
{
    // Blow away any existing allocated memory
    Purge();

    CUtlMemory<T>::m_pMemory = (T*)Align(pMemory);
    CUtlMemory<T>::m_nAllocationCount = ((int)(pMemory + numElements) - (int)CUtlMemory<T>::m_pMemory) / sizeof(T);

    // Indicate that we don't own the memory
    CUtlMemory<T>::m_nGrowSize = CUtlMemory<T>::EXTERNAL_CONST_BUFFER_MARKER;
}


//-----------------------------------------------------------------------------
// Grows the memory
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
void CUtlMemoryAligned<T, nAlignment>::Grow(int num)
{
    assert(num > 0);

    if(this->IsExternallyAllocated()) {
        // Can't grow a buffer whose memory was externally allocated 
        assert(0);
        return;
    }

    UTLMEMORY_TRACK_FREE();

    // Make sure we have at least numallocated + num allocations.
    // Use the grow rules specified for this memory (in m_nGrowSize)
    int nAllocationRequested = CUtlMemory<T>::m_nAllocationCount + num;

    CUtlMemory<T>::m_nAllocationCount = UtlMemory_CalcNewAllocationCount(CUtlMemory<T>::m_nAllocationCount, CUtlMemory<T>::m_nGrowSize, nAllocationRequested, sizeof(T));

    UTLMEMORY_TRACK_ALLOC();

    if(CUtlMemory<T>::m_pMemory) {
        MEM_ALLOC_CREDIT_CLASS();
        CUtlMemory<T>::m_pMemory = (T*)MemAlloc_ReallocAligned(CUtlMemory<T>::m_pMemory, CUtlMemory<T>::m_nAllocationCount * sizeof(T), nAlignment);
        assert(CUtlMemory<T>::m_pMemory);
    } else {
        MEM_ALLOC_CREDIT_CLASS();
        CUtlMemory<T>::m_pMemory = (T*)MemAlloc_AllocAligned(CUtlMemory<T>::m_nAllocationCount * sizeof(T), nAlignment);
        assert(CUtlMemory<T>::m_pMemory);
    }
}


//-----------------------------------------------------------------------------
// Makes sure we've got at least this much memory
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
inline void CUtlMemoryAligned<T, nAlignment>::EnsureCapacity(int num)
{
    if(CUtlMemory<T>::m_nAllocationCount >= num)
        return;

    if(this->IsExternallyAllocated()) {
        // Can't grow a buffer whose memory was externally allocated 
        assert(0);
        return;
    }

    UTLMEMORY_TRACK_FREE();

    CUtlMemory<T>::m_nAllocationCount = num;

    UTLMEMORY_TRACK_ALLOC();

    if(CUtlMemory<T>::m_pMemory) {
        MEM_ALLOC_CREDIT_CLASS();
        CUtlMemory<T>::m_pMemory = (T*)MemAlloc_ReallocAligned(CUtlMemory<T>::m_pMemory, CUtlMemory<T>::m_nAllocationCount * sizeof(T), nAlignment);
    } else {
        MEM_ALLOC_CREDIT_CLASS();
        CUtlMemory<T>::m_pMemory = (T*)MemAlloc_AllocAligned(CUtlMemory<T>::m_nAllocationCount * sizeof(T), nAlignment);
    }
}


//-----------------------------------------------------------------------------
// Memory deallocation
//-----------------------------------------------------------------------------
template< class T, int nAlignment >
void CUtlMemoryAligned<T, nAlignment>::Purge()
{
    if(!this->IsExternallyAllocated()) {
        if(CUtlMemory<T>::m_pMemory) {
            UTLMEMORY_TRACK_FREE();
            MemAlloc_FreeAligned(CUtlMemory<T>::m_pMemory);
            CUtlMemory<T>::m_pMemory = 0;
        }
        CUtlMemory<T>::m_nAllocationCount = 0;
    }
}