//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: A class to wrap data for transport over a boundary like a thread
//			or window.
//
//=============================================================================

#include "tier0/basetypes.h"
#include "tier1/utlstring.h"

#ifndef UTLENVELOPE_H
#define UTLENVELOPE_H

#if defined(_WIN32)
#pragma once
#endif

//-----------------------------------------------------------------------------

class CUtlDataEnvelope {
   public:
    CUtlDataEnvelope(const void *pData, int nBytes);
    CUtlDataEnvelope(const CUtlDataEnvelope &from);
    ~CUtlDataEnvelope();

    CUtlDataEnvelope &operator=(const CUtlDataEnvelope &from);

    operator void *();
    operator void *() const;

   private:
    void Assign(const void *pData, int nBytes);
    void Assign(const CUtlDataEnvelope &from);
    void Purge();

    // TODO: switch to a reference counted array?
    union {
        byte *m_pData;
        byte m_data[4];
    };
    int m_nBytes;
};

//-----------------------------------------------------------------------------

template <typename T>
class CUtlEnvelope : protected CUtlDataEnvelope {
   public:
    CUtlEnvelope(const T *pData, int nElems = 1);
    CUtlEnvelope(const CUtlEnvelope<T> &from);

    CUtlEnvelope<T> &operator=(const CUtlEnvelope<T> &from);

    operator T *();
    operator T *() const;

    operator void *();
    operator void *() const;
};

//-----------------------------------------------------------------------------

template <>
class CUtlEnvelope<const char *> {
   public:
    CUtlEnvelope(const char *pData) { m_string = pData; }

    CUtlEnvelope(const CUtlEnvelope<const char *> &from) {
        m_string = from.m_string;
    }

    CUtlEnvelope<const char *> &operator=(
        const CUtlEnvelope<const char *> &from) {
        m_string = from.m_string;
        return *this;
    }

    operator char *() { return (char *)m_string.Get(); }

    operator char *() const { return (char *)m_string.Get(); }

    operator void *() { return (void *)m_string.Get(); }

    operator void *() const { return (void *)m_string.Get(); }

   private:
    CUtlString m_string;
};

//-----------------------------------------------------------------------------

#include "tier0/memdbgon.h"

inline void CUtlDataEnvelope::Assign(const void *pData, int nBytes) {
    if (pData) {
        m_nBytes = nBytes;
        if (m_nBytes > 4) {
            m_pData = new byte[nBytes];
            memcpy(m_pData, pData, nBytes);
        } else {
            memcpy(m_data, pData, nBytes);
        }
    } else {
        m_pData = NULL;
        m_nBytes = 0;
    }
}

inline void CUtlDataEnvelope::Assign(const CUtlDataEnvelope &from) {
    Assign(from.operator void *(), from.m_nBytes);
}

inline void CUtlDataEnvelope::Purge() {
    if (m_nBytes > 4) delete[] m_pData;
    m_nBytes = 0;
}

inline CUtlDataEnvelope::CUtlDataEnvelope(const void *pData, int nBytes) {
    Assign(pData, nBytes);
}

inline CUtlDataEnvelope::CUtlDataEnvelope(const CUtlDataEnvelope &from) {
    Assign(from);
}

inline CUtlDataEnvelope::~CUtlDataEnvelope() { Purge(); }

inline CUtlDataEnvelope &CUtlDataEnvelope::operator=(
    const CUtlDataEnvelope &from) {
    Purge();
    Assign(from);
    return *this;
}

inline CUtlDataEnvelope::operator void *() {
    if (!m_nBytes) {
        return NULL;
    }

    return (m_nBytes > 4) ? m_pData : m_data;
}

inline CUtlDataEnvelope::operator void *() const {
    if (!m_nBytes) {
        return NULL;
    }

    return (m_nBytes > 4) ? (void *)m_pData : (void *)m_data;
}

//-----------------------------------------------------------------------------

template <typename T>
inline CUtlEnvelope<T>::CUtlEnvelope(const T *pData, int nElems)
    : CUtlDataEnvelope(pData, sizeof(T) * nElems) {}

template <typename T>
inline CUtlEnvelope<T>::CUtlEnvelope(const CUtlEnvelope<T> &from)
    : CUtlDataEnvelope(from) {}

template <typename T>
inline CUtlEnvelope<T> &CUtlEnvelope<T>::operator=(
    const CUtlEnvelope<T> &from) {
    CUtlDataEnvelope::operator=(from);
    return *this;
}

template <typename T>
inline CUtlEnvelope<T>::operator T *() {
    return (T *)CUtlDataEnvelope::operator void *();
}

template <typename T>
inline CUtlEnvelope<T>::operator T *() const {
    return (T *)((const_cast<CUtlEnvelope<T> *>(this))->operator T *());
}

template <typename T>
inline CUtlEnvelope<T>::operator void *() {
    return CUtlDataEnvelope::operator void *();
}

template <typename T>
inline CUtlEnvelope<T>::operator void *() const {
    return ((const_cast<CUtlEnvelope<T> *>(this))->operator void *());
}

//-----------------------------------------------------------------------------

#include "tier0/memdbgoff.h"

#endif  // UTLENVELOPE_H