/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

  ==============================================================================
*/

MemoryBlock::MemoryBlock() noexcept
    : size (0)
{
}

MemoryBlock::MemoryBlock (const size_t initialSize, const bool initialiseToZero)
{
    if (initialSize > 0)
    {
        size = initialSize;
        data.allocate (initialSize, initialiseToZero);
    }
    else
    {
        size = 0;
    }
}

MemoryBlock::MemoryBlock (const MemoryBlock& other)
    : size (other.size)
{
    if (size > 0)
    {
        jassert (other.data != nullptr);
        data.malloc (size);
        memcpy (data, other.data, size);
    }
}

MemoryBlock::MemoryBlock (const void* const dataToInitialiseFrom, const size_t sizeInBytes)
    : size (sizeInBytes)
{
    jassert (((ssize_t) sizeInBytes) >= 0);

    if (size > 0)
    {
        jassert (dataToInitialiseFrom != nullptr); // non-zero size, but a zero pointer passed-in?

        data.malloc (size);

        if (dataToInitialiseFrom != nullptr)
            memcpy (data, dataToInitialiseFrom, size);
    }
}

MemoryBlock::~MemoryBlock() noexcept
{
}

MemoryBlock& MemoryBlock::operator= (const MemoryBlock& other)
{
    if (this != &other)
    {
        setSize (other.size, false);
        memcpy (data, other.data, size);
    }

    return *this;
}

#if JUCE_COMPILER_SUPPORTS_MOVE_SEMANTICS
MemoryBlock::MemoryBlock (MemoryBlock&& other) noexcept
    : data (static_cast<HeapBlock<char>&&> (other.data)),
      size (other.size)
{
}

MemoryBlock& MemoryBlock::operator= (MemoryBlock&& other) noexcept
{
    data = static_cast<HeapBlock<char>&&> (other.data);
    size = other.size;
    return *this;
}
#endif


//==============================================================================
bool MemoryBlock::operator== (const MemoryBlock& other) const noexcept
{
    return matches (other.data, other.size);
}

bool MemoryBlock::operator!= (const MemoryBlock& other) const noexcept
{
    return ! operator== (other);
}

bool MemoryBlock::matches (const void* dataToCompare, size_t dataSize) const noexcept
{
    return size == dataSize
            && memcmp (data, dataToCompare, size) == 0;
}

//==============================================================================
// this will resize the block to this size
void MemoryBlock::setSize (const size_t newSize, const bool initialiseToZero)
{
    if (size != newSize)
    {
        if (newSize <= 0)
        {
            reset();
        }
        else
        {
            if (data != nullptr)
            {
                data.realloc (newSize);

                if (initialiseToZero && (newSize > size))
                    zeromem (data + size, newSize - size);
            }
            else
            {
                data.allocate (newSize, initialiseToZero);
            }

            size = newSize;
        }
    }
}

void MemoryBlock::reset()
{
    data.free();
    size = 0;
}

void MemoryBlock::ensureSize (const size_t minimumSize, const bool initialiseToZero)
{
    if (size < minimumSize)
        setSize (minimumSize, initialiseToZero);
}

void MemoryBlock::swapWith (MemoryBlock& other) noexcept
{
    std::swap (size, other.size);
    data.swapWith (other.data);
}

//==============================================================================
void MemoryBlock::fillWith (const uint8 value) noexcept
{
    memset (data, (int) value, size);
}

void MemoryBlock::append (const void* const srcData, const size_t numBytes)
{
    if (numBytes > 0)
    {
        jassert (srcData != nullptr); // this must not be null!
        const size_t oldSize = size;
        setSize (size + numBytes);
        memcpy (data + oldSize, srcData, numBytes);
    }
}

void MemoryBlock::replaceWith (const void* const srcData, const size_t numBytes)
{
    if (numBytes > 0)
    {
        jassert (srcData != nullptr); // this must not be null!
        setSize (numBytes);
        memcpy (data, srcData, numBytes);
    }
}

void MemoryBlock::insert (const void* const srcData, const size_t numBytes, size_t insertPosition)
{
    if (numBytes > 0)
    {
        jassert (srcData != nullptr); // this must not be null!
        insertPosition = jmin (size, insertPosition);
        const size_t trailingDataSize = size - insertPosition;
        setSize (size + numBytes, false);

        if (trailingDataSize > 0)
            memmove (data + insertPosition + numBytes,
                     data + insertPosition,
                     trailingDataSize);

        memcpy (data + insertPosition, srcData, numBytes);
    }
}

void MemoryBlock::removeSection (const size_t startByte, const size_t numBytesToRemove)
{
    if (startByte + numBytesToRemove >= size)
    {
        setSize (startByte);
    }
    else if (numBytesToRemove > 0)
    {
        memmove (data + startByte,
                 data + startByte + numBytesToRemove,
                 size - (startByte + numBytesToRemove));

        setSize (size - numBytesToRemove);
    }
}

void MemoryBlock::copyFrom (const void* const src, int offset, size_t num) noexcept
{
    const char* d = static_cast<const char*> (src);

    if (offset < 0)
    {
        d -= offset;
        num += (size_t) -offset;
        offset = 0;
    }

    if ((size_t) offset + num > size)
        num = size - (size_t) offset;

    if (num > 0)
        memcpy (data + offset, d, num);
}

void MemoryBlock::copyTo (void* const dst, int offset, size_t num) const noexcept
{
    char* d = static_cast<char*> (dst);

    if (offset < 0)
    {
        zeromem (d, (size_t) -offset);
        d -= offset;
        num -= (size_t) -offset;
        offset = 0;
    }

    if ((size_t) offset + num > size)
    {
        const size_t newNum = (size_t) size - (size_t) offset;
        zeromem (d + newNum, num - newNum);
        num = newNum;
    }

    if (num > 0)
        memcpy (d, data + offset, num);
}

String MemoryBlock::toString() const
{
    return String::fromUTF8 (data, (int) size);
}

//==============================================================================
int MemoryBlock::getBitRange (const size_t bitRangeStart, size_t numBits) const noexcept
{
    int res = 0;

    size_t byte = bitRangeStart >> 3;
    size_t offsetInByte = bitRangeStart & 7;
    size_t bitsSoFar = 0;

    while (numBits > 0 && (size_t) byte < size)
    {
        const size_t bitsThisTime = jmin (numBits, 8 - offsetInByte);
        const int mask = (0xff >> (8 - bitsThisTime)) << offsetInByte;

        res |= (((data[byte] & mask) >> offsetInByte) << bitsSoFar);

        bitsSoFar += bitsThisTime;
        numBits -= bitsThisTime;
        ++byte;
        offsetInByte = 0;
    }

    return res;
}

void MemoryBlock::setBitRange (const size_t bitRangeStart, size_t numBits, int bitsToSet) noexcept
{
    size_t byte = bitRangeStart >> 3;
    size_t offsetInByte = bitRangeStart & 7;
    uint32 mask = ~((((uint32) 0xffffffff) << (32 - numBits)) >> (32 - numBits));

    while (numBits > 0 && (size_t) byte < size)
    {
        const size_t bitsThisTime = jmin (numBits, 8 - offsetInByte);

        const uint32 tempMask = (mask << offsetInByte) | ~((((uint32) 0xffffffff) >> offsetInByte) << offsetInByte);
        const uint32 tempBits = (uint32) bitsToSet << offsetInByte;

        data[byte] = (char) (((uint32) data[byte] & tempMask) | tempBits);

        ++byte;
        numBits -= bitsThisTime;
        bitsToSet >>= bitsThisTime;
        mask >>= bitsThisTime;
        offsetInByte = 0;
    }
}

//==============================================================================
void MemoryBlock::loadFromHexString (StringRef hex)
{
    ensureSize ((size_t) hex.length() >> 1);
    char* dest = data;
    String::CharPointerType t (hex.text);

    for (;;)
    {
        int byte = 0;

        for (int loop = 2; --loop >= 0;)
        {
            byte <<= 4;

            for (;;)
            {
                const juce_wchar c = t.getAndAdvance();

                if (c >= '0' && c <= '9')    { byte |= c - '0';        break; }
                if (c >= 'a' && c <= 'z')    { byte |= c - ('a' - 10); break; }
                if (c >= 'A' && c <= 'Z')    { byte |= c - ('A' - 10); break; }

                if (c == 0)
                {
                    setSize (static_cast<size_t> (dest - data));
                    return;
                }
            }
        }

        *dest++ = (char) byte;
    }
}

//==============================================================================
static const char base64EncodingTable[] = ".ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+";

String MemoryBlock::toBase64Encoding() const
{
    const size_t numChars = ((size << 3) + 5) / 6;

    String destString ((unsigned int) size); // store the length, followed by a '.', and then the data.
    const int initialLen = destString.length();
    destString.preallocateBytes (sizeof (String::CharPointerType::CharType) * (size_t) initialLen + 2 + numChars);

    String::CharPointerType d (destString.getCharPointer());
    d += initialLen;
    d.write ('.');

    for (size_t i = 0; i < numChars; ++i)
        d.write ((juce_wchar) (uint8) base64EncodingTable [getBitRange (i * 6, 6)]);

    d.writeNull();
    return destString;
}

static const char base64DecodingTable[] =
{
    63, 0, 0, 0, 0, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 0, 0, 0, 0, 0, 0, 0,
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
    0, 0, 0, 0, 0, 0, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52
};

bool MemoryBlock::fromBase64Encoding (StringRef s)
{
    String::CharPointerType dot (CharacterFunctions::find (s.text, (juce_wchar) '.'));

    if (dot.isEmpty())
        return false;

    const int numBytesNeeded = String (s.text, dot).getIntValue();

    setSize ((size_t) numBytesNeeded, true);

    String::CharPointerType srcChars (dot + 1);
    int pos = 0;

    for (;;)
    {
        int c = (int) srcChars.getAndAdvance();

        if (c == 0)
            return true;

        c -= 43;
        if (isPositiveAndBelow (c, numElementsInArray (base64DecodingTable)))
        {
            setBitRange ((size_t) pos, 6, base64DecodingTable [c]);
            pos += 6;
        }
    }
}
