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#include "qv4compilationunit_moth_p.h"
#ifndef V4_BOOTSTRAP
#include <private/qv4function_p.h>
#include <private/qv4vme_moth_p.h>
#endif
#include <wtf/StdLibExtras.h>

using namespace QV4;
using namespace QV4::Moth;

CompilationUnit::~CompilationUnit()
{
}

#if !defined(V4_BOOTSTRAP)

void CompilationUnit::linkBackendToEngine(QV4::ExecutionEngine *engine)
{
    runtimeFunctions.resize(data->functionTableSize);
    runtimeFunctions.fill(0);
    for (int i = 0 ;i < runtimeFunctions.size(); ++i) {
        const QV4::CompiledData::Function *compiledFunction = data->functionAt(i);

        QV4::Function *runtimeFunction = new QV4::Function(engine, this, compiledFunction, &VME::exec);
        runtimeFunction->codeData = reinterpret_cast<const uchar *>(codeRefs.at(i).constData());
        runtimeFunctions[i] = runtimeFunction;
    }
}

bool CompilationUnit::memoryMapCode(QString *errorString)
{
    Q_UNUSED(errorString);
    codeRefs.resize(data->functionTableSize);

    const char *basePtr = reinterpret_cast<const char *>(data);

    for (uint i = 0; i < data->functionTableSize; ++i) {
        const CompiledData::Function *compiledFunction = data->functionAt(i);
        const char *codePtr = const_cast<const char *>(reinterpret_cast<const char *>(basePtr + compiledFunction->codeOffset));
#ifdef MOTH_THREADED_INTERPRETER
        // for the threaded interpreter we need to make a copy of the data because it needs to be
        // modified for the instruction handler addresses.
        QByteArray code(codePtr, compiledFunction->codeSize);
#else
        QByteArray code = QByteArray::fromRawData(codePtr, compiledFunction->codeSize);
#endif
        codeRefs[i] = code;
    }

    return true;
}

#endif // V4_BOOTSTRAP

void CompilationUnit::prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit)
{
    const int codeAlignment = 16;
    quint64 offset = WTF::roundUpToMultipleOf(codeAlignment, unit->unitSize);
    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());
    for (int i = 0; i < codeRefs.size(); ++i) {
        CompiledData::Function *compiledFunction = const_cast<CompiledData::Function *>(unit->functionAt(i));
        compiledFunction->codeOffset = offset;
        compiledFunction->codeSize = codeRefs.at(i).size();
        offset = WTF::roundUpToMultipleOf(codeAlignment, offset + compiledFunction->codeSize);
    }
}

bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString)
{
    Q_ASSERT(device->pos() == unit->unitSize);
    Q_ASSERT(device->atEnd());
    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());

    QByteArray padding;

    for (int i = 0; i < codeRefs.size(); ++i) {
        const CompiledData::Function *compiledFunction = unit->functionAt(i);

        if (device->pos() > qint64(compiledFunction->codeOffset)) {
            *errorString = QStringLiteral("Invalid state of cache file to write.");
            return false;
        }

        const quint64 paddingSize = compiledFunction->codeOffset - device->pos();
        padding.fill(0, paddingSize);
        qint64 written = device->write(padding);
        if (written != padding.size()) {
            *errorString = device->errorString();
            return false;
        }

        QByteArray code = codeRefs.at(i);

        written = device->write(code.constData(), compiledFunction->codeSize);
        if (written != qint64(compiledFunction->codeSize)) {
            *errorString = device->errorString();
            return false;
        }
    }
    return true;
}