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#include "qstdweb_p.h"

#include <emscripten/bind.h>
#include <cstdint>
#include <iostream>

QT_BEGIN_NAMESPACE

namespace qstdweb {

typedef double uint53_t; // see Number.MAX_SAFE_INTEGER

ArrayBuffer::ArrayBuffer(const emscripten::val &arrayBuffer)
    :m_arrayBuffer(arrayBuffer)
{

}

uint32_t ArrayBuffer::byteLength() const
{
    if (m_arrayBuffer.isUndefined() || m_arrayBuffer.isNull())
        return 0;

    return m_arrayBuffer["byteLength"].as<uint32_t>();
}

Blob::Blob(const emscripten::val &blob)
    :m_blob(blob)
{

}

uint32_t Blob::size() const
{
    return m_blob["size"].as<uint32_t>();
}

File::File(const emscripten::val &file)
:m_file(file)
{

}

Blob File::slice(uint64_t begin, uint64_t end) const
{
    return Blob(m_file.call<emscripten::val>("slice", uint53_t(begin), uint53_t(end)));
}

std::string File::name() const
{
    return m_file["name"].as<std::string>();
}

uint64_t File::size() const
{
    return uint64_t(m_file["size"].as<uint53_t>());
}

FileList::FileList(const emscripten::val &fileList)
    :m_fileList(fileList)
{

}

int FileList::length() const
{
    return m_fileList["length"].as<int>();
}

File FileList::item(int index) const
{
    return File(m_fileList[index]);
}

File FileList::operator[](int index) const
{
    return item(index);
}

ArrayBuffer FileReader::result() const
{
    return ArrayBuffer(m_fileReader["result"]);
}

void FileReader::readAsArrayBuffer(const Blob &blob) const
{
    m_fileReader.call<void>("readAsArrayBuffer", blob.m_blob);
}

void FileReader::onLoad(const std::function<void ()> &onLoad)
{
    m_onLoad.reset(new EventCallback(m_fileReader, "load", onLoad));
}

void FileReader::onError(const std::function<void ()> &onError)
{
    m_onError.reset(new EventCallback(m_fileReader, "error", onError));
}

void FileReader::onAbort(const std::function<void ()> &onAbort)
{
    m_onAbort.reset(new EventCallback(m_fileReader, "abort", onAbort));
}

Uint8Array Uint8Array::heap()
{
    return Uint8Array(heap_());
}

Uint8Array::Uint8Array(const emscripten::val &uint8Array)
: m_uint8Array(uint8Array)
{

}

Uint8Array::Uint8Array(const ArrayBuffer &buffer)
: m_uint8Array(Uint8Array::constructor_().new_(buffer.m_arrayBuffer))
{

}

Uint8Array::Uint8Array(const ArrayBuffer &buffer, uint32_t offset, uint32_t length)
: m_uint8Array(Uint8Array::constructor_().new_(buffer.m_arrayBuffer, offset, length))
{

}

Uint8Array::Uint8Array(char *buffer, uint32_t size)
:m_uint8Array(Uint8Array::constructor_().new_(Uint8Array::heap().buffer().m_arrayBuffer, uint32_t(buffer), size))
{

}

ArrayBuffer Uint8Array::buffer() const
{
    return ArrayBuffer(m_uint8Array["buffer"]);
}

uint32_t Uint8Array::length() const
{
    return m_uint8Array["length"].as<uint32_t>();
}

void Uint8Array::set(const Uint8Array &source)
{
    m_uint8Array.call<void>("set", source.m_uint8Array); // copies source content
}

void Uint8Array::copyTo(char *destination) const
{
    Uint8Array(destination, length()).set(*this);
}

void Uint8Array::copy(char *destination, const Uint8Array &source)
{
    Uint8Array(destination, source.length()).set(source);
}

emscripten::val Uint8Array::heap_()
{
    return emscripten::val::module_property("HEAPU8");
}

emscripten::val Uint8Array::constructor_()
{
    return emscripten::val::global("Uint8Array");
}

// Registers a callback function for a named event on the given element. The event
// name must be the name as returned by the Event.type property: e.g. "load", "error".
EventCallback::EventCallback(emscripten::val element, const std::string &name, const std::function<void ()> &fn)
:m_fn(fn)
{
    element.set(contextPropertyName(name).c_str(), emscripten::val(intptr_t(this)));
    element.set((std::string("on") + name).c_str(), emscripten::val::module_property("qtStdWebEventCallbackActivate"));
}

void EventCallback::activate(emscripten::val event)
{
    emscripten::val target = event["target"];
    std::string eventName = event["type"].as<std::string>();
    EventCallback *that = reinterpret_cast<EventCallback *>(target[contextPropertyName(eventName).c_str()].as<intptr_t>());
    that->m_fn();
}

std::string EventCallback::contextPropertyName(const std::string &eventName)
{
    return std::string("data-qtEventCallbackContext") + eventName;
}

EMSCRIPTEN_BINDINGS(QtStdwebCalback) {
    emscripten::function("qtStdWebEventCallbackActivate", &EventCallback::activate);
}

} // namespace qstdweb

QT_END_NAMESPACE