#include <qpdf/Pl_Buffer.hh>

#include <algorithm>
#include <stdexcept>
#include <stdlib.h>
#include <string.h>

Pl_Buffer::Members::Members() :
    ready(true),
    total_size(0)
{
}

Pl_Buffer::Pl_Buffer(char const* identifier, Pipeline* next) :
    Pipeline(identifier, next),
    m(new Members())
{
}

Pl_Buffer::~Pl_Buffer()
{
    // Must be explicit and not inline -- see QPDF_DLL_CLASS in
    // README-maintainer
}

void
Pl_Buffer::write(unsigned char* buf, size_t len)
{
    if (this->m->data.get() == 0) {
        this->m->data = std::make_shared<Buffer>(len);
    }
    size_t cur_size = this->m->data->getSize();
    size_t left = cur_size - this->m->total_size;
    if (left < len) {
        size_t new_size = std::max(this->m->total_size + len, 2 * cur_size);
        auto b = std::make_shared<Buffer>(new_size);
        memcpy(b->getBuffer(), this->m->data->getBuffer(), this->m->total_size);
        this->m->data = b;
    }
    if (len) {
        memcpy(this->m->data->getBuffer() + this->m->total_size, buf, len);
        this->m->total_size += len;
    }
    this->m->ready = false;

    if (getNext(true)) {
        getNext()->write(buf, len);
    }
}

void
Pl_Buffer::finish()
{
    this->m->ready = true;
    if (getNext(true)) {
        getNext()->finish();
    }
}

Buffer*
Pl_Buffer::getBuffer()
{
    if (!this->m->ready) {
        throw std::logic_error("Pl_Buffer::getBuffer() called when not ready");
    }

    Buffer* b = new Buffer(this->m->total_size);
    if (this->m->total_size > 0) {
        unsigned char* p = b->getBuffer();
        memcpy(p, this->m->data->getBuffer(), this->m->total_size);
    }
    this->m = std::shared_ptr<Members>(new Members());
    return b;
}

std::shared_ptr<Buffer>
Pl_Buffer::getBufferSharedPointer()
{
    return std::shared_ptr<Buffer>(getBuffer());
}

void
Pl_Buffer::getMallocBuffer(unsigned char** buf, size_t* len)
{
    if (!this->m->ready) {
        throw std::logic_error(
            "Pl_Buffer::getMallocBuffer() called when not ready");
    }

    *len = this->m->total_size;
    if (this->m->total_size > 0) {
        *buf = reinterpret_cast<unsigned char*>(malloc(this->m->total_size));
        memcpy(*buf, this->m->data->getBuffer(), this->m->total_size);
    } else {
        *buf = nullptr;
    }
    this->m = std::shared_ptr<Members>(new Members());
}