//------------------------------------------------------------------------------
/*
    This file is part of Beast: https://github.com/vinniefalco/Beast
    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>

    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 THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
//==============================================================================

#ifndef BEAST_HTTP_STREAM_IPP_INCLUDED
#define BEAST_HTTP_STREAM_IPP_INCLUDED

#include <beast/bind_handler.hpp>
#include <beast/handler_alloc.hpp>
#include <beast/http/read.hpp>
#include <beast/http/write.hpp>
#include <cassert>

namespace beast {
namespace http {

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers,
    class Handler>
class stream<NextLayer, Allocator>::read_op
{
    using alloc_type =
        handler_alloc<char, Handler>;

    struct data
    {
        stream<NextLayer>& s;
        message<isRequest, Body, Headers>& m;
        Handler h;
        bool cont;
        int state = 0;

        template<class DeducedHandler>
        data(DeducedHandler&& h_, stream<NextLayer>& s_,
                message<isRequest, Body, Headers>& m_)
            : s(s_)
            , m(m_)
            , h(std::forward<DeducedHandler>(h_))
            , cont(boost_asio_handler_cont_helpers::
                is_continuation(h))
        {
        }
    };

    std::shared_ptr<data> d_;

public:
    read_op(read_op&&) = default;
    read_op(read_op const&) = default;

    template<class DeducedHandler, class... Args>
    read_op(DeducedHandler&& h,
            stream<NextLayer>& s, Args&&... args)
        : d_(std::allocate_shared<data>(alloc_type{h},
            std::forward<DeducedHandler>(h), s,
                std::forward<Args>(args)...))
    {
        (*this)(error_code{}, false);
    }

    void operator()(error_code const& ec, bool again = true);

    friend
    void* asio_handler_allocate(
        std::size_t size, read_op* op)
    {
        return boost_asio_handler_alloc_helpers::
            allocate(size, op->d_->h);
    }

    friend
    void asio_handler_deallocate(
        void* p, std::size_t size, read_op* op)
    {
        return boost_asio_handler_alloc_helpers::
            deallocate(p, size, op->d_->h);
    }

    friend
    bool asio_handler_is_continuation(read_op* op)
    {
        return op->d_->cont;
    }

    template <class Function>
    friend
    void asio_handler_invoke(Function&& f, read_op* op)
    {
        return boost_asio_handler_invoke_helpers::
            invoke(f, op->d_->h);
    }
};

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers, class Handler>
void
stream<NextLayer, Allocator>::
read_op<isRequest, Body, Headers, Handler>::
operator()(error_code const& ec, bool again)
{
    auto& d = *d_;
    d.cont = d.cont || again;
    while(! ec && d.state != 99)
    {
        switch(d.state)
        {
        case 0:
            d.state = 99;
            beast::http::async_read(d.s.next_layer_,
                d.s.rd_buf_, d.m, std::move(*this));
            return;
        }
    }
    d.h(ec);
}

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

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers,
    class Handler>
class stream<NextLayer, Allocator>::write_op : public op
{
    using alloc_type =
        handler_alloc<char, Handler>;

    struct data
    {
        stream<NextLayer>& s;
        message<isRequest, Body, Headers> m;
        Handler h;
        bool cont;
        int state = 0;

        template<class DeducedHandler>
        data(DeducedHandler&& h_, stream<NextLayer>& s_,
            message<isRequest, Body, Headers> const& m_,
                bool cont_)
            : s(s_)
            , m(m_)
            , h(std::forward<DeducedHandler>(h_))
            , cont(cont_)
        {
        }

        template<class DeducedHandler>
        data(DeducedHandler&& h_, stream<NextLayer>& s_,
            message<isRequest, Body, Headers>&& m_,
                bool cont_)
            : s(s_)
            , m(std::move(m_))
            , h(std::forward<DeducedHandler>(h_))
            , cont(cont_)
        {
        }
    };

    std::shared_ptr<data> d_;

public:
    write_op(write_op&&) = default;
    write_op(write_op const&) = default;

    template<class DeducedHandler, class... Args>
    write_op(DeducedHandler&& h,
        stream<NextLayer>& s, Args&&... args)
        : d_(std::allocate_shared<data>(alloc_type{h},
            std::forward<DeducedHandler>(h), s,
                std::forward<Args>(args)...))
    {
    }

    void
    operator()() override
    {
        (*this)(error_code{}, false);
    }

    void cancel() override;

    void operator()(error_code const& ec, bool again = true);

    friend
    void* asio_handler_allocate(
        std::size_t size, write_op* op)
    {
        return boost_asio_handler_alloc_helpers::
            allocate(size, op->d_->h);
    }

    friend
    void asio_handler_deallocate(
        void* p, std::size_t size, write_op* op)
    {
        return boost_asio_handler_alloc_helpers::
            deallocate(p, size, op->d_->h);
    }

    friend
    bool asio_handler_is_continuation(write_op* op)
    {
        return op->d_->cont;
    }

    template <class Function>
    friend
    void asio_handler_invoke(Function&& f, write_op* op)
    {
        return boost_asio_handler_invoke_helpers::
            invoke(f, op->d_->h);
    }
};

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers, class Handler>
void
stream<NextLayer, Allocator>::
write_op<isRequest, Body, Headers, Handler>::
cancel()
{
    auto& d = *d_;
    d.s.get_io_service().post(
        bind_handler(std::move(*this),
            boost::asio::error::operation_aborted));
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers, class Handler>
void
stream<NextLayer, Allocator>::
write_op<isRequest, Body, Headers, Handler>::
operator()(error_code const& ec, bool again)
{
    auto& d = *d_;
    d.cont = d.cont || again;
    while(! ec && d.state != 99)
    {
        switch(d.state)
        {
        case 0:
            d.state = 99;
            beast::http::async_write(d.s.next_layer_,
                d.m, std::move(*this));
            return;
        }
    }
    d.h(ec);
    if(! d.s.wr_q_.empty())
    {
        auto& op = d.s.wr_q_.front();
        op();
        // VFALCO Use allocator
        delete &op;
        d.s.wr_q_.pop_front();
    }
    else
    {
        d.s.wr_active_ = false;
    }
}

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

template<class NextLayer, class Allocator>
stream<NextLayer, Allocator>::
~stream()
{
    // Can't destroy with pending operations!
    assert(wr_q_.empty());
}

template<class NextLayer, class Allocator>
template<class... Args>
stream<NextLayer, Allocator>::
stream(Args&&... args)
    : next_layer_(std::forward<Args>(args)...)
{
}

template<class NextLayer, class Allocator>
void
stream<NextLayer, Allocator>::
cancel(error_code& ec)
{
    cancel_all();
    lowest_layer().cancel(ec);
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers>
void
stream<NextLayer, Allocator>::
read(message<isRequest, Body, Headers>& msg,
    error_code& ec)
{
    beast::http::read(next_layer_, rd_buf_, msg, ec);
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers,
    class ReadHandler>
auto
stream<NextLayer, Allocator>::
async_read(message<isRequest, Body, Headers>& msg,
    ReadHandler&& handler) ->
        typename async_completion<
            ReadHandler, void(error_code)>::result_type
{
    async_completion<
        ReadHandler, void(error_code)
            > completion(handler);
    read_op<isRequest, Body, Headers,
        decltype(completion.handler)>{
            completion.handler, *this, msg};
    return completion.result.get();
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers>
void
stream<NextLayer, Allocator>::
write(message<isRequest, Body, Headers> const& msg,
    error_code& ec)
{
    beast::http::write(next_layer_, msg, ec);
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers,
    class WriteHandler>
auto
stream<NextLayer, Allocator>::
async_write(message<isRequest, Body, Headers> const& msg,
    WriteHandler&& handler) ->
        typename async_completion<
            WriteHandler, void(error_code)>::result_type
{
    async_completion<
        WriteHandler, void(error_code)> completion(handler);
    auto const cont = wr_active_ ||
        boost_asio_handler_cont_helpers::is_continuation(handler);
    if(! wr_active_)
    {
        wr_active_ = true;
        write_op<isRequest, Body, Headers,
            decltype(completion.handler)>{
                completion.handler, *this, msg, cont }();
    }
    else
    {
        // VFALCO Use allocator
        wr_q_.push_back(*new write_op<isRequest, Body, Headers,
            decltype(completion.handler)>(
                completion.handler, *this, msg, cont));
    }
    return completion.result.get();
}

template<class NextLayer, class Allocator>
template<bool isRequest, class Body, class Headers,
    class WriteHandler>
auto
stream<NextLayer, Allocator>::
async_write(message<isRequest, Body, Headers>&& msg,
    WriteHandler&& handler) ->
        typename async_completion<
            WriteHandler, void(error_code)>::result_type
{
    async_completion<
        WriteHandler, void(error_code)> completion(handler);
    auto const cont = wr_active_ ||
        boost_asio_handler_cont_helpers::is_continuation(handler);
    if(! wr_active_)
    {
        wr_active_ = true;
        write_op<isRequest, Body, Headers,
            decltype(completion.handler)>{completion.handler,
            *this, std::move(msg), cont}();
    }
    else
    {
        // VFALCO Use allocator
        wr_q_.push_back(*new write_op<isRequest, Body, Headers,
            decltype(completion.handler)>(completion.handler,
                *this, std::move(msg), cont));
    }
    return completion.result.get();
}

template<class NextLayer, class Allocator>
void
stream<NextLayer, Allocator>::
cancel_all()
{
    for(auto it = wr_q_.begin(); it != wr_q_.end();)
    {
        auto& op = *it++;
        op.cancel();
        // VFALCO Use allocator
        delete &op;
    }
    wr_q_.clear();
}

} // http
} // beast

#endif