// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk
//
// 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 is present in all copies.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
// IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

#pragma once
#define HAVE_IRCD_SERVER_TAG_H

namespace ircd::server
{
	struct tag;

	void associate(request &, tag &);
	void associate(request &, tag &, tag &&) noexcept;
	void associate(request &, tag &, request &&) noexcept;
	void disassociate(request &, tag &);
	void cancel(request &, tag &) noexcept;
}

/// Internal portion of the request
///
struct ircd::server::tag
{
	ctx::promise<http::code> p;
	server::request *request {nullptr};
	size_t written {0};
	size_t head_read {0};
	size_t content_read {0};
	size_t content_over {0};
	http::code status {(http::code)0};
	std::unique_ptr<char[]> cancellation;

	void set_exception(std::exception_ptr);
	template<class... args> void set_exception(args&&...);
	template<class... args> void set_value(args&&...);

	const_buffer make_write_content_buffer() const;
	const_buffer make_write_head_buffer() const;

	mutable_buffer make_read_discard_buffer() const;
	mutable_buffer make_read_content_buffer() const;
	mutable_buffer make_read_head_buffer() const;

	const_buffer read_content(const const_buffer &, bool &done);
	const_buffer read_head(const const_buffer &, bool &done);

  public:
	size_t write_total() const;
	size_t write_completed() const;
	size_t write_remaining() const;

	size_t read_total() const;               // not accurate until content-length
	size_t read_completed() const;           // reports all received so far
	size_t read_remaining() const;           // not accurate until content-length

	bool committed() const;                  // Tag has revealed data to remote
	bool abandoned() const;                  // User has abandoned their future
	bool canceled() const;                   // User has abandoned their *request

	const_buffer make_write_buffer() const;
	void wrote_buffer(const const_buffer &);

	mutable_buffer make_read_buffer() const;
	const_buffer read_buffer(const const_buffer &, bool &done);

	tag() = default;
	tag(server::request &);
	tag(tag &&) noexcept;
	tag(const tag &) = delete;
	tag &operator=(tag &&) noexcept;
	tag &operator=(const tag &) = delete;
	~tag() noexcept;
};

inline
ircd::server::tag::tag(server::request &request)
{
	associate(request, *this);
}

inline
ircd::server::tag::tag(tag &&o)
noexcept
:p{std::move(o.p)}
,request{std::move(o.request)}
,written{std::move(o.written)}
,head_read{std::move(o.head_read)}
,content_read{std::move(o.content_read)}
,content_over{std::move(o.content_over)}
,status{std::move(o.status)}
,cancellation{std::move(o.cancellation)}
{
	if(request)
		associate(*request, *this, std::move(o));

	assert(!o.request);
}

inline ircd::server::tag &
ircd::server::tag::operator=(tag &&o)
noexcept
{
	this->~tag();

	p = std::move(o.p);
	request = std::move(o.request);
	written = std::move(o.written);
	head_read = std::move(o.head_read);
	content_read = std::move(o.content_read);
	content_over = std::move(o.content_over);
	status = std::move(o.status);
	cancellation = std::move(o.cancellation);

	if(request)
		associate(*request, *this, std::move(o));

	assert(!o.request);
	return *this;
}

inline
ircd::server::tag::~tag()
noexcept
{
	if(request)
		disassociate(*request, *this);

	assert(!request);
}