// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// 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. The
// full license for this software is available in the LICENSE file.

#include "user.h"

using namespace ircd;

resource::response
get__filter(client &client,
            const resource::request &request,
            const m::user::id &user_id)
{
	char filter_id_buf[64];
	const auto filter_id
	{
		url::decode(filter_id_buf, request.parv[2])
	};

	const m::user user
	{
		user_id
	};

	const m::user::filter filter
	{
		user_id
	};

	filter.get(filter_id, [&client]
	(const string_view &filter_id, const json::object &filter)
	{
		resource::response
		{
			client, filter
		};
	});

	// Responded from closure.
	return {};
}

// (5.2) Uploads a new filter definition to the homeserver. Returns a filter ID that
// may be used in future requests to restrict which events are returned to the client.
resource::response
post__filter(client &client,
             const resource::request::object<const m::filter> &request,
             const m::user::id &user_id)
{
	// (5.2) Required. The id of the user uploading the filter. The access
	// token must be authorized to make requests for this user id.
	if(user_id != request.user_id)
		throw m::FORBIDDEN
		{
			"Trying to post a filter for `%s' but you are `%s'",
			user_id,
			request.user_id
		};

	// (5.2) List of event fields to include. If this list is absent then all fields are
	// included. The entries may include '.' charaters to indicate sub-fields. So
	// ['content.body'] will include the 'body' field of the 'content' object. A literal '.'
	// character in a field name may be escaped using a '\'. A server may include more
	// fields than were requested.
	const auto &event_fields
	{
		json::get<"event_fields"_>(request)
	};

	// (5.2) The format to use for events. 'client' will return the events in a format suitable
	// for clients. 'federation' will return the raw event as receieved over federation.
	// The default is 'client'. One of: ["client", "federation"]
	const auto &event_format
	{
		json::get<"event_format"_>(request)
	};

	// (5.2) The user account data that isn't associated with rooms to include.
	const auto &account_data
	{
		json::get<"account_data"_>(request)
	};

	// (5.2) Filters to be applied to room data.
	const auto &room
	{
		json::get<"room"_>(request)
	};

	const auto &state
	{
		json::get<"state"_>(room)
	};

	const auto &presence
	{
		// (5.2) The presence updates to include.
		json::get<"presence"_>(request)
	};

	const m::user user
	{
		user_id
	};

	const m::user::filter filter
	{
		user
	};

	char filter_id_buf[m::id::MAX_SIZE];
	const auto filter_id
	{
		filter.set(filter_id_buf, request.body)
	};

	return resource::response
	{
		client, http::CREATED,
		{
			{ "filter_id", filter_id }
		}
	};
}

string_view
IRCD_MODULE_EXPORT
ircd::m::user::filter::set(const mutable_buffer &idbuf,
                           const m::user &user,
                           const json::object &filter)
{
	const user::room user_room
	{
		user
	};

	const sha256::buf hash
	{
		sha256{filter}
	};

	const string_view filter_id
	{
		b64encode_unpadded(idbuf, hash)
	};

	//TODO: ABA
	if(user_room.has("ircd.filter", filter_id))
		return {};

	//TODO: ABA
	send(user_room, user.user_id, "ircd.filter", filter_id, filter);
	return filter_id;
}

bool
IRCD_MODULE_EXPORT
ircd::m::user::filter::get(std::nothrow_t,
                           const m::user &user,
                           const string_view &filter_id,
                           const closure &closure)
{
	static const event::fetch::opts fopts
	{
		event::keys::include {"content"}
	};

	const user::room user_room
	{
		user, nullptr, &fopts
	};

	return user_room.get(std::nothrow, "ircd.filter", filter_id, [&filter_id, &closure]
	(const m::event &event)
	{
		const json::object &content
		{
			at<"content"_>(event)
		};

		closure(filter_id, content);
	});
}

bool
IRCD_MODULE_EXPORT
ircd::m::user::filter::for_each(const m::user &user,
                                const closure_bool &closure)
{
	const user::room user_room
	{
		user
	};

	const room::state state
	{
		user_room
	};

	return state.for_each("ircd.filter", event::closure_idx_bool{[&closure]
	(const m::event::idx &event_idx)
	{
		static const event::fetch::opts fopts
		{
			event::keys::include {"state_key", "content"}
		};

		const event::fetch event
		{
			event_idx, std::nothrow, fopts
		};

		if(!event.valid)
			return true;

		const auto &filter_id
		{
			at<"state_key"_>(event)
		};

		const json::object &content
		{
			at<"content"_>(event)
		};

		return closure(filter_id, content);
	}});
}