/*

Copyright (c) 2009-2015, Arvid Norberg
All rights reserved.

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modification, are permitted provided that the following conditions
are met:

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      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
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      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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*/

#ifndef TORRENT_ADD_TORRENT_PARAMS_HPP_INCLUDED
#define TORRENT_ADD_TORRENT_PARAMS_HPP_INCLUDED

#include <string>
#include <vector>
#include <boost/shared_ptr.hpp>

#include "libtorrent/storage_defs.hpp"
#include "libtorrent/peer_id.hpp" // sha1_hash
#include "libtorrent/version.hpp"

namespace libtorrent
{
	class torrent_info;
	struct torrent_plugin;
	struct torrent_handle;

	// The add_torrent_params is a parameter pack for adding torrents to a
	// session. The key fields when adding a torrent are:
	//
	// * ti - when you have a .torrent file
	// * url - when you have a magnet link or http URL to the .torrent file
	// * info_hash - when all you have is an info-hash (this is similar to a
	//   magnet link)
	//
	// one of those fields need to be set. Another mandatory field is
	// ``save_path``. The add_torrent_params object is passed into one of the
	// ``session::add_torrent()`` overloads or ``session::async_add_torrent()``.
	//
	// If you only specify the info-hash, the torrent file will be downloaded
	// from peers, which requires them to support the metadata extension. For
	// the metadata extension to work, libtorrent must be built with extensions
	// enabled (``TORRENT_DISABLE_EXTENSIONS`` must not be defined). It also
	// takes an optional ``name`` argument. This may be left empty in case no
	// name should be assigned to the torrent. In case it's not, the name is
	// used for the torrent as long as it doesn't have metadata. See
	// ``torrent_handle::name``.
	//
	struct TORRENT_EXPORT add_torrent_params
	{
		// The constructor can be used to initialize the storage constructor,
		// which determines the storage mechanism for the downloaded or seeding
		// data for the torrent. For more information, see the ``storage`` field.
		add_torrent_params(storage_constructor_type sc = default_storage_constructor)
			: version(LIBTORRENT_VERSION_NUM)
#ifndef TORRENT_NO_DEPRECATE
			, tracker_url(0)
#endif
			, storage_mode(storage_mode_sparse)
			, storage(sc)
			, userdata(0)
#ifndef TORRENT_NO_DEPRECATE
			, flags(flag_ignore_flags | default_flags)
#else
			, flags(default_flags)
#endif
			, max_uploads(-1)
			, max_connections(-1)
			, upload_limit(-1)
			, download_limit(-1)
#ifndef TORRENT_NO_DEPRECATE
			, seed_mode(false)
			, override_resume_data(false)
			, upload_mode(false)
			, share_mode(false)
			, apply_ip_filter(true)
			, paused(true)
			, auto_managed(true)
			, duplicate_is_error(false)
			, merge_resume_trackers(false)
#endif
		{
		}

#ifndef TORRENT_NO_DEPRECATE
		void update_flags() const
		{
			if (flags != (flag_ignore_flags | default_flags)) return;

			boost::uint64_t& f = const_cast<boost::uint64_t&>(flags);
			f = flag_update_subscribe;
			if (seed_mode) f |= flag_seed_mode;
			if (override_resume_data) f |= flag_override_resume_data;
			if (upload_mode) f |= flag_upload_mode;
			if (share_mode) f |= flag_share_mode;
			if (apply_ip_filter) f |= flag_apply_ip_filter;
			if (paused) f |= flag_paused;
			if (auto_managed) f |= flag_auto_managed;
			if (duplicate_is_error) f |= flag_duplicate_is_error;
			if (merge_resume_trackers) f |= flag_merge_resume_trackers;
		}
#endif

		// values for the ``flags`` field
		enum flags_t
		{
			// If ``flag_seed_mode`` is set, libtorrent will assume that all files
			// are present for this torrent and that they all match the hashes in
			// the torrent file. Each time a peer requests to download a block,
			// the piece is verified against the hash, unless it has been verified
			// already. If a hash fails, the torrent will automatically leave the
			// seed mode and recheck all the files. The use case for this mode is
			// if a torrent is created and seeded, or if the user already know
			// that the files are complete, this is a way to avoid the initial
			// file checks, and significantly reduce the startup time.
			// 
			// Setting ``flag_seed_mode`` on a torrent without metadata (a
			// .torrent file) is a no-op and will be ignored.
			// 
			// If resume data is passed in with this torrent, the seed mode saved
			// in there will override the seed mode you set here.
			flag_seed_mode = 0x001,

			// If ``flag_override_resume_data`` is set, flags set for this torrent
			// in this ``add_torrent_params`` object will take precedence over
			// whatever states are saved in the resume data. For instance, the
			// ``paused``, ``auto_managed``, ``sequential_download``, ``seed_mode``,
			// ``super_seeding``, ``max_uploads``, ``max_connections``,
			// ``upload_limit`` and ``download_limit`` are all affected by this
			// flag. The intention of this flag is to have any field in
			// add_torrent_params configuring the torrent override the corresponding
			// configuration from the resume file, with the one exception of save
			// resume data, which has its own flag (for historic reasons).
			// If this flag is set, but file_priorities is empty, file priorities
			// are still loaded from the resume data, if present.
			flag_override_resume_data = 0x002,

			// If ``flag_upload_mode`` is set, the torrent will be initialized in
			// upload-mode, which means it will not make any piece requests. This
			// state is typically entered on disk I/O errors, and if the torrent
			// is also auto managed, it will be taken out of this state
			// periodically. This mode can be used to avoid race conditions when
			// adjusting priorities of pieces before allowing the torrent to start
			// downloading.
			// 
			// If the torrent is auto-managed (``flag_auto_managed``), the torrent
			// will eventually be taken out of upload-mode, regardless of how it
			// got there. If it's important to manually control when the torrent
			// leaves upload mode, don't make it auto managed.
			flag_upload_mode = 0x004,

			// determines if the torrent should be added in *share mode* or not.
			// Share mode indicates that we are not interested in downloading the
			// torrent, but merley want to improve our share ratio (i.e. increase
			// it). A torrent started in share mode will do its best to never
			// download more than it uploads to the swarm. If the swarm does not
			// have enough demand for upload capacity, the torrent will not
			// download anything. This mode is intended to be safe to add any
			// number of torrents to, without manual screening, without the risk
			// of downloading more than is uploaded.
			// 
			// A torrent in share mode sets the priority to all pieces to 0,
			// except for the pieces that are downloaded, when pieces are decided
			// to be downloaded. This affects the progress bar, which might be set
			// to "100% finished" most of the time. Do not change file or piece
			// priorities for torrents in share mode, it will make it not work.
			// 
			// The share mode has one setting, the share ratio target, see
			// ``session_settings::share_mode_target`` for more info.
			flag_share_mode = 0x008,

			// determines if the IP filter should apply to this torrent or not. By
			// default all torrents are subject to filtering by the IP filter
			// (i.e. this flag is set by default). This is useful if certain
			// torrents needs to be excempt for some reason, being an auto-update
			// torrent for instance.
			flag_apply_ip_filter = 0x010,

			// specifies whether or not the torrent is to be started in a paused
			// state. I.e. it won't connect to the tracker or any of the peers
			// until it's resumed. This is typically a good way of avoiding race
			// conditions when setting configuration options on torrents before
			// starting them.
			flag_paused = 0x020,

			// If the torrent is auto-managed (``flag_auto_managed``), the torrent
			// may be resumed at any point, regardless of how it paused. If it's
			// important to manually control when the torrent is paused and
			// resumed, don't make it auto managed.
			// 
			// If ``flag_auto_managed`` is set, the torrent will be queued,
			// started and seeded automatically by libtorrent. When this is set,
			// the torrent should also be started as paused. The default queue
			// order is the order the torrents were added. They are all downloaded
			// in that order. For more details, see queuing_.
			// 
			// If you pass in resume data, the auto_managed state of the torrent
			// when the resume data was saved will override the auto_managed state
			// you pass in here. You can override this by setting
			// ``override_resume_data``.
			flag_auto_managed = 0x040,
			flag_duplicate_is_error = 0x080,

			// defaults to off and specifies whether tracker URLs loaded from
			// resume data should be added to the trackers in the torrent or
			// replace the trackers.
			flag_merge_resume_trackers = 0x100,

			// on by default and means that this torrent will be part of state
			// updates when calling post_torrent_updates().
			flag_update_subscribe = 0x200,

			// sets the torrent into super seeding mode. If the torrent is not a
			// seed, this flag has no effect. It has the same effect as calling
			// ``torrent_handle::super_seeding(true)`` on the torrent handle
			// immediately after adding it.
			flag_super_seeding = 0x400,

			// sets the sequential download state for the torrent. It has the same
			// effect as calling ``torrent_handle::sequential_download(true)`` on
			// the torrent handle immediately after adding it.
			flag_sequential_download = 0x800,

			// if this flag is set, the save path from the resume data file, if
			// present, is honored. This defaults to not being set, in which
			// case the save_path specified in add_torrent_params is always used.
			flag_use_resume_save_path = 0x1000,

			// indicates that this torrent should never be unloaded from RAM, even
			// if unloading torrents are allowed in general. Setting this makes
			// the torrent exempt from loading/unloading management.
			flag_pinned = 0x2000,

			// internal
			default_flags = flag_pinned | flag_update_subscribe
				| flag_auto_managed | flag_paused | flag_apply_ip_filter

#ifndef TORRENT_NO_DEPRECATE
			, flag_ignore_flags = 0x80000000
#endif
		};
	
		// filled in by the constructor and should be left untouched. It is used
		// for forward binary compatibility.
		int version;
		// torrent_info object with the torrent to add. Unless the url or
		// info_hash is set, this is required to be initiazlied.
		boost::shared_ptr<torrent_info> ti;

#ifndef TORRENT_NO_DEPRECATE
		char const* tracker_url;
#endif
		// If the torrent doesn't have a tracker, but relies on the DHT to find
		// peers, the ``trackers`` can specify tracker URLs for the torrent.
		std::vector<std::string> trackers;

		// url seeds to be added to the torrent (`BEP 17`_).
		std::vector<std::string> url_seeds;

		// a list of hostname and port pairs, representing DHT nodes to be added
		// to the session (if DHT is enabled). The hostname may be an IP address.
		std::vector<std::pair<std::string, int> > dht_nodes;
		std::string name;

		// the path where the torrent is or will be stored. Note that this may
		// alos be stored in resume data. If you want the save path saved in
		// the resume data to be used, you need to set the
		// flag_use_resume_save_path flag.
		//
		// .. note::
		// 	On windows this path (and other paths) are interpreted as UNC
		// 	paths. This means they must use backslashes as directory separators
		// 	and may not contain the special directories "." or "..".
		std::string save_path;

		// The optional parameter, ``resume_data`` can be given if up to date
		// fast-resume data is available. The fast-resume data can be acquired
		// from a running torrent by calling save_resume_data() on
		// torrent_handle. See fast-resume_. The ``vector`` that is passed in
		// will be swapped into the running torrent instance with
		// ``std::vector::swap()``.
		std::vector<char> resume_data;

		// One of the values from storage_mode_t. For more information, see
		// storage-allocation_.
		storage_mode_t storage_mode;

		// can be used to customize how the data is stored. The default storage
		// will simply write the data to the files it belongs to, but it could be
		// overridden to save everything to a single file at a specific location
		// or encrypt the content on disk for instance. For more information
		// about the storage_interface that needs to be implemented for a custom
		// storage, see storage_interface.
		storage_constructor_type storage;

		// The ``userdata`` parameter is optional and will be passed on to the
		// extension constructor functions, if any
		// (see torrent_handle::add_extension()).
		void* userdata;

		// can be set to control the initial file priorities when adding a
		// torrent. The semantics are the same as for
		// ``torrent_handle::prioritize_files()``.
		std::vector<boost::uint8_t> file_priorities;

		// torrent extension construction functions can be added to this vector
		// to have them be added immediately when the torrent is constructed.
		// This may be desired over the torrent_handle::add_extension() in order
		// to avoid race conditions. For instance it may be important to have the
		// plugin catch events that happen very early on after the torrent is
		// created.
		std::vector<boost::function<boost::shared_ptr<torrent_plugin>(torrent_handle const&, void*)> >
			extensions;

		// the default tracker id to be used when announcing to trackers. By
		// default this is empty, and no tracker ID is used, since this is an
		// optional argument. If a tracker returns a tracker ID, that ID is used
		// instead of this.
		std::string trackerid;

		// If you specify a ``url``, the torrent will be set in
		// ``downloading_metadata`` state until the .torrent file has been
		// downloaded. If there's any error while downloading, the torrent will
		// be stopped and the torrent error state (``torrent_status::error``)
		// will indicate what went wrong. The ``url`` may refer to a magnet link
		// or a regular http URL.
		// 
		// If it refers to an HTTP URL, the info-hash for the added torrent will
		// not be the true info-hash of the .torrent. Instead a placeholder,
		// unique, info-hash is used which is later updated once the .torrent
		// file has been downloaded.
		// 
		// Once the info-hash change happens, a torrent_update_alert is posted.
		std::string url;

		// if ``uuid`` is specified, it is used to find duplicates. If another
		// torrent is already running with the same UUID as the one being added,
		// it will be considered a duplicate. This is mainly useful for RSS feed
		// items which has UUIDs specified.
		std::string uuid;

		// should point to the URL of the RSS feed this torrent comes from, if it
		// comes from an RSS feed.
		std::string source_feed_url;

		// flags controlling aspects of this torrent and how it's added. See
		// flags_t for details.
		boost::uint64_t flags;

		// set this to the info hash of the torrent to add in case the info-hash
		// is the only known property of the torrent. i.e. you don't have a
		// .torrent file nor a magnet link.
		sha1_hash info_hash;

		// ``max_uploads``, ``max_connections``, ``upload_limit``,
		// ``download_limit`` correspond to the ``set_max_uploads()``,
		// ``set_max_connections()``, ``set_upload_limit()`` and
		// ``set_download_limit()`` functions on torrent_handle. These values let
		// you initialize these settings when the torrent is added, instead of
		// calling these functions immediately following adding it.
		// 
		// -1 means unlimited on these settings just like their counterpart
		// functions on torrent_handle
		int max_uploads;
		int max_connections;
		int upload_limit;
		int download_limit;

#ifndef TORRENT_NO_DEPRECATE
		bool seed_mode;
		bool override_resume_data;
		bool upload_mode;
		bool share_mode;
		bool apply_ip_filter;
		bool paused;
		bool auto_managed;
		bool duplicate_is_error;
		bool merge_resume_trackers;
#endif

	};
}

#endif

