/*
Minetest
Copyright (C) 2010-2017 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#pragma once

#include "activeobject.h"
#include "environment.h"
#include "mapnode.h"
#include "settings.h"
#include "server/activeobjectmgr.h"
#include "util/numeric.h"
#include <set>
#include <random>

class IGameDef;
class ServerMap;
struct GameParams;
class MapBlock;
class RemotePlayer;
class PlayerDatabase;
class AuthDatabase;
class PlayerSAO;
class ServerEnvironment;
class ActiveBlockModifier;
struct StaticObject;
class ServerActiveObject;
class Server;
class ServerScripting;

/*
	{Active, Loading} block modifier interface.

	These are fed into ServerEnvironment at initialization time;
	ServerEnvironment handles deleting them.
*/

class ActiveBlockModifier
{
public:
	ActiveBlockModifier() = default;
	virtual ~ActiveBlockModifier() = default;

	// Set of contents to trigger on
	virtual const std::vector<std::string> &getTriggerContents() const = 0;
	// Set of required neighbors (trigger doesn't happen if none are found)
	// Empty = do not check neighbors
	virtual const std::vector<std::string> &getRequiredNeighbors() const = 0;
	// Trigger interval in seconds
	virtual float getTriggerInterval() = 0;
	// Random chance of (1 / return value), 0 is disallowed
	virtual u32 getTriggerChance() = 0;
	// Whether to modify chance to simulate time lost by an unnattended block
	virtual bool getSimpleCatchUp() = 0;
	// This is called usually at interval for 1/chance of the nodes
	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n){};
	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
		u32 active_object_count, u32 active_object_count_wider){};
};

struct ABMWithState
{
	ActiveBlockModifier *abm;
	float timer = 0.0f;

	ABMWithState(ActiveBlockModifier *abm_);
};

struct LoadingBlockModifierDef
{
	// Set of contents to trigger on
	std::set<std::string> trigger_contents;
	std::string name;
	bool run_at_every_load = false;

	virtual ~LoadingBlockModifierDef() = default;

	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n){};
};

struct LBMContentMapping
{
	typedef std::unordered_map<content_t, std::vector<LoadingBlockModifierDef *>> lbm_map;
	lbm_map map;

	std::vector<LoadingBlockModifierDef *> lbm_list;

	// Needs to be separate method (not inside destructor),
	// because the LBMContentMapping may be copied and destructed
	// many times during operation in the lbm_lookup_map.
	void deleteContents();
	void addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamedef);
	const std::vector<LoadingBlockModifierDef *> *lookup(content_t c) const;
};

class LBMManager
{
public:
	LBMManager() = default;
	~LBMManager();

	// Don't call this after loadIntroductionTimes() ran.
	void addLBMDef(LoadingBlockModifierDef *lbm_def);

	void loadIntroductionTimes(const std::string &times,
		IGameDef *gamedef, u32 now);

	// Don't call this before loadIntroductionTimes() ran.
	std::string createIntroductionTimesString();

	// Don't call this before loadIntroductionTimes() ran.
	void applyLBMs(ServerEnvironment *env, MapBlock *block, u32 stamp);

	// Warning: do not make this std::unordered_map, order is relevant here
	typedef std::map<u32, LBMContentMapping> lbm_lookup_map;

private:
	// Once we set this to true, we can only query,
	// not modify
	bool m_query_mode = false;

	// For m_query_mode == false:
	// The key of the map is the LBM def's name.
	// TODO make this std::unordered_map
	std::map<std::string, LoadingBlockModifierDef *> m_lbm_defs;

	// For m_query_mode == true:
	// The key of the map is the LBM def's first introduction time.
	lbm_lookup_map m_lbm_lookup;

	// Returns an iterator to the LBMs that were introduced
	// after the given time. This is guaranteed to return
	// valid values for everything
	lbm_lookup_map::const_iterator getLBMsIntroducedAfter(u32 time)
	{ return m_lbm_lookup.lower_bound(time); }
};

/*
	List of active blocks, used by ServerEnvironment
*/

class ActiveBlockList
{
public:
	void update(std::vector<PlayerSAO*> &active_players,
		s16 active_block_range,
		s16 active_object_range,
		std::set<v3s16> &blocks_removed,
		std::set<v3s16> &blocks_added);

	bool contains(v3s16 p){
		return (m_list.find(p) != m_list.end());
	}

	void clear(){
		m_list.clear();
	}

	std::set<v3s16> m_list;
	std::set<v3s16> m_abm_list;
	std::set<v3s16> m_forceloaded_list;

private:
};

/*
	Operation mode for ServerEnvironment::clearObjects()
*/
enum ClearObjectsMode {
	// Load and go through every mapblock, clearing objects
		CLEAR_OBJECTS_MODE_FULL,

	// Clear objects immediately in loaded mapblocks;
	// clear objects in unloaded mapblocks only when the mapblocks are next activated.
		CLEAR_OBJECTS_MODE_QUICK,
};

/*
	The server-side environment.

	This is not thread-safe. Server uses an environment mutex.
*/

typedef std::unordered_map<u16, ServerActiveObject *> ServerActiveObjectMap;

class ServerEnvironment : public Environment
{
public:
	ServerEnvironment(ServerMap *map, ServerScripting *scriptIface,
		Server *server, const std::string &path_world);
	~ServerEnvironment();

	Map & getMap();

	ServerMap & getServerMap();

	//TODO find way to remove this fct!
	ServerScripting* getScriptIface()
	{ return m_script; }

	Server *getGameDef()
	{ return m_server; }

	float getSendRecommendedInterval()
	{ return m_recommended_send_interval; }

	void kickAllPlayers(AccessDeniedCode reason,
		const std::string &str_reason, bool reconnect);
	// Save players
	void saveLoadedPlayers(bool force = false);
	void savePlayer(RemotePlayer *player);
	PlayerSAO *loadPlayer(RemotePlayer *player, bool *new_player, session_t peer_id,
		bool is_singleplayer);
	void addPlayer(RemotePlayer *player);
	void removePlayer(RemotePlayer *player);
	bool removePlayerFromDatabase(const std::string &name);

	/*
		Save and load time of day and game timer
	*/
	void saveMeta();
	void loadMeta();

	u32 addParticleSpawner(float exptime);