#ifndef MUTATORS_BASE_H
#define MUTATORS_BASE_H
const int CBC_ORDER_FIRST = 1;
const int CBC_ORDER_LAST = 2;
const int CBC_ORDER_EXCLUSIVE = 3;
const int CBC_ORDER_ANY = 4;

bool CallbackChain_ReturnValue; // read-only field of the current return value

entity CallbackChain_New(string name);
bool CallbackChain_Add(entity cb, bool() func, int order);
int CallbackChain_Remove(entity cb, bool() func);
// a callback function is like this:
// bool mycallback(entity me)
// {
//   do something
//   return false;
// }
bool CallbackChain_Call(entity cb);

enum {
	MUTATOR_REMOVING,
	MUTATOR_ADDING,
	MUTATOR_ROLLING_BACK
};
typedef bool(int) mutatorfunc_t;
bool Mutator_Add(mutatorfunc_t func, string name);
void Mutator_Remove(mutatorfunc_t func, string name); // calls error() on fail

#define MUTATOR_ADD(name) Mutator_Add(MUTATOR_##name, #name)
#define MUTATOR_REMOVE(name) Mutator_Remove(MUTATOR_##name, #name)
#define MUTATOR_DEFINITION(name) bool MUTATOR_##name(int mode)
#define MUTATOR_DECLARATION(name) bool MUTATOR_##name(int mode)
#define MUTATOR_HOOKFUNCTION(name) bool HOOKFUNCTION_##name()
#define MUTATOR_HOOK(cb, func, order) do { 										\
	MUTATOR_ONADD { 															\
		if (!HOOK_##cb) HOOK_##cb = CallbackChain_New(#cb); 					\
		if (!CallbackChain_Add(HOOK_##cb, HOOKFUNCTION_##func, order)) { 		\
			print("HOOK FAILED: ", #func, "\n"); 								\
			return true; 														\
		} 																		\
	} 																			\
	MUTATOR_ONROLLBACK_OR_REMOVE { 												\
		if (HOOK_##cb) CallbackChain_Remove(HOOK_##cb, HOOKFUNCTION_##func);	\
	} 																			\
} while(0)
#define MUTATOR_ONADD if (mode == MUTATOR_ADDING)
#define MUTATOR_ONREMOVE if (mode == MUTATOR_REMOVING)
#define MUTATOR_ONROLLBACK_OR_REMOVE if (mode == MUTATOR_REMOVING || mode == MUTATOR_ROLLING_BACK)

#define _MUTATOR_HOOKABLE(id, ...) entity HOOK_##id; bool __Mutator_Send_##id(__VA_ARGS__)
#define MUTATOR_CALLHOOK(id, ...) APPLY(__Mutator_Send_##id, 0, ##__VA_ARGS__)

#define MUTATOR_RETURNVALUE CallbackChain_ReturnValue

#define HANDLE_NOP(type, id)
#define HANDLE_PARAMS(type, id) , type in_##id
#define HANDLE_PREPARE(type, id) id = in_##id;
#define HANDLE_PUSHTMP(type, id) type tmp_##id = id;
#define HANDLE_PUSHOUT(type, id) type out_##id = id;
#define HANDLE_POPTMP(type, id) id = tmp_##id;
#define HANDLE_POPOUT(type, id) id = out_##id;

#define MUTATOR_HOOKABLE(id, params) \
	_MUTATOR_HOOKABLE(id, int params(HANDLE_PARAMS, HANDLE_NOP)) { \
		params(HANDLE_PUSHTMP, HANDLE_NOP) \
		params(HANDLE_PREPARE, HANDLE_NOP) \
		bool ret = CallbackChain_Call(HOOK_##id); \
		params(HANDLE_NOP,     HANDLE_PUSHOUT) \
		params(HANDLE_POPTMP,  HANDLE_NOP) \
		params(HANDLE_NOP,     HANDLE_POPOUT) \
		return ret; \
	}



// register all possible hooks here
// some parameters are commented to avoid duplicate declarations

#define EV_NO_ARGS(i, o)

/** called when a player becomes observer, after shared setup */
#define EV_MakePlayerObserver(i, o) \
    /**/
MUTATOR_HOOKABLE(MakePlayerObserver, EV_MakePlayerObserver)

/** */
#define EV_PutClientInServer(i, o) \
    /** client wanting to spawn */ i(entity, self) \
    /**/
MUTATOR_HOOKABLE(PutClientInServer, EV_PutClientInServer);

/** called when a player spawns as player, after shared setup, before his weapon is chosen (so items may be changed in here) */
#define EV_PlayerSpawn(i, o) \
    /** spot that was used, or world */ i(entity, spawn_spot) \
    /**/
entity spawn_spot;
MUTATOR_HOOKABLE(PlayerSpawn, EV_PlayerSpawn);

/** called in reset_map */
#define EV_reset_map_global(i, o) \
    /**/
MUTATOR_HOOKABLE(reset_map_global, EV_reset_map_global);

/** called in reset_map */
#define EV_reset_map_players(i, o) \
    /**/
MUTATOR_HOOKABLE(reset_map_players, EV_reset_map_players);

/** returns 1 if clearing player score shall not be allowed */
#define EV_ForbidPlayerScore_Clear(i, o) \
    /**/
MUTATOR_HOOKABLE(ForbidPlayerScore_Clear, EV_ForbidPlayerScore_Clear);

/** called when a player disconnects */
#define EV_ClientDisconnect(i, o) \
    /**/
MUTATOR_HOOKABLE(ClientDisconnect, EV_ClientDisconnect);

/** called when a player dies to e.g. remove stuff he was carrying. */
#define EV_PlayerDies(i, o) \
    /**/ i(entity, frag_inflictor) \
    /**/ i(entity, frag_attacker) \
    /** same as self */ i(entity, frag_target) \
    /**/ i(int, frag_deathtype) \
    /**/
entity frag_inflictor;
entity frag_attacker;
entity frag_target;
int frag_deathtype;
MUTATOR_HOOKABLE(PlayerDies, EV_PlayerDies);

/** called when a player presses the jump key */
#define EV_PlayerJump(i, o) \
    /**/ i(float, player_multijump) \
    /**/ i(float, player_jumpheight) \
    /**/ o(float, player_multijump) \
    /**/ o(float, player_jumpheight) \
    /**/
float player_multijump;
float player_jumpheight;
MUTATOR_HOOKABLE(PlayerJump, EV_PlayerJump);

/** called when someone was fragged by "self", and is expected to change frag_score to adjust scoring for the kill */
#define EV_GiveFragsForKill(i, o) \
    /** same as self */ i(entity, frag_attacker) \
    /**/ i(entity, frag_target) \
    /**/ i(float, frag_score) \
    /**/ o(float, frag_score) \
    /**/
float frag_score;
MUTATOR_HOOKABLE(GiveFragsForKill, EV_GiveFragsForKill);

/** called when the match ends */
MUTATOR_HOOKABLE(MatchEnd, EV_NO_ARGS);

/** should adjust ret_float to contain the team count */
#define EV_GetTeamCount(i, o) \
    /**/ i(float, ret_float) \
    /**/ o(float, ret_float) \
    /**/
float ret_float;
MUTATOR_HOOKABLE(GetTeamCount, EV_GetTeamCount);

/** copies variables for spectating "other" to "self" */
#define EV_SpectateCopy(i, o) \
    /**/ i(entity, other) \
    /**/ i(entity, self) \
    /**/
MUTATOR_HOOKABLE(SpectateCopy, EV_SpectateCopy);

/** returns 1 if throwing the current weapon shall not be allowed */
MUTATOR_HOOKABLE(ForbidThrowCurrentWeapon, EV_NO_ARGS);

/** allows changing attack rate */
#define EV_WeaponRateFactor(i, o) \
    /**/ i(float, weapon_rate) \
    /**/ o(float, weapon_rate) \
    /**/
float weapon_rate;
MUTATOR_HOOKABLE(WeaponRateFactor, EV_WeaponRateFactor);

/** allows changing weapon speed (projectiles mostly) */
#define EV_WeaponSpeedFactor(i, o) \
    /**/ i(float, ret_float) \
    /**/ o(float, ret_float) \
    /**/
MUTATOR_HOOKABLE(WeaponSpeedFactor, EV_WeaponSpeedFactor);

/** adjusts {warmup_}start_{items,weapons,ammo_{cells,plasma,rockets,nails,shells,fuel}} */
MUTATOR_HOOKABLE(SetStartItems, EV_NO_ARGS);

/** appends ":mutatorname" to ret_string for logging */
#define EV_BuildMutatorsString(i, o) \
    /**/ i(string, ret_string) \
    /**/ o(string, ret_string) \
    /**/
string ret_string;
MUTATOR_HOOKABLE(BuildMutatorsString, EV_BuildMutatorsString);

/** appends ", Mutator name" to ret_string for display */
#define EV_BuildMutatorsPrettyString(i, o) \
    /**/ i(string, ret_string) \
    /**/ o(string, ret_string) \
    /**/
MUTATOR_HOOKABLE(BuildMutatorsPrettyString, EV_BuildMutatorsPrettyString);

/** called every frame. customizes the waypoint for spectators */
#define EV_CustomizeWaypoint(i, o) \
    /** waypoint */ i(entity, self) \
    /** player; other.enemy = spectator */ i(entity, other) \
    /**/
MUTATOR_HOOKABLE(CustomizeWaypoint, EV_CustomizeWaypoint);

/**
 * checks if the current item may be spawned (self.items and self.weapons may be read and written to, as well as the ammo_ fields)
 * return error to request removal
 */
MUTATOR_HOOKABLE(FilterItem, EV_NO_ARGS);

/** return error to request removal */
#define EV_TurretSpawn(i, o) \
    /** turret */ i(entity, self) \
    /**/
MUTATOR_HOOKABLE(TurretSpawn, EV_TurretSpawn);

/** return error to prevent entity spawn, or modify the entity */
MUTATOR_HOOKABLE(OnEntityPreSpawn, EV_NO_ARGS);

/** runs in the event loop for players; is called for ALL player entities, also bots, also the dead, or spectators */
MUTATOR_HOOKABLE(PlayerPreThink, EV_NO_ARGS);

/** TODO change this into a general PlayerPostThink hook? */
MUTATOR_HOOKABLE(GetPressedKeys, EV_NO_ARGS);

/**
 * called before any player physics, may adjust variables for movement,
 * is run AFTER bot code and idle checking
 */
MUTATOR_HOOKABLE(PlayerPhysics, EV_NO_ARGS);

/** is meant to call GetCvars_handle*(get_cvars_s, get_cvars_f, cvarfield, "cvarname") for cvars this mutator needs from the client */
#define EV_GetCvars(i, o) \
    /**/ i(float, get_cvars_f) \
    /**/ i(string, get_cvars_s) \
    /**/
float get_cvars_f;
string get_cvars_s;
MUTATOR_HOOKABLE(GetCvars, EV_NO_ARGS); // NOTE: Can't use EV_GetCvars because of `SZ_GetSpace: overflow`

/** can edit any "just fired" projectile */
#define EV_EditProjectile(i, o) \
    /**/ i(entity, self) \
    /**/ i(entity, other) \
    /**/
MUTATOR_HOOKABLE(EditProjectile, EV_EditProjectile);

/** called when a monster spawns */
MUTATOR_HOOKABLE(MonsterSpawn, EV_NO_ARGS);

/** called when a monster dies */
#define EV_MonsterDies(i, o) \
    /**/ i(entity, frag_attacker) \
    /**/
MUTATOR_HOOKABLE(MonsterDies, EV_MonsterDies);

MUTATOR_HOOKABLE(MonsterRespawn, EV_NO_ARGS);
	// called when a monster wants to respawn
	// INPUT:
//		entity other;

MUTATOR_HOOKABLE(MonsterDropItem, EV_NO_ARGS);
	// called when a monster is dropping loot
	// INPUT, OUTPUT:
		.void() monster_loot;
//		entity other;

MUTATOR_HOOKABLE(MonsterMove, EV_NO_ARGS);
	// called when a monster moves
	// returning true makes the monster stop
	// INPUT:
		float monster_speed_run;
		float monster_speed_walk;
		entity monster_target;

MUTATOR_HOOKABLE(MonsterFindTarget, EV_NO_ARGS);
	// called when a monster looks for another target

MUTATOR_HOOKABLE(MonsterCheckBossFlag, EV_NO_ARGS);
    // called to change a random monster to a miniboss

MUTATOR_HOOKABLE(AllowMobSpawning, EV_NO_ARGS);
	// called when a player tries to spawn a monster
	// return 1 to prevent spawning

MUTATOR_HOOKABLE(PlayerDamage_SplitHealthArmor, EV_NO_ARGS);
	// called when a player gets damaged to e.g. remove stuff he was carrying.
	// INPUT:
//		entity frag_inflictor;
//		entity frag_attacker;
//		entity frag_target; // same as self
		vector damage_force; // NOTE: this force already HAS been applied
	// INPUT, OUTPUT:
		float damage_take;
		float damage_save;

MUTATOR_HOOKABLE(PlayerDamage_Calculate, EV_NO_ARGS);
	// called to adjust damage and force values which are applied to the player, used for e.g. strength damage/force multiplier
	// i'm not sure if I should change this around slightly (Naming of the entities, and also how they're done in g_damage).
	// INPUT:
//		entity frag_attacker;
//		entity frag_target;
//		float frag_deathtype;
	// INPUT, OUTPUT:
		float frag_damage;
		float frag_mirrordamage;
		vector frag_force;

MUTATOR_HOOKABLE(PlayerPowerups, EV_NO_ARGS);
	// called at the end of player_powerups() in cl_client.qc, used for manipulating the values which are set by powerup items.
	// INPUT
//	entity self;
	int olditems; // also technically output, but since it is at the end of the function it's useless for that :P

MUTATOR_HOOKABLE(PlayerRegen, EV_NO_ARGS);
	// called every player think frame
	// return 1 to disable regen
	// INPUT, OUTPUT:
		float regen_mod_max;
		float regen_mod_regen;
		float regen_mod_rot;
		float regen_mod_limit;

MUTATOR_HOOKABLE(PlayerUseKey, EV_NO_ARGS);
	// called when the use key is pressed
	// if MUTATOR_RETURNVALUE is 1, don't do anything
	// return 1 if the use key actually did something

MUTATOR_HOOKABLE(SV_ParseClientCommand, EV_NO_ARGS);
	// called when a client command is parsed
	// NOTE: hooks MUST start with if(MUTATOR_RETURNVALUE) return 0;
	// NOTE: return 1 if you handled the command, return 0 to continue handling
	// NOTE: THESE HOOKS MUST NEVER EVER CALL tokenize()
	// INPUT
	string cmd_name; // command name
	int cmd_argc; // also, argv() can be used
	string cmd_string; // whole command, use only if you really have to
	/*
		// example:
		MUTATOR_HOOKFUNCTION(foo_SV_ParseClientCommand)
		{
			if(MUTATOR_RETURNVALUE) // command was already handled?
				return 0;
			if(cmd_name == "echocvar" && cmd_argc >= 2)
			{
				print(cvar_string(argv(1)), "\n");
				return 1;
			}
			if(cmd_name == "echostring" && cmd_argc >= 2)
			{
				print(substring(cmd_string, argv_start_index(1), argv_end_index(-1) - argv_start_index(1)), "\n");
				return 1;
			}
			return 0;
		}
	*/

MUTATOR_HOOKABLE(Spawn_Score, EV_NO_ARGS);
	// called when a spawnpoint is being evaluated
	// return 1 to make the spawnpoint unusable
	// INPUT
//	entity self; // player wanting to spawn
//	entity spawn_spot; // spot to be evaluated
	// IN+OUT
	vector spawn_score; // _x is priority, _y is "distance"

MUTATOR_HOOKABLE(SV_StartFrame, EV_NO_ARGS);
	// runs globally each server frame

MUTATOR_HOOKABLE(SetModname, EV_NO_ARGS);
	// OUT
//	string modname; // name of the mutator/mod if it warrants showing as such in the server browser

MUTATOR_HOOKABLE(Item_Spawn, EV_NO_ARGS);
	// called for each item being spawned on a map, including dropped weapons
	// return 1 to remove an item
	// INPUT
//	entity self; // the item

MUTATOR_HOOKABLE(SetWeaponreplace, EV_NO_ARGS);
	// IN
//		entity self; // map entity
//		entity other; // weapon info
	// IN+OUT
//		string ret_string;

MUTATOR_HOOKABLE(Item_RespawnCountdown, EV_NO_ARGS);
	// called when an item is about to respawn
	// INPUT+OUTPUT:
	string item_name;
	vector item_color;

MUTATOR_HOOKABLE(BotShouldAttack, EV_NO_ARGS);
	// called when a bot checks a target to attack
	// INPUT
	entity checkentity;

MUTATOR_HOOKABLE(PortalTeleport, EV_NO_ARGS);
	// called whenever a player goes through a portal gun teleport
	// allows you to strip a player of an item if they go through the teleporter to help prevent cheating
	// INPUT
//	entity self;

MUTATOR_HOOKABLE(HelpMePing, EV_NO_ARGS);
	// called whenever a player uses impulse 33 (help me) in cl_impulse.qc
	// normally help me ping uses self.waypointsprite_attachedforcarrier,
	// but if your mutator uses something different then you can handle it
	// in a special manner using this hook
	// INPUT
//	entity self; // the player who pressed impulse 33

MUTATOR_HOOKABLE(VehicleSpawn, EV_NO_ARGS);
	// called when a vehicle initializes
	// return true to remove the vehicle

MUTATOR_HOOKABLE(VehicleEnter, EV_NO_ARGS);
	// called when a player enters a vehicle
	// allows mutators to set special settings in this event
	// INPUT
	entity vh_player; // player
	entity vh_vehicle; // vehicle

MUTATOR_HOOKABLE(VehicleTouch, EV_NO_ARGS);
	// called when a player touches a vehicle
	// return true to stop player from entering the vehicle
	// INPUT
//	entity self; // vehicle
//	entity other; // player

MUTATOR_HOOKABLE(VehicleExit, EV_NO_ARGS);
	// called when a player exits a vehicle
	// allows mutators to set special settings in this event
	// INPUT
//	entity vh_player; // player
//	entity vh_vehicle; // vehicle

MUTATOR_HOOKABLE(AbortSpeedrun, EV_NO_ARGS);
	// called when a speedrun is aborted and the player is teleported back to start position
	// INPUT
//	entity self; // player

MUTATOR_HOOKABLE(ItemTouch, EV_NO_ARGS);
	// called at when a item is touched. Called early, can edit item properties.
//	entity self;	// item
//	entity other; 	// player
enum {
	MUT_ITEMTOUCH_CONTINUE, // return this flag to make the function continue as normal
	MUT_ITEMTOUCH_RETURN, // return this flag to make the function return (handled entirely by mutator)
	MUT_ITEMTOUCH_PICKUP // return this flag to have the item "picked up" and taken even after mutator handled it
};

MUTATOR_HOOKABLE(ClientConnect, EV_NO_ARGS);
	// called at when a player connect
//	entity self;	// player

MUTATOR_HOOKABLE(HavocBot_ChooseRole, EV_NO_ARGS);
//	entity self;

MUTATOR_HOOKABLE(AccuracyTargetValid, EV_NO_ARGS);
	// called when a target is checked for accuracy
//	entity frag_attacker; // attacker
//	entity frag_target; // target
enum {
	MUT_ACCADD_VALID, // return this flag to make the function continue if target is a client
	MUT_ACCADD_INVALID, // return this flag to make the function always continue
	MUT_ACCADD_INDIFFERENT // return this flag to make the function always return
};
#endif