#include <stdlib.h>

#include "templates.h"
#include "m_random.h"
#include "m_alloc.h"
#include "i_system.h"
#include "doomdef.h"
#include "p_local.h"
#include "p_lnspec.h"
#include "p_effect.h"
#include "s_sound.h"
#include "g_game.h"
#include "doomstat.h"
#include "r_state.h"
#include "c_cvars.h"
#include "p_enemy.h"
#include "a_sharedglobal.h"
#include "a_doomglobal.h"
#include "a_action.h"
#include "thingdef/thingdef.h"

#include "gi.h"

AActor *LookForTIDinBlock (AActor *lookee, int index);
bool P_LookForEnemies (AActor *actor, INTBOOL allaround);
bool P_LookForMonsters (AActor *actor);

static FRandom pr_look2 ("LookyLookyEx");
static FRandom pr_look3 ("IGotHookyEx");
static FRandom pr_lookforplayers ("LookForPlayersEx");


// [KS] *** Start additions by me - p_enemy.cpp ***

// P_NewLookTID (copied from P_LookForTID)
// P_NewLookPlayers (copied from P_LookForPlayers)
// Takes FOV and sight distances into account when acquiring a target.
// TODO: This is very unfriendly to the friendly monster logic due to the intermingled code.
// TODO: Default the FOV to 360 if the monster has +LOOKALLAROUND set.
//  ~Kate S. 12/19/2007

bool P_NewLookTID (AActor *actor, angle_t fov, fixed_t mindist, fixed_t maxdist, bool chasegoal)
{
	AActor *other;
	bool reachedend = false;
	fixed_t 	dist;
	angle_t		an;

	other = P_BlockmapSearch (actor, 0, LookForTIDinBlock);

	if (other != NULL)
	{
		if (actor->goal && actor->target == actor->goal)
			actor->reactiontime = 0;

		actor->target = other;
		actor->LastLook.Actor = other;
		return true;
	}

	// The actor's TID could change because of death or because of
	// Thing_ChangeTID. If it's not what we expect, then don't use
	// it as a base for the iterator.
	if (actor->LastLook.Actor != NULL &&
		actor->LastLook.Actor->tid != actor->TIDtoHate)
	{
		actor->LastLook.Actor = NULL;
	}

	FActorIterator iterator (actor->TIDtoHate, actor->LastLook.Actor);
	int c = (pr_look3() & 31) + 7;	// Look for between 7 and 38 hatees at a time
	while ((other = iterator.Next()) != actor->LastLook.Actor)
	{
		if (other == NULL)
		{
			if (reachedend)
			{
				// we have cycled through the entire list at least once
				// so let's abort because even if we continue nothing can
				// be found.
				break;
			}
			reachedend = true;
			continue;
		}

		if (!(other->flags & MF_SHOOTABLE))
			continue;			// not shootable (observer or dead)

		if (other == actor)
			continue;			// don't hate self

		if (other->health <= 0)
			continue;			// dead

		if (other->flags2 & MF2_DORMANT)
			continue;			// don't target dormant things

		if (--c == 0)
			break;

		if (!(actor->flags3 & MF3_NOSIGHTCHECK))
		{
			if (!P_CheckSight (actor, other, 2))
				continue;			// out of sight

			dist = P_AproxDistance (other->x - actor->x,
									other->y - actor->y);

			if (maxdist && dist > maxdist)
				continue;			// [KS] too far

			if (mindist && dist < mindist)
				continue;			// [KS] too close

			if (fov)
			{
				an = R_PointToAngle2 (actor->x,
									  actor->y, 
									  other->x,
									  other->y)
					- actor->angle;

				if (an > (fov / 2) && an < (ANGLE_MAX - (fov / 2)))
				{
					// if real close, react anyway
					// [KS] but respect minimum distance rules
					if (mindist || dist > MELEERANGE)
						continue;	// outside of fov
				}
			}
			else
			{
				an = R_PointToAngle2 (actor->x,
									  actor->y, 
									  other->x,
									  other->y)
					- actor->angle;

				if (an > ANG90 && an < ANG270)
				{
					// if real close, react anyway
					if (dist > MELEERANGE)
						continue;	// behind back
				}
			}
		}
		
		// [RH] Need to be sure the reactiontime is 0 if the monster is
		//		leaving its goal to go after something else.
		if (actor->goal && actor->target == actor->goal)
			actor->reactiontime = 0;

		actor->target = other;
		actor->LastLook.Actor = other;
		return true;
	}
	actor->LastLook.Actor = other;
	if (actor->target == NULL)
	{
		// [RH] use goal as target
		if (actor->goal != NULL && chasegoal)
		{
			actor->target = actor->goal;
			return true;
		}
		// Use last known enemy if no hatee sighted -- killough 2/15/98:
		if (actor->lastenemy != NULL && actor->lastenemy->health > 0)
		{
			if (!actor->IsFriend(actor->lastenemy))
			{
				actor->target = actor->lastenemy;
				actor->lastenemy = NULL;
				return true;
			}
			else
			{
				actor->lastenemy = NULL;
			}
		}
	}
	return false;
}

bool P_NewLookPlayers (AActor *actor, angle_t fov, fixed_t mindist, fixed_t maxdist, bool chasegoal)
{
	int 		c;
	int 		stop;
	int			pnum;
	player_t*	player;
	angle_t 	an;
	fixed_t 	dist;

	if (actor->TIDtoHate != 0)
	{
		if (P_NewLookTID (actor, fov, mindist, maxdist, chasegoal))
		{
			return true;
		}
		if (!(actor->flags3 & MF3_HUNTPLAYERS))
		{
			return false;
		}
	}
	else if (actor->flags & MF_FRIENDLY)
	{
		return P_LookForEnemies (actor, fov? (fov > ANG270) : 0);
	}

	if (!(gameinfo.gametype & (GAME_Doom|GAME_Strife)) &&
		!multiplayer &&
		players[0].health <= 0)
	{ // Single player game and player is dead; look for monsters
		return P_LookForMonsters (actor);
	}

	c = 0;
	if (actor->TIDtoHate != 0)
	{
		pnum = pr_look2() & (MAXPLAYERS-1);
	}
	else
	{
		pnum = actor->LastLook.PlayerNumber;
	}
	stop = (pnum - 1) & (MAXPLAYERS-1);
		
	for (;;)
	{
		pnum = (pnum + 1) & (MAXPLAYERS-1);
		if (!playeringame[pnum])
			continue;

		if (actor->TIDtoHate == 0)
		{
			actor->LastLook.PlayerNumber = pnum;
		}

		if (++c == MAXPLAYERS-1 || pnum == stop)
		{
			// done looking
			if (actor->target == NULL)
			{
				// [RH] use goal as target
				// [KS] ...unless we're ignoring goals and we don't already have one
				if (actor->goal != NULL && chasegoal)
				{
					actor->target = actor->goal;
					return true;
				}
				// Use last known enemy if no players sighted -- killough 2/15/98:
				if (actor->lastenemy != NULL && actor->lastenemy->health > 0)
				{
					if (!actor->IsFriend(actor->lastenemy))
					{
						actor->target = actor->lastenemy;
						actor->lastenemy = NULL;
						return true;
					}
					else
					{
						actor->lastenemy = NULL;
					}
				}
			}
			return actor->target == actor->goal && actor->goal != NULL;
		}

		player = &players[pnum];

		if (!(player->mo->flags & MF_SHOOTABLE))
			continue;			// not shootable (observer or dead)

		if (player->cheats & CF_NOTARGET)
			continue;			// no target

		if (player->health <= 0)
			continue;			// dead

		if (!P_CheckSight (actor, player->mo, 2))
			continue;			// out of sight

		dist = P_AproxDistance (player->mo->x - actor->x,
								player->mo->y - actor->y);

		if (maxdist && dist > maxdist)
			continue;			// [KS] too far

		if (mindist && dist < mindist)
			continue;			// [KS] too close

		if (fov)
		{
			an = R_PointToAngle2 (actor->x,
								  actor->y, 
								  player->mo->x,
								  player->mo->y)
				- actor->angle;

			if (an > (fov / 2) && an < (ANGLE_MAX - (fov / 2)))
			{
				// if real close, react anyway
				// [KS] but respect minimum distance rules
				if (mindist || dist > MELEERANGE)
					continue;	// outside of fov
			}
		}
		else
		{
			an = R_PointToAngle2 (actor->x,
								  actor->y, 
								  player->mo->x,
								  player->mo->y)
				- actor->angle;

			if (an > ANG90 && an < ANG270)
			{
				// if real close, react anyway
				if (dist > MELEERANGE)
					continue;	// behind back
			}
		}
		if ((player->mo->flags & MF_SHADOW && !(i_compatflags & COMPATF_INVISIBILITY)) ||
			player->mo->flags3 & MF3_GHOST)
		{
			if ((P_AproxDistance (player->mo->x - actor->x,
					player->mo->y - actor->y) > 2*MELEERANGE)
				&& P_AproxDistance (player->mo->momx, player->mo->momy)
				< 5*FRACUNIT)
			{ // Player is sneaking - can't detect
				return false;
			}
			if (pr_lookforplayers() < 225)
			{ // Player isn't sneaking, but still didn't detect
				return false;
			}
		}
		
		// [RH] Need to be sure the reactiontime is 0 if the monster is
		//		leaving its goal to go after a player.
		if (actor->goal && actor->target == actor->goal)
			actor->reactiontime = 0;

		actor->target = player->mo;
		return true;
	}
}

//
// ACTION ROUTINES
//

//
// A_Look
// Stay in state until a player is sighted.
// [RH] Will also leave state to move to goal.
//
// A_LookEx (int flags, fixed minseedist, fixed maxseedist, fixed maxheardist, fixed fov, state wakestate)
// [KS] Borrowed the A_Look code to make a parameterized version.
//

enum LO_Flags
{
	LOF_NOSIGHTCHECK = 1,
	LOF_NOSOUNDCHECK = 2,
	LOF_DONTCHASEGOAL = 4,
	LOF_NOSEESOUND = 8,
	LOF_FULLVOLSEESOUND = 16,
};

void A_LookEx (AActor *actor)
{
	int index=CheckIndex(6, &CallingState);
	if (index<0) return;

	int flags = EvalExpressionI (StateParameters[index], actor);
	//if ((flags & LOF_NOSIGHTCHECK) && (flags & LOF_NOSOUNDCHECK)) return; // [KS] Can't see and can't hear so it'd be redundant to continue with a check we know would be false.
	//But it can still be used to make an actor leave to a goal without waking up immediately under certain conditions.

	fixed_t minseedist = fixed_t(EvalExpressionF (StateParameters[index+1], actor) * FRACUNIT);
	fixed_t maxseedist = fixed_t(EvalExpressionF (StateParameters[index+2], actor) * FRACUNIT);
	fixed_t maxheardist = fixed_t(EvalExpressionF (StateParameters[index+3], actor) * FRACUNIT);
	angle_t fov = angle_t(EvalExpressionF (StateParameters[index+4], actor) * ANGLE_1);
	FState *seestate = P_GetState(actor, CallingState, StateParameters[index+5]);

	AActor *targ = NULL; // Shuts up gcc
	fixed_t dist;

	// [KS] I -had- some sanity checks for the parameters here but they caused the rest of the code to fail so I removed them again.

	// [RH] Set goal now if appropriate
	if (actor->special == Thing_SetGoal && actor->args[0] == 0) 
	{
		NActorIterator iterator (NAME_PatrolPoint, actor->args[1]);
		actor->special = 0;
		actor->goal = iterator.Next ();
		actor->reactiontime = actor->args[2] * TICRATE + level.maptime;
		if (actor->args[3] == 0) actor->flags5 &=~ MF5_CHASEGOAL;
		else actor->flags5 |= MF5_CHASEGOAL;
	}

	actor->threshold = 0;		// any shot will wake up

	if (actor->TIDtoHate != 0)
	{
		targ = actor->target;
	}
	else
	{
		if (!(flags & LOF_NOSOUNDCHECK))
		{
			targ = (i_compatflags & COMPATF_SOUNDTARGET || actor->flags & MF_NOSECTOR)? 
				actor->Sector->SoundTarget : actor->LastHeard;
			if (targ != NULL)
			{
				// [RH] If the soundtarget is dead, don't chase it
				if (targ->health <= 0)
				{
					targ = NULL;
				}

				dist = P_AproxDistance (targ->x - actor->x,
										targ->y - actor->y);

				// [KS] If the target is too far away, don't respond to the sound.
				if (maxheardist && dist > maxheardist)
				{
					targ = NULL;
					actor->LastHeard = NULL;
				}
			}

			if (targ && targ->player && (targ->player->cheats & CF_NOTARGET))
			{
				return;
			}
		}
	}

	// [RH] Andy Baker's stealth monsters
	if (actor->flags & MF_STEALTH)
	{
		actor->visdir = -1;
	}

	if (targ && (targ->flags & MF_SHOOTABLE))
	{
		if (actor->IsFriend (targ))	// be a little more precise!
		{
			if (!(flags & LOF_NOSIGHTCHECK))
			{
				// If we find a valid target here, the wandering logic should *not*
				// be activated! If would cause the seestate to be set twice.
				if (P_NewLookPlayers(actor, fov, minseedist, maxseedist, !(flags & LOF_DONTCHASEGOAL)))
					goto seeyou;
			}

			// Let the actor wander around aimlessly looking for a fight
			if (actor->SeeState != NULL)
			{
				if (!(actor->flags & MF_INCHASE))
				{
					if (seestate)
					{
						actor->SetState (seestate);
					}
					else
					{
						actor->SetState (actor->SeeState);
					}
				}
			}
			else
			{
				A_Wander (actor);
			}
		}
		else
		{
			actor->target = targ; //We already have a target?

			if (actor->flags & MF_AMBUSH)
			{
				dist = P_AproxDistance (targ->x - actor->x,
										targ->y - actor->y);
				if (P_CheckSight (actor, actor->target, 2) &&
					(!minseedist || dist > minseedist) &&
					(!maxseedist || dist < maxseedist))
				{
					goto seeyou;
				}
			}
			else
				goto seeyou;
		}
	}

	if (!(flags & LOF_NOSIGHTCHECK))
	{
		if (!P_NewLookPlayers(actor, fov, minseedist, maxseedist, !(flags & LOF_DONTCHASEGOAL)))
			return;
	}
	else
	{
		return;
	}
				
	// go into chase state
  seeyou:
	// [RH] Don't start chasing after a goal if it isn't time yet.
	if (actor->target == actor->goal)
	{
		if (actor->reactiontime > level.maptime)
			actor->target = NULL;
	}
	else if (actor->SeeSound && !(flags & LOF_NOSEESOUND))
	{
		if (flags & LOF_FULLVOLSEESOUND)
		{ // full volume
			S_SoundID (actor, CHAN_VOICE, actor->SeeSound, 1, ATTN_SURROUND);
		}
		else
		{
			S_SoundID (actor, CHAN_VOICE, actor->SeeSound, 1, ATTN_NORM);
		}
	}

	if (actor->target && !(actor->flags & MF_INCHASE))
	{
		if (seestate)
		{
			actor->SetState (seestate);
		}
		else
		{
			actor->SetState (actor->SeeState);
		}
	}
}

// [KS] *** End additions by me ***