// Copyright (c) Athena Dev Teams - Licensed under GNU GPL
// For more information, see LICENCE in the main folder

#include "../common/showmsg.h"
#include "../common/timer.h"
#include "../common/nullpo.h"
#include "../common/db.h"
#include "../common/malloc.h"
#include "unit.h"
#include "map.h"
#include "path.h"
#include "pc.h"
#include "mob.h"
#include "pet.h"
#include "mercenary.h"
#include "skill.h"
#include "clif.h"
#include "npc.h"
#include "guild.h"
#include "status.h"
#include "battle.h"
#include "chat.h"
#include "trade.h"
#include "vending.h"
#include "party.h"
#include "intif.h"
#include "chrif.h"
#include "script.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


const short dirx[8]={0,-1,-1,-1,0,1,1,1};
const short diry[8]={1,1,0,-1,-1,-1,0,1};

struct unit_data* unit_bl2ud(struct block_list *bl)
{
	if( bl == NULL) return NULL;
	if( bl->type == BL_PC)  return &((struct map_session_data*)bl)->ud;
	if( bl->type == BL_MOB) return &((struct mob_data*)bl)->ud;
	if( bl->type == BL_PET) return &((struct pet_data*)bl)->ud;
	if( bl->type == BL_NPC) return &((struct npc_data*)bl)->ud;
	if( bl->type == BL_HOM) return &((struct homun_data*)bl)->ud;	//[orn]
	return NULL;
}

static int unit_attack_timer(int tid,unsigned int tick,int id,int data);
static int unit_walktoxy_timer(int tid,unsigned int tick,int id,int data);

int unit_walktoxy_sub(struct block_list *bl)
{
	int i;
	struct walkpath_data wpd;
	struct unit_data *ud = NULL;

	nullpo_retr(1, bl);
	ud = unit_bl2ud(bl);
	if(ud == NULL) return 0;

	if( !path_search(&wpd,bl->m,bl->x,bl->y,ud->to_x,ud->to_y,ud->state.walk_easy,CELL_CHKNOPASS) )
		return 0;

	memcpy(&ud->walkpath,&wpd,sizeof(wpd));
	
	if (ud->target && ud->chaserange>1) {
		//Generally speaking, the walk path is already to an adjacent tile
		//so we only need to shorten the path if the range is greater than 1.
		int dir;
		//Trim the last part of the path to account for range,
		//but always move at least one cell when requested to move.
		for (i = ud->chaserange*10; i > 0 && ud->walkpath.path_len>1;) {
		   ud->walkpath.path_len--;
			dir = ud->walkpath.path[ud->walkpath.path_len];
			if(dir&1)
				i-=14;
			else
				i-=10;
			ud->to_x -= dirx[dir];
			ud->to_y -= diry[dir];
		}
	}

	ud->state.change_walk_target=0;

	if (bl->type == BL_PC) {
		((TBL_PC *)bl)->head_dir = 0;
		clif_walkok((TBL_PC*)bl);
	}
	clif_move(ud);

	if(ud->walkpath.path_pos>=ud->walkpath.path_len)
		i = -1;
	else if(ud->walkpath.path[ud->walkpath.path_pos]&1)
		i = status_get_speed(bl)*14/10;
	else
		i = status_get_speed(bl);
	if( i > 0)
		ud->walktimer = add_timer(gettick()+i,unit_walktoxy_timer,bl->id,i);
	return 1;
}

static int unit_walktoxy_timer(int tid,unsigned int tick,int id,int data)
{
	int i;
	int x,y,dx,dy;
	uint8 dir;
	struct block_list       *bl;
	struct map_session_data *sd;
	struct mob_data         *md;
	struct unit_data        *ud;

	bl = map_id2bl(id);
	if(bl == NULL)
		return 0;
	sd = BL_CAST(BL_PC, bl);
	md = BL_CAST(BL_MOB, bl);
	ud = unit_bl2ud(bl);
	
	if(ud == NULL) return 0;

	if(ud->walktimer != tid){
		ShowError("unit_walk_timer mismatch %d != %d\n",ud->walktimer,tid);
		return 0;
	}
	ud->walktimer=-1;
	if( bl->prev == NULL ) return 0; // block_list から抜けているので移動停止する

	if(ud->walkpath.path_pos>=ud->walkpath.path_len)
		return 0;

	if(ud->walkpath.path[ud->walkpath.path_pos]>=8)
		return 1;
	x = bl->x;
	y = bl->y;

	dir = ud->walkpath.path[ud->walkpath.path_pos];
	ud->dir = dir;

	dx = dirx[(int)dir];
	dy = diry[(int)dir];

	if(map_getcell(bl->m,x+dx,y+dy,CELL_CHKNOPASS))
		return unit_walktoxy_sub(bl);
	
	// バシリカ判定

	map_foreachinmovearea(clif_outsight, bl, AREA_SIZE, dx, dy, sd?BL_ALL:BL_PC, bl);

	x += dx;
	y += dy;
	map_moveblock(bl, x, y, tick);
	ud->walk_count++; //walked cell counter, to be used for walk-triggered skills. [Skotlex]

	if (bl->x != x || bl->y != y || ud->walktimer != -1)
		return 0; //map_moveblock has altered the object beyond what we expected (moved/warped it)

	ud->walktimer = 1;
	map_foreachinmovearea(clif_insight, bl, AREA_SIZE, -dx, -dy, sd?BL_ALL:BL_PC, bl);
	ud->walktimer = -1;
	
	if(sd) {
		if(map_getcell(bl->m,x,y,CELL_CHKNPC)) {
			npc_touch_areanpc(sd,bl->m,x,y);
			if (bl->prev == NULL) //Script could have warped char, abort remaining of the function.
				return 0;
		} else
			sd->areanpc_id=0;
		if (sd->state.gmaster_flag &&
			(battle_config.guild_aura&(agit_flag?2:1)) &&
			(battle_config.guild_aura&(map_flag_gvg2(bl->m)?8:4))
		)
		{ //Guild Aura: Likely needs to be recoded, this method seems inefficient.
			struct guild *g = sd->state.gmaster_flag;
			int skill, strvit= 0, agidex = 0;
			if ((skill = guild_checkskill(g, GD_LEADERSHIP)) > 0) strvit |= (skill&0xFFFF)<<16;
			if ((skill = guild_checkskill(g, GD_GLORYWOUNDS)) > 0) strvit |= (skill&0xFFFF);
			if ((skill = guild_checkskill(g, GD_SOULCOLD)) > 0) agidex |= (skill&0xFFFF)<<16;
			if ((skill = guild_checkskill(g, GD_HAWKEYES)) > 0) agidex |= skill&0xFFFF;
			if (strvit || agidex)
				map_foreachinrange(skill_guildaura_sub, bl,2, BL_PC,
					bl->id, sd->status.guild_id, strvit, agidex);
		}
	} else if (md) {
		if(battle_config.mob_warp&1 && map_getcell(bl->m,x,y,CELL_CHKNPC) &&
			npc_touch_areanpc2(bl)) // Enable mobs to step on warps. [Skotlex]
	  		return 0;
		if (md->min_chase > md->db->range3) md->min_chase--;
		//Walk skills are triggered regardless of target due to the idle-walk mob state.
		//But avoid triggering on stop-walk calls.
		if(tid != -1 &&
			!(ud->walk_count%WALK_SKILL_INTERVAL) &&
			mobskill_use(md, tick, -1))
	  	{
			if (!(ud->skillid == NPC_SELFDESTRUCTION && ud->skilltimer != -1))
			{	//Skill used, abort walking
				clif_fixpos(bl); //Fix position as walk has been cancelled.
				return 0;
			}
			//Resend walk packet for proper Self Destruction display.
			clif_move(ud);
		}
	}

	if(tid == -1) //A directly invoked timer is from battle_stop_walking, therefore the rest is irrelevant.
		return 0;
		
	if(ud->state.change_walk_target)
		return unit_walktoxy_sub(bl);

	ud->walkpath.path_pos++;
	if(ud->walkpath.path_pos>=ud->walkpath.path_len)
		i = -1;
	else if(ud->walkpath.path[ud->walkpath.path_pos]&1)
		i = status_get_speed(bl)*14/10;
	else
		i = status_get_speed(bl);

	if(i > 0)
		ud->walktimer = add_timer(tick+i,unit_walktoxy_timer,id,i);
	else if(ud->state.running) {
		//Keep trying to run.
		if (!unit_run(bl))
			ud->state.running = 0;
	} else if (ud->target) {
		//Update target trajectory.
		struct block_list *tbl = map_id2bl(ud->target);
		if (!tbl || !status_check_visibility(bl, tbl)) {	//Cancel chase.
			ud->to_x = bl->x;
			ud->to_y = bl->y;
			if (tbl && bl->type == BL_MOB) //See if the mob can do a warp chase.
				mob_warpchase((TBL_MOB*)bl, tbl);
			return 0;
		}
		if (tbl->m == bl->m && check_distance_bl(bl, tbl, ud->chaserange))
		{	//Reached destination.
			if (ud->state.attack_continue)
			{	//Aegis uses one before every attack, we should
				//only need this one for syncing purposes. [Skotlex]
				clif_fixpos(bl);
				unit_attack(bl, tbl->id, ud->state.attack_continue);
			}
		} else { //Update chase-path
			unit_walktobl(bl, tbl, ud->chaserange, ud->state.walk_easy|(ud->state.attack_continue?2:0));
			return 0;
		}
	} else {	//Stopped walking. Update to_x and to_y to current location [Skotlex]
		ud->to_x = bl->x;
		ud->to_y = bl->y;
		if(md && md->nd) // Tell the script engine we've finished walking (for AI pathfinding)
			mob_script_callback(md, NULL, CALLBACK_WALKACK);
	}
	return 0;
}

static int unit_delay_walktoxy_timer(int tid, unsigned int tick, int id, int data)
{
	struct block_list *bl = map_id2bl(id);

	if (!bl || bl->prev == NULL)
		return 0;
	unit_walktoxy(bl, data>>16, data&0xffff, 0);
	return 1;
}

//flag parameter:
//&1 -> 1/0 = easy/hard
//&2 -> force walking
//&4 -> Delay walking if the reason you can't walk is the canwalk delay
int unit_walktoxy( struct block_list *bl, short x, short y, int flag)
{
	struct unit_data* ud = NULL;
	struct status_change* sc = NULL;

	nullpo_retr(0, bl);
	
	ud = unit_bl2ud(bl);
	
	if( ud == NULL) return 0;

	if (flag&4 && DIFF_TICK(ud->canmove_tick, gettick()) > 0 &&
		DIFF_TICK(ud->canmove_tick, gettick()) < 2000)
  	{	// Delay walking command. [Skotlex]
		add_timer(ud->canmove_tick+1, unit_delay_walktoxy_timer, bl->id, (x<<16)|(y&0xFFFF));
		return 1;
	}

	if(!(flag&2) && (!(status_get_mode(bl)&MD_CANMOVE) || !unit_can_move(bl)))
		return 0;
	
	ud->state.walk_easy = flag&1;
	ud->target = 0;
	ud->to_x = x;
	ud->to_y = y;
	
	sc = status_get_sc(bl);
	if (sc && sc->data[SC_CONFUSION]) //Randomize the target position
		map_random_dir(bl, &ud->to_x, &ud->to_y);

	if(ud->walktimer != -1) {
		// 現在歩いている最中の目的地変更なのでマス目の中心に来た時に
		// timer関数からunit_walktoxy_subを呼ぶようにする
		ud->state.change_walk_target = 1;
		return 1;
	}

	if(ud->attacktimer != -1) {
		delete_timer( ud->attacktimer, unit_attack_timer );
		ud->attacktimer = -1;
	}

	return unit_walktoxy_sub(bl);
}

//To set Mob's CHASE/FOLLOW states (shouldn't be done if there's no path to reach)
#define set_mobstate(bl, flag) \
	if((bl)->type == BL_MOB && (flag)) \
		((TBL_MOB*)(bl))->state.skillstate = ((TBL_MOB*)(bl))->state.aggressive?MSS_FOLLOW:MSS_RUSH;

static int unit_walktobl_sub(int tid,unsigned int tick,int id,int data)
{
	struct block_list *bl = map_id2bl(id);
	struct unit_data *ud = bl?unit_bl2ud(bl):NULL;

	if (ud && ud->walktimer == -1 && ud->target == data)
	{
		if (DIFF_TICK(ud->canmove_tick, tick) > 0) //Keep waiting?
			add_timer(ud->canmove_tick+1, unit_walktobl_sub, id, data);
		else if (unit_can_move(bl))
		{
			if (unit_walktoxy_sub(bl))
				set_mobstate(bl, ud->state.attack_continue);
		}
	}
	return 0;	
}

// Chases a tbl. If the flag&1, use hard-path seek,
// if flag&2, start attacking upon arrival within range, otherwise just walk to that character.
int unit_walktobl(struct block_list *bl, struct block_list *tbl, int range, int flag)
{
	struct unit_data        *ud = NULL;
	struct status_change		*sc = NULL;
	nullpo_retr(0, bl);
	nullpo_retr(0, tbl);
	
	ud = unit_bl2ud(bl);
	if( ud == NULL) return 0;

	if (!(status_get_mode(bl)&MD_CANMOVE))
		return 0;
	
	if (!unit_can_reach_bl(bl, tbl, distance_bl(bl, tbl)+1, flag&1, &ud->to_x, &ud->to_y)) {
		ud->to_x = bl->x;
		ud->to_y = bl->y;
		return 0;
	}

	ud->state.walk_easy = flag&1;
	ud->target = tbl->id;
	ud->chaserange = range; //Note that if flag&2, this SHOULD be attack-range
	ud->state.attack_continue = flag&2?1:0; //Chase to attack.

	sc = status_get_sc(bl);
	if (sc && sc->data[SC_CONFUSION]) //Randomize the target position
		map_random_dir(bl, &ud->to_x, &ud->to_y);

	if(ud->walktimer != -1) {
		ud->state.change_walk_target = 1;
		set_mobstate(bl, flag&2);
		return 1;
	}

	if(DIFF_TICK(ud->canmove_tick, gettick()) > 0)
	{	//Can't move, wait a bit before invoking the movement.
		add_timer(ud->canmove_tick+1, unit_walktobl_sub, bl->id, ud->target);
		return 1;
	}

	if(!unit_can_move(bl))
		return 0;

	if(ud->attacktimer != -1) {
		delete_timer( ud->attacktimer, unit_attack_timer );
		ud->attacktimer = -1;
	}

	if (unit_walktoxy_sub(bl)) {
		set_mobstate(bl, flag&2);
		return 1;
	}
	return 0;
}
#undef set_mobstate

int unit_run(struct block_list *bl)
{
	struct status_change *sc = status_get_sc(bl);
	short to_x,to_y,dir_x,dir_y;
	int lv;
	int i;

	if (!(sc && sc->data[SC_RUN]))
		return 0;
	
	if (!unit_can_move(bl)) {
		status_change_end(bl,SC_RUN,-1);
		return 0;
	}
	
	lv = sc->data[SC_RUN]->val1;
	dir_x = dirx[sc->data[SC_RUN]->val2];
	dir_y = diry[sc->data[SC_RUN]->val2];

	// determine destination cell
	to_x = bl->x;
	to_y = bl->y;
	for(i=0;i<AREA_SIZE;i++)
	{
		if(!map_getcell(bl->m,to_x+dir_x,to_y+dir_y,CELL_CHKPASS))
			break;

		//if sprinting and there's a PC/Mob/NPC, block the path [Kevin]
		if(sc->data[SC_RUN] && map_count_oncell(bl->m, to_x+dir_x, to_y+dir_y, BL_PC|BL_MOB|BL_NPC))
			break;
			
		to_x += dir_x;
		to_y += dir_y;
	}

	if(to_x == bl->x && to_y == bl->y) {
		//If you can't run forward, you must be next to a wall, so bounce back. [Skotlex]
		clif_status_change(bl, SI_BUMP, 1);
		status_change_end(bl,SC_RUN,-1);
		skill_blown(bl,bl,skill_get_blewcount(TK_RUN,lv),unit_getdir(bl),0);
		clif_fixpos(bl); //Why is a clif_slide (skill_blown) AND a fixpos needed? Ask Aegis.
		clif_status_change(bl, SI_BUMP, 0);
		return 0;
	}
	if (unit_walktoxy(bl, to_x, to_y, 1))
		return 1;
	//There must be an obstacle nearby. Attempt walking one cell at a time.
	do {
		to_x -= dir_x;
		to_y -= dir_y;
	} while (--i > 0 && !unit_walktoxy(bl, to_x, to_y, 1));
	if (i==0) {
		// copy-paste from above
		clif_status_change(bl, SI_BUMP, 1);
		status_change_end(bl,SC_RUN,-1);
		skill_blown(bl,bl,skill_get_blewcount(TK_RUN,lv),unit_getdir(bl),0);
		clif_fixpos(bl);
		clif_status_change(bl, SI_BUMP, 0);
		return 0;
	}
	return 1;
}

//Makes bl attempt to run dist cells away from target. Uses hard-paths.
int unit_escape(struct block_list *bl, struct block_list *target, short dist)
{
	int dir = map_calc_dir(target, bl->x, bl->y);
	while( dist > 0 && map_getcell(bl->m, bl->x + dist*dirx[dir], bl->y + dist*diry[dir], CELL_CHKNOREACH) )
		dist--;
	return ( dist > 0 && unit_walktoxy(bl, bl->x + dist*dirx[dir], bl->y + dist*diry[dir], 0) );
}

//Instant warp function.
int unit_movepos(struct block_list *bl, short dst_x, short dst_y, int easy, bool checkpath)
{
	short dx,dy;
	uint8 dir;
	struct unit_data        *ud = NULL;
	struct map_session_data *sd = NULL;

	nullpo_retr(0, bl);
	sd = BL_CAST(BL_PC, bl);
	ud = unit_bl2ud(bl);

	if( ud == NULL) return 0;

	unit_stop_walking(bl,1);
	unit_stop_attack(bl);

	if( checkpath && (map_getcell(bl->m,dst_x,dst_y,CELL_CHKNOPASS) || !path_search(NULL,bl->m,bl->x,bl->y,dst_x,dst_y,easy,CELL_CHKNOREACH)) )
		return 0; // unreachable

	dir = map_calc_dir(bl, dst_x,dst_y);
	ud->dir = dir;

	dx = dst_x - bl->x;
	dy = dst_y - bl->y;

	map_foreachinmovearea(clif_outsight, bl, AREA_SIZE, dx, dy, sd?BL_ALL:BL_PC, bl);

	map_moveblock(bl, dst_x, dst_y, gettick());
	
	ud->walktimer = 1;
	map_foreachinmovearea(clif_insight, bl, AREA_SIZE, -dx, -dy, sd?BL_ALL:BL_PC, bl);
	ud->walktimer = -1;
		
	if(sd) {
		if(map_getcell(bl->m,bl->x,bl->y,CELL_CHKNPC)) {
			npc_touch_areanpc(sd,bl->m,bl->x,bl->y);
			if (bl->prev == NULL) //Script could have warped char, abort remaining of the function.
				return 0;
		} else
			sd->areanpc_id=0;
		if(sd->status.pet_id > 0 && sd->pd && sd->pd->pet.intimate > 0)
		{	//Check if pet needs to be teleported. [Skotlex]
			int flag = 0;
			struct block_list* bl = &sd->pd->bl;
			if( !checkpath && !path_search(NULL,bl->m,bl->x,bl->y,dst_x,dst_y,0,CELL_CHKNOPASS) )
				flag = 1;
			else if (!check_distance_bl(&sd->bl, bl, AREA_SIZE)) //Too far, teleport.
				flag = 2;
			if (flag) {
				unit_movepos(bl,sd->bl.x,sd->bl.y, 0, 0);
				clif_slide(bl,bl->x,bl->y);
			}
		}
	}
	return 1;
}

int unit_setdir(struct block_list *bl,unsigned char dir)
{
	struct unit_data *ud;
	nullpo_retr( 0, bl );
	ud = unit_bl2ud(bl);
	if (!ud) return 0;
	ud->dir = dir;
	if (bl->type == BL_PC) 
		((TBL_PC *)bl)->head_dir = 0;
	clif_changed_dir(bl, AREA);
	return 0;
}

uint8 unit_getdir(struct block_list *bl)
{
	struct unit_data *ud;
	nullpo_retr( 0, bl );
	ud = unit_bl2ud(bl);
	if (!ud) return 0;
	return ud->dir;
}

//Warps a unit/ud to a given map/position. 
//In the case of players, pc_setpos is used.
//it respects the no warp flags, so it is safe to call this without doing nowarpto/nowarp checks.
int unit_warp(struct block_list *bl,short m,short x,short y,int type)
{
	struct unit_data *ud;
	nullpo_retr(0, bl);
	ud = unit_bl2ud(bl);
	
	if(bl->prev==NULL || !ud)
		return 1;

	if (type < 0 || type == 1)
		//Type 1 is invalid, since you shouldn't warp a bl with the "death" 
		//animation, it messes up with unit_remove_map! [Skotlex]
		return 1;
	
	if( m<0 ) m=bl->m;
	
	switch (bl->type) {
		case BL_MOB:
			if (map[bl->m].flag.monster_noteleport)
				return 1;
			if (m != bl->m && map[m].flag.nobranch && battle_config.mob_warp&4)
				return 1;
			break;
		case BL_PC:
			if (map[bl->m].flag.noteleport)
				return 1;
			break;
	}
	
	if (x<0 || y<0)
  	{	//Random map position.
		if (!map_search_freecell(NULL, m, &x, &y, -1, -1, 1)) {
			ShowWarning("unit_warp failed. Unit Id:%d/Type:%d, target position map %d (%s) at [%d,%d]\n", bl->id, bl->type, m, map[m].name, x, y);
			return 2;
			
		}
	} else if (map_getcell(m,x,y,CELL_CHKNOREACH))
	{	//Invalid target cell
		ShowWarning("unit_warp: Specified non-walkable target cell: %d (%s) at [%d,%d]\n", m, map[m].name, x,y);
		
		if (!map_search_freecell(NULL, m, &x, &y, 4, 4, 1))
	 	{	//Can't find a nearby cell
			ShowWarning("unit_warp failed. Unit Id:%d/Type:%d, target position map %d (%s) at [%d,%d]\n", bl->id, bl->type, m, map[m].name, x, y);
			return 2;
		}
	}

	if (bl->type == BL_PC) //Use pc_setpos
		return pc_setpos((TBL_PC*)bl, map_id2index(m), x, y, type);
	
	if (!unit_remove_map(bl, type))
		return 3;
	
	if (bl->m != m && battle_config.clear_unit_onwarp &&
		battle_config.clear_unit_onwarp&bl->type)
		skill_clear_unitgroup(bl);

	bl->x=ud->to_x=x;
	bl->y=ud->to_y=y;
	bl->m=m;

	map_addblock(bl);
	clif_spawn(bl);
	skill_unit_move(bl,gettick(),1);

	if(bl->type == BL_MOB){
		TBL_MOB *md = (TBL_MOB *)bl;
		if(md->nd) // Tell the script engine we've warped
			mob_script_callback(md, NULL, CALLBACK_WARPACK);
	}
	return 0;
}

/*==========================================
 * 歩行停止
 *------------------------------------------*/
int unit_stop_walking(struct block_list *bl,int type)
{
	struct unit_data *ud;
	struct TimerData *data;
	unsigned int tick;
	nullpo_retr(0, bl);

	ud = unit_bl2ud(bl);
	if(!ud || ud->walktimer == -1)
		return 0;
	//NOTE: We are using timer data after deleting it because we know the 
	//delete_timer function does not messes with it. If the function's 
	//behaviour changes in the future, this code could break!
	data = get_timer(ud->walktimer);
	delete_timer(ud->walktimer, unit_walktoxy_timer);
	ud->walktimer = -1;
	ud->state.change_walk_target = 0;
	tick = gettick();
	if ((type&0x02 && !ud->walkpath.path_pos) //Force moving at least one cell.
		|| (data && DIFF_TICK(data->tick, tick) <= data->data/2)) //Enough time has passed to cover half-cell
	{	
		ud->walkpath.path_len = ud->walkpath.path_pos+1;
		unit_walktoxy_timer(-1, tick, bl->id, ud->walkpath.path_pos);
	}

	if(type&0x01)
		clif_fixpos(bl);
	
	ud->walkpath.path_len = 0;
	ud->walkpath.path_pos = 0;
	ud->to_x = bl->x;
	ud->to_y = bl->y;
	if(bl->type == BL_PET && type&~0xff)
		ud->canmove_tick = gettick() + (type>>8);

	//Don't stop running because of dmg, just apply the instant stop then keep running [Kevin]
	//if (ud->state.running)
	//	status_change_end(bl, SC_RUN, -1);
	return 1;
}

int unit_skilluse_id(struct block_list *src, int target_id, short skill_num, short skill_lv)
{
	if(skill_num < 0) return 0;

	return unit_skilluse_id2(
		src, target_id, skill_num, skill_lv,
		skill_castfix(src, skill_num, skill_lv),
		skill_get_castcancel(skill_num)
	);
}

int unit_is_walking(struct block_list *bl)
{
	struct unit_data *ud = unit_bl2ud(bl);
	nullpo_retr(0, bl);
	if(!ud) return 0;
	return (ud->walktimer != -1);
}

/*==========================================
 * Determines if the bl can move based on status changes. [Skotlex]
 *------------------------------------------*/
int unit_can_move(struct block_list *bl)
{
	struct map_session_data *sd;
	struct unit_data *ud;
	struct status_change *sc;
	
	nullpo_retr(0, bl);
	ud = unit_bl2ud(bl);
	sc = status_get_sc(bl);
	sd = BL_CAST(BL_PC, bl);
	
	if (!ud)
		return 0;
	
	if (ud->skilltimer != -1 && (!sd || !pc_checkskill(sd, SA_FREECAST) || skill_get_inf2(ud->skillid)&INF2_GUILD_SKILL))
		return 0; // prevent moving while casting
	
	if (DIFF_TICK(ud->canmove_tick, gettick()) > 0)
		return 0;
	
	if (sd && (
		pc_issit(sd) ||
		sd->vender_id ||
		sd->state.blockedmove
	))
		return 0; //Can't move
	
	if (sc) {
		if (sc->opt1 > 0 && sc->opt1 != OPT1_STONEWAIT)
			return 0;

		if ((sc->option & OPTION_HIDE) && (!sd || pc_checkskill(sd, RG_TUNNELDRIVE) <= 0))
			return 0;

		if (sc->count && (
			sc->data[SC_ANKLE]
			|| sc->data[SC_AUTOCOUNTER]
			|| sc->data[SC_TRICKDEAD]
			|| sc->data[SC_BLADESTOP]
			|| sc->data[SC_BLADESTOP_WAIT]
			|| sc->data[SC_SPIDERWEB]
			|| (sc->data[SC_DANCING] && sc->data[SC_DANCING]->val4 && (
				!sc->data[SC_LONGING] ||
				(sc->data[SC_DANCING]->val1&0xFFFF) == CG_MOONLIT ||
				(sc->data[SC_DANCING]->val1&0xFFFF) == CG_HERMODE
			))
			|| (sc->data[SC_GOSPEL] && sc->data[SC_GOSPEL]->val4 == BCT_SELF)	// cannot move while gospel is in effect
			|| sc->data[SC_STOP]
			|| sc->data[SC_CLOSECONFINE]
			|| sc->data[SC_CLOSECONFINE2]
			|| (sc->data[SC_CLOAKING] && //Need wall at level 1-2
				sc->data[SC_CLOAKING]->val1 < 3 && !(sc->data[SC_CLOAKING]->val4&1))
			|| sc->data[SC_MADNESSCANCEL]
			|| (sc->data[SC_GRAVITATION] && sc->data[SC_GRAVITATION]->val3 == BCT_SELF)
		))
			return 0;
	}
	return 1;
}

/*==========================================
 * Applies walk delay to character, considering that 
 * if type is 0, this is a damage induced delay: if previous delay is active, do not change it.
 * if type is 1, this is a skill induced delay: walk-delay may only be increased, not decreased.
 *------------------------------------------*/
int unit_set_walkdelay(struct block_list *bl, unsigned int tick, int delay, int type)
{
	struct unit_data *ud = unit_bl2ud(bl);
	if (delay <= 0 || !ud) return 0;
	
	if (type) {
		if (DIFF_TICK(ud->canmove_tick, tick+delay) > 0)
			return 0;
	} else {
		if (DIFF_TICK(ud->canmove_tick, tick) > 0)
			return 0;
	}
	ud->canmove_tick = tick + delay;
	if (ud->walktimer != -1)
	{	//Stop walking, if chasing, readjust timers.
		if (delay == 1)
		{	//Minimal delay (walk-delay) disabled. Just stop walking.
			unit_stop_walking(bl,0);
		} else {
			unit_stop_walking(bl,2);
			if(ud->target)
				add_timer(ud->canmove_tick+1, unit_walktobl_sub, bl->id, ud->target);
		}
	}
	return 1;
}

int unit_skilluse_id2(struct block_list *src, int target_id, short skill_num, short skill_lv, int casttime, int castcancel)
{
	struct unit_data *ud;
	struct status_data *tstatus;
	struct status_change *sc;
	struct map_session_data *sd = NULL;
	struct block_list * target = NULL;
	unsigned int tick = gettick();
	int temp;

	nullpo_retr(0, src);
	if(status_isdead(src))
		return 0; // 死んでいないか

	sd = BL_CAST(BL_PC, src);
	ud = unit_bl2ud(src);

	if(ud == NULL) return 0;
	sc = status_get_sc(src);	
	if (sc && !sc->count)
		sc = NULL; //Unneeded
	//temp: used to signal combo-skills right now.
	temp = (target_id == src->id && !(sd && sd->state.skill_flag)
		&& skill_get_inf(skill_num)&INF_SELF_SKILL
		&& skill_get_inf2(skill_num)&INF2_NO_TARGET_SELF);
	if (temp)
		target_id = ud->target; //Auto-select skills. [Skotlex]

	if (sd) {
		//Target_id checking.
		if(skillnotok(skill_num, sd)) // [MouseJstr]
			return 0;

		mob_ksprotected(src, map_id2bl(target_id));

		switch(skill_num)
		{	//Check for skills that auto-select target
		case MO_CHAINCOMBO:
			if (sc && sc->data[SC_BLADESTOP]){
				if ((target=(struct block_list *)sc->data[SC_BLADESTOP]->val4) == NULL)
					return 0;
			}
			break;
		case TK_JUMPKICK:
		case TK_COUNTER:
		case HT_POWER:
			if (sc && sc->data[SC_COMBO] && sc->data[SC_COMBO]->val1 == skill_num)
				target_id = sc->data[SC_COMBO]->val2;
			break;
		case WE_MALE:
		case WE_FEMALE:
			if (!sd->status.partner_id)
				return 0;
			target = (struct block_list*)map_charid2sd(sd->status.partner_id);
			if (!target) {
				clif_skill_fail(sd,skill_num,0,0);
				return 0;
			}
			break;
		}
		if (target)
			target_id = target->id;
	}
	if (src->type==BL_HOM)
	switch(skill_num)
	{ //Homun-auto-target skills.
		case HLIF_HEAL:
		case HLIF_AVOID:
		case HAMI_DEFENCE:
		case HAMI_CASTLE:
			target = battle_get_master(src);
			if (!target) return 0;
			target_id = target->id;
	}

	if( !target ) // choose default target
		target = map_id2bl(target_id);

	if( !target || src->m != target->m || !src->prev || !target->prev )
		return 0;

	//Normally not needed because clif.c checks for it, but the at/char/script commands don't! [Skotlex]
	if(ud->skilltimer != -1 && skill_num != SA_CASTCANCEL)
		return 0;

	if(skill_get_inf2(skill_num)&INF2_NO_TARGET_SELF && src->id == target_id)
		return 0;

	if(!status_check_skilluse(src, target, skill_num, 0))
		return 0;

	tstatus = status_get_status_data(target);
	//直前のスキル状況の記録
	if(sd) {
		switch(skill_num){
		case SA_CASTCANCEL:
			if(ud->skillid != skill_num){
				sd->skillid_old = ud->skillid;
				sd->skilllv_old = ud->skilllv;
			}
			break;
		case BD_ENCORE:
			//Prevent using the dance skill if you no longer have the skill in your tree. 
			if(!sd->skillid_dance || pc_checkskill(sd,sd->skillid_dance)<=0){
				clif_skill_fail(sd,skill_num,0,0);
				return 0;
			}
			sd->skillid_old = skill_num;
			break;
		case BD_LULLABY:
		case BD_RICHMANKIM:
		case BD_ETERNALCHAOS:
		case BD_DRUMBATTLEFIELD:
		case BD_RINGNIBELUNGEN:
		case BD_ROKISWEIL:
		case BD_INTOABYSS:
		case BD_SIEGFRIED:
		case CG_MOONLIT:
			if (skill_check_pc_partner(sd, skill_num, &skill_lv, 1, 0) < 1)
			{
				clif_skill_fail(sd,skill_num,0,0);
				return 0;
			}
			break;
		}
		if (!skill_check_condition(sd, skill_num, skill_lv, 0))
			return 0;
	}
	//TODO: Add type-independant skill_check_condition function.
	if (src->type == BL_MOB) {
		switch (skill_num) {
			case NPC_SUMMONSLAVE:
			case NPC_SUMMONMONSTER:
			case AL_TELEPORT:
				if (((TBL_MOB*)src)->master_id && ((TBL_MOB*)src)->special_state.ai)
					return 0;
		}
	}

	//Check range when not using skill on yourself or is a combo-skill during attack
	//(these are supposed to always have the same range as your attack)
	if(src->id != target_id && (!temp || ud->attacktimer == -1))
	{
		if (skill_get_state(ud->skillid) == ST_MOVE_ENABLE)
		{
			if (!unit_can_reach_bl(src, target, skill_get_range2(src, skill_num,skill_lv)+1, 1, NULL, NULL))
				return 0; //Walk-path check failed.
		} else
		if	(!battle_check_range(src, target, skill_get_range2(src, skill_num,skill_lv)
			+(skill_num==RG_CLOSECONFINE?0:1)))
			//Close confine is exploitable thanks to this extra range "feature" of the client. [Skotlex]
			return 0; //Arrow-path check failed.
	}

	if (!temp) //Stop attack on non-combo skills [Skotlex]
		unit_stop_attack(src);
	else if(ud->attacktimer != -1) //Elsewise, delay current attack sequence
		ud->attackabletime = tick + status_get_adelay(src);
	
	ud->state.skillcastcancel = castcancel;

	//temp: Used to signal force cast now.
	temp = 0;
	
	switch(skill_num){
	case ALL_RESURRECTION:
		if(battle_check_undead(tstatus->race,tstatus->def_ele)) {	
			temp = 1;
			casttime = skill_castfix(src, PR_TURNUNDEAD, skill_lv);
		} else if (!status_isdead(target))
			return 0; //Can't cast on non-dead characters.
	break;
	case MO_FINGEROFFENSIVE:
		if(sd)
			casttime += casttime * min(skill_lv, sd->spiritball);
	break;
	case MO_EXTREMITYFIST:
		if (sc && sc->data[SC_COMBO] &&
		   (sc->data[SC_COMBO]->val1 == MO_COMBOFINISH ||
			sc->data[SC_COMBO]->val1 == CH_TIGERFIST ||
			sc->data[SC_COMBO]->val1 == CH_CHAINCRUSH))
			casttime = 0;
		temp = 1;
	break;
	case SA_SPELLBREAKER:
		temp = 1;
	break;
	case ST_CHASEWALK:
		if (sc && sc->data[SC_CHASEWALK])
			casttime = 0;
	break;
	case TK_RUN:
		if (sc && sc->data[SC_RUN])
			casttime = 0;
	break;
	case KN_CHARGEATK:
		{
		unsigned int k = (distance_bl(src,target)-1)/3; //+100% every 3 cells of distance
		if( k > 2 ) k = 2; // ...but hard-limited to 300%.
		casttime += casttime * k; 
		}
	break;
	}
  	
	// moved here to prevent Suffragium from ending if skill fails
	if (!(skill_get_castnodex(skill_num, skill_lv)&2))
		casttime = skill_castfix_sc(src, casttime);

	if( casttime>0 || temp){ 

		clif_skillcasting(src, src->id, target_id, 0,0, skill_num, skill_get_ele(skill_num, skill_lv), casttime);

		if (sd && target->type == BL_MOB)
		{
			TBL_MOB *md = (TBL_MOB*)target;
			mobskill_event(md, src, tick, -1); //Cast targetted skill event.
			//temp: used to store mob's mode now.
			if (tstatus->mode&(MD_CASTSENSOR_IDLE|MD_CASTSENSOR_CHASE) &&
				battle_check_target(target, src, BCT_ENEMY) > 0)
			{
				switch (md->state.skillstate) {
				case MSS_RUSH:
				case MSS_FOLLOW:
					if (!(tstatus->mode&MD_CASTSENSOR_CHASE))
						break;
					md->target_id = src->id;
					md->state.aggressive = (temp&MD_ANGRY)?1:0;
					md->min_chase = md->db->range3;
					break;
				case MSS_IDLE:
				case MSS_WALK:
					if (!(tstatus->mode&MD_CASTSENSOR_IDLE))
						break;
					md->target_id = src->id;
					md->state.aggressive = (temp&MD_ANGRY)?1:0;
					md->min_chase = md->db->range3;
					break;
				}
			}
		}
	}

	if( casttime<=0 )
		ud->state.skillcastcancel=0;

	ud->canact_tick  = tick + casttime + 100;
	ud->skilltarget  = target_id;
	ud->skillx       = 0;
	ud->skilly       = 0;
	ud->skillid      = skill_num;
	ud->skilllv      = skill_lv;

 	if(sc && sc->data[SC_CLOAKING] &&
		!(sc->data[SC_CLOAKING]->val4&4) && skill_num != AS_CLOAKING)
	{
		status_change_end(src,SC_CLOAKING,-1);
		if (!src->prev) return 0; //Warped away!
	}

	if(casttime > 0) {
		ud->skilltimer = add_timer( tick+casttime, skill_castend_id, src->id, 0 );
		if(sd && pc_checkskill(sd,SA_FREECAST))
			status_freecast_switch(sd);
		else
			unit_stop_walking(src,1);
	}
	else
		skill_castend_id(ud->skilltimer,tick,src->id,0);
	return 1;
}

int unit_skilluse_pos(struct block_list *src, short skill_x, short skill_y, short skill_num, short skill_lv)
{
	if(skill_num < 0)
		return 0;
	return unit_skilluse_pos2(
		src, skill_x, skill_y, skill_num, skill_lv,
		skill_castfix(src, skill_num, skill_lv),
		skill_get_castcancel(skill_num)
	);
}

int unit_skilluse_pos2( struct block_list *src, short skill_x, short skill_y, short skill_num, short skill_lv, int casttime, int castcancel)
{
	struct map_session_data *sd = NULL;
	struct unit_data        *ud = NULL;
	struct status_change *sc;
	struct block_list    bl;
	unsigned int tick = gettick();

	nullpo_retr(0, src);

	if(!src->prev) return 0; // map 上に存在するか
	if(status_isdead(src)) return 0;

	sd = BL_CAST(BL_PC, src);
	ud = unit_bl2ud(src);
	if(ud == NULL) return 0;

	if(ud->skilltimer != -1) //Normally not needed since clif.c checks for it, but at/char/script commands don't! [Skotlex]
		return 0;
	
	sc = status_get_sc(src);
	if (sc && !sc->count)
		sc = NULL;
	
	if(sd) {
		if (skillnotok(skill_num, sd) || !skill_check_condition(sd, skill_num, skill_lv,0))
		return 0;
	} 
	
	if (!status_check_skilluse(src, NULL, skill_num, 0))
		return 0;

	if( map_getcell(src->m, skill_x, skill_y, CELL_CHKWALL) )
	{// can't cast ground targeted spells on wall cells
		if (sd) clif_skill_fail(sd,skill_num,0,0);
		return 0;
	}

	/* 射程と障害物チェック */
	bl.type = BL_NUL;
	bl.m = src->m;
	bl.x = skill_x;
	bl.y = skill_y;

	if (skill_get_state(ud->skillid) == ST_MOVE_ENABLE)
	{
		if (!unit_can_reach_bl(src, &bl, skill_get_range2(src, skill_num,skill_lv)+1, 1, NULL, NULL))
			return 0; //Walk-path check failed.
	} else
	if	(!battle_check_range(src,&bl,skill_get_range2(src, skill_num,skill_lv)+1))
		return 0; //Arrow-path check failed.

	unit_stop_attack(src);
	ud->state.skillcastcancel = castcancel;

	// moved here to prevent Suffragium from ending if skill fails
	if (!(skill_get_castnodex(skill_num, skill_lv)&2))
		casttime = skill_castfix_sc(src, casttime);

	if( casttime>0 ) {
		unit_stop_walking( src, 1);
		clif_skillcasting(src, src->id, 0, skill_x, skill_y, skill_num, skill_get_ele(skill_num, skill_lv), casttime);
	} else
		ud->state.skillcastcancel=0;

	ud->canact_tick  = tick + casttime + 100;
	ud->skillid      = skill_num;
	ud->skilllv      = skill_lv;
	ud->skillx       = skill_x;
	ud->skilly       = skill_y;
	ud->skilltarget  = 0;

	if (sc && sc->data[SC_CLOAKING] && !(sc->data[SC_CLOAKING]->val4&4))
	{
		status_change_end(src,SC_CLOAKING,-1);
		if (!src->prev) return 0; //Warped away!
	}

	if(casttime > 0) {
		ud->skilltimer = add_timer( tick+casttime, skill_castend_pos, src->id, 0 );
		if(sd && pc_checkskill(sd,SA_FREECAST))
			status_freecast_switch(sd);
		else
			unit_stop_walking(src,1);
	}
	else {
		ud->skilltimer = -1;
		skill_castend_pos(ud->skilltimer,tick,src->id,0);
	}
	return 1;
}

static int unit_attack_timer(int tid,unsigned int tick,int id,int data);

int unit_stop_attack(struct block_list *bl)
{
	struct unit_data *ud = unit_bl2ud(bl);
	nullpo_retr(0, bl);

	if(!ud || ud->attacktimer == -1)
		return 0;

	delete_timer( ud->attacktimer, unit_attack_timer );
	ud->attacktimer = -1;
	ud->target = 0;
	return 0;
}

//Means current target is unattackable. For now only unlocks mobs.
int unit_unattackable(struct block_list *bl)
{
	struct unit_data *ud = unit_bl2ud(bl);
	if (ud) {
		ud->target = 0;
		ud->state.attack_continue = 0;
	}
	
	if(bl->type == BL_MOB)
		mob_unlocktarget((struct mob_data*)bl, gettick()) ;
	else if(bl->type == BL_PET)
		pet_unlocktarget((struct pet_data*)bl);
	return 0;
}

/*==========================================
 * 攻撃要求
 * typeが1なら継続攻撃
 *------------------------------------------*/
int unit_attack(struct block_list *src,int target_id,int continuous)
{
	struct block_list *target;
	struct unit_data  *ud;

	nullpo_retr(0, ud = unit_bl2ud(src));

	target=map_id2bl(target_id);
	if(target==NULL || status_isdead(target)) {
		unit_unattackable(src);
		return 1;
	}

	if( src->type == BL_PC ){
		TBL_PC* sd = (TBL_PC*)src;
		if( target->type == BL_NPC )
		{// monster npcs [Valaris]
			npc_click(sd,(TBL_NPC*)target); // submitted by leinsirk10 [Celest]
			return 0;
		} else if( pc_is90overweight(sd) )
		{// overwheight - stop attacking and walking
			unit_stop_attack(src);
			unit_stop_walking(src,1);
			return 0;
		}
	}

	if(battle_check_target(src,target,BCT_ENEMY)<=0 ||
		!status_check_skilluse(src, target, 0, 0)
	) {
		unit_unattackable(src);
		return 1;
	}

	ud->target = target_id;
	ud->state.attack_continue = continuous;
	if (continuous) //If you're to attack continously, set to auto-case character
		ud->chaserange = status_get_range(src);

	//Just change target/type. [Skotlex]
	if(ud->attacktimer != -1)
		return 0;

	//Set Mob's ANGRY/BERSERK states.
	if(src->type == BL_MOB)
		((TBL_MOB*)src)->state.skillstate = ((TBL_MOB*)src)->state.aggressive?MSS_ANGRY:MSS_BERSERK;

	if(DIFF_TICK(ud->attackabletime, gettick()) > 0)
		//Do attack next time it is possible. [Skotlex]
		ud->attacktimer=add_timer(ud->attackabletime,unit_attack_timer,src->id,0);
	else //Attack NOW.
		unit_attack_timer(-1,gettick(),src->id,0);

	return 0;
}

//Cancels an ongoing combo, resets attackable time and restarts the 
//attack timer to resume attacking after amotion time. [Skotlex]
int unit_cancel_combo(struct block_list *bl)
{
	struct unit_data  *ud;

	if (!status_change_end(bl, SC_COMBO, -1))
		return 0; //Combo wasn't active.

	ud = unit_bl2ud(bl);
	nullpo_retr(0, ud);

	ud->attackabletime = gettick() + status_get_amotion(bl);

	if (ud->attacktimer == -1)
		return 1; //Nothing more to do.
	
	delete_timer(ud->attacktimer, unit_attack_timer);
	ud->attacktimer=add_timer(ud->attackabletime,unit_attack_timer,bl->id,0);
	return 1;
}
/*==========================================
 *
 *------------------------------------------*/
bool unit_can_reach_pos(struct block_list *bl,int x,int y, int easy)
{
	nullpo_retr(false, bl);

	if( bl->x==x && bl->y==y )	// 同じマス
		return true;

	return path_search(NULL,bl->m,bl->x,bl->y,x,y,easy,CELL_CHKNOREACH);
}

/*==========================================
 *
 *------------------------------------------*/
bool unit_can_reach_bl(struct block_list *bl,struct block_list *tbl, int range, int easy, short *x, short *y)
{
	int i;
	short dx,dy;
	nullpo_retr(false, bl);
	nullpo_retr(false, tbl);

	if( bl->m != tbl->m)
		return false;
	
	if( bl->x==tbl->x && bl->y==tbl->y )
		return true;

	if(range>0 && !check_distance_bl(bl, tbl, range))
		return false;

	// It judges whether it can adjoin or not.
	dx=tbl->x - bl->x;
	dy=tbl->y - bl->y;
	dx=(dx>0)?1:((dx<0)?-1:0);
	dy=(dy>0)?1:((dy<0)?-1:0);
	
	if (map_getcell(tbl->m,tbl->x-dx,tbl->y-dy,CELL_CHKNOPASS))
	{	//Look for a suitable cell to place in.
		for(i=0;i<9 && map_getcell(tbl->m,tbl->x-dirx[i],tbl->y-diry[i],CELL_CHKNOPASS);i++);
		if (i==9) return false; //No valid cells.
		dx = dirx[i];
		dy = diry[i];
	}

	if (x) *x = tbl->x-dx;
	if (y) *y = tbl->y-dy;
	return path_search(NULL,bl->m,bl->x,bl->y,tbl->x-dx,tbl->y-dy,easy,CELL_CHKNOREACH);
}


/*==========================================
 * PCの攻撃 (timer関数)
 *------------------------------------------*/
static int unit_attack_timer_sub(struct block_list* src, int tid, unsigned int tick)
{
	struct block_list *target;
	struct unit_data *ud;
	struct status_data *sstatus;
	struct map_session_data *sd = NULL;
	struct mob_data *md = NULL;
	int range;
	
	if((ud=unit_bl2ud(src))==NULL)
		return 0;
	if(ud->attacktimer != tid){
		ShowError("unit_attack_timer %d != %d\n",ud->attacktimer,tid);
		return 0;
	}
	sd = BL_CAST(BL_PC, src);
	md = BL_CAST(BL_MOB, src);
	ud->attacktimer=-1;
	target=map_id2bl(ud->target);

	if(src == NULL || src->prev == NULL || target==NULL || target->prev == NULL)
		return 0;

	if(status_isdead(src) || status_isdead(target) || !status_check_skilluse(src, target, 0, 0))
		return 0; // can't attack under these conditions

	if (src->m != target->m)
	{
		if (src->type == BL_MOB && mob_warpchase((TBL_MOB*)src, target))
			return 1; // Follow up.
		return 0;
	}

	if(ud->skilltimer != -1 && !(sd && pc_checkskill(sd,SA_FREECAST) > 0))
		return 0; // can't attack while casting
	
	if(!battle_config.sdelay_attack_enable && DIFF_TICK(ud->canact_tick,tick) > 0 && !(sd && pc_checkskill(sd,SA_FREECAST) > 0))
	{	// attacking when under cast delay has restrictions:
		if (tid == -1) { //requested attack.
			if(sd) clif_skill_fail(sd,1,4,0);
			return 0;
		}
		//Otherwise, we are in a combo-attack, delay this until your canact time is over. [Skotlex]
		if(ud->state.attack_continue) {
			if (DIFF_TICK(ud->canact_tick, ud->attackabletime) > 0)
				ud->attackabletime = ud->canact_tick;
			ud->attacktimer=add_timer(ud->attackabletime,unit_attack_timer,src->id,0);
		}
		return 1;
	}

	sstatus = status_get_status_data(src);
	range = sstatus->rhw.range;
	
	if(!sd || sd->status.weapon != W_BOW) range++; //Dunno why everyone but bows gets this extra range...
	if(unit_is_walking(target)) range++; //Extra range when chasing

	if(!check_distance_bl(src,target,range) ) {
		//Chase if required.
		if(sd)
			clif_movetoattack(sd,target);
		else if(ud->state.attack_continue)
			unit_walktobl(src,target,ud->chaserange,ud->state.walk_easy|2);
		return 1;
	}
	if(!battle_check_range(src,target,range)) {
	  	//Within range, but no direct line of attack
		if(ud->state.attack_continue) {
			if(ud->chaserange > 2) ud->chaserange-=2;
			unit_walktobl(src,target,ud->chaserange,ud->state.walk_easy|2);
		}
		return 1;
	}

	//Sync packet only for players.
	//Non-players use the sync packet on the walk timer. [Skotlex]
	if (tid == -1 && sd) clif_fixpos(src);

	if(DIFF_TICK(ud->attackabletime,tick) <= 0)
	{
		if (battle_config.attack_direction_change && (src->type&battle_config.attack_direction_change)) {
			ud->dir = map_calc_dir(src, target->x,target->y );
		}
		if(ud->walktimer != -1)
			unit_stop_walking(src,1);
		if(md) {
			if (mobskill_use(md,tick,-1))
				return 1;
			if (sstatus->mode&MD_ASSIST && DIFF_TICK(md->last_linktime, tick) < MIN_MOBLINKTIME)
			{	// Link monsters nearby [Skotlex]
				md->last_linktime = tick;
				map_foreachinrange(mob_linksearch, src, md->db->range2, BL_MOB, md->class_, target, tick);
			}
		}
		if(src->type == BL_PET && pet_attackskill((TBL_PET*)src, target->id))
			return 1;
		
		map_freeblock_lock();
		ud->attacktarget_lv = battle_weapon_attack(src,target,tick,0);

		if(sd && sd->status.pet_id > 0 && sd->pd && battle_config.pet_attack_support)
			pet_target_check(sd,target,0);
		map_freeblock_unlock();

		ud->attackabletime = tick + sstatus->adelay;
//		You can't move if you can't attack neither.
		if (src->type&battle_config.attack_walk_delay)
			unit_set_walkdelay(src, tick, sstatus->amotion, 1);
	}

	if(ud->state.attack_continue)
		ud->attacktimer = add_timer(ud->attackabletime,unit_attack_timer,src->id,0);

	return 1;
}

static int unit_attack_timer(int tid,unsigned int tick,int id,int data)
{
	struct block_list *bl;
	bl = map_id2bl(id);
	if(bl && unit_attack_timer_sub(bl, tid, tick) == 0)
		unit_unattackable(bl);
	return 0;
}

/*==========================================
 * Cancels an ongoing skill cast.
 * flag&1: Cast-Cancel invoked.
 * flag&2: Cancel only if skill is cancellable.
 *------------------------------------------*/
int unit_skillcastcancel(struct block_list *bl,int type)
{
	struct map_session_data *sd = NULL;
	struct unit_data *ud = unit_bl2ud( bl);
	unsigned int tick=gettick();
	int ret=0, skill;
	
	nullpo_retr(0, bl);
	if (!ud || ud->skilltimer==-1)
		return 0; //Nothing to cancel.

	sd = BL_CAST(BL_PC, bl);

	if (type&2) {
		//See if it can be cancelled.
		if (!ud->state.skillcastcancel)
			return 0;

		if (sd && (sd->special_state.no_castcancel2 ||
			(sd->special_state.no_castcancel && !map_flag_gvg(bl->m)))) //fixed flags being read the wrong way around [blackhole89]
			return 0;
	}
	
	ud->canact_tick=tick;
	if(sd && pc_checkskill(sd,SA_FREECAST))
		status_freecast_switch(sd);
	
	if(type&1 && sd)
		skill = sd->skillid_old;
	else
		skill = ud->skillid;
	
	if (skill_get_inf(skill) & INF_GROUND_SKILL)
		ret=delete_timer( ud->skilltimer, skill_castend_pos );
	else
		ret=delete_timer( ud->skilltimer, skill_castend_id );
	if(ret<0)
		ShowError("delete timer error : skillid : %d\n",ret);
	
	if(bl->type==BL_MOB) ((TBL_MOB*)bl)->skillidx  = -1;

	ud->skilltimer = -1;
	clif_skillcastcancel(bl);
	return 1;
}

// unit_data の初期化処理
void unit_dataset(struct block_list *bl)
{
	struct unit_data *ud;
	nullpo_retv(ud = unit_bl2ud(bl));

	memset( ud, 0, sizeof( struct unit_data) );
	ud->bl             = bl;
	ud->walktimer      = -1;
	ud->skilltimer     = -1;
	ud->attacktimer    = -1;
	ud->attackabletime = 
	ud->canact_tick    = 
	ud->canmove_tick   = gettick();
}

/*==========================================
 * Returns 1 if this unit is attacking target 'id'
 *------------------------------------------*/
static int unit_counttargeted_sub(struct block_list* bl, va_list ap)
{
	int id = va_arg(ap, int);
	int target_lv = va_arg(ap, int); // extra condition
	struct unit_data* ud;

	if(bl->id == id)
		return 0;

	ud = unit_bl2ud(bl);

	if (ud && ud->target == id && ud->attacktimer != -1 && ud->attacktarget_lv >= target_lv)
		return 1;

	return 0;	
}

/*==========================================
 * Counts the number of units attacking 'bl'
 *------------------------------------------*/
int unit_counttargeted(struct block_list* bl, int target_lv)
{
	nullpo_retr(0, bl);
	return (map_foreachinrange(unit_counttargeted_sub, bl, AREA_SIZE, BL_CHAR, bl->id, target_lv));
}

/*==========================================
 *
 *------------------------------------------*/
int unit_fixdamage(struct block_list *src,struct block_list *target,unsigned int tick,int sdelay,int ddelay,int damage,int div,int type,int damage2)
{
	nullpo_retr(0, target);

	if(damage+damage2 <= 0)
		return 0;
	
	return status_fix_damage(src,target,damage+damage2,clif_damage(target,target,tick,sdelay,ddelay,damage,div,type,damage2));
}

/*==========================================
 * 見た目のサイズを変更する
 *------------------------------------------*/
int unit_changeviewsize(struct block_list *bl,short size)
{
	nullpo_retr(0, bl);

	size=(size<0)?-1:(size>0)?1:0;

	if(bl->type == BL_PC) {
		((TBL_PC*)bl)->state.size=size;
	} else if(bl->type == BL_MOB) {
		((TBL_MOB*)bl)->special_state.size=size;
	} else
		return 0;
	if(size!=0)
		clif_misceffect2(bl,421+size);
	return 0;
}

/*==========================================
 * Removes a bl/ud from the map.
 * Returns 1 on success. 0 if it couldn't be removed or the bl was free'd
 * if clrtype is 1 (death), appropiate cleanup is performed. 
 * Otherwise it is assumed bl is being warped.
 * On-Kill specific stuff is not performed here, look at status_damage for that.
 *------------------------------------------*/
int unit_remove_map_(struct block_list *bl, int clrtype, const char* file, int line, const char* func)
{
	struct unit_data *ud = unit_bl2ud(bl);
	struct status_change *sc = status_get_sc(bl);
	nullpo_retr(0, ud);

	if(bl->prev == NULL)
		return 0; //Already removed?

	map_freeblock_lock();

	ud->target = 0; //Unlock walk/attack target.
	if (ud->walktimer != -1)
		unit_stop_walking(bl,0);
	if (ud->attacktimer != -1)
		unit_stop_attack(bl);
	if (ud->skilltimer != -1)
		unit_skillcastcancel(bl,0);
// Do not reset can-act delay. [Skotlex]
	ud->attackabletime = ud->canmove_tick /*= ud->canact_tick*/ = gettick();
	
	if(sc && sc->count ) { //map-change/warp dispells.
		if(sc->data[SC_BLADESTOP])
			status_change_end(bl,SC_BLADESTOP,-1);
		if(sc->data[SC_BASILICA])
			status_change_end(bl,SC_BASILICA,-1);
		if(sc->data[SC_ANKLE])
			status_change_end(bl, SC_ANKLE, -1);
		if (sc->data[SC_TRICKDEAD])
			status_change_end(bl, SC_TRICKDEAD, -1);
		if (sc->data[SC_BLADESTOP])
			status_change_end(bl,SC_BLADESTOP,-1);
		if (sc->data[SC_RUN])
			status_change_end(bl,SC_RUN,-1);
		if (sc->data[SC_DANCING]) // clear dance effect when warping [Valaris]
			skill_stop_dancing(bl);
		if (sc->data[SC_WARM])
			status_change_end(bl, SC_WARM, -1);
		if (sc->data[SC_DEVOTION])
			status_change_end(bl,SC_DEVOTION,-1);
		if (sc->data[SC_MARIONETTE])
			status_change_end(bl,SC_MARIONETTE,-1);
		if (sc->data[SC_MARIONETTE2])
			status_change_end(bl,SC_MARIONETTE2,-1);
		if (sc->data[SC_CLOSECONFINE])
			status_change_end(bl,SC_CLOSECONFINE,-1);
		if (sc->data[SC_CLOSECONFINE2])
			status_change_end(bl,SC_CLOSECONFINE2,-1);
		if (sc->data[SC_HIDING])
			status_change_end(bl, SC_HIDING, -1);
		if (sc->data[SC_CLOAKING])
			status_change_end(bl, SC_CLOAKING, -1);
		if (sc->data[SC_CHASEWALK])
			status_change_end(bl, SC_CHASEWALK, -1);
		if (sc->data[SC_GOSPEL] && sc->data[SC_GOSPEL]->val4 == BCT_SELF)
			status_change_end(bl, SC_GOSPEL, -1);
		if (sc->data[SC_CHANGE])
			status_change_end(bl, SC_CHANGE, -1);
		if (sc->data[SC_MIRACLE])
			status_change_end(bl, SC_MIRACLE, -1);
	}

	if (bl->type&BL_CHAR) {
		skill_unit_move(bl,gettick(),4);
		skill_cleartimerskill(bl);
	}

	switch( bl->type )
	{
	case BL_PC:
	{
		struct map_session_data *sd = (struct map_session_data*)bl;

		//Leave/reject all invitations.
		if(sd->chatID)
			chat_leavechat(sd,0);
		if(sd->trade_partner)
			trade_tradecancel(sd);
		if(sd->vender_id)
			vending_closevending(sd);
		if(sd->state.storage_flag == 1)
			storage_storage_quit(sd,0);
		else if (sd->state.storage_flag == 2)
			storage_guild_storage_quit(sd,0);
		sd->state.storage_flag = 0; //Force close it when being warped.
		if(sd->party_invite>0)
			party_reply_invite(sd,sd->party_invite_account,0);
		if(sd->guild_invite>0)
			guild_reply_invite(sd,sd->guild_invite,0);
		if(sd->guild_alliance>0)
			guild_reply_reqalliance(sd,sd->guild_alliance_account,0);
		if(sd->menuskill_id)
			sd->menuskill_id = sd->menuskill_val = 0;

		sd->npc_shopid = 0;
		sd->adopt_invite = 0;

		if(sd->pvp_timer!=-1) {
			delete_timer(sd->pvp_timer,pc_calc_pvprank_timer);
			sd->pvp_timer = -1;
			sd->pvp_rank = 0;
		}
		if(sd->duel_group > 0)
			duel_leave(sd->duel_group, sd);

		if(pc_issit(sd)) {
			pc_setstand(sd);
			skill_sit(sd,0);
		}
		party_send_dot_remove(sd);//minimap dot fix [Kevin]
		guild_send_dot_remove(sd);

		if( map[bl->m].users <= 0 || sd->state.debug_remove_map )
		{// this is only place where map users is decreased, if the mobs were removed too soon then this function was executed too many times [FlavioJS]
			if( sd->debug_file == NULL || !(sd->state.debug_remove_map) )
			{
				sd->debug_file = "";
				sd->debug_line = 0;
				sd->debug_func = "";
			}
			ShowDebug("unit_remove_map: unexpected state when removing player AID/CID:%d/%d"
				" (active=%d connect_new=%d rewarp=%d changemap=%d debug_remove_map=%d)"
				" from map=%s (users=%d)."
				" Previous call from %s:%d(%s), current call from %s:%d(%s)."
				" Please report this!!!\n",
				sd->status.account_id, sd->status.char_id,
				sd->state.active, sd->state.connect_new, sd->state.rewarp, sd->state.changemap, sd->state.debug_remove_map,
				map[bl->m].name, map[bl->m].users,
				sd->debug_file, sd->debug_line, sd->debug_func, file, line, func);
		}
		else
		if (--map[bl->m].users == 0 && battle_config.dynamic_mobs)	//[Skotlex]
			map_removemobs(bl->m);
		sd->state.debug_remove_map = 1; // temporary state to track double remove_map's [FlavioJS]
		sd->debug_file = file;
		sd->debug_line = line;
		sd->debug_func = func;

		break;
	}
	case BL_MOB:
	{
		struct mob_data *md = (struct mob_data*)bl;
		md->target_id=0;
		md->attacked_id=0;
		md->state.skillstate= MSS_IDLE;

		break;
	}
	case BL_PET:
	{
		struct pet_data *pd = (struct pet_data*)bl;
		if( pd->pet.intimate <= 0 && !(pd->msd && !pd->msd->state.active) )
		{	//If logging out, this is deleted on unit_free
			clif_clearunit_area(bl,clrtype);
			map_delblock(bl);
			unit_free(bl,0);
			map_freeblock_unlock();
			return 0;
		}

		break;
	}
	case BL_HOM:
	{
		struct homun_data *hd = (struct homun_data *) bl;
		ud->canact_tick = ud->canmove_tick; //It appears HOM do reset the can-act tick.
		if(!hd->homunculus.intimacy && !(hd->master && !hd->master->state.active) )
		{	//If logging out, this is deleted on unit_free
			clif_emotion(bl, 28) ;	//sob
			clif_clearunit_area(bl,clrtype);
			map_delblock(bl);
			unit_free(bl,0);
			map_freeblock_unlock();
			return 0;
		}

		break;
	}
	default: ;// do nothing
	}

	clif_clearunit_area(bl,clrtype);
	map_delblock(bl);
	map_freeblock_unlock();
	return 1;
}

void unit_remove_map_pc(struct map_session_data *sd, int clrtype)
{
	unit_remove_map(&sd->bl,clrtype);

	if (clrtype == 3) clrtype = 0; //3 is the warp from logging out, but pets/homunc need to just 'vanish' instead of showing the warping out animation.

	if(sd->pd)
		unit_remove_map(&sd->pd->bl, clrtype);
	if(merc_is_hom_active(sd->hd))
		unit_remove_map(&sd->hd->bl, clrtype);
}

void unit_free_pc(struct map_session_data *sd)
{
	if (sd->pd) unit_free(&sd->pd->bl,0);
	if (sd->hd) unit_free(&sd->hd->bl,0);
	unit_free(&sd->bl,3);
}

/*==========================================
 * Function to free all related resources to the bl
 * if unit is on map, it is removed using the clrtype specified
 * If clrtype is <0, no saving is performed. This is only for non-authed
 * objects that shouldn't be on a map yet.
 *------------------------------------------*/
int unit_free(struct block_list *bl, int clrtype)
{
	struct unit_data *ud = unit_bl2ud( bl );
	nullpo_retr(0, ud);

	map_freeblock_lock();
	if( bl->prev )	//Players are supposed to logout with a "warp" effect.
		unit_remove_map(bl, clrtype);
	
	if( bl->type == BL_PC ) {
		struct map_session_data *sd = (struct map_session_data*)bl;
		if(status_isdead(bl))
			pc_setrestartvalue(sd,2);

		pc_delinvincibletimer(sd);
	
		pc_autoscript_clear(sd->autoscript, ARRAYLENGTH(sd->autoscript));
		pc_autoscript_clear(sd->autoscript2, ARRAYLENGTH(sd->autoscript2));

		if (sd->followtimer != -1)
			pc_stop_following(sd);
			
		if(sd->duel_invite > 0)
			duel_reject(sd->duel_invite, sd);
	
		// Notify friends that this char logged out. [Skotlex]
		clif_foreachclient(clif_friendslist_toggle_sub, sd->status.account_id, sd->status.char_id, 0);
		party_send_logout(sd);
		guild_send_memberinfoshort(sd,0);
		pc_cleareventtimer(sd);
		pc_delspiritball(sd,sd->spiritball,1);

		if(sd->reg)
		{	//Double logout already freed pointer fix... [Skotlex]
			aFree(sd->reg);
			sd->reg = NULL;
			sd->reg_num = 0;
		}
		if(sd->regstr)
		{
			int i;
			for( i = 0; i < sd->regstr_num; ++i )
				if( sd->regstr[i].data )
					aFree(sd->regstr[i].data);
			aFree(sd->regstr);
			sd->regstr = NULL;
			sd->regstr_num = 0;
		}

		//Tell the script to end, not delete it, it will free itself when necessary [Kevin]
		if (sd->st) {
			sd->st->rid = 0;
			sd->st->state = 2;
		}
	} else if( bl->type == BL_PET ) {
		struct pet_data *pd = (struct pet_data*)bl;
		struct map_session_data *sd = pd->msd;
		pet_hungry_timer_delete(pd);
		if (pd->a_skill)
		{
			aFree(pd->a_skill);
			pd->a_skill = NULL;
		}
		if (pd->s_skill)
		{
			if (pd->s_skill->timer != -1) {
				if (pd->s_skill->id)
					delete_timer(pd->s_skill->timer, pet_skill_support_timer);
				else
					delete_timer(pd->s_skill->timer, pet_heal_timer);
			}
			aFree(pd->s_skill);
			pd->s_skill = NULL;
		}
		if(pd->recovery)
		{
			if(pd->recovery->timer != -1)
				delete_timer(pd->recovery->timer, pet_recovery_timer);
			aFree(pd->recovery);
			pd->recovery = NULL;
		}
		if(pd->bonus)
		{
			if (pd->bonus->timer != -1)
				delete_timer(pd->bonus->timer, pet_skill_bonus_timer);
			aFree(pd->bonus);
			pd->bonus = NULL;
		}
		if (pd->loot)
		{
			pet_lootitem_drop(pd,sd);
			if (pd->loot->item)
				aFree(pd->loot->item);
			aFree (pd->loot);
			pd->loot = NULL;
		}
		if (clrtype >= 0) {
			if(pd->pet.intimate > 0)
				intif_save_petdata(pd->pet.account_id,&pd->pet);
			else
			{	//Remove pet.
				intif_delete_petdata(pd->pet.pet_id);
				if (sd) sd->status.pet_id = 0;
			}
		}
		if (sd) sd->pd = NULL;
	} else if(bl->type == BL_MOB) {
		struct mob_data *md = (struct mob_data*)bl;
		if(md->deletetimer!=-1) {
			delete_timer(md->deletetimer,mob_timer_delete);
			md->deletetimer=-1;
		}
		if(md->lootitem) {
			aFree(md->lootitem);
			md->lootitem=NULL;
		}
		if(md->guardian_data)
		{
			if (md->guardian_data->number < MAX_GUARDIANS)
				md->guardian_data->castle->guardian[md->guardian_data->number].id = 0;
			aFree(md->guardian_data);
			md->guardian_data = NULL;
		}
		if(md->spawn)
		{
			md->spawn->active--;

			if( !md->spawn->state.dynamic )
			{// permanently remove the mob
				if( --md->spawn->num == 0 )
				{// Last freed mob is responsible for deallocating the group's spawn data.
					aFree(md->spawn);
					md->spawn = NULL;
				}
			}
		}
		if(md->base_status) {
			aFree(md->base_status);
			md->base_status = NULL;
		}
		if(mob_is_clone(md->class_))
			mob_clone_delete(md->class_);
	} else if(bl->type == BL_HOM) {
		struct homun_data *hd = (TBL_HOM*)bl;
		struct map_session_data *sd = hd->master;
		// Desactive timers
		merc_hom_hungry_timer_delete(hd);
		if (clrtype >= 0) {
			if (hd->homunculus.intimacy > 0)
				merc_save(hd); 
			else
			{
				intif_homunculus_requestdelete(hd->homunculus.hom_id);
				if (sd) sd->status.hom_id = 0;
			}
		}
		if(sd) sd->hd = NULL;
	}

	skill_clear_unitgroup(bl);
	status_change_clear(bl,1);
	map_deliddb(bl);
	if (bl->type != BL_PC) //Players are handled by map_quit
		map_freeblock(bl);
	map_freeblock_unlock();
	return 0;
}

int do_init_unit(void)
{
	add_timer_func_list(unit_attack_timer,  "unit_attack_timer");
	add_timer_func_list(unit_walktoxy_timer,"unit_walktoxy_timer");
	add_timer_func_list(unit_walktobl_sub, "unit_walktobl_sub");
	add_timer_func_list(unit_delay_walktoxy_timer,"unit_delay_walktoxy_timer");
	return 0;
}

int do_final_unit(void)
{
	// nothing to do
	return 0;
}