import util;
import game;

bool rocky(char c){ return c=='*'||c=='@'; }

class Solver_0
{
	this(in Game g) {}
	char single_step() { return 'W'; }
	void force(char c) {}
}

class Solver_1
{
	int wait_count = 0;
	int choke_count = 0;

	Game g;
	this(in Game g)
	{
		this.g = g.clone();
		forbidden_cell = new bool[][](g.map.H+2, g.map.W+2);
	}

	char single_step()
	{
		Tuple!(string,int) de = death_move(g);
		char c = act(g, de[0], de[1]);
		force(c);
		return c;
	}

	void force(char c)
	{
		if(c != 'A')
			g.command(c);
	}

	Tuple!(string,int) death_move(const(Game) g)
	{
		string death;
		int choice = 0;
		foreach(char c; "UDLRW") {
			Game gg = g.clone();
			gg.command(c);
			if( !gg.cleared && gg.dead )
				death ~= c;
			else if( gg.map.robot != g.map.robot )
				choice++;
			else if( c != 'W' ) // meaningless move
				death ~= c;
		}
		return tuple(death, choice);
	}

	Tuple!(Pos, int)[] log;
	bool[][] forbidden_cell;

	char act(const(Game) g, string death, int breath)
	{
		const Pos    ro = g.map.robot;
		const Pos    li = g.map.lift;
		Pos[] la = g.map.lambdas();
		sort!((Pos a,Pos b){
			int ad=abs(a.y-li.y)+abs(a.x-li.x);
			int bd=abs(b.y-li.y)+abs(b.x-li.x);
			return ad>bd;;
		})(la);
		Pos[] ra = g.map.razors();
		const(Pos)[] hi = g.map.objects('W');

		Tuple!(char,int)[] cand;
		char c = 'W';
		if( g.map.collected_lambda == g.map.total_lambda ) {
			cand = search(g, ro, [li], death);
		} else if( !la.empty ){
			cand ~= search(g, ro, la~ra, death);
		}

		// 'higesori' mode
		if( !hi.empty && g.map.razor>0 ) {
			int his = 0;
			for(int dy=-1; dy<=+1; ++dy)
			for(int dx=-1; dx<=+1; ++dx)
				if(g.map[ro.y+dy,ro.x+dx] == 'W')
					his++;

			if(his>=2 || his==hi.length)
				cand = [tuple('S',int.max)];
			if(cand.empty) {
				const(Pos)[] tgt;
				for(int y=1; y<=g.map.H; ++y)
				for(int x=1; x<=g.map.W; ++x)
					if(g.map[y,x]=='.'||g.map[y,x]==' ') {
						his = 0;
						for(int dy=-1; dy<=+1; ++dy)
						for(int dx=-1; dx<=+1; ++dx)
							if(g.map[y+dy,x+dx] == 'W')
								his++;
						if(his>=2)
							tgt ~= new Pos(y,x);
					}
				cand ~= search(g, ro, tgt, death, true);
			}
		}

		// 'dig' mode
		if(cand.empty) {
			const(Pos)[] tgt;
			for(int y=1; y<=g.map.H; ++y)
			for(int x=1; x<=g.map.W; ++x)
				if(g.map[y,x]=='.')
					if(rocky(g.map[y+1,x])||rocky(g.map[y+1,x-1])||rocky(g.map[y+1,x+1])
					 ||rocky(g.map[y,x+1])||rocky(g.map[y,x-1]))
						tgt ~= new Pos(y,x);
			cand ~= search(g, ro, tgt, death, true);
		}

		if(cand.empty) {
			choke_count++;
			cand ~= tuple('W',int.max);
		}
		sort!((Tuple!(char,int) c1, Tuple!(char,int) c2){
			if(c1[1] != c2[1])
				return c1[1] < c2[1];
			return c1[0] < c2[0];
		})(cand);
		c = cand[0][0];

		if(death.count(c) || wait_count>=2) {
			foreach(char live; "UDLRW")
				if(death.count(live)==0) {
					c=live;
					break;
				}
		}

		if(c == 'W')
			wait_count++;
		else
			wait_count = 0;
		if(choke_count >= g.map.H)
			c = 'A';

		bool[char] choice;
		foreach(t; cand)
			choice[t[0]] = true;
		log ~= tuple(ro.clone(), cast(int)choice.length);
		if(log.length > 5)
			log = log[$-5..$];
		int cnt = 0;
		foreach(l; log)
			if(l[0] == log[$-1][0])
				++cnt;
		if( cnt >= 3 && breath==1 ) {
			forbidden_cell[ro.y][ro.x] = true;
		}

		return c;
	}

	Tuple!(char,int)[] search(in Game g, in Pos s, in Pos[] gs, string death, bool danger_ok=false)
	{
		bool danger(int y, int x)
		{
			if(g.map[y,x] == ' ' || g.map[y,x] == 'R')
				return false;
			if(rocky(g.map[y+1,x]))
				return true;
			if(rocky(g.map[y+1,x-1]) && (g.map[y,x-1]=='\\'||rocky(g.map[y,x-1])) && (g.map[y+1,x]==' '||g.map[y+1,x]=='R'))
				return true;
			if(rocky(g.map[y+1,x+1]) && rocky(g.map[y,x+1]) && (g.map[y+1,x]==' '||g.map[y+1,x]=='R'))
				return true;
			if(rocky(g.map[y,x-1]) && (g.map[y-1,x-1]=='\\'||rocky(g.map[y-1,x-1])) && (g.map[y-1,x]==' '||g.map[y-1,x]=='R'))
				return true;
			if(rocky(g.map[y,x+1]) && rocky(g.map[y-1,x+1]) && (g.map[y-1,x]==' '||g.map[y-1,x]=='R'))
				return true;
			return false;
		}

		// avoid directly below '*'
		Tuple!(char,int)[] tryA() {
			const(Pos)[] q;
			foreach(p; gs)
				if(!danger(p.y,p.x))
					q ~= p;
			bool[][] v = new bool[][](g.map.H+2, g.map.W+2);
			foreach(p; q) v[p.y][p.x]=true;
			for(int step=1; q.length; ++step) {
				Pos[] q2;
				foreach(p; q) {
					int[] yyy=[p.y-1,p.y+1,p.y,p.y];
					int[] xxx=[p.x,p.x,p.x-1,p.x+1];
					for(int i=0; i<yyy.length; ++i) {
						int y = yyy[i];
						int x = xxx[i];
						if('1'<=g.map[y,x]&&g.map[y,x]<='9') {
							foreach(ppp; g.map.tr_source[g.map[y,x]]) {
								yyy ~= ppp.y;
								xxx ~= ppp.x;
							}
							continue;
						}
						if(v[y][x]) continue;
						if(y==s.y && x==s.x && i<4) {
							char c = "UDRL"[i];
							if( death.count(c) == 0 )
								return [tuple(c,step)];
						} else if(forbidden_cell[y][x]){
						} else if(g.map[y,x]==' '||g.map[y,x]=='\\'||g.map[y,x]=='.'||g.map[y,x]=='!'||i>=4) {
							if(danger(y,x))
								continue;
							q2 ~= new Pos(y,x);
							v[y][x]=true;
						}
					}
				}
				q = q2;
			}
			return [];
		}

		// any empty space is my ground
		Tuple!(char,int)[] tryB() {
			const(Pos)[] q;
			foreach(p; gs) q ~= p;
			bool[][] v = new bool[][](g.map.H+2, g.map.W+2);
			foreach(p; q) v[p.y][p.x]=true;
			for(int step=10; q.length; ++step) {
				Pos[] q2;
				foreach(p; q) {
					int[] yyy=[p.y-1,p.y+1,p.y,p.y];
					int[] xxx=[p.x,p.x,p.x-1,p.x+1];
					for(int i=0; i<yyy.length; ++i) {
						int y = yyy[i];
						int x = xxx[i];
						if('1'<=g.map[y,x]&&g.map[y,x]<='9') {
							foreach(ppp; g.map.tr_source[g.map[y,x]]) {
								yyy ~= ppp.y;
								xxx ~= ppp.x;
							}
							continue;
						}
						if(v[y][x]) continue;
						if(y==s.y && x==s.x && i<4) {
							char c = "UDRL"[i];
							if( death.count(c) == 0 )
								return [tuple(c,step)];
						} else if(forbidden_cell[y][x]){
						} else if(g.map[y,x]==' '||g.map[y,x]=='\\'||g.map[y,x]=='.'||g.map[y,x]=='!'||i>=4) {
							q2 ~= new Pos(y,x);
							v[y][x]=true;
						}
					}
				}
				q = q2;
			}
			return [];
		}

		// push rocks!
		Tuple!(char,int)[] tryC() {
			const(Pos)[] q;
			foreach(p; gs) q ~= p;
			bool[][] v = new bool[][](g.map.H+2, g.map.W+2);
			foreach(p; q) v[p.y][p.x]=true;
			for(int step=20; q.length; ++step) {
				Pos[] q2;
				foreach(p; q) {
					int[] yyy=[p.y-1,p.y+1,p.y,p.y];
					int[] xxx=[p.x,p.x,p.x-1,p.x+1];
					for(int i=0; i<yyy.length; ++i) {
						int y = yyy[i];
						int x = xxx[i];
						if(rocky(g.map[p])) {
							if(i>=4)continue;
							if(y!=p.y)continue;
							if(g.map[y,p.x+(p.x-x)]!=' '&&g.map[y,p.x+(p.x-x)]!='R')continue;
						}
						if('1'<=g.map[y,x]&&g.map[y,x]<='9') {
							foreach(ppp; g.map.tr_source[g.map[y,x]]) {
								yyy ~= ppp.y;
								xxx ~= ppp.x;
							}
							continue;
						}
						if(v[y][x]) continue;
						if(y==s.y && x==s.x && i<4) {
							char c = "UDRL"[i];
							if( death.count(c) == 0 )
								return [tuple(c,step)];
						} else if(forbidden_cell[y][x]){
						} else if(g.map[y,x]==' '||g.map[y,x]=='\\'||g.map[y,x]=='.'||rocky(g.map[y,x])||g.map[y,x]=='!'||i>=4) {
							q2 ~= new Pos(y,x);
							v[y][x]=true;
						}
					}
				}
				q = q2;
			}
			return [];
		}
		return (danger_ok ? [] : tryA()) ~ tryB() ~ tryC();
	}
}

class Solver_2(Solver)
{
	string plan;
	bool plan_broken = true;

	Game g;
	this(in Game g)
	{
		this.g = g.clone();
		make_plan(g);
	}

	Tuple!(Solver,string) run_sub_solver(in Game g)
	{
		string log;
		auto s = new Solver(g);
		while(!g.cleared && !g.dead && plan.length<=g.map.H*g.map.W) {
			char c = s.single_step();
			if( c == 'A' )
				break;
			log ~= c;
		}
		while(log.length>0 && log[$-1]=='W')
			log.length--;
		return tuple(s, log);
	}

	void make_plan(in Game g) {
		plan_broken = false;
		Tuple!(Solver,string) x = run_sub_solver(g);
		plan = x[1];
		if(x[0].g.cleared)
			return;
		modify_plan(g, x[0].g.score);
	}

	void modify_plan(in Game ini, long unmod)
	{
		int bp = max(0, (cast(int)plan.length)-10);
		Game g = ini.clone();
		for(int i=0; i<bp; ++i) g.command(plan[i]);

		Tuple!(string,long) cand = tuple(plan, unmod);
		for(int i=bp; i<plan.length; ++i) {
			foreach(string c; ["U","D","L","R","UD","DU","LR","RL"])
				if(c[0] != plan[i]) {
					Tuple!(string,long) zz = try_plan(c, g);
					if(cand[1]<zz[1])
						cand = tuple(plan[0..i]~c~zz[0], zz[1]);
				}
			g.command(plan[i]);
		}
		plan = cand[0];
	}

	Tuple!(string,long) try_plan(string c, in Game g)
	{
		Game gg = g.clone();
		foreach(cc;c)gg.command(cc);
		Tuple!(Solver, string) x = run_sub_solver(gg);
		return tuple(x[1], x[0].g.score);
	}

	char single_step() {
		if(plan_broken)
			make_plan(g);
		if(plan.empty)
			return 'A';
		char c = plan[0];
		plan = plan[1..$];
		g.command(c);
		return c;
	}

	void force(char c) {
		g.command(c);
		if(plan.length==0 || plan[0]!=c) {
			plan = "";
			plan_broken = true;
		}
		else
			plan = plan[1..$];
	}
}

alias Solver_2!(Solver_1) MainSolver;
//alias Solver_1 MainSolver;
//alias Solver_0 MainSolver;
