/**
 * Author: Bystroushaak (bystrousak@kitakitsune.org)
 *
 * TODO:
 *   Procházení skrz okraje
 *   Closest i diagonálně
*/


module MyBot;

import ants;
import std.stdio : stdout;
import std.algorithm : remove;
import std.string : indexOf;


bool notIn(Loc strange_ant, const(Loc)[] ants){
    foreach(ant; ants){
        if (strange_ant == ant)
            return false;
    }

    return true;
}


class MyBot : IBot {
    private Ants engine;
    public Loc[] planed_steps;
    public Direction[Loc] last_direction;

    /// vrati nejblizsi prvek z pole
    Loc findClosestDest(Loc ant, const(Loc)[] locations){
        Loc cl;
        foreach(l; locations){
            if (l == Loc()){
                cl = l;
                continue;
            }

            if (engine.distance(l, ant) < engine.distance(cl, ant))
                cl = l;
        }

        return cl;
    }

    /// vrati nejblizsi jidlo ke kteremu ma mravenec cisty pristup
    Loc findClosestClear(Loc ant, const(Loc)[] where){
        Loc[] cf;
        foreach(f; where){
            if (hasClearRoad(ant, f))
                cf ~= f;
        }

        return findClosestDest(ant, cf);
    }
    Loc findClosestEnemyClear(Loc ant, const(Loc)[] where){
        Loc[] cf;
        foreach(f; where){
            if (hasClearRoad(ant, f))
                cf ~= f;
        }

        return findClosestDest(ant, cf);
    }

    bool hasClearRoad(Loc ant, Loc dest){
        if (ant == dest)
            return true;

        auto d = closestDirection(ant, dest);
        Loc next = engine.destination(ant, d);

        return (engine.passable(next) && notIn(next, this.planed_steps) && notIn(next, this.engine.myAnts()) && hasClearRoad(next, dest));
    }
    bool hasEnemyClearRoad(Loc ant, Loc dest){
        if (ant == dest)
            return true;

        auto d = closestDirection(ant, dest);
        Loc next = engine.destination(ant, d);

        bool no_enemy_around = true;
        Loc around;
        foreach(delta_row; [-1, 0, 1]){
            around.row = next.row + delta_row;
            foreach(delta_col; [-1, 0, 1]){
                around.col = next.col + delta_col;
                no_enemy_around = no_enemy_around && notIn(around, this.engine.enemyAnts());
                if (!no_enemy_around)
                    break;
            }
            if (!no_enemy_around)
                    break;
        }

        return (engine.passable(next) && notIn(next, this.planed_steps) && notIn(next, this.engine.myAnts()) && no_enemy_around && hasClearRoad(next, dest));
    }

    void moveTo(Loc ant, Direction d){
        Loc next = engine.destination(ant, d);

        if (!hasClearRoad(ant, next))
            return;

        engine.issueOrder(ant, d);
        planed_steps ~= next;

        last_direction.remove(ant);
        last_direction[next] = d;
    }

    Direction closestDirection(const(Loc) ant, const(Loc) dest){
        struct smer{
            float l;
            Direction d;
        }

        smer s;
        foreach(d; engine.direction(ant, dest)){
            auto destination = engine.destination(ant, d);

            if (s == smer()){
                s.l =  engine.distance(ant, destination);
                s.d = d;
                continue;
            }

            if (s.l > engine.distance(ant, destination)){
                s.l = engine.distance(ant, destination);
                s.d = d;
            }
        }

        return s.d;
    }

    const(Loc)[] hillsToLoc(const(Hill)[] hills){
        const(Loc)[] l_hills;

        foreach(h; hills){
            l_hills ~= h.loc;
        }

        return l_hills;
    }

    void doTurn(Ants engine) {
        this.engine = engine;
        this.planed_steps = [];

        foreach(ant; engine.myAnts){
            Loc food  = findClosestClear(ant, engine.food());
            Loc enemy = findClosestClear(ant, engine.enemyAnts());
            Loc enemyHill = findClosestEnemyClear(ant, hillsToLoc(engine.enemyHills));

            if (enemyHill != Loc()){
                this.moveTo(ant, closestDirection(ant, enemyHill));
            }else if (food != Loc()){
                this.moveTo(ant, closestDirection(ant, food)); // mozna predelat na fci pro nejkratsi cestu?
            }else if (engine.myAnts().length > engine.enemyAnts().length + 3 && engine.myAnts().length > 20 && enemy != Loc()){
                this.moveTo(ant, closestDirection(ant, enemy)); // mozna predelat na fci pro nejkratsi cestu?
            }else{
                Direction new_d;
                if (ant in last_direction)
                    new_d = last_direction[ant];
                else
                    new_d = AIM[0];

                Loc antGoto = engine.destination(ant, new_d);
                int cnt = 0;
                while(!hasClearRoad(ant, antGoto) && cnt++ <= 4){
                    new_d = AIM["wnes".indexOf(new_d.key)];
                    antGoto = engine.destination(ant, new_d);
                }

                moveTo(ant, new_d);
            }
        }
    }
}



void main() {
    version(unittest) {
        // We don't run the bot or wait for input in this case
    } else {
        Ants.run(new MyBot());
    }
}