OneNightDuel/ONDServer/Enemies/RoamingPathfinder.cs

using GlobalClassLib;
using ONDServer.Map;
using ONDServer.Net;

namespace ONDServer.Enemies;

public class RoamingPathfinder(Enemy enemy, int tolerance) : Pathfinder(enemy) {

    public Predicate<MapTile> AdditionalTileFilter{ get; set; } = _ => true;
    public Predicate<TileConnector> AdditionalConnectorFilter{ get; set; } = _ => true;
    
    protected int Tolerance = tolerance;
    public List<MapTile> TakenPath { get; } = new();
    
    private Random random = new();

    protected Dictionary<MapTile, int> Search(MapTile startingTile) {
        Dictionary<MapTile, int> distances = new(){ [startingTile] = 0 };
        Queue<MapTile> tilesToSearch = new();
        tilesToSearch.Enqueue(startingTile); 
        
        while (tilesToSearch.Count > 0){
            MapTile currentTile = tilesToSearch.Dequeue();
            
            List<MapTile> neighbours = GetNeighbours(currentTile, 
                c => 
                    AdditionalConnectorFilter(c) &&
                    (!c.Blocked || c.Type == ConnectorType.DOOR_OFFICE) && 
                    (!distances.ContainsKey(c.OtherTile(currentTile)) || distances[c.OtherTile(currentTile)] > distances[currentTile] + c.Value),
                t => 
                    AdditionalTileFilter(t) &&
                    (!Enemy.BlocksTile || EnemyManager.GetByLocation(t).All(e => !e.BlocksTile || e == Enemy)) &&
                    Server.Players.All(p => p.Value.State.OfficeTileId != t.Id));
            
            neighbours.ForEach(t => {
                distances[t] = distances[currentTile] + currentTile.GetConnector(t)!.Value;
                tilesToSearch.Enqueue(t);
            });
        }
        
        return distances;
    }
    
    public override Decision DecideNext(MapTile goal) {
        if (Enemy.Location == null) return Decision.Wait();
        
        Dictionary<MapTile, int> distances = Search(goal);
            
        List<MapTile> closerTiles = GetNeighbours(Enemy.Location,
            c => AdditionalConnectorFilter(c) && !c.Blocked || c.Type == ConnectorType.DOOR_OFFICE, 
            t => AdditionalTileFilter(t) && distances.ContainsKey(t) && distances[t] + t.GetConnector(Enemy.Location)!.Value <= distances[Enemy.Location] + Tolerance);
        if (closerTiles.Contains(goal)){
            if (Enemy.Location.GetConnector(goal)!.Blocked){
                return Decision.Reset();
            }

            IEnumerable<ServerPlayer> players = Server.Players.Values.Where(p => p.State.OfficeTileId == goal.Id);
            if (players.Count() == 1){
                return Decision.Attack(players.First());
            }
            return Decision.Move(goal);
        }
            
        if (closerTiles.Count != 0 && closerTiles.All(t => TakenPath.Contains(t))){
            TakenPath.Clear();
            return DecideNext(goal);
        }
        closerTiles.RemoveAll(t => TakenPath.Contains(t));
            
        closerTiles.ForEach(t => distances[t] += Enemy.Location.GetConnector(t)!.Value);
        double roll = random.NextDouble() * closerTiles.Sum(t => 1.0 / distances[t]);
        foreach (var tile in closerTiles){
            double value = 1.0 / distances[tile];
            if (roll <= value){
                TakenPath.Add(tile);
                return Decision.Move(tile);
            }
            roll -= value;
        }

        return Decision.Wait();
    }
}