using System;
using System.Collections.Generic;
using HexagonSurvive.Managers;
using HexagonSurvive.Map.Models;
using JetBrains.Annotations;
using UnityEngine;

namespace HexagonSurvive.Navigation
{
    public class PathUnit : IComparable<PathUnit>
    {
        public int F => G + H;
        public int G;
        public int H;
        [CanBeNull]
        public PathUnit prior;
        public readonly HexUnit hexUnit;

        private HexUnit _destination;

        public PathUnit(HexUnit hexUnit, HexUnit destination)
        {
            this.hexUnit = hexUnit;
            _destination = destination;
            G = 0;
            H = 0;
            prior = null;
        }

        public override int GetHashCode() =>
            hexUnit.GetHashCode();

        public override bool Equals(object obj) =>
            obj != null && obj.GetHashCode() == GetHashCode();

        public int CompareTo(PathUnit other)
        {
            if (hexUnit.coordinate == other.hexUnit.coordinate) return 0;
            if (F < other.F) return -1;
            if (F == other.F && H < other.H) return -1;
            return 1;
        }

        public List<PathUnit> GetNeighbours()
        {
            var m = EnvironmentManager.Instance.targetMap;
            var c = hexUnit.coordinate;
            return new List<PathUnit>
            {
                new(m.GetUnit(c + new Vector3Int(1, 0, -1)), _destination),
                new(m.GetUnit(c + new Vector3Int(0, 1, -1)), _destination),
                new(m.GetUnit(c + new Vector3Int(-1, 1, 0)), _destination),
                new(m.GetUnit(c + new Vector3Int(-1, 0, 1)), _destination),
                new(m.GetUnit(c + new Vector3Int(0, -1, 1)), _destination),
                new(m.GetUnit(c + new Vector3Int(1, -1, 0)), _destination)
            };
        }
    }
}