using System.Collections.Generic;
using UnityEngine;

namespace Hallucinate.GameSetup.Maze
{
    /// <summary>
    /// Implements a simplified version of Prim's algorithm for maze generation.
    /// It picks walls at random and converts them into corridors if they only have one corridor neighbor.
    /// </summary>
    public class Prims : Maze
    {
        /// <summary>
        /// Generates the maze using Prim's algorithm logic.
        /// </summary>
        public override void Generate()
        {
            int x = 2;
            int z = 2;

            map[x, z] = Corridor;

            List<MapLocation> walls = new List<MapLocation>
            {
                new MapLocation(x + 1, z),
                new MapLocation(x - 1, z),
                new MapLocation(x, z + 1),
                new MapLocation(x, z - 1)
            };

            int countloops = 0;
            while (walls.Count > 0 && countloops < 5000)
            {
                int rwall = Random.Range(0, walls.Count);
                x = walls[rwall].x;
                z = walls[rwall].z;
                walls.RemoveAt(rwall);

                if (CountSquareNeighbours(x, z) == 1)
                {
                    map[x, z] = Corridor;
                    walls.Add(new MapLocation(x + 1, z));
                    walls.Add(new MapLocation(x - 1, z));
                    walls.Add(new MapLocation(x, z + 1));
                    walls.Add(new MapLocation(x, z - 1));
                }

                countloops++;
            }
        }
    }
}