using System.Collections;
using UnityEngine;

namespace Hallucinate.GameSetup.Maze
{
    public class CrawlerAlgorithm : IMazeAlgorithm
    {
        private const int CrawlChance = 50;
        private const int MinBoundary = 1;
        private const int VerticalCrawlerCount = 3;
        private const int HorizontalCrawlerCount = 3;

        public void Generate(MazeGrid grid)
        {
            for (int i = 0; i < VerticalCrawlerCount; i++) CrawlV(grid, 0);
            for (int i = 0; i < HorizontalCrawlerCount; i++) CrawlH(grid, 0);
        }

        public IEnumerator GenerateStepByStep(MazeGrid grid, float interval)
        {
            for (int i = 0; i < VerticalCrawlerCount; i++) yield return CrawlV(grid, interval);
            for (int i = 0; i < HorizontalCrawlerCount; i++) yield return CrawlH(grid, interval);
        }

        private IEnumerator CrawlV(MazeGrid grid, float interval)
        {
            bool done = false;
            int x = Random.Range(MinBoundary, grid.Width - MinBoundary);
            int z = MinBoundary;

            while (!done)
            {
                grid.SetCell(x, z, MazeCellType.Processing);
                if (interval > 0) yield return new WaitForSeconds(interval);
                
                grid.SetCell(x, z, MazeCellType.Corridor);

                if (Random.Range(0, 100) < CrawlChance)
                {
                    x += Random.Range(-1, 2);
                }
                else
                {
                    z += Random.Range(0, 2);
                }

                done |= (x < MinBoundary || x >= grid.Width - MinBoundary || z < MinBoundary || z >= grid.Depth - MinBoundary);
            }
        }

        private IEnumerator CrawlH(MazeGrid grid, float interval)
        {
            bool done = false;
            int x = MinBoundary;
            int z = Random.Range(MinBoundary, grid.Depth - MinBoundary);

            while (!done)
            {
                grid.SetCell(x, z, MazeCellType.Processing);
                if (interval > 0) yield return new WaitForSeconds(interval);
                
                grid.SetCell(x, z, MazeCellType.Corridor);

                if (Random.Range(0, 100) < CrawlChance)
                {
                    x += Random.Range(0, 2);
                }
                else
                {
                    z += Random.Range(-1, 2);
                }

                done |= (x < MinBoundary || x >= grid.Width - MinBoundary || z < MinBoundary || z >= grid.Depth - MinBoundary);
            }
        }
    }
}