using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Remoting.Messaging;
using System.Threading.Tasks;
using GameOfLife.Entities;
using GameOfLife.IO;

namespace GameOfLife.Search
{
    public class LibrarySearcher
    {
        private readonly PatternLibrary _patternLibrary;
        private Dictionary<Cell, List<Pattern>> _cellPatterns;

        public LibrarySearcher(PatternLibrary patternLibrary)
        {
            _patternLibrary = patternLibrary;

            var cellPatterns = 
                from patternProjections in _patternLibrary.PatternProjections
                from projection in patternProjections.Item2
                from cell in projection
                group projection by cell into cellGroups
                select cellGroups;

            _cellPatterns = cellPatterns.ToDictionary(t => t.Key, t => t.ToList());
        }

        //public IEnumerable<Tuple<PatternMetadata, Pattern[]>> MatchLibraryPatternsLookup(IEnumerable<Cell> cells)
        //{
        //    var pattern = cells.ToPattern();
        //}

        public IEnumerable<Tuple<PatternMetadata, Pattern[]>> MatchLibraryPatterns(IEnumerable<Cell> cells)
        {
            var inputCells = cells.ToPattern();

            var matches = new ConcurrentBag<Tuple<PatternMetadata, Pattern[]>>();

            Parallel.ForEach(_patternLibrary.PatternProjections, tuple =>
                {
                    var patternMetadata = tuple.Item1;
                    var projections = tuple.Item2;

                    var foundPatterns = inputCells.FindPatterns_Serial(projections).ToArray();
                    if (foundPatterns.Any())
                        matches.Add(Tuple.Create(patternMetadata, foundPatterns.ToArray()));
                }
            );
            return matches;
        }
    }
}