using OpenNest.Engine.Fill;
using OpenNest.Geometry;
using OpenNest.Math;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace OpenNest.Engine.Strategies
{
    public static class FillHelpers
    {
        public static Pattern BuildRotatedPattern(List<Part> groupParts, double angle)
        {
            var pattern = new Pattern();
            var center = ((IEnumerable<IBoundable>)groupParts).GetBoundingBox().Center;

            foreach (var part in groupParts)
            {
                var clone = (Part)part.Clone();
                clone.UpdateBounds();

                if (!angle.IsEqualTo(0))
                    clone.Rotate(angle, center);

                pattern.Parts.Add(clone);
            }

            pattern.UpdateBounds();
            return pattern;
        }

        public static List<Part> FillPattern(FillLinear engine, List<Part> groupParts, List<double> angles, Box workArea)
        {
            var results = new ConcurrentBag<(List<Part> Parts, FillScore Score)>();

            Parallel.ForEach(angles, angle =>
            {
                var pattern = BuildRotatedPattern(groupParts, angle);

                if (pattern.Parts.Count == 0)
                    return;

                var h = engine.Fill(pattern, NestDirection.Horizontal);
                if (h != null && h.Count > 0)
                    results.Add((h, FillScore.Compute(h, workArea)));

                var v = engine.Fill(pattern, NestDirection.Vertical);
                if (v != null && v.Count > 0)
                    results.Add((v, FillScore.Compute(v, workArea)));
            });

            List<Part> best = null;
            var bestScore = default(FillScore);

            foreach (var res in results)
            {
                if (best == null || res.Score > bestScore)
                {
                    best = res.Parts;
                    bestScore = res.Score;
                }
            }

            return best;
        }
    }
}