using System;
using System.Collections.Generic;
using OpenNest.Geometry;
using OpenNest.Math;
using OpenNest.RectanglePacking;

namespace OpenNest
{
    public class NestEngine
    {
        public NestEngine(Plate plate)
        {
            Plate = plate;
        }

        public Plate Plate { get; set; }

        public NestDirection NestDirection { get; set; }

        public bool Fill(NestItem item)
        {
            var workArea = Plate.WorkArea();
            return FillArea(workArea, item);
        }

        public bool Fill(NestItem item, int maxCount)
        {
            var workArea = Plate.WorkArea();
            return FillArea(workArea, item, maxCount);
        }

        public bool FillArea(Box box, NestItem item)
        {
            var binItem = ConvertToRectangleItem(item);

            var bin = new Bin
            {
                Location = box.Location,
                Size = box.Size
            };

            bin.Width += Plate.PartSpacing;
            bin.Height += Plate.PartSpacing;

            var engine = new FillBestFit(bin);
            engine.Fill(binItem);

            var nestItems = new List<NestItem>();
            nestItems.Add(item);

            var parts = ConvertToParts(bin, nestItems);
            Plate.Parts.AddRange(parts);

            return parts.Count > 0;
        }

        public bool FillArea(Box box, NestItem item, int maxCount)
        {
            var binItem = ConvertToRectangleItem(item);

            var bin = new Bin
            {
                Location = box.Location,
                Size = box.Size
            };

            bin.Width += Plate.PartSpacing;
            bin.Height += Plate.PartSpacing;

            var engine = new FillBestFit(bin);
            engine.Fill(binItem, maxCount);

            var nestItems = new List<NestItem>();
            nestItems.Add(item);

            var parts = ConvertToParts(bin, nestItems);
            Plate.Parts.AddRange(parts);

            return parts.Count > 0;
        }

        public bool Pack(List<NestItem> items)
        {
            var workArea = Plate.WorkArea();
            return PackArea(workArea, items);
        }

        public bool PackArea(Box box, List<NestItem> items)
        {
            var binItems = ConvertToRectangleItems(items);

            var bin = new Bin
            {
                Location = box.Location,
                Size = box.Size
            };

            bin.Width += Plate.PartSpacing;
            bin.Height += Plate.PartSpacing;

            var engine = new PackBottomLeft(bin);
            engine.Pack(binItems);

            var parts = ConvertToParts(bin, items);
            Plate.Parts.AddRange(parts);

            return parts.Count > 0;
        }

        private List<Part> ConvertToParts(Bin bin, List<NestItem> items)
        {
            var parts = new List<Part>();

            foreach (var item in bin.Items)
            {
                var nestItem = items[item.Id];
                var part = ConvertToPart(item, nestItem.Drawing);
                parts.Add(part);
            }

            return parts;
        }

        private Part ConvertToPart(Item item, Drawing dwg)
        {
            var part = new Part(dwg);

            if (item.IsRotated)
                part.Rotate(Angle.HalfPI);

            var boundingBox = part.Program.BoundingBox();
            var offset = item.Location - boundingBox.Location;

            part.Offset(offset);

            return part;
        }

        private List<Item> ConvertToRectangleItems(List<NestItem> items)
        {
            var binItems = new List<Item>();

            for (int i = 0; i < items.Count; i++)
            {
                var item = items[i];
                var binItem = ConvertToRectangleItem(item, i);

                int maxQty = (int)System.Math.Floor(Plate.Area() / binItem.Area());

                int qty = item.Quantity < maxQty
                    ? item.Quantity
                    : maxQty;

                for (int j = 0; j < qty; j++)
                    binItems.Add(binItem.Clone() as Item);
            }

            return binItems;
        }

        private Item ConvertToRectangleItem(NestItem item, int id = 0)
        {
            var box = item.Drawing.Program.BoundingBox();

            box.Width += Plate.PartSpacing;
            box.Height += Plate.PartSpacing;

            

            return new Item
            {
                Id = id,
                Location = box.Location,
                Size = box.Size
            };
        }
    }
}