using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

namespace PamhagenSysCtrl.Helpers.Pipeline {
    public class Tank : INode, ISink, ISource {

        public const double WIDTH = 12;
        public const double HEIGHT = 20;

        public double CenterX { get; set; }
        public double CenterY { get; set; }
        public double TopY => CenterY - HEIGHT / 2;
        public double BottomY => CenterY + HEIGHT / 2;
        public string Label { get; set; }
        public FillState FillState => CallbackFillState();
        public bool IsFull => FillState == FillState.Full;
        public bool IsFilled => FillState != FillState.Empty;

        public ISet<IEdge> Inputs { get; init; }
        public ISet<IEdge> Outputs { get; init; }

        public int? CapacityLiters { get; set; }

        protected Func<FillState> CallbackFillState;

        private Shape? _rect;
        private TextBlock? _text;

        public Tank(string label, double x, double y, int capacityLiters, Func<FillState> cbFillState) {
            CenterX = x;
            CenterY = y;
            Label = label;
            CapacityLiters = capacityLiters;
            CallbackFillState = cbFillState;
            Inputs = new HashSet<IEdge>();
            Outputs = new HashSet<IEdge>();
        }

        public void Draw(Canvas canvas) {
            _rect = new Rectangle() {
                Stroke = Brushes.Black,
                Fill = Brushes.WhiteSmoke,
            };
            _text = new() {
                Text = CapacityLiters.HasValue ? $"{Label}\n{CapacityLiters:N0}" : Label,
                TextAlignment = TextAlignment.Center,
                VerticalAlignment = VerticalAlignment.Center,
            };
            canvas.Children.Add(_rect);
            canvas.Children.Add(_text);
        }

        public void Scale(double scale) {
            var border = Graph.ToBorder(scale);
            _rect?.Height = Graph.ToPx(HEIGHT, scale);
            _rect?.Width = Graph.ToPx(WIDTH, scale);
            _rect?.StrokeThickness = border;
            _rect?.SetValue(Canvas.LeftProperty, (CenterX - WIDTH / 2) * scale);
            _rect?.SetValue(Canvas.TopProperty, (CenterY - HEIGHT / 2) * scale);
            _text?.Width = Graph.ToPx(WIDTH, scale);
            _text?.FontSize = 12;
            _text?.SetValue(Canvas.LeftProperty, (CenterX - WIDTH / 2) * scale);
            _text?.SetValue(Canvas.TopProperty, (CenterY * scale) - (CapacityLiters.HasValue ? 16 : 8));
        }

        public bool IsInside(double x, double y) {
            return Math.Abs(x - CenterX) <= WIDTH / 2 && Math.Abs(y - CenterY) <= HEIGHT / 2;
        }

        public void Update(bool isHovering, bool isPressed) {
            _rect?.Fill = PamhagenBrushes.ForFillState(FillState,
                isHovering && isPressed ? Brushes.DarkGray :
                isHovering ? Brushes.LightGray :
                Brushes.WhiteSmoke
            );
        }
    }
}