using PamhagenSysCtrl.Helpers;
using PamhagenSysCtrl.Helpers.Pipeline;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;

namespace PamhagenSysCtrl.Windows {
    public partial class PlantSchemeWindow : Window {

        private readonly PamhagenGraph Graph;
        private readonly List<Path> Paths = [];

        private ISource? _lastSource;
        private ISet<INode>? _lastSelected;

        public PlantSchemeWindow() {
            InitializeComponent();
            App.Plant?.Update += OnUpdate;
            Graph = new();
            Graph.Draw(SchemeCanvas);
        }

        private void SchemeCanvas_MouseMove(object sender, MouseEventArgs evt) {
            var p = evt.GetPosition(SchemeCanvas);
            UpdateScheme(evt.GetPosition(SchemeCanvas), evt.LeftButton == MouseButtonState.Pressed);
        }

        private void SchemeCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs evt) {
            var p = evt.GetPosition(SchemeCanvas);
            _lastSelected = UpdateScheme(evt.GetPosition(SchemeCanvas), evt.LeftButton == MouseButtonState.Pressed);
        }

        private void SchemeCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs evt) {
            var p = evt.GetPosition(SchemeCanvas);
            var curSelected = UpdateScheme(evt.GetPosition(SchemeCanvas), evt.LeftButton == MouseButtonState.Pressed);
            var clicked = curSelected.Intersect(_lastSelected ?? new HashSet<INode>()).ToList();
            _lastSource?.IsSelected = false;
            if (clicked.Count == 0) {
                _lastSource = null;
            }
            foreach (var c in clicked) {
                if (_lastSource != null && c is ISink sink) {
                    var path = Graph.GetPath(_lastSource, sink, (n) => n is not ISink && (n is not Valve v || !v.IsLocked));
                    if (path != null) {
                        Paths.Add(path.Value);
                        _lastSource = null;
                    }
                } else if (c is ISource source) {
                    _lastSource = source;
                    _lastSource.IsSelected = true;
                } else {
                    _lastSource = null;
                }
            }
            UpdateScheme(evt.GetPosition(SchemeCanvas), evt.LeftButton == MouseButtonState.Pressed);
        }

        private ISet<INode> UpdateScheme(Point pos, bool down) {
            foreach (var e in Graph.Edges) {
                e.Highlight = null;
            }
            foreach (var p in Paths) {
                var c = Brushes.Green;
                foreach (var (edge, node) in p.Hops) {
                    edge.Highlight = Brushes.Green;
                    if (node is Pump) c = Brushes.Orange;
                    ColorSubgraph(node, c, (v) => v.IsLocked = true);
                }
            }
            var hover = Graph.Update(pos.X, pos.Y, down);
            if (_lastSource != null && hover.Count > 0) {
                var path = Graph.GetPath(_lastSource, hover.First(), (n) => n is not ISink && (n is not Valve v || !v.IsLocked));
                if (path != null) {
                    var c = Brushes.Green;
                    foreach (var (edge, node) in path.Value.Hops) {
                        edge.Highlight = Brushes.Green;
                        if (node is Pump) c = Brushes.Orange;
                        ColorSubgraph(node, c);
                    }
                }
                Graph.Update(pos.X, pos.Y, down);
            }
            return hover;
        }

        private void ColorSubgraph(INode start, Brush color, Action<Valve>? valveAction = null) {
            if (start is Valve v) {
                valveAction?.Invoke(v);
                return;
            } else if (start is ISink || start is Pump) {
                return;
            }
            foreach (var edge in start.Inputs) {
                if (edge.Highlight != null) continue;
                edge.Highlight = color;
                ColorSubgraph(edge.Start, color, valveAction);
            }
            foreach (var edge in start.Outputs) {
                if (edge.Highlight != null) continue;
                edge.Highlight = color;
                ColorSubgraph(edge.End, color, valveAction);
            }
        }

        public void OnUpdate(object? sender, PlantEventArgs evt) {
            if (sender is not PamhagenPlant plant) return;


        }
    }
}