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

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

        private readonly PamhagenGraph Graph;

        private ISource? _lastSource;
        private List<INode> _path = [];
        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 pos = evt.GetPosition(SchemeCanvas);
            var curSelected = UpdateScheme(pos, evt.LeftButton == MouseButtonState.Pressed);
            var clicked = curSelected.Intersect(_lastSelected ?? new HashSet<INode>()).ToList();
            if (clicked.Count == 0) {
                _lastSource = null;
            }
            foreach (var c in clicked) {
                if (_lastSource == null && Graph.SelectedPaths.Any(p => p.Start == c)) {
                    var path = Graph.SelectedPaths.First(p => p.Start == c);
                    Graph.RemovePath(path);
                } else if (_lastSource != null && c is ISink sink) {
                    var res = Graph.GetPath([_lastSource, .._path, sink], (n) => n is not ISink && (n is not Valve v || !v.IsLocked));
                    if (res is Path path) {
                        Graph.AddPath(path);
                        _lastSource = null;
                    }
                } else if (_lastSource != null) {
                    var path = Graph.GetPath([_lastSource, .. _path, c], (n) => n is not ISink && (n is not Valve v || !v.IsLocked));
                    if (path != null) {
                        _path.Add(c);
                    }
                } else if (c is ISource source) {
                    _lastSource = source;
                    _path = [];
                } else {
                    _lastSource = null;
                }
                if (c is EntryTrough trough) {
                    trough.IsActive = !trough.IsActive;
                } else if (c is Rebler rebler) {
                    rebler.IsActive = !rebler.IsActive;
                } else if (c is EncasedAuger auger) {
                    auger.IsActive = !auger.IsActive;
                } else if (c is ConveyorBelt belt) {
                    belt.IsActive = !belt.IsActive;
                }
            }
            UpdateScheme(pos, 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 Graph.SelectedPaths) {
                Graph.ColorPipesAdjacientToPath(p, PamhagenBrushes.Green, PamhagenBrushes.DimOrange);
            }
            var hover = Graph.GetHover(pos.X, pos.Y);
            if (_lastSource != null && (hover.Count > 0 || _path.Count > 0)) {
                List<INode> points = [_lastSource, .. _path];
                if (hover.Count > 0 && !points.Contains(hover.First())) {
                    points.Add(hover.First());
                }
                if (points.Count >= 2) {
                    var res = Graph.GetPath(points, (n) => n is not ISink && (n is not Valve v || !v.IsLocked));
                    if (res is Path path) {
                        Graph.ColorPipesAdjacientToPath(path, PamhagenBrushes.Green, PamhagenBrushes.DimOrange);
                    }
                }
            } else if (_lastSource == null && hover.Count > 0 && Graph.SelectedPaths.Any(p => p.Start == hover.First())) {
                var path = Graph.SelectedPaths.First(p => p.Start == hover.First());
                Graph.ColorPipesAdjacientToPath(path, PamhagenBrushes.Red, null);
            }
            if (_lastSource != null) {
                foreach (var edge in _lastSource.Outputs) {
                    edge.Highlight = PamhagenBrushes.Green;
                }
            }
            Graph.Update(hover, down);
            return hover;
        }

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