using System;
using System.Collections.Generic;
using System.Windows.Media;
using JD.AssetBrowser.ViewModel;
using QuickGraph;

namespace JD.AssetDependencies.Graph
{
    public class DependencyGraph : BidirectionalGraph<DataVertex, DataEdge>
    {
        private static readonly SolidColorBrush SelectedColor = new SolidColorBrush(Color.FromRgb(199, 234, 215));

        private static readonly SolidColorBrush ChildDependencyColor = new SolidColorBrush(Color.FromRgb(219, 219, 219));

        private static readonly SolidColorBrush ParentDependencyColor = new SolidColorBrush(Color.FromRgb(197, 208, 221));

        private static readonly SolidColorBrush ErrorColor = Brushes.LightCoral;

        public enum DependencyType
        {
            Parent, 
            Children
        }

        private readonly Dictionary<AssetViewModel, DataVertex> _dictionary = new Dictionary<AssetViewModel, DataVertex>();

        private DataVertex GetOrCreate(AssetViewModel fileEntry)
        {
            if (_dictionary.ContainsKey(fileEntry))
                return _dictionary[fileEntry];
            var vertex = new DataVertex { File = fileEntry };
            _dictionary.Add(fileEntry, vertex);
            return vertex;
        }

        public static DependencyGraph FromFile(AssetViewModel asset, int parentsMaxDepth = 3, int childrenMaxDepth = 3, Predicate<object> filterFunc = null)
        {
            var graph = new DependencyGraph();
            if (asset != null)
            {
                var root = graph.GetOrCreate(asset);
                root.Color = SelectedColor;

                graph.AddVertex(root);
                graph.AddDependencies(root, DependencyType.Children, childrenMaxDepth, filterFunc);
                graph.AddDependencies(root, DependencyType.Parent, parentsMaxDepth, filterFunc);
            }
            return graph;
        }

        public void AddDependencies(DataVertex vertex, DependencyType dependencyType, int maxDepth, Predicate<object> filterFunc = null)
        {
            if (maxDepth <= 0) return;

            var dependencies = dependencyType == DependencyType.Parent ? vertex.File.Model.ReferencedBy.AsFiles() : vertex.File.Model.Dependencies.AsFiles();
            foreach (var file in dependencies)
            {
                if (filterFunc != null && !filterFunc(file))
                {
                    continue;
                }

                var dependencyVertex = GetOrCreate((AssetViewModel)AssetDatabaseViewModel.Instance.GetOrCreateViewModel(file.Path));
                AddVertex(dependencyVertex);
                if (dependencyType == DependencyType.Children)
                {
                    dependencyVertex.Color = ChildDependencyColor;
                    AddEdge(new DataEdge { Source = vertex, Target = dependencyVertex });
                }
                else
                {
                    dependencyVertex.Color = ParentDependencyColor;
                    AddEdge(new DataEdge { Source = dependencyVertex, Target = vertex });
                }
                AddDependencies(dependencyVertex, dependencyType, maxDepth - 1, filterFunc);
            }
        }
    }
}