using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine.UIElements;

namespace Module.ProjectValidator.Editor
{
    internal sealed class EditorProjectValidatorWindow : EditorWindow
    {
        private VisualElement _groupWarnings;
        private Label _labelWarnings;

        private VisualElement _groupErrors;
        private Label _labelErrors;
        
        private MultiColumnTreeView _treeView;
        private string _searchFilter;

        private readonly List<TreeViewItemData<Report.Entry>> _list = new();
        private readonly List<TreeViewItemData<Report.Entry>> _filteredList = new();

        public void CreateGUI()
        {
            var root = rootVisualElement;
            var asset = EditorAssetUtility.LoadFirstAsset<VisualTreeAsset>("UxmlEditorProjectValidatorWindow");
            root.styleSheets.Add(EditorAssetUtility.LoadFirstAsset<StyleSheet>("StyleSheetEditorProjectValidatorWindow"));
            root.Add(asset.Instantiate());

            _groupWarnings = root.Q<VisualElement>("status-warnings");
            _labelWarnings = _groupWarnings.Q<Label>("label-warnings");
            
            _groupErrors = root.Q<VisualElement>("status-errors");
            _labelErrors = _groupErrors.Q<Label>("label-errors");
            
            _groupWarnings.style.display = DisplayStyle.None;
            _groupErrors.style.display = DisplayStyle.None;

            root.Q<ToolbarButton>("button-run").clicked += OnToolbarButtonRunClicked;
            root.Q<ToolbarButton>("button-clear").clicked += OnToolbarButtonClearClicked;
            root.Q<ToolbarSearchField>().RegisterValueChangedCallback(OnToolbarSearchFieldChanged);
            root.Q<ToolbarButton>("button-settings").clicked += OnToolbarButtonSettingsClicked;
            
            _treeView = root.Q<MultiColumnTreeView>();
            _treeView.columns["asset"].makeCell = CreateObjectField;
            _treeView.columns["type"].makeCell = CreateLabel;
            _treeView.columns["severity"].makeCell = CreateLabel;
            _treeView.columns["severity-message"].makeCell = CreateLabel;
            _treeView.columns["relative-path"].makeCell = CreateLabel;
            _treeView.columns["field-path"].makeCell = CreateLabel;

            _treeView.columns["asset"].bindCell = OnTreeViewBindCellAsset;
            _treeView.columns["type"].bindCell = OnTreeViewBindCellType;
            _treeView.columns["severity"].bindCell = OnTreeViewBindCellSeverity;
            _treeView.columns["severity-message"].bindCell = OnTreeViewBindCellSeverityMessage;
            _treeView.columns["relative-path"].bindCell = OnTreeViewBindCellRelativePath;
            _treeView.columns["field-path"].bindCell = OnTreeViewBindCellFieldPath;
            
            _treeView.columns["severity"].unbindCell = OnTreeViewUnbindCellSeverity;
            
            _treeView.columns["asset"].comparison = OnTreeViewComparisonCellAsset;
            _treeView.columns["type"].comparison = OnTreeViewComparisonCellType;
            _treeView.columns["severity"].comparison = OnTreeViewComparisonCellSeverity;
            _treeView.columns["severity-message"].comparison = OnTreeViewComparisonCellSeverityMessage;
            _treeView.columns["relative-path"].comparison = OnTreeViewComparisonCellRelativePath;
            _treeView.columns["field-path"].comparison = OnTreeViewComparisonCellFieldPath;
            
            _treeView.selectionChanged += OnTreeViewSelectionChanged;
            Rebuild();
        }
        
        public void Rebuild()
        {
            if (!Report.HasActive)
                return;
            
            _list.Clear();

            var entries = Report.Active.Entries;
            var warningCount = 0;
            var errorCount = 0;

            for (var i = 0; i < entries.Count; i++)
            {
                _list.Add(new TreeViewItemData<Report.Entry>(i, entries[i]));

                if (entries[i].Severity == EValidatorSeverity.Warning)
                    warningCount++;
                if (entries[i].Severity == EValidatorSeverity.Error)
                    errorCount++;
            }

            _groupWarnings.style.display = warningCount > 0 ? DisplayStyle.Flex : DisplayStyle.None;
            _labelWarnings.text = warningCount.ToString();
            
            _groupErrors.style.display = errorCount > 0 ? DisplayStyle.Flex : DisplayStyle.None;
            _labelErrors.text = errorCount.ToString();
            
            Filter();
        }
        
        public void Clear()
        {
            _list.Clear();
            Filter();
        }
        
        private void Filter()
        {
            _treeView.Clear();
            
            if (string.IsNullOrEmpty(_searchFilter))
            {
                _treeView.SetRootItems(_list);
            }
            else
            {
                _filteredList.Clear();

                for (var i = 0; i < _list.Count; i++)
                {
                    if (_list[i].data.Filter(_searchFilter))
                        _filteredList.Add(_list[i]);
                }
                
                _treeView.SetRootItems(_filteredList);
            }

            _treeView.Rebuild();
        }

        private static VisualElement CreateLabel()
        {
            var label = new Label();
            label.AddToClassList("tree-view-label");
            return label;
        }

        private static VisualElement CreateObjectField()
        {
            return new ObjectField
            {
                objectType = typeof(UnityEngine.Object),
                allowSceneObjects = true,
                label = string.Empty
            };
        }

        private void OnToolbarButtonRunClicked()
        {
            if (!ValidatorRunner.Run())
                EditorUtility.DisplayDialog("Project Validator", "Failed to run validators, due to either project in play mode or compiling", "Ok");
        }

        private void OnToolbarButtonClearClicked()
        {
            _groupWarnings.style.display = DisplayStyle.None;
            _groupErrors.style.display = DisplayStyle.None;
            ValidatorRunner.Clear();
        }

        private void OnToolbarButtonSettingsClicked()
        {
            SettingsService.OpenProjectSettings(ProjectValidatorSettings.MenuPath);
        }

        private void OnToolbarSearchFieldChanged(ChangeEvent<string> evt)
        {
            _searchFilter = evt.newValue;
            Filter();
        }

        private void OnTreeViewBindCellAsset(VisualElement ve, int index)
        {
            var objectField = (ObjectField)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);

            if (!entry.AssetGuid.Empty())
            {
                objectField.value = AssetDatabase.LoadAssetByGUID(entry.AssetGuid, typeof(UnityEngine.Object));
                objectField.style.display = DisplayStyle.Flex;
            }
            else
            {
                objectField.style.display = DisplayStyle.None;
            }
        }

        private void OnTreeViewBindCellType(VisualElement ve, int index)
        {
            var label = (Label)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);
            label.text = entry.Type;
        }

        private void OnTreeViewBindCellSeverity(VisualElement ve, int index)
        {
            var label = (Label)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);
            label.text = entry.SeverityStr;
            label.AddToClassList(entry.SeverityStr.ToLower());
        }

        private void OnTreeViewBindCellSeverityMessage(VisualElement ve, int index)
        {
            var label = (Label)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);
            label.text = entry.SeverityResult;
        }

        private void OnTreeViewBindCellRelativePath(VisualElement ve, int index)
        {
            var label = (Label)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);
            label.text = entry.RelativePathRichText;
        }

        private void OnTreeViewBindCellFieldPath(VisualElement ve, int index)
        {
            var label = (Label)ve;
            var entry = _treeView.GetItemDataForIndex<Report.Entry>(index);
            label.text = entry.FieldPathRichText;
        }
        
        private void OnTreeViewUnbindCellSeverity(VisualElement ve, int index)
        {
            var label = (Label)ve;
            label.RemoveFromClassList("error");
            label.RemoveFromClassList("warning");
        }
        
        private int OnTreeViewComparisonCellAsset(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);

            var assetName0 = EditorAssetUtility.GetAssetName(entry0.AssetGuid);
            var assetName1 = EditorAssetUtility.GetAssetName(entry1.AssetGuid);
            return string.Compare(assetName0, assetName1, StringComparison.Ordinal);
        }

        private int OnTreeViewComparisonCellType(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);
            return string.Compare(entry0.Type, entry1.Type, StringComparison.Ordinal);
        }

        private int OnTreeViewComparisonCellSeverity(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);
            return entry0.Severity.CompareTo(entry1.Severity);
        }

        private int OnTreeViewComparisonCellSeverityMessage(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);
            return string.Compare(entry0.SeverityResult, entry1.SeverityResult, StringComparison.Ordinal);
        }

        private int OnTreeViewComparisonCellRelativePath(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);
            return string.Compare(entry0.RelativePath, entry1.RelativePath, StringComparison.Ordinal);
        }

        private int OnTreeViewComparisonCellFieldPath(int index0, int index1)
        {
            var entry0 = _treeView.GetItemDataForIndex<Report.Entry>(index0);
            var entry1 = _treeView.GetItemDataForIndex<Report.Entry>(index1);
            return string.Compare(entry0.FieldPath, entry1.FieldPath, StringComparison.Ordinal);
        }

        private void OnTreeViewSelectionChanged(IEnumerable<object> selection)
        {
            foreach (var obj in selection)
            {
                if (obj is Report.Entry entry)
                    ProjectValidatorUtility.PingObject(entry);    
            }
        }
    }
}