TheVVaS-Assets/RPGCoreCommon/DropTable/Editor/DropTableGroupRowElement.cs

using System;
using System.Linq;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine;
using UnityEngine.UIElements;
using Cursor = UnityEngine.Cursor;

namespace RPGCoreCommon.DropTable.Editor
{
    internal class DropTableGroupRowElement : VisualElement
    {
        // Property data
        private SerializedProperty _property;
        private SerializedProperty _propertyInlineGroup;
        private DropTableGroupRow value => (DropTableGroupRow)_property.boxedValue;
        
        // Elements
        private readonly VisualElement _percentBackground;
        private readonly Label _percentLabel;
        private readonly VisualElement _rightElement;
        private readonly FloatField _chanceField;
        private readonly IntegerField _countField;
        private readonly ObjectField _itemField;
        private readonly ObjectField _groupReferenceField;
        private readonly DropTableGroupElement _groupInline;
        private readonly Label _newInlineLabel;
        private readonly VisualElement _dropHere;

        internal DropTableGroupRowElement()
        {
            DropTableDrawer.rowVisualTreeAsset.CloneTree(this);
            
            this.AddManipulator(new  ContextualMenuManipulator(null));
            RegisterCallback<ContextualMenuPopulateEvent>(ev =>
            {
                ev.StopImmediatePropagation();
                
                ev.menu.InsertAction(0, "Reset row", _ =>
                {
                    SetEditingMode(EditTypeEnum.None);
                });
                ev.menu.InsertAction(1, "Remove row", _ =>
                {
                    var arrayPath = string.Join(".", _property.propertyPath.Split(".").SkipLast(2));
                    var arrayProperty = _property.serializedObject.FindProperty(arrayPath);
                    var i = int.Parse(_property.propertyPath[_property.propertyPath.LastIndexOf('[')..].Trim('[', ']'));
                    arrayProperty.DeleteArrayElementAtIndex(i); 
                    _property.serializedObject.ApplyModifiedProperties();
                });
                ev.menu.InsertSeparator(null, 2);
            });

            // PERCENTAGE
            _percentBackground = this.Q("dt-percent-background");
            _percentLabel = this.Q<Label>("dt-percent");
            
            // RIGHT SIDE
            _rightElement = this.Q("dt-right");
            
            // CHANCE
            _chanceField = this.Q<FloatField>("dt-chance");
            _chanceField.RegisterValueChangedCallback(_ =>
            {
                _chanceField.SetValueWithoutNotify(Mathf.Clamp(_chanceField.value, 0, 100));
                RefreshGroup();
            });
            
            // COUNT
            _countField = this.Q<IntegerField>("dt-count");
            _countField.RegisterValueChangedCallback(_ => _countField.SetValueWithoutNotify(Mathf.Max(0, _countField.value)));
            
            // CREATE INLINE
            _newInlineLabel = this.Q<Label>("dt-new-inline");
            _newInlineLabel.RegisterCallback<ClickEvent>(_ => SetEditingMode(EditTypeEnum.InlineGroup));
            
            // DROP AREA
            _dropHere = this.Q("dt-drop-here");
            RegisterCallback<DragLeaveEvent>(_ => ShowDropHere());
            RegisterCallback<DragExitedEvent>(_ => ShowDropHere());
            RegisterCallback<DragUpdatedEvent>(ev =>
            {
                if ((ev.target as VisualElement).GetFirstAncestorOfType<DropTableGroupRowElement>() != this)
                {
                    ShowDropHere(false);
                    return;
                }

                if (value.subGroupInline is not null)
                {
                    ShowDropHere(false);
                    return;
                }
            
                ShowDropHere(true);
            });
            RegisterCallback<DragPerformEvent>(ev =>
            {
                ev.StopImmediatePropagation();
                
                if (DragAndDrop.objectReferences.Length > 1)
                    Debug.LogWarning("Trying to drag more than one <b>Object</b> to row, using only first one.");
                
                SetEditingMode(EditTypeEnum.None);
                
                var obj = DragAndDrop.objectReferences[0];
                if (obj is DropTableSO dropTableSO)
                {
                    _groupReferenceField.value = dropTableSO;
                    SetEditingMode(EditTypeEnum.ReferenceGroup);
                }
                else
                {
                    _itemField.value = obj;
                    SetEditingMode(EditTypeEnum.Item);
                }
            
                ShowDropHere();
            });
            
            // ITEM
            _itemField = this.Q<ObjectField>("dt-item");
            
            // SUBGROUP REF
            _groupReferenceField = this.Q<ObjectField>("dt-group-reference");
            _groupReferenceField.objectType = typeof(DropTableSO);
            
            // SUBGROUP INLINE
            _groupInline = new DropTableGroupElement { name = "dt-group-inline" };
            this.Q("dt-body").Add(_groupInline);
            
            SetEnabled(false);
        }

        private void ShowDropHere()
        {
            ShowDropHere(!value.item && !value.subGroupRef && value.subGroupInline is null);
        }
        
        private void ShowDropHere(bool show)
        {
            if (show)
            {
                _dropHere.style.display = DisplayStyle.Flex;
                _dropHere.pickingMode = PickingMode.Position;
                DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
                
                ShowCreateNewInline(!value.item && !value.subGroupRef && value.subGroupInline is null);
            }
            else
            {
                _dropHere.style.display = DisplayStyle.None;
                _dropHere.pickingMode = PickingMode.Ignore;
                ShowCreateNewInline(false);
            }
        }

        private void ShowCreateNewInline(bool show)
        {
            _newInlineLabel.style.display = show ? DisplayStyle.Flex : DisplayStyle.None;
        }
        
        internal void BindProperty(SerializedProperty property)
        {
            SetEnabled(true);

            _property = property;
            _propertyInlineGroup = property.FindPropertyRelative(nameof(DropTableGroupRow.subGroupInline));
            var value = _property.boxedValue as DropTableGroupRow;
            
            _chanceField.BindProperty(_property.FindPropertyRelative(nameof(DropTableGroupRow.chance)));
            _countField.BindProperty(_property.FindPropertyRelative(nameof(DropTableGroupRow.count)));
            _itemField.BindProperty(_property.FindPropertyRelative(nameof(DropTableGroupRow.item)));
            _groupReferenceField.BindProperty(_property.FindPropertyRelative(nameof(DropTableGroupRow.subGroupRef)));
            
            // Default editing mode by currently set content
            if (value.item) SetEditingMode(EditTypeEnum.Item);
            else if (value.subGroupRef) SetEditingMode(EditTypeEnum.ReferenceGroup);
            else if (value.subGroupInline != null) SetEditingMode(EditTypeEnum.InlineGroup);
            else SetEditingMode(EditTypeEnum.None);
        }

        private void SetEditingMode(EditTypeEnum @enum)
        {
            // Hide all
            _itemField.style.display = DisplayStyle.None;
            _groupReferenceField.style.display = DisplayStyle.None;
            _groupInline.style.display = DisplayStyle.None;
            
            switch (@enum)
            {
                // 1. Starting point when row is newly created with no values
                // 2. When row is resetting - clean values
                case EditTypeEnum.None:
                    _itemField.value = null;
                    _groupReferenceField.value = null;
                    _propertyInlineGroup.managedReferenceValue = null;
                    _rightElement.EnableInClassList("single-line", false);
                    ShowDropHere(true);
                    break;
                // Editing selected - item
                case EditTypeEnum.Item:
                    _itemField.style.display = DisplayStyle.Flex;
                    _rightElement.EnableInClassList("single-line", true);
                    ShowDropHere(false);
                    break;
                // Editing selected - recursion by reference (ScriptableObject)
                case EditTypeEnum.ReferenceGroup:
                    _groupReferenceField.style.display = DisplayStyle.Flex;
                    _rightElement.EnableInClassList("single-line", true);
                    ShowDropHere(false);
                    break;
                // Editing selected - recursion by inline definition
                case EditTypeEnum.InlineGroup:
                    _groupInline.style.display = DisplayStyle.Flex;
                    _propertyInlineGroup.managedReferenceValue ??= new DropTableGroup();
                    _property.serializedObject.ApplyModifiedProperties();
                    _groupInline.BindProperty(_propertyInlineGroup);
                    _rightElement.EnableInClassList("single-line", false);
                    ShowDropHere(false);
                    break;
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        internal void RefreshGroup()
        {
            GetFirstAncestorOfType<DropTableGroupElement>().Refresh();
        }

        internal void Refresh(ChanceTypeEnum chanceType, float weightSum)
        {
            switch (chanceType)
            {
                case ChanceTypeEnum.All:
                    _chanceField.style.display = DisplayStyle.None;
                    _percentBackground.style.display = DisplayStyle.None;
                    break;
                case ChanceTypeEnum.ByWeight:
                    _chanceField.style.display = DisplayStyle.Flex;
                    _chanceField.label = "Weight:";
                    _percentBackground.style.display = DisplayStyle.Flex;
                    SetPercent(_chanceField.value/weightSum*100);
                    break;
                case ChanceTypeEnum.ByPercent:
                    _chanceField.style.display = DisplayStyle.Flex;
                    _chanceField.label = "Percent:";
                    _percentBackground.style.display = DisplayStyle.Flex;
                    SetPercent(_chanceField.value);
                    break;
                default:
                    throw new ArgumentOutOfRangeException(nameof(chanceType), chanceType, null);
            }
        }

        private void SetPercent(float percent)
        {
            _percentBackground.style.backgroundColor = Color.Lerp(Color.red, Color.green, percent / 100);
            _percentLabel.text = $"{percent:F}%";
        }
    }
}