using System.Collections.Generic;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.UIElements;
using Streamingle.Background;

namespace Streamingle.Background.Editor
{
    [CustomPropertyDrawer(typeof(SkyboxTimeController.MaterialPropertyOverride))]
    public class MaterialPropertyOverrideDrawer : PropertyDrawer
    {
        public override VisualElement CreatePropertyGUI(SerializedProperty property)
        {
            var root = new VisualElement();
            root.style.backgroundColor = new Color(0f, 0f, 0f, 0.08f);
            root.style.borderBottomLeftRadius = 4;
            root.style.borderBottomRightRadius = 4;
            root.style.borderTopLeftRadius = 4;
            root.style.borderTopRightRadius = 4;
            root.style.paddingTop = 4;
            root.style.paddingBottom = 4;
            root.style.paddingLeft = 4;
            root.style.paddingRight = 4;
            root.style.marginBottom = 4;

            var matProp = property.FindPropertyRelative("targetMaterial");
            var nameProp = property.FindPropertyRelative("propertyName");
            var typeProp = property.FindPropertyRelative("propertyType");

            // ── Material ──
            var matField = new PropertyField(matProp, "Material");
            root.Add(matField);

            // ── Property Dropdown ──
            var dropdownRow = new VisualElement();
            dropdownRow.style.flexDirection = FlexDirection.Row;
            dropdownRow.style.alignItems = Align.Center;

            var dropdown = new PopupField<string>("Property", new List<string> { "(none)" }, 0);
            dropdown.style.flexGrow = 1;
            dropdownRow.Add(dropdown);
            root.Add(dropdownRow);

            // ── Type (자동 설정되지만 표시) ──
            var typeField = new PropertyField(typeProp, "Type");
            typeField.SetEnabled(false);
            root.Add(typeField);

            // ── Stage value containers ──
            var floatContainer = CreateStageRow("Float",
                property.FindPropertyRelative("floatStage1"),
                property.FindPropertyRelative("floatStage2"),
                property.FindPropertyRelative("floatStage3"));

            var colorContainer = CreateStageRow("Color",
                property.FindPropertyRelative("colorStage1"),
                property.FindPropertyRelative("colorStage2"),
                property.FindPropertyRelative("colorStage3"));

            var vectorContainer = CreateStageRow("Vector",
                property.FindPropertyRelative("vectorStage1"),
                property.FindPropertyRelative("vectorStage2"),
                property.FindPropertyRelative("vectorStage3"));

            root.Add(floatContainer);
            root.Add(colorContainer);
            root.Add(vectorContainer);

            // ── 셰이더 프로퍼티 목록 캐시 ──
            var shaderProps = new List<ShaderPropertyInfo>();

            // 드롭다운 rebuild
            void RebuildDropdown()
            {
                shaderProps.Clear();
                var choices = new List<string> { "(none)" };

                var mat = matProp.objectReferenceValue as Material;
                if (mat != null && mat.shader != null)
                {
                    var shader = mat.shader;
                    int count = shader.GetPropertyCount();
                    for (int i = 0; i < count; i++)
                    {
                        var sType = shader.GetPropertyType(i);
                        // Float, Range, Color, Vector만 지원 (텍스쳐 제외)
                        if (sType != ShaderPropertyType.Float &&
                            sType != ShaderPropertyType.Range &&
                            sType != ShaderPropertyType.Color &&
                            sType != ShaderPropertyType.Vector)
                            continue;

                        // HideInInspector 제외
                        var flags = shader.GetPropertyFlags(i);
                        if ((flags & ShaderPropertyFlags.HideInInspector) != 0) continue;

                        var propName = shader.GetPropertyName(i);
                        var propDesc = shader.GetPropertyDescription(i);
                        var displayName = string.IsNullOrEmpty(propDesc)
                            ? propName
                            : $"{propDesc} ({propName})";

                        var mpType = SkyboxTimeController.MaterialPropertyType.Float;
                        if (sType == ShaderPropertyType.Color)
                            mpType = SkyboxTimeController.MaterialPropertyType.Color;
                        else if (sType == ShaderPropertyType.Vector)
                            mpType = SkyboxTimeController.MaterialPropertyType.Vector;

                        shaderProps.Add(new ShaderPropertyInfo
                        {
                            name = propName,
                            displayName = displayName,
                            type = mpType,
                        });
                        choices.Add(displayName);
                    }
                }

                // 현재 값 찾기
                int selectedIdx = 0;
                string currentName = nameProp.stringValue;
                if (!string.IsNullOrEmpty(currentName))
                {
                    for (int i = 0; i < shaderProps.Count; i++)
                    {
                        if (shaderProps[i].name == currentName)
                        {
                            selectedIdx = i + 1; // +1 for "(none)"
                            break;
                        }
                    }
                }

                dropdown.choices = choices;
                dropdown.index = selectedIdx;
            }

            // 드롭다운 선택 시 프로퍼티 이름 + 타입 자동 설정
            dropdown.RegisterValueChangedCallback(evt =>
            {
                int idx = dropdown.index;
                if (idx <= 0 || idx > shaderProps.Count)
                {
                    nameProp.stringValue = "";
                    nameProp.serializedObject.ApplyModifiedProperties();
                }
                else
                {
                    var info = shaderProps[idx - 1];
                    nameProp.stringValue = info.name;
                    typeProp.enumValueIndex = (int)info.type;
                    nameProp.serializedObject.ApplyModifiedProperties();
                    UpdateVisibility(info.type, floatContainer, colorContainer, vectorContainer);
                }
            });

            // 머티리얼 변경 시 드롭다운 재구성
            matField.RegisterValueChangeCallback(evt =>
            {
                // schedule로 다음 프레임에 rebuild (objectReference 반영 대기)
                root.schedule.Execute(() => RebuildDropdown());
            });

            // 초기 세팅
            root.schedule.Execute(() =>
            {
                RebuildDropdown();
                UpdateVisibility(
                    (SkyboxTimeController.MaterialPropertyType)typeProp.enumValueIndex,
                    floatContainer, colorContainer, vectorContainer);
            });

            return root;
        }

        private void UpdateVisibility(
            SkyboxTimeController.MaterialPropertyType type,
            VisualElement floatContainer,
            VisualElement colorContainer,
            VisualElement vectorContainer)
        {
            floatContainer.style.display = type == SkyboxTimeController.MaterialPropertyType.Float
                ? DisplayStyle.Flex : DisplayStyle.None;
            colorContainer.style.display = type == SkyboxTimeController.MaterialPropertyType.Color
                ? DisplayStyle.Flex : DisplayStyle.None;
            vectorContainer.style.display = type == SkyboxTimeController.MaterialPropertyType.Vector
                ? DisplayStyle.Flex : DisplayStyle.None;
        }

        private VisualElement CreateStageRow(string label,
            SerializedProperty s1, SerializedProperty s2, SerializedProperty s3)
        {
            var container = new VisualElement();
            container.style.marginTop = 4;

            var header = new Label($"── {label} Values ──");
            header.style.unityFontStyleAndWeight = FontStyle.Bold;
            header.style.unityTextAlign = TextAnchor.MiddleCenter;
            header.style.marginBottom = 2;
            header.style.color = new Color(0.6f, 0.8f, 1f);
            container.Add(header);

            container.Add(new PropertyField(s1, "Stage 1"));
            container.Add(new PropertyField(s2, "Stage 2"));
            container.Add(new PropertyField(s3, "Stage 3"));

            return container;
        }

        private struct ShaderPropertyInfo
        {
            public string name;
            public string displayName;
            public SkyboxTimeController.MaterialPropertyType type;
        }
    }
}