using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEngine;

namespace UltraCombos
{
    [CustomEditor(typeof(DebugSettingsGUI))]
    public class DebugSettingsGUIEditor : Editor
    {
        // ── Supported field types ─────────────────────────────────────────────────

        private static readonly HashSet<Type> supportedTypes = new()
        {
            typeof(bool), typeof(int), typeof(float),
            typeof(string), typeof(Vector2), typeof(Vector3), typeof(Color)
        };

        private static bool IsSupported(Type t) => supportedTypes.Contains(t) || t.IsEnum;

        // ── Cached SerializedProperties ───────────────────────────────────────────

        private SerializedProperty toggleKeyProp;
        private SerializedProperty initialRectProp;

        private void OnEnable()
        {
            toggleKeyProp = serializedObject.FindProperty("toggleKey");
            initialRectProp = serializedObject.FindProperty("initialRect");
        }

        // ── Inspector ─────────────────────────────────────────────────────────────

        public override void OnInspectorGUI()
        {
            var gui = (DebugSettingsGUI)target;
            serializedObject.Update();

            EditorGUILayout.LabelField("General", EditorStyles.boldLabel);
            EditorGUILayout.PropertyField(toggleKeyProp, new GUIContent("Toggle Key"));
            EditorGUILayout.PropertyField(initialRectProp, new GUIContent("Initial Rect"));

            serializedObject.ApplyModifiedProperties();

            EditorGUILayout.Space(10);
            EditorGUILayout.LabelField("Entries", EditorStyles.boldLabel);

            for (var i = 0; i < gui.entries.Count; i++)
            {
                var removed = DrawEntry(gui, gui.entries[i], i);
                if (removed)
                {
                    Undo.RecordObject(gui, "Remove Entry");
                    gui.entries.RemoveAt(i);
                    EditorUtility.SetDirty(gui);
                    i--;
                }
                EditorGUILayout.Space(2);
            }

            EditorGUILayout.Space(4);

            if (GUILayout.Button("＋  Add Entry", GUILayout.Height(26)))
            {
                Undo.RecordObject(gui, "Add Entry");
                gui.entries.Add(new DebugSettingsGUI.Entry());
                EditorUtility.SetDirty(gui);
            }
        }

        // ── Draw one Entry — returns true when the user clicked Remove ─────────────

        private static bool DrawEntry(DebugSettingsGUI gui, DebugSettingsGUI.Entry entry, int index)
        {
            var removed = false;

            using (new EditorGUILayout.VerticalScope(EditorStyles.helpBox))
            {
                // Header row
                using (new EditorGUILayout.HorizontalScope())
                {
                    var title = string.IsNullOrEmpty(entry.groupLabel)
                        ? $"Entry {index}"
                        : $"Entry {index}  —  {entry.groupLabel}";
                    EditorGUILayout.LabelField(title, EditorStyles.boldLabel);
                    GUILayout.FlexibleSpace();
                    if (GUILayout.Button("✕", GUILayout.Width(22), GUILayout.Height(18)))
                    {
                        removed = true;
                    }
                }

                // Group label
                EditorGUI.BeginChangeCheck();
                var newLabel = EditorGUILayout.TextField("Group Label", entry.groupLabel);
                if (EditorGUI.EndChangeCheck())
                {
                    Undo.RecordObject(gui, "Edit Group Label");
                    entry.groupLabel = newLabel;
                    EditorUtility.SetDirty(gui);
                }

                // Target object.
                // Drag any Component or ScriptableObject here.
                // Dropping a GameObject picks its first non-Transform Component automatically.
                EditorGUI.BeginChangeCheck();
                var newTarget = EditorGUILayout.ObjectField(
                    new GUIContent("Target",
                        "Drag any Component or ScriptableObject here.\n" +
                        "Dropping a GameObject picks its first non-Transform Component."),
                    entry.target,
                    typeof(UnityEngine.Object),
                    allowSceneObjects: true);

                if (EditorGUI.EndChangeCheck())
                {
                    Undo.RecordObject(gui, "Set Target");

                    if (newTarget is GameObject go)
                    {
                        var comps = go.GetComponents<Component>();
                        newTarget = comps.FirstOrDefault(c => c is not Transform) ??
                                    comps.FirstOrDefault() ??
                                    (UnityEngine.Object)go;
                    }

                    entry.target = newTarget;
                    entry.fields.Clear();
                    EditorUtility.SetDirty(gui);
                }

                // Field selection
                if (entry.target != null)
                {
                    DrawFieldSelection(gui, entry);
                }
            }

            return removed;
        }

        // ── Field checkboxes ──────────────────────────────────────────────────────

        private static void DrawFieldSelection(DebugSettingsGUI gui, DebugSettingsGUI.Entry entry)
        {
            var type = entry.target.GetType();
            var fields = CollectFields(type);

            if (fields.Count == 0)
            {
                EditorGUILayout.HelpBox(
                    "No displayable fields found on this object.\n" +
                    "Supported types: bool · int · float · string · Vector2 · Vector3 · Color · Enum\n" +
                    "Fields must be public or marked [SerializeField].",
                    MessageType.Info);
                return;
            }

            EditorGUILayout.Space(4);

            // Select All / None
            using (new EditorGUILayout.HorizontalScope())
            {
                EditorGUILayout.LabelField("Fields to Display", EditorStyles.boldLabel);
                GUILayout.FlexibleSpace();

                if (GUILayout.Button("All", GUILayout.Width(36)))
                {
                    Undo.RecordObject(gui, "Select All Fields");
                    entry.fields = fields.Select(f => f.Name).ToList();
                    EditorUtility.SetDirty(gui);
                }
                if (GUILayout.Button("None", GUILayout.Width(38)))
                {
                    Undo.RecordObject(gui, "Deselect All Fields");
                    entry.fields.Clear();
                    EditorUtility.SetDirty(gui);
                }
            }

            // Per-field toggles
            EditorGUI.indentLevel++;

            foreach (var fi in fields)
            {
                var isSelected = entry.fields.Contains(fi.Name);
                var niceName = ObjectNames.NicifyVariableName(fi.Name);
                var typeName = FriendlyType(fi.FieldType);
                var hasRange = fi.GetCustomAttribute<RangeAttribute>() != null;

                var label = new GUIContent(
                    $"{niceName}  ({typeName}{(hasRange ? ", Range" : string.Empty)})",
                    tooltip: $"Field: {fi.Name}\nType: {fi.FieldType.FullName}");

                EditorGUI.BeginChangeCheck();
                var next = EditorGUILayout.ToggleLeft(label, isSelected);

                if (EditorGUI.EndChangeCheck())
                {
                    Undo.RecordObject(gui, next ? "Add Field" : "Remove Field");
                    if (next)
                    {
                        entry.fields.Add(fi.Name);
                    }
                    else
                    {
                        entry.fields.Remove(fi.Name);
                    }
                    EditorUtility.SetDirty(gui);
                }
            }

            EditorGUI.indentLevel--;
        }

        // ── Reflection helpers ────────────────────────────────────────────────────

        private static List<FieldInfo> CollectFields(Type type)
        {
            const BindingFlags flags =
                BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;

            var result = new List<FieldInfo>();

            for (var t = type; t != null && t != typeof(UnityEngine.Object); t = t.BaseType)
            {
                foreach (var fi in t.GetFields(flags | BindingFlags.DeclaredOnly))
                {
                    var exposed = fi.IsPublic || fi.GetCustomAttribute<SerializeField>() != null;
                    if (!exposed)
                    {
                        continue;
                    }
                    if (fi.GetCustomAttribute<HideInInspector>() != null)
                    {
                        continue;
                    }
                    if (!IsSupported(fi.FieldType))
                    {
                        continue;
                    }
                    if (!result.Any(r => r.Name == fi.Name))
                    {
                        result.Add(fi);
                    }
                }
            }

            return result;
        }

        private static string FriendlyType(Type t)
        {
            if (t == typeof(float)) { return "float"; }
            if (t == typeof(int)) { return "int"; }
            if (t == typeof(bool)) { return "bool"; }
            if (t == typeof(string)) { return "string"; }
            if (t == typeof(Vector2)) { return "Vector2"; }
            if (t == typeof(Vector3)) { return "Vector3"; }
            if (t == typeof(Color)) { return "Color"; }
            if (t.IsEnum) { return t.Name; }
            return t.Name;
        }
    }
}