using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEditor.Build;
using UnityEditor.Build.Reporting;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor.AddressableAssets;
using UnityEditor.AddressableAssets.Settings;
#endif

namespace BaseGames.Editor
{
    /// <summary>
    /// Editor 工具：验证 <see cref="BaseGames.Core.Assets.AddressKeys"/> 中所有常量
    /// 是否与 Addressable 分组中实际存在的地址同步（架构 13_AssetPoolModule §10）。
    ///
    /// 菜单：BaseGames → Tools → Validate Address Keys
    /// Build 回调顺序 = 0（在 SOValidationRunner callbackOrder = 1 之前执行）
    /// </summary>
    public class AddressKeyValidatorBuildHook : IPreprocessBuildWithReport
    {
        public int callbackOrder => 0;

        public void OnPreprocessBuild(BuildReport report)
        {
            var results = AddressKeyValidator.RunValidation();
            int missing = results.Count(r => !r.ExistsInAddressables);
            if (missing > 0)
            {
                var orphans = results
                    .Where(r => !r.ExistsInAddressables)
                    .Select(r => $"AddressKeys.{r.FieldName} = \"{r.Value}\"");
                throw new BuildFailedException(
                    $"[AddressKeyValidator] {missing} 个孤儿 AddressKey，构建中止：\n"
                    + string.Join("\n", orphans));
            }
        }
    }

    /// <summary>
    /// Editor 静态工具类：验证逻辑和 MenuItem 入口。
    /// </summary>
    public static class AddressKeyValidator
    {
        [MenuItem("BaseGames/Tools/Validate Address Keys")]
        public static void ValidateAll()
        {
            var results = RunValidation();
            LogResults(results);
        }

        /// <summary>
        /// 执行验证，返回每个 key 的验证结果。供 Build Pre-process 或测试调用。
        /// </summary>
        public static List<ValidationResult> RunValidation()
        {
            var results = new List<ValidationResult>();
            var registeredAddresses = GetAllAddressableAddresses();

            // 通过反射取出 AddressKeys 中所有 public const string 字段
            var keyType = typeof(BaseGames.Core.Assets.AddressKeys);
            var fields  = keyType.GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy)
                                 .Where(f => f.IsLiteral && !f.IsInitOnly && f.FieldType == typeof(string));

            foreach (var field in fields)
            {
                var value = (string)field.GetRawConstantValue();
                var exists = registeredAddresses.Contains(value);
                results.Add(new ValidationResult(field.Name, value, exists));
            }

            return results;
        }

        // ── Internal ──────────────────────────────────────────────────────────

        private static HashSet<string> GetAllAddressableAddresses()
        {
            var addresses = new HashSet<string>(StringComparer.Ordinal);

#if UNITY_EDITOR
            var settings = AddressableAssetSettingsDefaultObject.Settings;
            if (settings == null)
            {
                Debug.LogWarning("[AddressKeyValidator] Addressable Settings 未找到，请先初始化 Addressables。");
                return addresses;
            }

            foreach (var group in settings.groups)
            {
                if (group == null) continue;
                foreach (var entry in group.entries)
                {
                    if (entry != null)
                        addresses.Add(entry.address);
                }
            }
#endif
            return addresses;
        }

        private static void LogResults(List<ValidationResult> results)
        {
            int missing = 0;
            foreach (var r in results)
            {
                if (!r.ExistsInAddressables)
                {
                    Debug.LogWarning($"[AddressKeyValidator] ⚠ 孤儿 Key：AddressKeys.{r.FieldName} = \"{r.Value}\" — 未在 Addressable 分组中找到对应地址。");
                    missing++;
                }
            }

            if (missing == 0)
                Debug.Log($"[AddressKeyValidator] ✓ 所有 {results.Count} 个 AddressKeys 常量均在 Addressable 分组中存在。");
            else
                    Debug.LogWarning($"[AddressKeyValidator] 共 {results.Count} 个常量，发现 {missing} 个孤儿 Key。" +
                        $"尚未创建的 Prefab/Scene 资产请在创建后添加至 Addressables 分组。");
        }

        // ── 结果结构 ──────────────────────────────────────────────────────────

        public readonly struct ValidationResult
        {
            public readonly string FieldName;
            public readonly string Value;
            public readonly bool   ExistsInAddressables;

            public ValidationResult(string fieldName, string value, bool exists)
            {
                FieldName = fieldName;
                Value     = value;
                ExistsInAddressables = exists;
            }
        }
    }

    /// <summary>
    /// 资产导入后自动触发 AddressKey 验证（架构 13_AssetPoolModule §10）。
    /// 仅在 Addressable Group 资产发生变更时触发，避免每次导入都验证。
    /// </summary>
    public class AddressKeyImportWatcher : AssetPostprocessor
    {
        private const string AddressableGroupAssetExt = ".asset";
        private const string AddressableGroupFolder   = "Assets/AddressableAssetsData";

        private static void OnPostprocessAllAssets(
            string[] importedAssets,
            string[] deletedAssets,
            string[] movedAssets,
            string[] movedFromAssetPaths)
        {
            bool addressablesChanged = false;

            foreach (var path in importedAssets)
            {
                if (path.StartsWith(AddressableGroupFolder, StringComparison.OrdinalIgnoreCase)
                    && path.EndsWith(AddressableGroupAssetExt, StringComparison.OrdinalIgnoreCase))
                {
                    addressablesChanged = true;
                    break;
                }
            }

            if (!addressablesChanged)
            {
                foreach (var path in deletedAssets)
                {
                    if (path.StartsWith(AddressableGroupFolder, StringComparison.OrdinalIgnoreCase))
                    {
                        addressablesChanged = true;
                        break;
                    }
                }
            }

            if (addressablesChanged)
            {
                // 延迟一帧执行，等待 AssetDatabase 完全刷新
                EditorApplication.delayCall += () =>
                {
                    Debug.Log("[AddressKeyImportWatcher] 检测到 Addressable 分组变更，自动触发 Key 验证...");
                    AddressKeyValidator.ValidateAll();
                };
            }
        }
    }
}