using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Cysharp.Threading.Tasks;
using Newtonsoft.Json.Linq;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.TestTools;
using Object = UnityEngine.Object;

namespace ShrinkDataSaver.Tests
{
    [TestFixture]
    public class ShrinkSaveTests
    {
        private MockStorageProvider _storage;
        private ShrinkDataSaverSettings _settings;

        [Serializable]
        private class PlayerData
        {
            public string Name = "TestPlayer";
            public int Level = 1;
            public int Coins = 100;
        }

        private PlayerData _playerData;

        [SetUp]
        public void SetUp()
        {
            _storage = new MockStorageProvider();
            _settings = ScriptableObject.CreateInstance<ShrinkDataSaverSettings>();
            _settings.maxSlots = 10;
            ShrinkDataSaverSettings.Instance = _settings;

            ShrinkSave.ResetForTesting();
            MigrationChain.Clear();
            ShrinkSave.Initialize(_storage, "saves", ".sav", 1);

            _playerData = new PlayerData();
        }

        [TearDown]
        public void TearDown()
        {
            ShrinkSave.ResetForTesting();
            MigrationChain.Clear();
            if (_settings != null) Object.DestroyImmediate(_settings);
        }

        // ── 模块注册 ──

        [Test]
        public void RegisterModule_Lambda()
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            Assert.IsTrue(ShrinkSave.HasModule("player"));
        }

        [Test]
        public void RegisterModule_WithConfig()
        {
            var config = new ModuleConfig
            {
                EnableCloudSync = false,
                AutoSaveIntervalSeconds = 30f,
                CriticalModule = true
            };
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d, config);

            var restored = ShrinkSave.GetModuleConfig("player");
            Assert.IsFalse(restored.EnableCloudSync);
            Assert.AreEqual(30f, restored.AutoSaveIntervalSeconds);
            Assert.IsTrue(restored.CriticalModule);
        }

        [Test]
        public void UnregisterModule_RemovesModuleAndConfig()
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d,
                new ModuleConfig { CriticalModule = true });

            ShrinkSave.UnregisterModule("player");
            Assert.IsFalse(ShrinkSave.HasModule("player"));
            Assert.IsNull(ShrinkSave.GetModuleConfig("player"));
        }

        [Test]
        public void GetModuleConfig_NonExistent_ReturnsNull()
        {
            Assert.IsNull(ShrinkSave.GetModuleConfig("ghost"));
        }

        [Test]
        public void HasModule_ReturnsFalse_WhenNotRegistered()
        {
            Assert.IsFalse(ShrinkSave.HasModule("nonexistent"));
        }

        [Test]
        public void GetRegisteredModuleNames_ReturnsAll()
        {
            ShrinkSave.RegisterModule("a", () => 1, _ => { });
            ShrinkSave.RegisterModule("b", () => 2, _ => { });

            var names = ShrinkSave.GetRegisteredModuleNames();
            Assert.AreEqual(2, names.Count);
            Assert.IsTrue(names.Contains("a"));
            Assert.IsTrue(names.Contains("b"));
        }

        // ── 保存 / 加载 / 删除 ──

        [UnityTest]
        public IEnumerator SaveSlotAsync_ThenExists() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "TestSave" });

            Assert.IsTrue(await ShrinkSave.SlotExistsAsync(0));
        });

        [UnityTest]
        public IEnumerator SaveLoad_RoundTrip_DataIntegrity() => UniTask.ToCoroutine(async () =>
        {
            _playerData = new PlayerData { Name = "Alice", Level = 10, Coins = 500 };
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);

            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "TestSave" });

            // 清除内存数据
            _playerData = new PlayerData();
            Assert.AreEqual("TestPlayer", _playerData.Name);

            // 重新加载
            await ShrinkSave.LoadSlotAsync(0);
            Assert.AreEqual("Alice", _playerData.Name);
            Assert.AreEqual(10, _playerData.Level);
            Assert.AreEqual(500, _playerData.Coins);
        });

        [UnityTest]
        public IEnumerator SaveLoad_Encrypted_RoundTrip() => UniTask.ToCoroutine(async () =>
        {
            _playerData = new PlayerData { Name = "Encrypted", Level = 99, Coins = 9999 };
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);

            await ShrinkSave.SaveSlotAsync(0, new SaveOptions
            {
                SlotName = "Encrypted Save",
                Encrypt = true,
                EncryptionKey = "secret123"
            });

            _playerData = new PlayerData();
            await ShrinkSave.LoadSlotAsync(0, "secret123");

            Assert.AreEqual("Encrypted", _playerData.Name);
            Assert.AreEqual(99, _playerData.Level);
        });

        [UnityTest]
        public IEnumerator DeleteSlotAsync_RemovesSlot() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);

            Assert.IsTrue(await ShrinkSave.SlotExistsAsync(0));

            await ShrinkSave.DeleteSlotAsync(0);
            Assert.IsFalse(await ShrinkSave.SlotExistsAsync(0));
        });

        [UnityTest]
        public IEnumerator LoadSlotAsync_NonExistent_ThrowsAndFiresLoadFailed() => UniTask.ToCoroutine(async () =>
        {
            LoadFailedEventArgs failArgs = null;
            ShrinkSave.OnLoadFailed += args => failArgs = args;

            try
            {
                await ShrinkSave.LoadSlotAsync(99);
                Assert.Fail("Should have thrown");
            }
            catch (System.IO.FileNotFoundException) { }

            Assert.IsNotNull(failArgs);
            Assert.AreEqual(99, failArgs.SlotIndex);
            Assert.IsTrue(failArgs.ErrorMessage.Contains("99"));
        });

        [UnityTest]
        public IEnumerator SaveSlotAsync_NegativeIndex_Throws() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            try
            {
                await ShrinkSave.SaveSlotAsync(-1);
                Assert.Fail("Should have thrown");
            }
            catch (ArgumentOutOfRangeException) { }
        });

        [UnityTest]
        public IEnumerator SaveSlotAsync_ExceedsMaxSlots_Throws() => UniTask.ToCoroutine(async () =>
        {
            _settings.maxSlots = 3;
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            try
            {
                await ShrinkSave.SaveSlotAsync(5);
                Assert.Fail("Should have thrown");
            }
            catch (ArgumentOutOfRangeException) { }
        });

        // ── 事件 ──

        [UnityTest]
        public IEnumerator Events_SaveStarted_FiredBeforeSave() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);

            SaveStartedEventArgs startArgs = null;
            ShrinkSave.OnSaveStarted += args => startArgs = args;

            await ShrinkSave.SaveSlotAsync(0);

            Assert.IsNotNull(startArgs);
            Assert.AreEqual(0, startArgs.SlotIndex);
            Assert.IsTrue(startArgs.Timestamp > 0);
        });

        [UnityTest]
        public IEnumerator Events_SaveCompleted_ContainsModuleNames() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            ShrinkSave.RegisterModule("settings", () => new { volume = 1f }, _ => { });

            SaveCompletedEventArgs completedArgs = null;
            ShrinkSave.OnSaveCompleted += args => completedArgs = args;

            await ShrinkSave.SaveSlotAsync(0);

            Assert.IsNotNull(completedArgs);
            Assert.AreEqual(0, completedArgs.SlotIndex);
            Assert.AreEqual(2, completedArgs.ModuleNames.Length);
            Assert.IsTrue(completedArgs.Timestamp > 0);
        });

        [UnityTest]
        public IEnumerator Events_LoadCompleted_ContainsVersionAndModules() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);

            LoadCompletedEventArgs loadArgs = null;
            ShrinkSave.OnLoadCompleted += args => loadArgs = args;

            await ShrinkSave.LoadSlotAsync(0);

            Assert.IsNotNull(loadArgs);
            Assert.AreEqual(0, loadArgs.SlotIndex);
            Assert.AreEqual(1, loadArgs.Version);
            Assert.IsTrue(loadArgs.ModuleNames.Length > 0);
        });

        [UnityTest]
        public IEnumerator Events_LoadStarted_Fired() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);

            LoadStartedEventArgs startArgs = null;
            ShrinkSave.OnLoadStarted += args => startArgs = args;

            await ShrinkSave.LoadSlotAsync(0);

            Assert.IsNotNull(startArgs);
            Assert.AreEqual(0, startArgs.SlotIndex);
        });

        [UnityTest]
        public IEnumerator Events_DeleteCompleted_Fired() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);

            SlotDeletedEventArgs deleteArgs = null;
            ShrinkSave.OnDeleteCompleted += args => deleteArgs = args;

            await ShrinkSave.DeleteSlotAsync(0);

            Assert.IsNotNull(deleteArgs);
            Assert.AreEqual(0, deleteArgs.SlotIndex);
        });

        // ── 关键模块 ──

        [UnityTest]
        public IEnumerator CriticalModule_FailedSerialize_AbortsSave() => UniTask.ToCoroutine(async () =>
        {
            // 注册一个会抛异常的关键模块
            ShrinkSave.RegisterModule<object>("broken",
                () => throw new Exception("boom"),
                _ => { },
                new ModuleConfig { CriticalModule = true });

            SaveFailedEventArgs failArgs = null;
            ShrinkSave.OnSaveFailed += args => failArgs = args;

            try
            {
                await ShrinkSave.SaveSlotAsync(0);
                Assert.Fail("Should have thrown");
            }
            catch (InvalidOperationException) { }

            Assert.IsNotNull(failArgs);
            Assert.IsTrue(failArgs.ErrorMessage.Contains("broken"));
        });

        [UnityTest]
        public IEnumerator NonCriticalModule_FailedSerialize_ContinuesSave() => UniTask.ToCoroutine(async () =>
        {
            // 正常模块
            ShrinkSave.RegisterModule("good", () => _playerData, d => _playerData = d);
            // 会失败的非关键模块
            ShrinkSave.RegisterModule<object>("bad",
                () => throw new Exception("oops"),
                _ => { },
                new ModuleConfig { CriticalModule = false });

            SaveCompletedEventArgs completedArgs = null;
            ShrinkSave.OnSaveCompleted += args => completedArgs = args;

            LogAssert.Expect(LogType.Error, "[ShrinkDataSaver] 模块 'bad' 序列化失败（已跳过）: oops");
            await ShrinkSave.SaveSlotAsync(0);

            // 保存应该成功（跳过了失败的非关键模块）
            Assert.IsNotNull(completedArgs);
            Assert.IsTrue(await ShrinkSave.SlotExistsAsync(0));
        });

        // ── 版本迁移事件 ──

        [UnityTest]
        public IEnumerator MigrationCompleted_FiredOnVersionMismatch() => UniTask.ToCoroutine(async () =>
        {
            // 以 v1 保存
            ShrinkSave.SetCurrentSaveVersion(1);
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);

            // 设置迁移并升级到 v2
            MigrationChain.Register(1, 2, data =>
            {
                data["migrated"] = true;
                return data;
            });
            ShrinkSave.SetCurrentSaveVersion(2);

            MigrationCompletedEventArgs migArgs = null;
            ShrinkSave.OnMigrationCompleted += args => migArgs = args;

            await ShrinkSave.LoadSlotAsync(0);

            Assert.IsNotNull(migArgs);
            Assert.AreEqual(0, migArgs.SlotIndex);
            Assert.AreEqual(1, migArgs.FromVersion);
            Assert.AreEqual(2, migArgs.ToVersion);
        });

        // ── 跨模块查询 ──

        [Test]
        public void QueryModule_ReturnsCurrentData()
        {
            _playerData = new PlayerData { Name = "Query", Level = 5, Coins = 200 };
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);

            var result = ShrinkSave.QueryModule<PlayerData>("player");
            Assert.IsNotNull(result);
            Assert.AreEqual("Query", result.Name);
            Assert.AreEqual(5, result.Level);
        }

        [Test]
        public void QueryModule_NonExistentModule_ReturnsDefault()
        {
            var result = ShrinkSave.QueryModule<PlayerData>("ghost");
            Assert.IsNull(result);
        }

        [UnityTest]
        public IEnumerator HasKey_AfterLoad_ChecksModuleData() => UniTask.ToCoroutine(async () =>
        {
            _playerData = new PlayerData { Name = "KeyTest", Level = 1, Coins = 0 };
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);
            await ShrinkSave.LoadSlotAsync(0);

            Assert.IsTrue(ShrinkSave.HasKey("player", "Name"));
            Assert.IsTrue(ShrinkSave.HasKey("player", "Level"));
            Assert.IsFalse(ShrinkSave.HasKey("player", "NonExistentField"));
            Assert.IsFalse(ShrinkSave.HasKey("ghost_module", "Name"));
        });

        [Test]
        public void HasKey_BeforeLoad_ReturnsFalse()
        {
            Assert.IsFalse(ShrinkSave.HasKey("player", "Name"));
        }

        // ── 自动保存间隔 ──

        [Test]
        public void GetMinAutoSaveInterval_NoModules_ReturnsZero()
        {
            Assert.AreEqual(0f, ShrinkSave.GetMinAutoSaveInterval());
        }

        [Test]
        public void GetMinAutoSaveInterval_ReturnsMinimum()
        {
            ShrinkSave.RegisterModule("a", () => 1, _ => { },
                new ModuleConfig { AutoSaveIntervalSeconds = 60f });
            ShrinkSave.RegisterModule("b", () => 2, _ => { },
                new ModuleConfig { AutoSaveIntervalSeconds = 30f });
            ShrinkSave.RegisterModule("c", () => 3, _ => { },
                new ModuleConfig { AutoSaveIntervalSeconds = 0f }); // 不参与

            Assert.AreEqual(30f, ShrinkSave.GetMinAutoSaveInterval());
        }

        // ── 元数据 ──

        [UnityTest]
        public IEnumerator GetMetaAsync_ReturnsMeta() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "MetaTest" });

            var meta = await ShrinkSave.GetMetaAsync(0);
            Assert.IsNotNull(meta);
            Assert.AreEqual(0, meta.SlotIndex);
            Assert.AreEqual("MetaTest", meta.SlotName);
            Assert.AreEqual(1, meta.SaveVersion);
            Assert.IsFalse(meta.IsEncrypted);
        });

        [UnityTest]
        public IEnumerator GetMetaAsync_NonExistent_ReturnsNull() => UniTask.ToCoroutine(async () =>
        {
            var meta = await ShrinkSave.GetMetaAsync(99);
            Assert.IsNull(meta);
        });

        [UnityTest]
        public IEnumerator GetAllMetaAsync_ReturnsAllSlots() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "Slot0" });
            await ShrinkSave.SaveSlotAsync(1, new SaveOptions { SlotName = "Slot1" });

            var allMeta = await ShrinkSave.GetAllMetaAsync();
            Assert.AreEqual(2, allMeta.Length);
            Assert.AreEqual(0, allMeta[0].SlotIndex);
            Assert.AreEqual(1, allMeta[1].SlotIndex);
        });

        // ── LoadedSlot ──

        [Test]
        public void LoadedSlot_InitiallyNegative()
        {
            Assert.AreEqual(-1, ShrinkSave.LoadedSlot);
        }

        [UnityTest]
        public IEnumerator LoadedSlot_UpdatedAfterLoad() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);
            await ShrinkSave.LoadSlotAsync(0);

            Assert.AreEqual(0, ShrinkSave.LoadedSlot);
        });

        [UnityTest]
        public IEnumerator LoadedSlot_ResetAfterDelete() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(0);
            await ShrinkSave.LoadSlotAsync(0);
            Assert.AreEqual(0, ShrinkSave.LoadedSlot);

            await ShrinkSave.DeleteSlotAsync(0);
            Assert.AreEqual(-1, ShrinkSave.LoadedSlot);
        });

        // ── 多模块 ──

        [UnityTest]
        public IEnumerator MultipleModules_SaveLoad_AllRestored() => UniTask.ToCoroutine(async () =>
        {
            var inventory = new int[] { 1, 2, 3 };
            var questFlag = new bool[] { true, false, true };
            int[] loadedInv = null;
            bool[] loadedQuest = null;

            ShrinkSave.RegisterModule("inventory", () => inventory, d => loadedInv = d);
            ShrinkSave.RegisterModule("quests", () => questFlag, d => loadedQuest = d);

            await ShrinkSave.SaveSlotAsync(0);
            await ShrinkSave.LoadSlotAsync(0);

            Assert.AreEqual(new[] { 1, 2, 3 }, loadedInv);
            Assert.AreEqual(new[] { true, false, true }, loadedQuest);
        });

        [UnityTest]
        public IEnumerator LoadSlotAsync_FallsBackToBackup_WhenPrimaryCorrupted() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            _playerData = new PlayerData { Name = "BackupPlayer", Level = 7, Coins = 321 };
            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "BackupSlot" });

            var backupBytes = await _storage.ReadAsync("saves/slot_0.sav");
            await _storage.WriteAsync("saves/slot_0.sav.bak1", backupBytes);
            await _storage.WriteAsync("saves/slot_0.sav", DataSerializer.Serialize(new { broken = true }));

            _playerData = new PlayerData();
            await ShrinkSave.LoadSlotAsync(0);

            Assert.AreEqual("BackupPlayer", _playerData.Name);

            var repairedPrimary = await _storage.ReadAsync("saves/slot_0.sav");
            CollectionAssert.AreEqual(backupBytes, repairedPrimary);
        });

        [UnityTest]
        public IEnumerator GetAllMetaAsync_UsesBackupOnlySlot_WhenPrimaryMissing() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);
            await ShrinkSave.SaveSlotAsync(2, new SaveOptions { SlotName = "BackupOnly" });

            var backupBytes = await _storage.ReadAsync("saves/slot_2.sav");
            await _storage.WriteAsync("saves/slot_2.sav.bak1", backupBytes);
            await _storage.DeleteAsync("saves/slot_2.sav");

            var metas = await ShrinkSave.GetAllMetaAsync();

            Assert.AreEqual(1, metas.Length);
            Assert.AreEqual(2, metas[0].SlotIndex);
            Assert.AreEqual("BackupOnly", metas[0].SlotName);
            Assert.IsTrue(await _storage.ExistsAsync("saves/slot_2.sav"));
        });

        [UnityTest]
        public IEnumerator GetRecommendedContinueSlotAsync_PrefersRecentAndSelfHeals() => UniTask.ToCoroutine(async () =>
        {
            ShrinkSave.RegisterModule("player", () => _playerData, d => _playerData = d);

            _playerData = new PlayerData { Name = "Slot0", Level = 1, Coins = 10 };
            await ShrinkSave.SaveSlotAsync(0, new SaveOptions { SlotName = "Slot0" });

            _playerData = new PlayerData { Name = "Slot3", Level = 3, Coins = 30 };
            await ShrinkSave.SaveSlotAsync(3, new SaveOptions { SlotName = "Slot3" });

            await ShrinkSettings.LoadAsync();
            ShrinkSettings.Set("ShrinkDataSaver.RecentSlotIndex", 3);
            await ShrinkSettings.SaveAsync();

            var preferred = await ShrinkSave.GetRecommendedContinueSlotAsync();
            Assert.AreEqual(3, preferred);

            await ShrinkSave.DeleteSlotAsync(3);
            preferred = await ShrinkSave.GetRecommendedContinueSlotAsync();
            Assert.AreEqual(0, preferred);
            Assert.AreEqual(0, ShrinkSave.GetRecentSlotIndex());
        });
    }

    [TestFixture]
    public class LocalStorageProviderTests
    {
        private string _rootPath;
        private LocalStorageProvider _provider;

        [SetUp]
        public void SetUp()
        {
            _rootPath = Path.Combine(Path.GetTempPath(), $"ShrinkDataSaverTests_{Guid.NewGuid():N}");
            Directory.CreateDirectory(_rootPath);
            _provider = new LocalStorageProvider(_rootPath);
        }

        [TearDown]
        public void TearDown()
        {
            if (Directory.Exists(_rootPath))
            {
                Directory.Delete(_rootPath, true);
            }
        }

        [UnityTest]
        public IEnumerator WriteAsync_RotatesTwoBackupsAtomically() => UniTask.ToCoroutine(async () =>
        {
            var relativePath = "saves/sample.sav";

            await _provider.WriteAsync(relativePath, DataSerializer.Serialize(new { version = 1 }));
            await _provider.WriteAsync(relativePath, DataSerializer.Serialize(new { version = 2 }));
            await _provider.WriteAsync(relativePath, DataSerializer.Serialize(new { version = 3 }));

            var primary = DataSerializer.Deserialize<JObject>(await _provider.ReadAsync(relativePath));
            var backup1 = DataSerializer.Deserialize<JObject>(await _provider.ReadAsync(relativePath + ".bak1"));
            var backup2 = DataSerializer.Deserialize<JObject>(await _provider.ReadAsync(relativePath + ".bak2"));

            Assert.AreEqual(3, primary["version"]?.Value<int>());
            Assert.AreEqual(2, backup1["version"]?.Value<int>());
            Assert.AreEqual(1, backup2["version"]?.Value<int>());
        });
    }
}