using GFramework.Core.Abstractions.storage;
using GFramework.Core.extensions;
using GFramework.Core.utility;
using GFramework.Game.Abstractions.setting;
using GFramework.Game.setting.events;

namespace GFramework.Game.setting;

/// <summary>
/// 设置持久化服务类，负责处理设置数据的加载、保存、删除等操作
/// </summary>
public class SettingsPersistence : AbstractContextUtility, ISettingsPersistence
{
    private IStorage _storage = null!;

    /// <summary>
    /// 异步加载指定类型的设置数据
    /// </summary>
    /// <typeparam name="T">设置数据类型，必须实现ISettingsData接口</typeparam>
    /// <returns>如果存在则返回存储的设置数据，否则返回新创建的实例</returns>
    public async Task<T> LoadAsync<T>() where T : class, ISettingsData, new()
    {
        var key = GetKey<T>();

        if (await _storage.ExistsAsync(key))
        {
            var result = await _storage.ReadAsync<T>(key);
            this.SendEvent(new SettingsLoadedEvent<T>(result));
            return result;
        }

        var newSettings = new T();
        this.SendEvent(new SettingsLoadedEvent<T>(newSettings));
        return newSettings;
    }

    /// <summary>
    /// 异步保存设置数据到存储中
    /// </summary>
    /// <typeparam name="T">设置数据类型，必须实现ISettingsData接口</typeparam>
    /// <param name="section">要保存的设置数据实例</param>
    public async Task SaveAsync<T>(T section) where T : class, ISettingsData
    {
        var key = GetKey<T>();
        await _storage.WriteAsync(key, section);
        this.SendEvent(new SettingsSavedEvent<T>(section));
    }

    /// <summary>
    /// 检查指定类型的设置数据是否存在
    /// </summary>
    /// <typeparam name="T">设置数据类型，必须实现ISettingsData接口</typeparam>
    /// <returns>如果存在返回true，否则返回false</returns>
    public async Task<bool> ExistsAsync<T>() where T : class, ISettingsData
    {
        var key = GetKey<T>();
        return await _storage.ExistsAsync(key);
    }

    /// <summary>
    /// 异步删除指定类型的设置数据
    /// </summary>
    /// <typeparam name="T">设置数据类型，必须实现ISettingsData接口</typeparam>
    public async Task DeleteAsync<T>() where T : class, ISettingsData
    {
        var key = GetKey<T>();
        _storage.Delete(key);
        this.SendEvent(new SettingsDeletedEvent(typeof(T)));
        await Task.CompletedTask;
    }

    /// <summary>
    /// 异步保存所有设置数据到存储中
    /// </summary>
    /// <param name="allData">包含所有设置数据的可枚举集合</param>
    public async Task SaveAllAsync(IEnumerable<ISettingsData> allData)
    {
        var dataList = allData.ToList();
        foreach (var data in dataList)
        {
            var type = data.GetType();
            var key = GetKey(type);
            await _storage.WriteAsync(key, data);
        }

        this.SendEvent(new SettingsBatchSavedEvent(dataList));
    }

    /// <summary>
    /// 异步加载所有已知类型的设置数据
    /// </summary>
    /// <param name="knownTypes">已知设置数据类型的集合</param>
    /// <returns>类型与对应设置数据的字典映射</returns>
    public async Task<IDictionary<Type, ISettingsData>> LoadAllAsync(IEnumerable<Type> knownTypes)
    {
        var result = new Dictionary<Type, ISettingsData>();
        var allSettings = new List<ISettingsSection>();

        foreach (var type in knownTypes)
        {
            var key = GetKey(type);

            if (!await _storage.ExistsAsync(key)) continue;
            // 使用反射调用泛型方法
            var method = typeof(IStorage)
                .GetMethod(nameof(IStorage.ReadAsync))!
                .MakeGenericMethod(type);

            var task = (Task)method.Invoke(_storage, [key])!;
            await task;

            var loaded = (ISettingsData)((dynamic)task).Result;
            result[type] = loaded;
            allSettings.Add(loaded);
        }

        this.SendEvent(new SettingsAllLoadedEvent(allSettings));
        return result;
    }

    public async Task<T> ResetAsync<T>() where T : class, ISettingsData, new()
    {
        var type = typeof(T);
        var key = GetKey(type);

        T oldSettings;
        if (await _storage.ExistsAsync(key))
        {
            oldSettings = await _storage.ReadAsync<T>(key);
        }
        else
        {
            oldSettings = new T();
        }

        var newSettings = new T();
        await _storage.WriteAsync(key, newSettings);

        this.SendEvent(new SettingsResetEvent<T>(oldSettings, newSettings));
        return newSettings;
    }

    public async Task ResetAllAsync()
    {
        var knownTypes = new List<Type>();

        var audioSettings = await LoadAllAsync(knownTypes);
        var allNewSettings = new List<ISettingsSection>();

        foreach (var kvp in audioSettings)
        {
            var type = kvp.Key;
            var key = GetKey(type);

            var newSettings = Activator.CreateInstance(type) as ISettingsSection;
            if (newSettings is null) continue;

            await _storage.WriteAsync(key, newSettings);
            allNewSettings.Add(newSettings);
        }

        this.SendEvent(new SettingsResetAllEvent(allNewSettings));
    }

    protected override void OnInit()
    {
        _storage = this.GetUtility<IStorage>()!;
    }

    /// <summary>
    /// 获取指定类型的存储键名
    /// </summary>
    /// <typeparam name="T">设置数据类型</typeparam>
    /// <returns>格式为"Settings_类型名称"的键名</returns>
    private static string GetKey<T>() where T : ISettingsData
        => GetKey(typeof(T));

    /// <summary>
    /// 获取指定类型的存储键名
    /// </summary>
    /// <param name="type">设置数据类型</param>
    /// <returns>格式为"Settings_类型名称"的键名</returns>
    private static string GetKey(Type type)
        => $"Settings_{type.Name}";
}