namespace CloudGaming.Core.Redis.Aop.Cache;

[AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public abstract class BaseCacheAttribute : AopMoAttribute
{
    /// <summary>
    /// 缓存Key 不填默认是 函数的命名空间.函数名称
    /// </summary>
    /// <value></value>
    public string? CacheKey { get; set; }

    /// <summary>
    /// Redis 服务类型 不传递默认 走内存缓存
    /// </summary>
    /// <value></value>
    public Type RedisServiceType { get; set; } = null!;

    /// <summary>
    /// 获取缓存Key
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    protected virtual string GetCacheKey(MethodContext context)
    {
        if (!string.IsNullOrWhiteSpace(CacheKey))
        {
            return ParseCacheKey(context);
        }

        var name = context.Method.Name;
        var prefix = context.Method.DeclaringType?.FullName;
        return $"{prefix}.{name}";
    }

    /// <summary>
    /// 解析缓存主键
    /// </summary>
    /// <param name="context">拦截器上下文</param>
    private string ParseCacheKey(MethodContext context)
    {
        //寻找大括号{} 内的内容
        var replaceParameters = Regex.Matches(CacheKey, @"\{(.+?)\}").Select(m => m.Groups[1].Value).ToList();
        if (replaceParameters.Count > 0)
        {
            // 获取所有方法参数
            var typeNames = context.Method.GetParameters().Select(t => t.Name).ToList();
            foreach (var replaceParameter in replaceParameters)
            {
                var firstName = replaceParameter.Split(".")[0];
                // 查询括号里的内容  .分割后第一位  能和参数名对的上吗
                if (typeNames.Contains(firstName))
                {
                    // 获取这个值对应的索引
                    int index = typeNames.FindIndex(tname => tname == firstName);
                    // 对内容进行分割
                    var names = replaceParameter.Split(".").ToList();

                    // 分割后大于长度大于一 说明存在实例内部属性调用
                    if (names.Count > 1)
                    {
                        var replaceName = "{" + replaceParameter + "}";
                        // 移除第一位
                        names.RemoveAt(0);
                        // 递归获取到属性值
                        var value = GetParameterValue(context.Arguments[index], names);
                        value = value ?? "null";
                        CacheKey = CacheKey.Replace(replaceName, value);
                    }
                    else
                    {
                        var replaceName = "{" + replaceParameter + "}";
                        var value = context.Arguments[index]?.ToString();
                        CacheKey = CacheKey.Replace(replaceName, value);
                    }
                }
            }
        }

        return CacheKey;
    }

    /// <summary>
    /// 递归获取属性值
    /// </summary>
    /// <param name="obj"></param>
    /// <param name="parameterNames"></param>
    /// <returns></returns>
    private string GetParameterValue(object obj, List<string> parameterNames)
    {
        if (obj == null)
        {
            return null;
        }

        if (parameterNames.Count > 1)
        {
            var name = parameterNames[0];
            parameterNames.RemoveAt(0);

            // 获取属性值
            var propertyInfo = GetPropertyInfo(obj, name);
            if (propertyInfo != null)
            {
                return GetParameterValue(propertyInfo.GetValue(obj), parameterNames);
            }
            return null;
        }
        else if (parameterNames.Count == 1)
        {
            // 获取属性值
            var propertyInfo = GetPropertyInfo(obj, parameterNames[0]);
            // 从对象里获取这个属性
            return propertyInfo?.GetValue(obj)?.ToString();
        }
        else
        {
            return null;
        }
    }

    /// <summary>
    /// 根据属性名称获取实例里的属性
    /// </summary>
    /// <param name="obj">实例</param>
    /// <param name="name">需要的属性名</param>
    /// <returns></returns>
    private PropertyInfo GetPropertyInfo(object obj, string name)
    {
        if (obj == null)
        {
            return null;
        }

        // 获取所有public属性和实例
        var propertyInfos = obj.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
        // 找找有没有我们要的
        return propertyInfos.FirstOrDefault(p => p.Name == name);
    }

    /// <summary>
    /// 获取Redis数据库
    /// </summary>
    /// <param name="MethodContext"></param>
    /// <returns></returns>
    protected IDatabase GetDatabase(MethodContext MethodContext)
    {
        var redisService = this.GetService(MethodContext, RedisServiceType);

        if (redisService == null)
        {
            throw new Exception($"Redis服务 {RedisServiceType.FullName} 找不到属性 public IDatabase {nameof(IDatabase.Database)} {{get;}}");
        }

        var propertyInfos = redisService.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
        var databasePropertyInfo = propertyInfos.FirstOrDefault(w => w.Name == nameof(IDatabase.Database) && w.PropertyType == typeof(IDatabase));
        if (databasePropertyInfo == null)
        {
            throw new Exception($"Redis服务 {RedisServiceType.FullName} 找不到属性 public IDatabase {nameof(IDatabase.Database)} {{get;}}");
        }
        // 获取 idatabase
        var redisCache = (IDatabase?)databasePropertyInfo.GetValue(redisService);
        if (redisCache == null)
        {
            throw new Exception($"Redis服务 {RedisServiceType.FullName} 属性 public IDatabase {nameof(IDatabase.Database)} {{get;}} 是 null ");
        }

        return redisCache;
    }
}