using System.Text.Json.Serialization;

namespace MAX.Framework.Dtos
{
	public static class ResultCode
	{
		public const int Success = 200;
		public const int Fail = 500;

		public const int Unauthorized = 401;
		public const int Forbidden = 403;
		public const int NotFound = 404;
		/// <summary>
		/// 参数校验失败
		/// </summary>
		public const int ValidationError = 1001;
		/// <summary>
		/// 业务逻辑异常
		/// </summary>
		public const int BusinessError = 2001;
		/// <summary>
		/// 服务器内部错误
		/// </summary>
		public const int ServerError = 5000;
	}
	/// <summary>
	/// 非泛型基类，用于统一处理
	/// </summary>
	public abstract class ApiResultBase
	{
		/// <summary>业务状态码</summary>
		public int Code { get; init; } = ResultCode.Success;

		/// <summary>提示信息</summary>
		public string? Msg { get; init; }

		/// <summary>失败请求的跟踪标识，用于关联服务器日志。</summary>
		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
		public string? TraceId { get; init; }

		/// <summary>请求是否成功</summary>
		public bool Success => Code == ResultCode.Success;

	}

	/// <summary>
	/// 泛型响应
	/// </summary>
	public class ApiResult<T> : ApiResultBase
	{
		/// <summary>响应数据；失败时不应依赖该值，值类型默认值并非 null。</summary>
		[JsonIgnore(Condition = JsonIgnoreCondition.Never)]
		public T? Data { get; init; }

		/// <summary>将无数据响应转换为当前数据类型，保留状态码和提示信息。</summary>
		public static implicit operator ApiResult<T>(ApiResult result)
		{
			ArgumentNullException.ThrowIfNull(result);
			return new ApiResult<T> { Code = result.Code, Msg = result.Msg, TraceId = result.TraceId, Data = default };
		}

		public static ApiResult<T> Ok(T data, string msg = "操作成功")
	   => new ApiResult<T> { Code = ResultCode.Success, Data = data, Msg = msg };

		public static ApiResult<T> Fail(string msg = "操作失败", int code = ResultCode.Fail, T? data = default)
		{
			ApiResult.ValidateFailureCode(code);
			return new ApiResult<T> { Code = code, Msg = msg, Data = data };
		}
	}

	/// <summary>
	/// 响应
	/// </summary>
	public class ApiResult : ApiResultBase
	{
		/// <summary>无数据响应仍输出 data: null，保持统一的响应字段。</summary>
		[JsonIgnore(Condition = JsonIgnoreCondition.Never)]
		public object? Data => null;

		/// <summary>创建带数据的成功响应，自动推断数据类型。</summary>
		public static ApiResult<T> Ok<T>(T data, string msg = "操作成功")
			=> ApiResult<T>.Ok(data, msg);

		/// <summary>创建带数据的失败响应，自动推断数据类型。</summary>
		public static ApiResult<T> Fail<T>(string msg, T data, int code = ResultCode.Fail)
			=> ApiResult<T>.Fail(msg, code, data);

		public static ApiResult Ok()
		=> new ApiResult { Code = ResultCode.Success, Msg = "操作成功" };

		public static ApiResult Fail(string msg = "操作失败", int code = ResultCode.Fail, string? traceId = null)
		{
			ValidateFailureCode(code);
			return new ApiResult { Code = code, Msg = msg, TraceId = traceId };
		}

		internal static void ValidateFailureCode(int code)
		{
			if (code == ResultCode.Success)
				throw new ArgumentOutOfRangeException(nameof(code), code, "失败响应不能使用成功状态码。");
		}
	}

}