namespace MyHomePage.Api.Common;

/// <summary>
/// 统一 API 响应包装。
/// 全部接口返回该类型，前端可依据 <see cref="Code"/> 判定业务结果。
/// </summary>
/// <typeparam name="T">业务数据类型</typeparam>
public class ApiResponse<T>
{
    /// <summary>业务状态码：0 表示成功，非 0 表示错误</summary>
    public int Code { get; set; }

    /// <summary>提示信息</summary>
    public string Message { get; set; } = string.Empty;

    /// <summary>业务数据</summary>
    public T? Data { get; set; }

    /// <summary>服务器时间戳（毫秒）</summary>
    public long Timestamp { get; set; } = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();

    /// <summary>构造成功响应</summary>
    public static ApiResponse<T> Ok(T data, string message = "ok") =>
        new() { Code = 0, Message = message, Data = data };

    /// <summary>构造成功响应（无数据）</summary>
    public static ApiResponse<T> Ok(string message = "ok") =>
        new() { Code = 0, Message = message };

    /// <summary>异步等待数据后构造成功响应（用于服务层返回 Task&lt;T&gt;）</summary>
    public static async Task<ApiResponse<T>> OkAsync(Task<T> dataTask, string message = "ok")
    {
        var data = await dataTask;
        return Ok(data, message);
    }

    /// <summary>异步等待数据后构造成功响应（列表场景，重命名避免类型参数遮蔽）</summary>
    public static async Task<ApiResponse<List<TItem>>> OkListAsync<TItem>(Task<List<TItem>> dataTask, string message = "ok")
    {
        var data = await dataTask;
        return new ApiResponse<List<TItem>> { Code = 0, Message = message, Data = data };
    }

    /// <summary>构造失败响应</summary>
    public static ApiResponse<T> Fail(int code, string message) =>
        new() { Code = code, Message = message };
}

/// <summary>无泛型版本的快捷响应（用于无数据的接口）</summary>
public class ApiResponse : ApiResponse<object>
{
    /// <summary>构造成功响应（无数据）</summary>
    public static ApiResponse Ok() => new() { Code = 0, Message = "ok" };
}