using Microsoft.AspNetCore.Http;

namespace Ds.Module.File.Model
{
    public class DsUserFile
    {
        /// <summary>
        /// 文件名
        /// </summary>
        public string FileName { get; set; } = "Ds_001";

        /// <summary>
        /// 文件大小
        /// </summary>
        public long Length { get; set; }

        /// <summary>
        /// 文件扩展名
        /// </summary>
        public string Extension { get; set; } = "_xxx_";

        /// <summary>
        /// 文件类型
        /// </summary>
        public string FileType { get; set; } = ".png";

        private static readonly string[] Filters = { ".jpg", ".png", ".bmp" };
        public bool IsValid => !string.IsNullOrEmpty(this.Extension) && Filters.Contains(this.Extension);

        private IFormFile file;

        public IFormFile File
        {
            get { return file; }
            set
            {
                if (value != null)
                {
                    this.file = value;

                    this.FileType = this.file.ContentType;
                    this.Length = this.file.Length;
                    this.Extension = this.file.FileName.Substring(file.FileName.LastIndexOf('.'));
                    if (string.IsNullOrEmpty(this.FileName))
                        this.FileName = this.FileName;
                }
            }
        }

        public async Task<string> SaveAs(string destinationDir = null)
        {
            if (this.file == null)
                throw new ArgumentNullException("没有需要保存的文件");

            if (destinationDir != null)
                Directory.CreateDirectory(destinationDir);

            var newName = DateTime.Now.Ticks;
            var newFile = Path.Combine(destinationDir ?? "", $"{newName}{this.Extension}");
            using (FileStream fs = new FileStream(newFile, FileMode.CreateNew))
            {
                await this.file.CopyToAsync(fs);
                fs.Flush();
            }
            return newFile;
        }
    }
}