using System;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Security.Cryptography;
using Infrastructure.Extensions;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Infrastructure.Web.Mvc
{
    public class FileController : Controller
    {
        private readonly IWebHostEnvironment _host;

        public FileController(IWebHostEnvironment host)
        {
            this._host = host;
        }

        public IActionResult Upload()
        {
            if (Request.Form.Files != null && Request.Form.Files.Count > 0)
            {
                var file = Request.Form.Files[0];
                var path = this.Save(file);
                return Content(new { error = 0, url = path }.ToJson());
            }

            return Content(new { error = 1, msg = "未选择文件" }.ToJson());
        }

        public IActionResult Json(string value)
        {
            return Content(value);
        }

        public string Save(IFormFile file)
        {
            if (file is null)
            {
                throw new ArgumentNullException(nameof(file));
            }

            using (Stream stream = file.OpenReadStream())
            {
                var ext = GetExtension(file.FileName);
                var md5 = GetFileNameHash(stream);
                var phicyPath = Path.Combine(this._host.WebRootPath, "upload");
                Directory.CreateDirectory(phicyPath);
                var name = string.Format(CultureInfo.CurrentCulture, "{0}.{1}", md5, ext);
                var fullName = Path.Combine(phicyPath, name);
                if (!System.IO.File.Exists(fullName))
                {
                    using (FileStream fs = System.IO.File.Create(fullName))
                    {
                        file.CopyTo(fs);
                    }
                    if (ext == "zip")
                    {
                        var zipDirectory = Path.Combine(phicyPath, md5);
                        Directory.CreateDirectory(Path.Combine(phicyPath, md5));
                        ZipFile.ExtractToDirectory(fullName, zipDirectory);
                    }
                }

                return $"/upload/{name}";
            }
        }

        #region private

        private static string GetExtension(string value)
        {
            return value.Substring(value.LastIndexOf('.') + 1).ToLower(CultureInfo.CurrentCulture);
        }

        private static string GetFileNameHash(Stream input)
        {
            using (var hashAlg = SHA256.Create())
            {
                byte[] hash = hashAlg.ComputeHash(input);
                return BitConverter.ToString(hash).Replace("-", string.Empty, true, CultureInfo.CurrentCulture).ToLower(CultureInfo.CurrentCulture);
            }
        }

        #endregion private
    }
}