raven/server/AyaNova/Controllers/ExportController.cs

using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Routing;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using AyaNova.Models;
using AyaNova.Api.ControllerHelpers;
using AyaNova.Biz;
using AyaNova.Util;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.IO;
using System.IO.Compression;

namespace AyaNova.Api.Controllers
{
    [ApiController]
    [ApiVersion("8.0")]
    [Route("api/v{version:apiVersion}/export")]
    [Produces("application/json")]
    [Authorize]
    public class ExportController : ControllerBase
    {
        private readonly AyContext ct;
        private readonly ILogger<ExportController> log;
        private readonly ApiServerState serverState;

        /// <summary>
        /// ctor
        /// </summary>
        /// <param name="dbcontext"></param>
        /// <param name="logger"></param>
        /// <param name="apiServerState"></param>  
        public ExportController(AyContext dbcontext, ILogger<ExportController> logger, ApiServerState apiServerState)
        {
            ct = dbcontext;
            log = logger;
            serverState = apiServerState;
        }


        /// <summary>
        /// Export to file
        /// </summary>
        /// <param name="format">Valid values are: "csv","json"</param>
        /// <param name="dataListSelection"></param>

        /// <returns>downloadable export file name</returns>
        [HttpPost("render")]
        public async Task<IActionResult> RenderExport([FromRoute] string format, [FromBody] DataListSelection dataListSelection)
        {

            if (!serverState.IsOpen)
                return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));
            if (!ModelState.IsValid)
                return BadRequest(new ApiErrorResponse(ModelState));

            if (dataListSelection.IsEmpty)
                return BadRequest(new ApiErrorResponse(ApiErrorCode.VALIDATION_REQUIRED, null, "DataListSelection is required"));

            if (!dataListSelection.ObjectType.HasAttribute(typeof(CoreBizObjectAttribute)))
                return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, "Not a taggable object type"));

            if (!Authorized.HasReadFullRole(HttpContext.Items, dataListSelection.ObjectType))
                return StatusCode(403, new ApiNotAuthorizedResponse());

            if (string.IsNullOrWhiteSpace(format))
                return BadRequest(new ApiErrorResponse(ApiErrorCode.VALIDATION_REQUIRED, null, "format required"));

            if (format != "csv" && format != "json")
                return BadRequest(new ApiErrorResponse(ApiErrorCode.VALIDATION_INVALID_VALUE, null, "format not valid, must be 'csv' or 'json'"));

            await dataListSelection.RehydrateIdList(ct, UserRolesFromContext.Roles(HttpContext.Items), log);
            if (dataListSelection.SelectedRowIds.Length == 0)
                return BadRequest(new ApiErrorResponse(ApiErrorCode.VALIDATION_REQUIRED, null, "List of ids"));


            log.LogDebug($"Instantiating biz object handler for {dataListSelection.ObjectType}");
            var biz = BizObjectFactory.GetBizObject(dataListSelection.ObjectType, ct);
            log.LogDebug($"Fetching data for {dataListSelection.SelectedRowIds.Length} {dataListSelection.ObjectType} items");
            var TheData = await ((IExportAbleObject)biz).GetExportData(dataListSelection.SelectedRowIds);

            string outputRandomFileNameNoExtension = StringUtil.ReplaceLastOccurrence(FileUtil.NewRandomFileName, ".", "");
            string outputSourceFileName = outputRandomFileNameNoExtension + "." + format;
            string outputSourceFullPath = System.IO.Path.Combine(FileUtil.TemporaryFilesFolder, outputSourceFileName);
            string outputZipFullpath = System.IO.Path.Combine(FileUtil.TemporaryFilesFolder, outputRandomFileNameNoExtension + ".zip");
            // string outputFullPathSourceFile=outputFullPathNoExtension
            // string outputFullpathZipFile=outputFullPathNoExtension + ".zip";
            log.LogDebug($"Calling render export data to file");
            switch (format)
            {
                case "csv":
                    throw new System.NotImplementedException("CSV export not implemented yet");
                    break;
                case "json":
                    using (StreamWriter file = System.IO.File.CreateText(outputSourceFullPath))
                    using (JsonTextWriter writer = new JsonTextWriter(file))
                    {
                        TheData.WriteTo(writer);
                    }
                    break;
            }

            //zip it
            using (FileStream fs = new FileStream(outputZipFullpath, FileMode.Create))
            using (ZipArchive arch = new ZipArchive(fs, ZipArchiveMode.Create))
            {
                arch.CreateEntryFromFile(outputSourceFullPath, outputSourceFileName);
            }

            log.LogDebug($"Completed, returning results");
            return Ok(ApiOkResponse.Response(outputRandomFileNameNoExtension + ".zip"));


        }


        /// <summary>
        /// Download a rendered Export
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="t">download token</param>
        /// <returns></returns>
        [HttpGet("download/{fileName}")]
        [AllowAnonymous]
        public async Task<IActionResult> DownloadAsync([FromRoute] string fileName, [FromQuery] string t)
        {
            if (!serverState.IsOpen)
                return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));

            if (await UserBiz.ValidateDownloadTokenAndReturnUserAsync(t, ct) == null)
            {
                await Task.Delay(ServerBootConfig.FAILED_AUTH_DELAY);//DOS protection
                return StatusCode(401, new ApiErrorResponse(ApiErrorCode.AUTHENTICATION_FAILED));
            }

            if (!FileUtil.TemporaryFileExists(fileName))
            {
                await Task.Delay(ServerBootConfig.FAILED_AUTH_DELAY);//fishing protection
                return NotFound(new ApiErrorResponse(ApiErrorCode.NOT_FOUND));
            }

            var FilePath = FileUtil.GetFullPathForTemporaryFile(fileName);
            return PhysicalFile(FilePath, "application/zip");
        }



        //-----------------------------------------





    }//eoc
}//eons