using System;
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.AspNetCore.Http.Features;
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;

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 outputFileName = StringUtil.ReplaceLastOccurrence(FileUtil.NewRandomFileName, ".", "") + ".pdf";
            string outputFullPath = System.IO.Path.Combine(FileUtil.TemporaryFilesFolder, outputFileName);
            log.LogDebug($"Calling render export data to file");
            //TODO: RENDER DATA TO FILE HERE   await page.PdfAsync(outputFullPath, PdfOptions);

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

            // var httpConnectionFeature = HttpContext.Features.Get<IHttpConnectionFeature>();
            // var API_URL = $"http://127.0.0.1:{httpConnectionFeature.LocalPort}/api/v8/";
            // try
            // {
            //     var result = await biz.RenderExport(ExportParam, API_URL);

            //     if (string.IsNullOrWhiteSpace(result))
            //         return BadRequest(new ApiErrorResponse(biz.Errors));
            //     else
            //         return Ok(ApiOkResponse.Response(result));
            // }
            // catch (System.Exception ex)
            // {
            //     //The Javascript evaluation stack trace can be in the message making it long and internalized,
            //     //however the info is useful as it can indicate exactly which function failed etc so sending it all back is best
            //     return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, ex.Message));
            // }
        }


        /// <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/pdf");
        }



        /// <summary>
        /// Download Export template
        /// </summary>
        /// <param name="id">Export id</param>
        /// <param name="t">download token</param>
        /// <returns>A single Export template as a file</returns>
        [AllowAnonymous]
        [HttpGet("export/{id}")]
        public async Task<IActionResult> DownloadTemplate([FromRoute] long id, [FromQuery] string t)
        {
            if (serverState.IsClosed)
                return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));

            if (!ModelState.IsValid)
                return BadRequest(new ApiErrorResponse(ModelState));

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

            var o = await ct.Export.SingleOrDefaultAsync(z => z.Id == id);
            //turn into correct format and then send as file
            if (o == null)
            {
                return NotFound(new ApiErrorResponse(ApiErrorCode.NOT_FOUND));
            }
            var asText = Newtonsoft.Json.JsonConvert.SerializeObject(
                o,
                Newtonsoft.Json.Formatting.None,
                new JsonSerializerSettings { ContractResolver = new AyaNova.Util.JsonUtil.ShouldSerializeContractResolver(new string[] { "Concurrency", "Id" }) });
            var bytes = System.Text.Encoding.UTF8.GetBytes(asText);
            var file = new FileContentResult(bytes, "application/octet-stream");
            file.FileDownloadName = Util.FileUtil.StringToSafeFileName(o.Name) + ".ayrt";
            return file;
        }




        /// <summary>
        /// Upload Reprot template export file
        /// Max 15mb total
        /// </summary>
        /// <returns>Accepted</returns>
        [Authorize]
        [HttpPost("upload")]
        [DisableFormValueModelBinding]
        [RequestSizeLimit(15000000)]//currently the largest v7 export for a Export template is 828kb, I'm guessing 15mb is more than enough
        public async Task<IActionResult> UploadAsync()
        {
            //Adapted from the example found here: https://docs.microsoft.com/en-us/aspnet/core/mvc/models/file-uploads#uploading-large-files-with-streaming

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


            // AyaTypeId attachToObject = null;
            ApiUploadProcessor.ApiUploadedFilesResult uploadFormData = null;
            try
            {
                if (!MultipartRequestHelper.IsMultipartContentType(Request.ContentType))
                    return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, $"Expected a multipart request, but got {Request.ContentType}"));

                //Save uploads to disk under temporary file names until we decide how to handle them
                uploadFormData = await ApiUploadProcessor.ProcessUploadAsync(HttpContext);



                List<UploadFileData> FileData = new List<UploadFileData>();

                if (!uploadFormData.FormFieldData.ContainsKey("FileData"))//only filedata is required
                {
                    return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, "Missing required FormFieldData value: FileData"));
                }

                //fileData in JSON stringify format
                FileData = Newtonsoft.Json.JsonConvert.DeserializeObject<List<UploadFileData>>(uploadFormData.FormFieldData["FileData"].ToString());

                //Instantiate the business object handler
                ExportBiz biz = ExportBiz.GetBiz(ct, HttpContext);


                //We have our files now can parse and insert into db
                if (uploadFormData.UploadedFiles.Count > 0)
                {
                    //deserialize each file and import
                    foreach (UploadedFileInfo a in uploadFormData.UploadedFiles)
                    {
                        JObject o = JObject.Parse(System.IO.File.ReadAllText(a.InitialUploadedPathName));
                        if (!await biz.ImportAsync(o))
                        {
                            //delete all the files temporarily uploaded and return bad request
                            DeleteTempUploadFile(uploadFormData);
                            return BadRequest(new ApiErrorResponse(biz.Errors));
                        }
                    }
                }
            }
            catch (System.IO.InvalidDataException ex)
            {
                return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, ex.Message));
            }
            finally
            {
                //delete all the files temporarily uploaded and return bad request

                DeleteTempUploadFile(uploadFormData);
            }

            //Return the list of attachment ids and filenames
            return Accepted();
        }

        private static void DeleteTempUploadFile(ApiUploadProcessor.ApiUploadedFilesResult uploadFormData)
        {
            if (uploadFormData.UploadedFiles.Count > 0)
            {
                foreach (UploadedFileInfo a in uploadFormData.UploadedFiles)
                {
                    System.IO.File.Delete(a.InitialUploadedPathName);
                }
            }
        }
        //-----------------------------------------





    }//eoc
}//eons