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

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

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





        /// <summary>
        /// Upload and import file
        /// Max 100MiB total
        /// </summary>
        /// <returns>Results</returns>
        [Authorize]
        [HttpPost("upload")]
        [DisableFormValueModelBinding]
        [RequestSizeLimit(AyaNova.Util.ServerBootConfig.MAX_IMPORT_FILE_UPLOAD_BYTES)]
        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;
            List<string> ImportResult = new List<string>();
            ImportResult.Add("Import results\n");
            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);


                string UploadObjectType = string.Empty;

                string errorMessage = string.Empty;
                string Notes = string.Empty;
                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"));


                if (uploadFormData.FormFieldData.ContainsKey("ObjectType"))
                    UploadObjectType = uploadFormData.FormFieldData["ObjectType"].ToString();
                else
                    return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, "Missing required FormFieldData value: ObjectType"));

                //fileData in JSON stringify format which contains the actual last modified dates etc
                //"[{\"name\":\"Client.csv\",\"lastModified\":1582822079618},{\"name\":\"wmi4fu06nrs41.jpg\",\"lastModified\":1586900220990}]"
                FileData = Newtonsoft.Json.JsonConvert.DeserializeObject<List<UploadFileData>>(uploadFormData.FormFieldData["FileData"].ToString());



                //Instantiate the business object handler
                AyaType TheType = System.Enum.Parse<AyaType>(UploadObjectType, true);
                log.LogDebug($"Instantiating biz object handler for {TheType}");
                var biz = BizObjectFactory.GetBizObject(TheType, ct);

                if (!(biz is IImportAbleObject))
                    return BadRequest(new ApiErrorResponse(ApiErrorCode.INVALID_OPERATION, null, $"Import not supported for {TheType} objects"));

                //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)
                    {
                        JArray ja = JArray.Parse(System.IO.File.ReadAllText(a.InitialUploadedPathName));
                        ImportResult.AddRange(await ((IImportAbleObject)biz).ImportData(ja));
                    }
                }
            }
            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

                ApiUploadProcessor.DeleteTempUploadFile(uploadFormData);
            }

            return Ok(ApiOkResponse.Response(ImportResult));
        }





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





    }//eoc
}//eons