using System;
using System.IO;
using System.Linq;
using System.Web.Mvc;
using MileageTraker.Web.Attributes;
using MileageTraker.Web.DAL;
using MileageTraker.Web.Utility;
using MileageTraker.Web.ViewModels.FuelLog;

namespace MileageTraker.Web.Controllers
{
	[Authorize(Roles = "Administrator, Developer")]
	public class FuelLogController : ControllerBase
    {
		public ViewResult Index(FuelLogQueryViewModel query)
		{
			var validLogYearMonths = DataService.GetValidFuelLogMonths();

			if (!validLogYearMonths.Any()) // this means no logs in DB
				return View("Empty");

			// default parameter processing
			if (!query.HasParameters())
			{
				query.Year = validLogYearMonths.First().Year;
				query.Month = validLogYearMonths.First().Month;
			}
			if (query.Year.HasValue && !query.Month.HasValue)
			{
				var validLogMonths = validLogYearMonths.Where(dt => dt.Year == query.Year).ToList();
				query.Month = validLogMonths.Min(dt => dt.Month);
			}

			var fuelLogs = DataService.GetFuelLogs();
			//fuelLogs.OrderBy(f => f.FuelLogId);

			//var filteredLogs =
			//	(from log in DataService.GetFuelLogIndexViewModels(DataService.FilterLogs(fuelLogs, query))
			//	 orderby log. descending
			//	 select log).ToList();

			var viewModel = new ResultsViewModel(fuelLogs, query, CustomExtensions.YearMonthList(validLogYearMonths));

			//Session.Add("FuelLogPage", Request.Url.PathAndQuery);

			return View(viewModel);
		}

		#region Import

		public ActionResult ImportUpload()
		{
			return View();
		}

		[HttpPost]
		[ActionLog]
		public ActionResult Import(ImportUploadViewModel viewModel)
		{
			if (ModelState.IsValid && viewModel.File != null && viewModel.File.ContentLength > 0)
			{
				var fileName = Path.GetFileName(viewModel.File.FileName);
				var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
				var fileInfo = new FileInfo(path);
				viewModel.File.SaveAs(path);

				try
				{
					var fuelLogs = FuelmanCsvImporter.Import(fileInfo);
					// todo: delete file?

					var fls = (from fuelLog in fuelLogs
					               let prevAdds = DataService.GetDuplicateFuelLogs(fuelLog)
					               select new {ImportedFuelLog = fuelLog, PrevAdded = prevAdds.FirstOrDefault()}).ToList();

					// add new logs to the database
					DataService.AddFuelLogs(fls.Where(fl => fl.PrevAdded == null).Select(fl => fl.ImportedFuelLog));

					var vms = from fl in fls
					          let vm = fl.PrevAdded == null
						                ? new ImportFuelLogViewModel(fl.ImportedFuelLog)
						                : new ImportFuelLogViewModel(fl.PrevAdded) {PreviouslyAdded = true}
					          select vm;
					return View(vms.ToList());
				}
				catch (Exception ex)
				{
					TempData["StatusMessage"] = "Problem reading document: " + ex.Message;
					TempData["StatusMessage-Type"] = "alert-error";
				}
				finally
				{
					if (fileInfo.Exists) 
						fileInfo.Delete();
				}
			}
			return RedirectToAction("ImportUpload");
		}

		enum MatchStatus
		{
			Match,
			NoMatch,
			Error
		}

		[HttpPost]
		public ActionResult Match(int fuelLogId)
		{
			var fuelLog = DataService.GetFuelLog(fuelLogId);
			if (fuelLog == null)
			{
				return Json(new
				{
					Status = MatchStatus.Error.ToString(),
					Message = "Fuel Log not found with given ID: " + fuelLogId
				}, JsonRequestBehavior.AllowGet);
			}
			if (fuelLog.Log != null)
			{
				return Json(new
				{
					Status = MatchStatus.NoMatch.ToString(),
					Message = "Already matched to log",
					Action = RenderRazorViewToString("ImportMatchLogView", fuelLog.Log.LogId)

				}, JsonRequestBehavior.AllowGet);
			}

			// run the match
			var matchingLog = DataService.GetMatchingLog(fuelLog);
			if (matchingLog == null)
			{
				return Json(new
				{
					Status = MatchStatus.NoMatch.ToString(),
					Message = "Unable to find match"
				}, JsonRequestBehavior.AllowGet);
			}
			fuelLog.Log = matchingLog;
			DataService.UpdateFuelLog(fuelLog);
			return Json(new
			{
				Status = MatchStatus.Match.ToString(),
				Action = RenderRazorViewToString("ImportMatchedLog", new ImportMatchedLogViewModel { LogId = fuelLog.Log.LogId })
			}, JsonRequestBehavior.AllowGet);
		}

		#endregion
	}
}