Dynamic update for all writes for VehiclePreviousLog

Web/Controllers/LogController.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using System.Web.Mvc;
 using MileageTraker.Web.DAL;
@@ -86,7 +85,7 @@ namespace MileageTraker.Web.Controllers
 		public ActionResult PreviousDetails(int id)
         {
 			var log = _dataService.GetLog(id);
-			var previousLog = _dataService.GetPreviousLog(log);
+			var previousLog = _dataService.SearchPreviousLog(log);
 			int logId;
 			if (previousLog != null)
 			{
@@ -103,7 +102,7 @@ namespace MileageTraker.Web.Controllers
 		public ActionResult NextDetails(int id)
 		{
 			var log = _dataService.GetLog(id);
-			var nextLog = _dataService.GetNextLog(log);
+			var nextLog = _dataService.SearchNextLog(log);
 			int logId;
 			if (nextLog != null)
 			{
@@ -170,6 +169,8 @@ namespace MileageTraker.Web.Controllers
     		ModelState.Remove("Source");
     		ModelState.Remove("UserAgent");
     		ModelState.Remove("UserHostAddress");
+			ModelState.Remove("VehiclePreviousLogId");
+			ModelState.Remove("VehiclePreviousLog");
     	}
 
 		public ActionResult Delete(int id)

Web/DAL/DataService.cs

@@ -20,6 +20,14 @@ namespace MileageTraker.Web.DAL
 		{
 			log.Created = DateTime.Now;
 			_db.Logs.Add(log);
+
+			// update previous log links
+			var previousLog = SearchPreviousLog(log);
+			log.VehiclePreviousLog = previousLog;
+			var nextLog = SearchNextLog(log);
+			if (nextLog != null)
+				nextLog.VehiclePreviousLog = log;
+
 			_db.SaveChanges();
 
 			UpdateCurrentOdometer(log.VehicleId);
@@ -190,60 +198,75 @@ namespace MileageTraker.Web.DAL
 			return logs;
 		}
 
-		public Log GetPreviousLog(Log current)
+		public Log SearchPreviousLog(Log current)
 		{
 			var vehicleId = current.VehicleId;
 			var date = current.Date;
 			var endOdometer = current.EndOdometer;
-			return GetPreviousLog(endOdometer, vehicleId, date, current.Created);
+			return SearchPreviousLog(endOdometer, vehicleId, date, current.Created, current.LogId);
 		}
 
-		public Log GetPreviousLog(int endOdometer, string vehicleId, DateTime date, DateTime created)
+		public Log SearchPreviousLog(int endOdometer, string vehicleId, DateTime date, DateTime created, int? excludeLogId = null)
 		{
-			return GetPreviousLogQuery(endOdometer, vehicleId, date, created).FirstOrDefault();
+			return (from pl in _db.Logs
+			        where pl.VehicleId == vehicleId &&
+			              ((pl.Date <= date && pl.EndOdometer < endOdometer)
+			               || (pl.EndOdometer == endOdometer && pl.Created < created)) &&
+						  pl.LogId != excludeLogId
+			        orderby pl.EndOdometer descending, pl.Created descending
+			        select pl).FirstOrDefault();
 		}
 
-		private IOrderedQueryable<Log> GetPreviousLogQuery(int endOdometer, string vehicleId, DateTime date, DateTime created)
+		public Log SearchNextLog(Log current)
-		{
-			return from pl in _db.Logs
-				   where pl.VehicleId == vehicleId &&
-					((pl.Date <= date && pl.EndOdometer < endOdometer)
-					|| (pl.EndOdometer == endOdometer && pl.Created < created))
-				   orderby pl.EndOdometer descending, pl.Created descending
-				   select pl;
-		}
-
-		public Log GetNextLog(Log current)
 		{
 			var vehicleId = current.VehicleId;
 			var date = current.Date;
 			var endOdometer = current.EndOdometer;
-			return GetNextLog(endOdometer, vehicleId, date, current.Created);
+			return SearchNextLog(endOdometer, vehicleId, date, current.Created, current.LogId);
 		}
 
-		public Log GetNextLog(int endOdometer, string vehicleId, DateTime date, DateTime created)
+		public Log SearchNextLog(int endOdometer, string vehicleId, DateTime date, DateTime created, int? excludeLogId = null)
 		{
 			return (from nl in GetLogs()
 					where nl.VehicleId == vehicleId &&
 						((nl.Date >= date && nl.EndOdometer > endOdometer)
-						|| (nl.EndOdometer == endOdometer && nl.Created > created))
+						|| (nl.EndOdometer == endOdometer && nl.Created > created)) &&
+						  nl.LogId != excludeLogId
 					orderby nl.EndOdometer ascending, nl.Created ascending 
 					select nl).FirstOrDefault();
 		}
-
+		
 		public void UpdateLog(Log log)
 		{
-			var currentLog = GetLog(log.LogId);
+			_db.Logs.Attach(log);
+			var original = _db.Logs.Find(log.LogId);
 
 			// ignore these properties while updating
-			log.Created = currentLog.Created;
+			log.Created = original.Created;
-			log.Source = currentLog.Source;
+			log.Source = original.Source;
-			log.UserAgent = currentLog.UserAgent;
+			log.UserAgent = original.UserAgent;
-			log.UserHostAddress = currentLog.UserHostAddress;
+			log.UserHostAddress = original.UserHostAddress;
 
-			_db.Entry(currentLog).CurrentValues.SetValues(log);
+			// remove from the list
+			var nextLog =
+				(from l in _db.Logs
+				 where l.VehiclePreviousLogId == log.LogId
+				 select l).FirstOrDefault();
+			if (nextLog != null)
+				nextLog.VehiclePreviousLogId = log.VehiclePreviousLogId;
 
-			_db.Entry(currentLog).State = EntityState.Modified;
+			log.VehiclePreviousLog = null;
+			log.VehiclePreviousLogId = null;
+
+			// add it back in new position
+			var previousLog = SearchPreviousLog(log);
+			if (previousLog != null)
+				log.VehiclePreviousLogId = previousLog.LogId;
+			var newNextLog = SearchNextLog(log);
+			if (newNextLog != null)
+				newNextLog.VehiclePreviousLogId = log.LogId;
+
+			_db.Entry(log).State = EntityState.Modified;
 			_db.SaveChanges();
 
 			UpdateCurrentOdometer(log.VehicleId);
@@ -252,6 +275,14 @@ namespace MileageTraker.Web.DAL
 		public void DeleteLog(int id)
 		{
 			var log = _db.Logs.Find(id);
+
+			var nextLog =
+				(from l in _db.Logs
+				where l.VehiclePreviousLogId == log.LogId
+				select l).FirstOrDefault();
+			if (nextLog != null)
+				nextLog.VehiclePreviousLog = log.VehiclePreviousLog;
+
 			_db.Logs.Remove(log);
 			_db.SaveChanges();
 
@@ -335,7 +366,7 @@ namespace MileageTraker.Web.DAL
 			// TODO HACK for testing, delete later
 			try
 			{
-				if (_db.Logs.Count() == 0)
+				if (!_db.Logs.Any())
 					return null;
 			}
 			catch (NullReferenceException)

Web/Migrations/201212042021486_AddVehiclePreviousLog.cs

@@ -10,9 +10,11 @@ namespace MileageTraker.Web.Migrations
             AddForeignKey("Log", "VehiclePreviousLogId", "Log", "LogId");
             CreateIndex("Log", "VehiclePreviousLogId");
 	        var populateSql =
-		        @"WITH summary AS (
+				@"WITH summary AS (
 					SELECT
-						ROW_NUMBER() OVER (PARTITION BY l.LogId ORDER BY l.LogId ASC, pl.EndOdometer DESC, pl.Created DESC) AS rk,
+						ROW_NUMBER() OVER (
+							PARTITION BY l.LogId 
+							ORDER BY pl.EndOdometer DESC, pl.Created DESC) AS rk,
 						l.LogId, pl.LogId as PreviousLogId
 					FROM
 						[Log] as l,
@@ -22,7 +24,7 @@ namespace MileageTraker.Web.Migrations
 						AND ((pl.[Date] <= l.[Date]
 								AND pl.EndOdometer < l.EndOdometer)
 							OR (
-								pl.EndOdometer < l.EndOdometer
+								pl.EndOdometer = l.EndOdometer
 								AND pl.Created < l.Created
 							))
 				)

Web/Models/MileageLogType.cs

@@ -26,7 +26,7 @@ namespace MileageTraker.Web.Models
 		
 		public static implicit operator MileageLogType(MileageLogTypeWrapper w)
 		{
-			return w == null ? default(MileageLogType) : w.Enum;
+			return w == null ? default(MileageLogType) : w.Enum; 
 		}
 
 		public static implicit operator MileageLogTypeWrapper(MileageLogType c)

Web/ViewModels/ConfirmCreateLogViewModel.cs

@@ -33,7 +33,7 @@ namespace MileageTraker.Web.ViewModels
 			var endOdometer = int.Parse(createLogViewModel.EndOdometer);
 			var date = DateTime.Parse(createLogViewModel.Date);
 
-			var previousLog = dataService.GetPreviousLog(endOdometer, createLogViewModel.VehicleId, date, DateTime.Now);
+			var previousLog = dataService.SearchPreviousLog(endOdometer, createLogViewModel.VehicleId, date, DateTime.Now);
 			if (previousLog != null)
 			{
 				PreviousOdometer = previousLog.EndOdometer;