These are the methods used by the controller to handle the actual searching and mapping of results to the view model.

SearchResultsIndexAgent.cs

public void Search(string term, string page)
      {
         if (string.IsNullOrEmpty(term))
         {
            ViewModel.SearchTerm = "No search term entered";
            return;
         }

         ViewModel.SearchTerm = term;
         var sitecoreService = new SitecoreService(Sitecore.Context.Database);
         var pageSize = sitecoreService.GetItem<ISetting>(Constants.SettingIds.SiteSearchPageSizeSettingId).IntegerValue;

         var requestedPage = 0;
         if (!string.IsNullOrEmpty(page))
         {
            if (!int.TryParse(page, out requestedPage))
            {
               requestedPage = 1;
            }
         }

         ViewModel.CurrentPage = requestedPage > 0 ? requestedPage : 1;

         var searchIndex =
            ContentSearchManager.GetIndex("sitesearch_web_index");

         using (var context = searchIndex.CreateSearchContext())
         {
            var results = context.GetQueryable<PageBaseSearchResult>()
            .Where(x => x.PageContentField.Contains(term)).GetResults().ToList();

            var searchResults = new List<SiteSearchResult>();
            foreach (var result in results)
            {
               var resultFields = result.Document.PageContentField.Split('|');
               if (!resultFields.Any()) continue;

               var resultPageId = Guid.Parse(resultFields[0]);
               var resultPage = sitecoreService.GetItem<IPageBase>(resultPageId);

               var newEntry = new SiteSearchResult
               {
                  Title = HighlightTermTitle(resultPage.PageTitle, term),
                  Content = CleanResultContent(resultFields[1], term),
                  PageLinkUrl = resultPage.Url
               };

               searchResults.Add(newEntry);
            }

            if (searchResults.Any())
            {
               ViewModel.TotalResults = searchResults.Count;
               ViewModel.TotalPageCount = (ViewModel.TotalResults / pageSize) +
                                          (ViewModel.TotalResults % pageSize > 0 ? 1 : 0);

               ViewModel.SearchResults = searchResults.Skip((requestedPage - 1) * pageSize).Take(pageSize).ToList();
            }
         }
      }

      private string HighlightTermTitle(string title, string searchTerm)
      {
         if (string.IsNullOrEmpty(title)) return string.Empty;
         var regexedText = Regex.Replace(title, searchTerm, x => string.Format("<b style='background-color:yellow;'>{0}</b>", x.Value), RegexOptions.IgnoreCase | RegexOptions.Compiled);
         return regexedText;
      }

      private string CleanResultContent(string result, string searchTerm)
      {
         if (string.IsNullOrEmpty(result)) return string.Empty;
         var regexedText = Regex.Replace(result, searchTerm, x => string.Format("<b>{0}</b>", x.Value), RegexOptions.IgnoreCase | RegexOptions.Compiled);

         if (regexedText.Length > 255)
         {
            var sentenceRegex = @"(?<=[\.!\?])\s+";
            var searchText = string.Format("<b>{0}</b>", searchTerm);
            var splitUpText = Regex.Split(regexedText, sentenceRegex, RegexOptions.IgnoreCase);
            var counter = 0;
            var cleanedText = new StringBuilder();
            foreach (var x in splitUpText)
            {
               if (x.Contains(searchText))
               {
                  if (counter <= 4)
                     cleanedText.Append(x);

                  counter++;
               }
            }
            return cleanedText.ToString();
         }

         return regexedText;
      }