Search based on a set of keywords

Question

I need to make a search based on a set of keywords, that return all the Ads related with those keywords. Then the result is a list of Categories with the Ads Count for each

Answer 1

I have posted my answer to: https://github.com/n074v41l4bl34u/StackOverflow19796132 Feel free to review it.

Here is the most important snippet.

---

with:

internal class SearchDomain
{
  public List Keywords { get; set; }
  public List Categories { get; set; }
  public List KeywordAdCategories { get; set; }
}

---

then:

private static char[] keywordPartsSplitter = new char[] { ' ', '-' };

internal static Dictionary>> FromStringInput(string searchPhrase, SearchDomain searchDomain)
{
  var identifiedKeywords = searchPhrase
    .Split(keywordPartsSplitter);

  var knownKeywordParts = identifiedKeywords
    .Where
    (ik =>
      searchDomain
      .Keywords
      .SelectMany(x => x.GetKeywordParts())
      .Any(kp => kp.Equals(ik, StringComparison.InvariantCultureIgnoreCase))
    );

  var keywordkSearches = knownKeywordParts
    .Select((kkp, n) => new KeywordSearch()
    {
      Id = n,
      Name = kkp,
      Keyword = searchDomain
        .Keywords
        .Single
        (k =>
          k.GetKeywordParts()
            .Any(kp => kp.Equals(kkp, StringComparison.InvariantCultureIgnoreCase))
        )
    });

  var relevantKeywords = keywordkSearches
    .Select(ks => ks.Keyword)
    .Distinct();

  var keywordAdCategoriesByCategory = searchDomain.Categories
    .GroupJoin
    (
      searchDomain.KeywordAdCategories,
      c => c.Id,
      kac => kac.Category_Id,
      (c, kac) => new { Category = c, AdKeywordsForCategory = kac }
    );

  var relevantKeywordAdCategories = keywordAdCategoriesByCategory
    .Where
    (kacbk =>
      relevantKeywords
        .All
        (rk =>
          kacbk
            .AdKeywordsForCategory
            .Any(kac => kac.Keyword_Id == rk.Id)
        )
    );

  var foundAdsInCategories = relevantKeywordAdCategories
    .ToDictionary
    (rkac =>
      rkac.Category,
      rkac => rkac.AdKeywordsForCategory
        .GroupBy(g => g.Ad_Id)
        .ToDictionary(x => x.Key, x => x.ToList())
    );

  return foundAdsInCategories;
}

---

It does exactly what you want however I find something fishy about keywords being divisible to sub-keywords. Than again, maybe it is just the naming.