Adicionando o MongoDB Atlas Vector Search a um aplicativo .NET Blazor C#

1
{
2
  "fields": [
3
    {
4
      "type": "vector",
5
      "path": "plot_embedding",
6
      "numDimensions": 1536,
7
      "similarity": "dotProduct"
8
    }
9
  ]
10
}

1
"OpenAPIKey": "<YOUR OPENAI API KEY>"

1
var openAPIKey = builder.Configuration.GetValue<string>("OpenAPIKey");

1
builder.Services.AddScoped(service => new MongoDBService(mongoDBSettings, openAPIKey));

1
public IEnumerable<Movie> MovieSearch(string textToSearch);

1
using System.Text; 
2
using System.Text.Json;

1
  private readonly string _openAPIKey;
2
  private readonly HttpClient _httpClient = new HttpClient();

1
public MongoDBService(MongoDBSettings settings, string openAPIKey)

1
public MongoDBService(MongoDBSettings settings, string openAPIKey)
2
{
3
    _client = new MongoClient(settings.AtlasURI);
4
    _mongoDatabase = _client.GetDatabase(settings.DatabaseName);
5
    _movies = _mongoDatabase.GetCollection<Movie>("embedded_movies");
6
    _openAPIKey = openAPIKey;
7
}

1
using MongoDB.Bson;
2
using MongoDB.Bson.Serialization.Attributes;
3
4
namespace SeeSharpMovies.Models;
5
6
7
public class Movie
8
{
9
   [BsonId]
10
   [BsonElement("_id")]
11
   public ObjectId Id { get; set; }
12
   
13
   [BsonElement("plot")]
14
   public string Plot { get; set; }
15
16
   [BsonElement("genres")]  
17
   public string[] Genres { get; set; }
18
19
   [BsonElement("runtime")]
20
   public int Runtime { get; set; }
21
22
   [BsonElement("cast")]
23
   public string[] Cast { get; set; }
24
25
   [BsonElement("num_mflix_comments")]
26
   public int NumMflixComments { get; set; }
27
28
   [BsonElement("poster")]
29
   public string Poster { get; set; }
30
31
   [BsonElement("title")]
32
   public string Title { get; set; }
33
34
   [BsonElement("fullplot")]
35
   public string FullPlot { get; set; }
36
37
   [BsonElement("languages")]
38
   public string[] Languages { get; set; }
39
40
   [BsonElement("directors")]
41
   public string[] Directors { get; set; }
42
43
   [BsonElement("writers")]
44
   public string[] Writers { get; set; }
45
46
   [BsonElement("awards")]
47
   public Awards Awards { get; set; }
48
   
49
   [BsonElement("year")]
50
   public string Year { get; set; }
51
52
   [BsonElement("imdb")]
53
   public Imdb Imdb { get; set; }
54
55
   [BsonElement("countries")]
56
   public string[] Countries { get; set; }
57
58
   [BsonElement("type")]
59
   public string Type { get; set; }
60
61
   [BsonElement("plot_embedding")]
62
   public float[] PlotEmbedding { get; set; }
63
64
}
65
66
public class Awards
67
{
68
   [BsonElement("wins")]
69
   public int Wins { get; set; }
70
   
71
   [BsonElement("nominations")]
72
   public int Nominations { get; set; }
73
   
74
   [BsonElement("text")]
75
   public string Text { get; set; }
76
}
77
78
public class Imdb
79
{
80
   [BsonElement("rating")]
81
   public float Rating { get; set; }
82
   
83
   [BsonElement("votes")]
84
   public int Votes { get; set; }
85
   
86
   [BsonElement("id")]
87
   public int Id { get; set; }
88
}

1
namespace SeeSharpMovies.Models
2
{
3
    public class EmbeddingResponse
4
    {
5
        public string @object { get; set; }
6
        public List<Data> data { get; set; }
7
        public string model { get; set; }
8
        public Usage usage { get; set; }
9
    }
10
11
    public class Data
12
    {
13
        public string @object { get; set; }
14
        public int index { get; set; }
15
        public List<double> embedding { get; set; }
16
    }
17
18
    public class Usage
19
    {
20
        public int prompt_tokens { get; set; }
21
        public int total_tokens { get; set; }
22
    }
23
}

1
private async Task<List<double>> GetEmbeddingsFromText(string text)
2
{
3
    Dictionary<string, object> body = new Dictionary<string, object>
4
    {
5
        { "model", "text-embedding-ada-002" },
6
        { "input", text }
7
    };
8
9
    _httpClient.BaseAddress = new Uri("https://api.openai.com");
10
    _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_openAPIKey}");
11
12
    string requestBody = JsonSerializer.Serialize(body);
13
    StringContent requestContent =
14
        new StringContent(requestBody, Encoding.UTF8, "application/json");
15
16
    var response = await _httpClient.PostAsync("/v1/embeddings", requestContent)
17
        .ConfigureAwait(false);
18
19
    if (response.IsSuccessStatusCode)
20
    {
21
        string responseBody = await response.Content.ReadAsStringAsync();
22
        EmbeddingResponse embeddingResponse = JsonSerializer.Deserialize<EmbeddingResponse>(responseBody);
23
        return embeddingResponse.data[0].embedding;
24
    }
25
26
    return new List<double>();
27
}

1
public IEnumerable<Movie> MovieSearch(string textToSearch)
2
{
3
4
    var vector = GetEmbeddingsFromText(textToSearch).Result.ToArray();
5
6
    var vectorOptions = new VectorSearchOptions<Movie>()
7
    {
8
        IndexName = "vector_index",
9
        NumberOfCandidates = 150
10
    };
11
12
  var movies = _movies.Aggregate()
13
    .VectorSearch(movie => movie.PlotEmbedding, vector, 150, vectorOptions)
14
    .Project<Movie>(Builders<Movie>.Projection
15
    .Include(m => m.Title)
16
    .Include(m => m.Plot)
17
    .Include(m => m.Poster))            
18
    .ToList();
19
20
21
    return movies;
22
}

1
 var movie = _movies.Find(movie => movie.Id.ToString() == id).FirstOrDefault();

1
 string searchTerm;

1
private void SearchMovies()
2
{
3
    if (string.IsNullOrWhiteSpace(searchTerm))
4
    {
5
        movies = MongoDBService.GetAllMovies();
6
    }
7
    else
8
    {
9
        movies = MongoDBService.MovieSearch(searchTerm);
10
    }
11
}

1
<header class="top-bar">
2
        <a href="/">See Sharp Movies</a>
3
    <div class="form-inline search-bar">
4
        <input class="form-control mr-sm-2"
5
               type="search" placeholder="Search"
6
               aria-label="Search"               
7
               @bind="searchTerm">
8
        <button class="btn btn-outline-success my-2 my-sm-0" @onclick="SearchMovies">Search</button>
9
    </div>
10
    </header>

1
.search-bar {
2
    padding: 5%;
3
}
4
5
.search-bar button {
6
    padding: 4px;
7
}