vector-search-csharp/VectorSearchApp/Program.cs

using Microsoft.Extensions.Configuration;
using VectorSearchApp.Configuration;
using VectorSearchApp.Models;
using VectorSearchApp.Services;

Console.WriteLine("=== Vector Search Address Application ===");
Console.WriteLine("Using sentence-transformers/all-MiniLM-L6-v2 model and Qdrant vector database");
Console.WriteLine();

// Load configuration
var configuration = new ConfigurationBuilder()
    .SetBasePath(AppContext.BaseDirectory)
    .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
    .Build();

var appConfig = new AppConfiguration();
configuration.GetSection("Qdrant").Bind(appConfig.Qdrant);
configuration.GetSection("Embedding").Bind(appConfig.Embedding);
configuration.GetSection("App").Bind(appConfig.App);

// Initialize services
Console.WriteLine("Initializing services...");
var embeddingService = new EmbeddingService(appConfig.Embedding);

// Check if HuggingFace API token is configured
if (string.IsNullOrEmpty(appConfig.Embedding.ApiToken))
{
    Console.WriteLine("Warning: HuggingFace API token is not configured.");
    Console.WriteLine("The application may have limited functionality without authentication.");
    Console.WriteLine("To get a free token, visit: https://huggingface.co/settings/tokens");
    Console.WriteLine();
}

IQdrantService? qdrantService = null;

try
{
    qdrantService = new QdrantService(appConfig.Qdrant, appConfig.Embedding.Dimension);
    Console.WriteLine("Initializing Qdrant collection...");
    await qdrantService.InitializeCollectionAsync();
    Console.WriteLine($"Collection '{appConfig.Qdrant.CollectionName}' is ready.");
}
catch (Exception ex)
{
    Console.WriteLine($"Warning: Could not connect to Qdrant at {appConfig.Qdrant.Host}:{appConfig.Qdrant.GrpcPort}");
    Console.WriteLine($"Error: {ex.Message}");
    Console.WriteLine();
    Console.WriteLine("Please ensure Qdrant is running. You can start it with:");
    Console.WriteLine("  cd VectorSearchApp && docker-compose up -d");
    Console.WriteLine();
    Console.WriteLine("The application will continue, but address storage/search will not be available.");
    Console.WriteLine();
}

Console.WriteLine("Type 'exit' to quit at any time.");
Console.WriteLine();

while (true)
{
    Console.WriteLine("Options:");
    Console.WriteLine("  1. Add a new address");
    Console.WriteLine("  2. Search for similar addresses");
    Console.WriteLine("  3. Exit");
    Console.Write("Select an option: ");

    var option = Console.ReadLine()?.Trim();

    if (option?.ToLower() == "exit" || option == "3")
    {
        Console.WriteLine("Goodbye!");
        return;
    }

    switch (option)
    {
        case "1":
            await AddAddressAsync(embeddingService, qdrantService, appConfig);
            break;
        case "2":
            await SearchAddressesAsync(embeddingService, qdrantService, appConfig);
            break;
        default:
            Console.WriteLine("Invalid option. Please try again.");
            break;
    }

    Console.WriteLine();
}

async Task AddAddressAsync(IEmbeddingService embeddingService, IQdrantService? qdrantService, AppConfiguration config)
{
    Console.Write("Enter the address: ");
    var addressText = Console.ReadLine()?.Trim();

    if (string.IsNullOrWhiteSpace(addressText))
    {
        Console.WriteLine("Address cannot be empty.");
        return;
    }

    Console.WriteLine("Generating embedding...");
    try
    {
        var embedding = await embeddingService.GenerateEmbeddingAsync(addressText);
        Console.WriteLine($"Embedding generated (dimension: {embedding.Length})");

        if (qdrantService != null)
        {
            var address = new Address
            {
                Id = Guid.NewGuid(),
                FullAddress = addressText,
                CreatedAt = DateTime.UtcNow
            };

            Console.WriteLine("Storing in Qdrant...");
            await qdrantService.StoreAddressAsync(address, embedding);
            Console.WriteLine($"Address stored successfully! (ID: {address.Id})");
        }
        else
        {
            Console.WriteLine("Address embedding generated but not stored (Qdrant not available).");
        }

        // Display first few values of embedding as confirmation
        Console.Write("Embedding preview: [");
        var previewCount = Math.Min(10, embedding.Length);
        for (int i = 0; i < previewCount; i++)
        {
            Console.Write($"{embedding[i]:F4}");
            if (i < previewCount - 1) Console.Write(", ");
        }
        if (embedding.Length > previewCount) Console.Write(", ...");
        Console.WriteLine("]");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error generating embedding: {ex.Message}");
    }
}

async Task SearchAddressesAsync(IEmbeddingService embeddingService, IQdrantService? qdrantService, AppConfiguration config)
{
    if (qdrantService == null)
    {
        Console.WriteLine("Search is not available because Qdrant is not connected.");
        return;
    }

    Console.Write("Enter search query: ");
    var query = Console.ReadLine()?.Trim();

    if (string.IsNullOrWhiteSpace(query))
    {
        Console.WriteLine("Query cannot be empty.");
        return;
    }

    Console.Write("Enter similarity threshold (0.0-1.0, lower = stricter, press Enter for 0.7): ");
    var thresholdInput = Console.ReadLine()?.Trim();
    float threshold = 0.7f;
    if (!string.IsNullOrEmpty(thresholdInput) && float.TryParse(thresholdInput, out var parsedThreshold))
    {
        threshold = Math.Clamp(parsedThreshold, 0f, 1f);
    }

    Console.Write("Enter max results to return (press Enter for 5, or '2' for top 2 most similar): ");
    var limitInput = Console.ReadLine()?.Trim();
    int limit = 5;
    if (!string.IsNullOrEmpty(limitInput) && int.TryParse(limitInput, out var parsedLimit))
    {
        limit = Math.Max(1, parsedLimit);
    }

    Console.WriteLine("Generating query embedding...");
    try
    {
        var queryEmbedding = await embeddingService.GenerateEmbeddingAsync(query);
        Console.WriteLine($"Searching for similar addresses (threshold: {threshold:F2}, max results: {limit})...");

        var results = await qdrantService.SearchSimilarAddressesAsync(queryEmbedding, limit: limit, scoreThreshold: threshold);

        if (results.Count == 0)
        {
            Console.WriteLine("No similar addresses found.");
            return;
        }

        Console.WriteLine($"\nFound {results.Count} similar address(es):");
        for (int i = 0; i < results.Count; i++)
        {
            Console.WriteLine($"  {i + 1}. {results[i].FullAddress} (Score: {results[i].Score:F4})");
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error during search: {ex.Message}");
    }
}