using ChatBot.Services;
using ChatBot.Services.Interfaces;
using OllamaSharp.Models;
using OllamaSharp.Models.Chat;

namespace ChatBot.Tests.Services;

public class OllamaClientAdapterTests
{
    [Fact]
    public void Constructor_WithValidUrl_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:11434";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithNullUrl_ShouldThrowArgumentException()
    {
        // Arrange
        string? url = null;

        // Act & Assert
        var exception = Assert.Throws<ArgumentException>(() => new OllamaClientAdapter(url!));
        Assert.Equal("URL cannot be empty (Parameter 'url')", exception.Message);
    }

    [Fact]
    public void Constructor_WithEmptyUrl_ShouldThrowArgumentException()
    {
        // Arrange
        var url = "";

        // Act & Assert
        var exception = Assert.Throws<ArgumentException>(() => new OllamaClientAdapter(url));
        Assert.Equal("URL cannot be empty (Parameter 'url')", exception.Message);
    }

    [Fact]
    public void Constructor_WithWhitespaceUrl_ShouldThrowArgumentException()
    {
        // Arrange
        var url = "   ";

        // Act & Assert
        var exception = Assert.Throws<ArgumentException>(() => new OllamaClientAdapter(url));
        Assert.Equal("URL cannot be empty (Parameter 'url')", exception.Message);
    }

    [Fact]
    public void Constructor_WithHttpsUrl_ShouldCreateInstance()
    {
        // Arrange
        var url = "https://ollama.example.com";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithCustomPort_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:8080";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void SelectedModel_GetAndSet_ShouldWork()
    {
        // Arrange
        var url = "http://localhost:11434";
        var adapter = new OllamaClientAdapter(url);
        var modelName = "llama2";

        // Act
        adapter.SelectedModel = modelName;
        var result = adapter.SelectedModel;

        // Assert
        Assert.Equal(modelName, result);
    }

    [Fact]
    public void SelectedModel_SetMultipleTimes_ShouldUpdateValue()
    {
        // Arrange
        var url = "http://localhost:11434";
        var adapter = new OllamaClientAdapter(url);

        // Act
        adapter.SelectedModel = "llama2";
        adapter.SelectedModel = "codellama";
        var result = adapter.SelectedModel;

        // Assert
        Assert.Equal("codellama", result);
    }

    [Fact]
    public void ChatAsync_ShouldReturnAsyncEnumerable()
    {
        // Arrange
        var url = "http://localhost:11434";
        var adapter = new OllamaClientAdapter(url);
        var request = new ChatRequest
        {
            Model = "llama2",
            Messages = new List<Message>
            {
                new() { Role = "user", Content = "Hello" },
            },
        };

        // Act
        var result = adapter.ChatAsync(request);

        // Assert
        Assert.NotNull(result);
        Assert.IsType<IAsyncEnumerable<ChatResponseStream?>>(result, exactMatch: false);
    }

    [Fact]
    public void ListLocalModelsAsync_ShouldReturnTask()
    {
        // Arrange
        var url = "http://localhost:11434";
        var adapter = new OllamaClientAdapter(url);

        // Act
        var result = adapter.ListLocalModelsAsync();

        // Assert
        Assert.NotNull(result);
        Assert.IsType<Task<IEnumerable<Model>>>(result, exactMatch: false);
    }

    [Fact]
    public void Constructor_WithSpecialCharactersInUrl_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://user:pass@localhost:11434/path?query=value#fragment";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithIpAddress_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://192.168.1.100:11434";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithLocalhostVariations_ShouldCreateInstance()
    {
        // Arrange
        var urls = new[]
        {
            "http://localhost:11434",
            "http://127.0.0.1:11434",
            "http://0.0.0.0:11434",
        };

        foreach (var url in urls)
        {
            // Act
            var adapter = new OllamaClientAdapter(url);

            // Assert
            Assert.NotNull(adapter);
        }
    }

    [Fact]
    public void Constructor_WithDifferentProtocols_ShouldCreateInstance()
    {
        // Arrange
        var urls = new[] { "http://localhost:11434", "https://localhost:11434" };

        foreach (var url in urls)
        {
            // Act
            var adapter = new OllamaClientAdapter(url);

            // Assert
            Assert.NotNull(adapter);
        }
    }

    [Fact]
    public void Constructor_WithTrailingSlash_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:11434/";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithPath_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:11434/api/v1";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithUnicodeUrl_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://тест.рф:11434";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithVeryLongUrl_ShouldThrowException()
    {
        // Arrange
        var url = "http://" + new string('a', 1000) + ".example.com:11434";

        // Act & Assert
        Assert.Throws<UriFormatException>(() => new OllamaClientAdapter(url));
    }

    [Fact]
    public void Constructor_WithUrlContainingSpaces_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:11434/path with spaces";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }

    [Fact]
    public void Constructor_WithUrlContainingSpecialCharacters_ShouldCreateInstance()
    {
        // Arrange
        var url = "http://localhost:11434/path!@#$%^&*()";

        // Act
        var adapter = new OllamaClientAdapter(url);

        // Assert
        Assert.NotNull(adapter);
    }
}