using ColaFlow.Modules.Mcp.Application.Services;
using ColaFlow.Modules.Mcp.Contracts.Resources;
using FluentAssertions;
using Microsoft.Extensions.Logging;
using NSubstitute;

namespace ColaFlow.Modules.Mcp.Tests.Services;

/// <summary>
/// Unit tests for McpResourceRegistry
/// </summary>
public class McpResourceRegistryTests
{
    private readonly ILogger<McpResourceRegistry> _logger;
    private readonly McpResourceRegistry _sut;

    public McpResourceRegistryTests()
    {
        _logger = Substitute.For<ILogger<McpResourceRegistry>>();
        _sut = new McpResourceRegistry(_logger);
    }

    [Fact]
    public void RegisterResource_AddsResourceToRegistry()
    {
        // Arrange
        var resource = CreateMockResource("colaflow://test", "Test Resource");

        // Act
        _sut.RegisterResource(resource);

        // Assert
        var resources = _sut.GetAllResources();
        resources.Should().ContainSingle();
        resources[0].Uri.Should().Be("colaflow://test");
    }

    [Fact]
    public void RegisterResource_WithDuplicateUri_Overwrites()
    {
        // Arrange
        var resource1 = CreateMockResource("colaflow://test", "Test Resource 1");
        var resource2 = CreateMockResource("colaflow://test", "Test Resource 2");

        // Act
        _sut.RegisterResource(resource1);
        _sut.RegisterResource(resource2);

        // Assert
        var resources = _sut.GetAllResources();
        resources.Count.Should().Be(2); // Both are in the list
        var foundResource = _sut.GetResourceByUri("colaflow://test");
        foundResource!.Name.Should().Be("Test Resource 2"); // But only the last one is returned
    }

    [Fact]
    public void GetResourceByUri_WithExactMatch_ReturnsResource()
    {
        // Arrange
        var resource = CreateMockResource("colaflow://projects.list", "Projects List");
        _sut.RegisterResource(resource);

        // Act
        var result = _sut.GetResourceByUri("colaflow://projects.list");

        // Assert
        result.Should().NotBeNull();
        result!.Uri.Should().Be("colaflow://projects.list");
    }

    [Fact]
    public void GetResourceByUri_WithTemplateMatch_ReturnsResource()
    {
        // Arrange
        var resource = CreateMockResource("colaflow://projects.get/{id}", "Project Details");
        _sut.RegisterResource(resource);

        // Act
        var result = _sut.GetResourceByUri("colaflow://projects.get/123");

        // Assert
        result.Should().NotBeNull();
        result!.Uri.Should().Be("colaflow://projects.get/{id}");
    }

    [Fact]
    public void GetResourceByUri_WithNonExistentUri_ReturnsNull()
    {
        // Act
        var result = _sut.GetResourceByUri("colaflow://nonexistent");

        // Assert
        result.Should().BeNull();
    }

    [Fact]
    public void GetResourceDescriptors_ReturnsAllDescriptors()
    {
        // Arrange
        var resource1 = CreateMockResource("colaflow://test1", "Test 1");
        var resource2 = CreateMockResource("colaflow://test2", "Test 2");
        _sut.RegisterResource(resource1);
        _sut.RegisterResource(resource2);

        // Act
        var descriptors = _sut.GetResourceDescriptors();

        // Assert
        descriptors.Should().HaveCount(2);
        descriptors.Should().Contain(d => d.Uri == "colaflow://test1");
        descriptors.Should().Contain(d => d.Uri == "colaflow://test2");
    }

    [Fact]
    public void GetAllResources_ReturnsReadOnlyList()
    {
        // Arrange
        var resource = CreateMockResource("colaflow://test", "Test");
        _sut.RegisterResource(resource);

        // Act
        var resources = _sut.GetAllResources();

        // Assert
        resources.Should().BeAssignableTo<IReadOnlyList<IMcpResource>>();
    }

    private IMcpResource CreateMockResource(string uri, string name)
    {
        var resource = Substitute.For<IMcpResource>();
        resource.Uri.Returns(uri);
        resource.Name.Returns(name);
        resource.Description.Returns($"Description for {name}");
        resource.MimeType.Returns("application/json");
        resource.GetContentAsync(Arg.Any<McpResourceRequest>(), Arg.Any<CancellationToken>())
            .Returns(new McpResourceContent
            {
                Uri = uri,
                MimeType = "application/json",
                Text = "{}"
            });
        return resource;
    }
}