using FluentAssertions;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using StellaOps.Microservice;
using Xunit;

namespace StellaOps.Microservice.Tests;

/// <summary>
/// Tests for MicroserviceYamlLoader.
/// </summary>
public class MicroserviceYamlLoaderTests : IDisposable
{
    private readonly string _tempDirectory;
    private readonly ILogger<MicroserviceYamlLoader> _logger;

    public MicroserviceYamlLoaderTests()
    {
        _tempDirectory = Path.Combine(Path.GetTempPath(), $"MicroserviceYamlLoaderTests_{Guid.NewGuid()}");
        Directory.CreateDirectory(_tempDirectory);
        _logger = NullLogger<MicroserviceYamlLoader>.Instance;
    }

    public void Dispose()
    {
        if (Directory.Exists(_tempDirectory))
        {
            Directory.Delete(_tempDirectory, true);
        }
    }

    [Fact]
    public void Load_ReturnsNull_WhenConfigFilePathIsNull()
    {
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = null
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().BeNull();
    }

    [Fact]
    public void Load_ReturnsNull_WhenConfigFilePathIsEmpty()
    {
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = ""
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().BeNull();
    }

    [Fact]
    public void Load_ReturnsNull_WhenFileDoesNotExist()
    {
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = Path.Combine(_tempDirectory, "nonexistent.yaml")
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().BeNull();
    }

    [Fact]
    public void Load_ParsesValidYaml()
    {
        var yamlContent = """
            endpoints:
              - method: GET
                path: /api/test
                defaultTimeout: 30s
                supportsStreaming: true
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().NotBeNull();
        result!.Endpoints.Should().HaveCount(1);
        result.Endpoints[0].Method.Should().Be("GET");
        result.Endpoints[0].Path.Should().Be("/api/test");
        result.Endpoints[0].DefaultTimeout.Should().Be("30s");
        result.Endpoints[0].SupportsStreaming.Should().BeTrue();
    }

    [Fact]
    public void Load_ParsesMultipleEndpoints()
    {
        var yamlContent = """
            endpoints:
              - method: GET
                path: /api/one
                defaultTimeout: 10s
              - method: POST
                path: /api/two
                defaultTimeout: 5m
              - method: DELETE
                path: /api/three
                defaultTimeout: 1h
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().NotBeNull();
        result!.Endpoints.Should().HaveCount(3);
    }

    [Fact]
    public void Load_ParsesClaimRequirements()
    {
        var yamlContent = """
            endpoints:
              - method: DELETE
                path: /api/admin
                requiringClaims:
                  - type: role
                    value: admin
                  - type: permission
                    value: delete
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().NotBeNull();
        result!.Endpoints.Should().HaveCount(1);
        result.Endpoints[0].RequiringClaims.Should().HaveCount(2);
        result.Endpoints[0].RequiringClaims![0].Type.Should().Be("role");
        result.Endpoints[0].RequiringClaims![0].Value.Should().Be("admin");
        result.Endpoints[0].RequiringClaims![1].Type.Should().Be("permission");
        result.Endpoints[0].RequiringClaims![1].Value.Should().Be("delete");
    }

    [Fact]
    public void Load_HandlesEmptyEndpointsList()
    {
        var yamlContent = """
            endpoints: []
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().NotBeNull();
        result!.Endpoints.Should().BeEmpty();
    }

    [Fact]
    public void Load_IgnoresUnknownProperties()
    {
        var yamlContent = """
            unknownProperty: value
            endpoints:
              - method: GET
                path: /api/test
                unknownField: ignored
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        var result = loader.Load();

        result.Should().NotBeNull();
        result!.Endpoints.Should().HaveCount(1);
    }

    [Fact]
    public void Load_ThrowsOnInvalidYaml()
    {
        var yamlContent = """
            endpoints:
              - method: GET
                path /api/test  # missing colon
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);
        var options = new StellaMicroserviceOptions
        {
            ServiceName = "test",
            Version = "1.0.0",
            Region = "us",
            ConfigFilePath = filePath
        };
        var loader = new MicroserviceYamlLoader(options, _logger);

        Action act = () => loader.Load();

        act.Should().Throw<Exception>();
    }

    [Fact]
    public void Load_ResolvesRelativePath()
    {
        var yamlContent = """
            endpoints:
              - method: GET
                path: /api/test
            """;
        var filePath = Path.Combine(_tempDirectory, "config.yaml");
        File.WriteAllText(filePath, yamlContent);

        // Save current directory and change to temp directory
        var originalDirectory = Environment.CurrentDirectory;
        try
        {
            Environment.CurrentDirectory = _tempDirectory;
            var options = new StellaMicroserviceOptions
            {
                ServiceName = "test",
                Version = "1.0.0",
                Region = "us",
                ConfigFilePath = "config.yaml" // relative path
            };
            var loader = new MicroserviceYamlLoader(options, _logger);

            var result = loader.Load();

            result.Should().NotBeNull();
        }
        finally
        {
            Environment.CurrentDirectory = originalDirectory;
        }
    }
}