using System.Reflection;
using NetArchTest.Rules;
using Xunit;
using FluentAssertions;

namespace StellaOps.Architecture.Tests;

/// <summary>
/// Architecture tests for module dependency rules.
/// Enforces proper layering between Core, Infrastructure, and WebService assemblies.
/// </summary>
[Trait("Category", "Architecture")]
public sealed class ModuleDependencyRulesTests
{
    /// <summary>
    /// Core libraries must not depend on infrastructure (e.g., Postgres storage).
    /// Core should be pure business logic, infrastructure-agnostic.
    /// </summary>
    [Fact]
    public void CoreLibraries_MustNot_Depend_On_Infrastructure()
    {
        var coreAssemblies = GetAssembliesByPattern("Core");
        
        if (!coreAssemblies.Any())
        {
            return;
        }

        var result = Types.InAssemblies(coreAssemblies)
            .ShouldNot()
            .HaveDependencyOnAny(
                "StellaOps.*.Storage.Postgres",
                "StellaOps.*.Storage.Valkey",
                "Npgsql",
                "StackExchange.Redis")
            .GetResult();

        result.IsSuccessful.Should().BeTrue(
            $"Core libraries must not depend on infrastructure. " +
            $"Violations: {string.Join(", ", result.FailingTypeNames ?? Enumerable.Empty<string>())}");
    }

    /// <summary>
    /// WebServices may depend on Core and Storage, but not on other WebServices.
    /// Each WebService should be independently deployable.
    /// </summary>
    [Fact]
    public void WebServices_MustNot_Depend_On_Other_WebServices()
    {
        var webServiceAssemblies = GetAssembliesByPattern("WebService");
        
        if (!webServiceAssemblies.Any())
        {
            return;
        }

        foreach (var assembly in webServiceAssemblies)
        {
            var assemblyName = assembly.GetName().Name;
            var otherWebServices = webServiceAssemblies
                .Where(a => a.GetName().Name != assemblyName)
                .Select(a => a.GetName().Name!)
                .ToArray();

            if (!otherWebServices.Any())
            {
                continue;
            }

            var result = Types.InAssembly(assembly)
                .ShouldNot()
                .HaveDependencyOnAny(otherWebServices)
                .GetResult();

            result.IsSuccessful.Should().BeTrue(
                $"WebService {assemblyName} must not depend on other WebServices. " +
                $"Violations: {string.Join(", ", result.FailingTypeNames ?? Enumerable.Empty<string>())}");
        }
    }

    /// <summary>
    /// Workers may depend on Core and Storage, but not directly on WebServices.
    /// Workers are background processes, independent of HTTP layer.
    /// </summary>
    [Fact]
    public void Workers_MustNot_Depend_On_WebServices()
    {
        var workerAssemblies = GetAssembliesByPattern("Worker");
        
        if (!workerAssemblies.Any())
        {
            return;
        }

        var result = Types.InAssemblies(workerAssemblies)
            .ShouldNot()
            .HaveDependencyOnAny("Microsoft.AspNetCore.Mvc", "StellaOps.*.WebService")
            .GetResult();

        result.IsSuccessful.Should().BeTrue(
            $"Worker assemblies must not depend on WebServices. " +
            $"Violations: {string.Join(", ", result.FailingTypeNames ?? Enumerable.Empty<string>())}");
    }

    /// <summary>
    /// Models/DTOs should not depend on infrastructure or services.
    /// </summary>
    [Fact]
    public void Models_MustNot_Depend_On_Services()
    {
        var modelAssemblies = GetAssembliesByPattern("Models");
        
        if (!modelAssemblies.Any())
        {
            return;
        }

        var result = Types.InAssemblies(modelAssemblies)
            .ShouldNot()
            .HaveDependencyOnAny(
                "StellaOps.*.Storage.*",
                "StellaOps.*.WebService",
                "Microsoft.AspNetCore.*")
            .GetResult();

        result.IsSuccessful.Should().BeTrue(
            $"Model assemblies must not depend on services. " +
            $"Violations: {string.Join(", ", result.FailingTypeNames ?? Enumerable.Empty<string>())}");
    }

    private static IEnumerable<Assembly> GetAssembliesByPattern(string pattern)
    {
        return AppDomain.CurrentDomain.GetAssemblies()
            .Where(a => a.GetName().Name?.Contains(pattern) == true);
    }
}