namespace BuildFlow.Architecture.Tests;

using System.Xml.Linq;
using Xunit;

/// <summary>
/// BuildFlow Host 架构约束测试。确保后台只有 BuildFlow Host 一个启动入口，
/// 业务模块（Domain/Application/Infrastructure 三层）不能退化为独立进程。
/// HTTP 层已统一并入 BuildFlow.Host，模块不再保留 Api 类库。
/// </summary>
public class HostArchitectureTests
{
    [Fact]
    public void BusinessModulesShouldNotContainStandaloneProgramEntryPoints()
    {
        var repoRoot = FindRepoRoot();
        var moduleRoot = Path.Combine(repoRoot.FullName, "src", "modules");

        var programFiles = Directory
            .EnumerateFiles(moduleRoot, "Program.cs", SearchOption.AllDirectories)
            .Where(path => !ContainsPathSegment(path, "bin") && !ContainsPathSegment(path, "obj"))
            .Where(path => !IsSsoPath(repoRoot, path))
            .Select(path => Path.GetRelativePath(repoRoot.FullName, path).Replace('\\', '/'))
            .Order(StringComparer.Ordinal)
            .ToArray();

        Assert.True(
            programFiles.Length == 0,
            "业务模块不允许包含独立 Program.cs，后台应只由 src/BuildFlow.Host/Program.cs 统一启动。当前残留：" +
            Environment.NewLine +
            string.Join(Environment.NewLine, programFiles));
    }

    [Fact]
    public void BusinessModulesShouldNotContainLaunchProfiles()
    {
        var repoRoot = FindRepoRoot();
        var moduleRoot = Path.Combine(repoRoot.FullName, "src", "modules");

        var launchProfiles = Directory
            .EnumerateFiles(moduleRoot, "launchSettings.json", SearchOption.AllDirectories)
            .Where(path => !ContainsPathSegment(path, "bin") && !ContainsPathSegment(path, "obj"))
            .Where(path => !IsSsoPath(repoRoot, path))
            .Select(path => Path.GetRelativePath(repoRoot.FullName, path).Replace('\\', '/'))
            .Order(StringComparer.Ordinal)
            .ToArray();

        Assert.True(
            launchProfiles.Length == 0,
            "业务模块不允许保留独立启动配置 launchSettings.json，启动配置应集中在 BuildFlow Host。当前残留：" +
            Environment.NewLine +
            string.Join(Environment.NewLine, launchProfiles));
    }

    [Fact]
    public void BusinessModulesShouldNotHaveStandaloneApiProjects()
    {
        var repoRoot = FindRepoRoot();
        var moduleRoot = Path.Combine(repoRoot.FullName, "src", "modules");

        // 合并后，业务模块（rag/file/im/workflow）不应再有 Api 类库项目；仅 SSO 保留独立 Api
        var apiProjects = Directory
            .EnumerateFiles(moduleRoot, "*.Api.csproj", SearchOption.AllDirectories)
            .Concat(Directory.EnumerateFiles(moduleRoot, "*Api.csproj", SearchOption.AllDirectories))
            .Where(path => !ContainsPathSegment(path, "bin") && !ContainsPathSegment(path, "obj"))
            .Where(path => !IsSsoPath(repoRoot, path))
            .Distinct(StringComparer.Ordinal)
            .Select(path => Path.GetRelativePath(repoRoot.FullName, path).Replace('\\', '/'))
            .Order(StringComparer.Ordinal)
            .ToArray();

        Assert.True(
            apiProjects.Length == 0,
            "业务模块不允许保留独立 Api 类库项目（HTTP 层已统一并入 BuildFlow.Host）。当前残留：" +
            Environment.NewLine +
            string.Join(Environment.NewLine, apiProjects));
    }

    [Fact]
    public void SsoApiShouldRemainStandaloneIdentityProvider()
    {
        var repoRoot = FindRepoRoot();
        var ssoApiDir = Path.Combine(repoRoot.FullName, "src", "modules", "sso", "Api");
        var ssoProjectPath = Path.Combine(ssoApiDir, "SSO.Api.csproj");

        var violations = new List<string>();
        if (!File.Exists(Path.Combine(ssoApiDir, "Program.cs")))
        {
            violations.Add("src/modules/sso/Api/Program.cs");
        }

        if (HasLibraryOutputType(ssoProjectPath))
        {
            violations.Add("src/modules/sso/Api/SSO.Api.csproj 设置了 <OutputType>Library</OutputType>");
        }

        Assert.True(
            violations.Count == 0,
            "SSO 是独立身份提供方，不归 BuildFlow Host 合并启动；它必须保留自己的进程入口。当前问题：" +
            Environment.NewLine +
            string.Join(Environment.NewLine, violations));
    }

    private static DirectoryInfo FindRepoRoot()
    {
        var current = new DirectoryInfo(AppContext.BaseDirectory);
        while (current is not null)
        {
            if (File.Exists(Path.Combine(current.FullName, "BuildFlow.slnx")))
            {
                return current;
            }

            current = current.Parent;
        }

        throw new InvalidOperationException("无法定位 BuildFlow.slnx，架构测试无法确定仓库边界。");
    }

    private static bool ContainsPathSegment(string path, string segment)
    {
        return path.Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
            .Any(part => string.Equals(part, segment, StringComparison.Ordinal));
    }

    private static bool HasLibraryOutputType(string projectPath)
    {
        var document = XDocument.Load(projectPath);
        return document
            .Descendants("OutputType")
            .Any(element => string.Equals(element.Value.Trim(), "Library", StringComparison.Ordinal));
    }

    private static bool IsSsoPath(DirectoryInfo repoRoot, string path)
    {
        var relativePath = Path.GetRelativePath(repoRoot.FullName, path).Replace('\\', '/');
        return relativePath.StartsWith("src/modules/sso/", StringComparison.Ordinal);
    }
}