using Fengling.Gateway.Plugin.Abstractions;
using Xunit;
using YarpGateway.Plugins;

namespace YarpGateway.Tests.Unit.Plugins;

public class PluginHostTests : IDisposable
{
    private readonly string _testDir;

    public PluginHostTests()
    {
        _testDir = Path.Combine(Path.GetTempPath(), "plugin-host-test-" + Guid.NewGuid());
        Directory.CreateDirectory(_testDir);
    }

    public void Dispose()
    {
        try
        {
            Directory.Delete(_testDir, true);
        }
        catch { }
    }

    [Fact]
    public void Constructor_ShouldInitialize()
    {
        // Act
        var host = new PluginHost(_testDir);

        // Assert
        Assert.NotNull(host);
    }

    [Fact]
    public void GetPlugins_Empty_ShouldReturnEmpty()
    {
        // Arrange
        var host = new PluginHost(_testDir);

        // Act
        var plugins = host.GetPlugins().ToList();

        // Assert
        Assert.Empty(plugins);
    }

    [Fact]
    public void LoadAllAsync_EmptyDirectory_ShouldReturnZero()
    {
        // Arrange
        var host = new PluginHost(_testDir);

        // Act
        var count = host.LoadAllAsync().Result;

        // Assert
        Assert.Equal(0, count);
    }

    [Fact]
    public async Task GetPluginInfo_AfterLoad_ShouldReturnPlugins()
    {
        // Arrange
        var host = new PluginHost(_testDir);

        // 创建测试插件目录
        var pluginDir = Path.Combine(_testDir, "test-plugin");
        Directory.CreateDirectory(pluginDir);

        // 创建 plugin.json
        var manifest = new
        {
            id = "test-plugin",
            name = "Test Plugin",
            version = "1.0.0",
            entryPoint = "TestPlugin.TestPlugin"
        };
        File.WriteAllText(Path.Combine(pluginDir, "plugin.json"), System.Text.Json.JsonSerializer.Serialize(manifest));

        // 创建 DLL（占位符，不会真正加载）
        File.WriteAllText(Path.Combine(pluginDir, "test-plugin.dll"), "dummy");

        // Act
        var count = await host.LoadAllAsync();

        // Assert - 加载会失败因为 DLL 是无效的，但应该返回 0
        Assert.Equal(0, count);
    }

    [Fact]
    public async Task UnloadAsync_NotLoaded_ShouldNotThrow()
    {
        // Arrange
        var host = new PluginHost(_testDir);

        // Act & Assert - 不应抛出异常
        await host.UnloadAsync("non-existent");
    }

    [Fact]
    public async Task UnloadAllAsync_Empty_ShouldNotThrow()
    {
        // Arrange
        var host = new PluginHost(_testDir);

        // Act & Assert - 不应抛出异常
        await host.UnloadAllAsync();
    }

    [Fact]
    public void VerifyUnload_AliveObject_ShouldReturnFalse()
    {
        // Arrange
        var obj = new object();
        var weakRef = new WeakReference(obj);

        // Act
        var result = PluginHost.VerifyUnload(weakRef, maxAttempts: 1);

        // Assert
        Assert.False(result);
    }
}

/// <summary>
/// 测试用插件实现
/// </summary>
public class TestPlugin : IGatewayPlugin
{
    public string Name => "TestPlugin";
    public string Version => "1.0.0";
    public string? Description => "A test plugin";

    public Task OnLoadAsync() => Task.CompletedTask;
    public Task OnUnloadAsync() => Task.CompletedTask;
}