using MAF1.PluginContract;
using MAF1.Web;

namespace MAF1.Plugins;

/// <summary>一次目录快照：系统节点 + 插件节点合并后的 Nodes 列表给画布用。</summary>
public sealed class NodeCatalogSnapshot
{
    public string PluginsRoot { get; init; } = "";
    public List<AgentTypeInfo> System { get; init; } = [];
    public List<AgentTypeInfo> Plugins { get; init; } = [];
    public List<AgentTypeInfo> Nodes { get; init; } = [];
    public List<CatalogIssue> Issues { get; init; } = [];
    public IReadOnlyList<LoadedPlugin> LoadedPlugins { get; init; } = [];
}

/// <summary>把扫描结果和 AgentCatalog 拼在一起。同名时插件覆盖系统实现。</summary>
public sealed class NodeCatalogService(PluginScanner scanner)
{
    public NodeCatalogSnapshot Load()
    {
        PluginScanResult scan = scanner.Scan();
        List<CatalogIssue> issues = [.. scan.Issues];
        List<AgentTypeInfo> system = AgentCatalog.SystemNodes
            .Select(Clone)
            .ToList();
        foreach (AgentTypeInfo item in system)
        {
            item.Origin = "system";
        }

        Dictionary<string, AgentTypeInfo> systemByType = system.ToDictionary(n => n.Type, StringComparer.OrdinalIgnoreCase);
        List<AgentTypeInfo> plugins = [];
        foreach (LoadedPlugin plugin in scan.Plugins)
        {
            AgentTypeInfo info = ToTypeInfo(plugin);
            if (systemByType.ContainsKey(info.Type))
            {
                issues.Add(new CatalogIssue
                {
                    Level = "info",
                    Source = info.Type,
                    Message = $"插件 `{info.Type}` 覆盖了同名系统节点，画布运行将走插件进程。",
                });
                systemByType[info.Type].Overridden = true;
            }

            plugins.Add(info);
        }

        Dictionary<string, AgentTypeInfo> merged = systemByType
            .ToDictionary(kv => kv.Key, kv => kv.Value, StringComparer.OrdinalIgnoreCase);
        foreach (AgentTypeInfo plugin in plugins)
        {
            merged[plugin.Type] = plugin;
        }

        return new NodeCatalogSnapshot
        {
            PluginsRoot = scan.Root,
            System = system,
            Plugins = plugins,
            Nodes = merged.Values.OrderBy(n => n.Origin).ThenBy(n => n.Name).ToList(),
            Issues = issues,
            LoadedPlugins = scan.Plugins,
        };
    }

    public LoadedPlugin? FindPlugin(string type)
        => Load().LoadedPlugins.FirstOrDefault(p => p.Manifest.Id.Equals(type, StringComparison.OrdinalIgnoreCase));

    private static AgentTypeInfo ToTypeInfo(LoadedPlugin plugin)
    {
        PluginManifest manifest = plugin.Manifest;
        return new AgentTypeInfo
        {
            Type = manifest.Id,
            Name = string.IsNullOrWhiteSpace(manifest.Name) ? manifest.Id : manifest.Name,
            Description = manifest.Description,
            Origin = "plugin",
            Version = manifest.Version,
            Folder = plugin.FolderName,
            Inputs = manifest.Inputs.Select(ToPort).ToList(),
            Outputs = manifest.Outputs.Select(ToPort).ToList(),
            Credentials = manifest.Credentials,
        };
    }

    private static PortInfo ToPort(PluginPort port)
        => new()
        {
            Name = port.Name,
            Type = port.Type,
            Description = port.Description,
            Required = port.Required,
        };

    private static AgentTypeInfo Clone(AgentTypeInfo source)
        => new()
        {
            Type = source.Type,
            Name = source.Name,
            Description = source.Description,
            Origin = source.Origin,
            Version = source.Version,
            Folder = source.Folder,
            Overridden = source.Overridden,
            Handler = source.Handler,
            Inputs = source.Inputs,
            Outputs = source.Outputs,
            Credentials = source.Credentials,
        };
}