using System.ComponentModel;
using k8s;
using k8s.Autorest;
using ModelContextProtocol.Server;

namespace LazyBear.MCP.Services.Kubernetes;

[McpServerToolType]
public sealed class K8sPodsTools(K8sClientProvider clientProvider, IConfiguration configuration)
{
    private readonly IKubernetes? _client = clientProvider.Client;
    private readonly string? _clientInitializationError = clientProvider.InitializationError;
    private readonly string _defaultNamespace = configuration["Kubernetes:DefaultNamespace"] ?? "default";

    [McpServerTool, Description("Список подов в namespace")]
    public async Task<string> ListPods(
        [Description("Namespace Kubernetes")] string? @namespace = null,
        CancellationToken cancellationToken = default)
    {
        var ns = ResolveNamespace(@namespace);
        if (!TryGetClient(out var client, out var clientError))
        {
            return clientError;
        }

        try
        {
            var pods = await client.CoreV1.ListNamespacedPodAsync(ns, cancellationToken: cancellationToken);

            if (pods.Items.Count == 0)
            {
                return $"В namespace '{ns}' поды не найдены.";
            }

            var lines = pods.Items.Select(pod =>
            {
                var podName = pod.Metadata?.Name ?? "unknown";
                var phase = pod.Status?.Phase ?? "Unknown";
                var node = pod.Spec?.NodeName ?? "-";
                var restarts = pod.Status?.ContainerStatuses?.Sum(s => s.RestartCount) ?? 0;
                return $"{podName}: phase={phase}, restarts={restarts}, node={node}";
            });

            return $"Поды namespace '{ns}':\n{string.Join('\n', lines)}";
        }
        catch (Exception ex)
        {
            return FormatError("list_pods", ns, ex);
        }
    }

    [McpServerTool, Description("Статус pod по имени")]
    public async Task<string> GetPodStatus(
        [Description("Имя pod")] string name,
        [Description("Namespace Kubernetes")] string? @namespace = null,
        CancellationToken cancellationToken = default)
    {
        var ns = ResolveNamespace(@namespace);
        if (!TryGetClient(out var client, out var clientError))
        {
            return clientError;
        }

        try
        {
            var pod = await client.CoreV1.ReadNamespacedPodAsync(name, ns, cancellationToken: cancellationToken);

            var phase = pod.Status?.Phase ?? "Unknown";
            var hostIp = pod.Status?.HostIP ?? "-";
            var podIp = pod.Status?.PodIP ?? "-";
            var conditions = pod.Status?.Conditions?.Select(c => $"{c.Type}={c.Status}") ?? [];

            return $"Pod '{name}' в namespace '{ns}': phase={phase}, hostIp={hostIp}, podIp={podIp}, conditions=[{string.Join(", ", conditions)}]";
        }
        catch (Exception ex)
        {
            return FormatError("get_pod_status", ns, ex, name);
        }
    }

    [McpServerTool, Description("Логи pod")]
    public async Task<string> GetPodLogs(
        [Description("Имя pod")] string name,
        [Description("Namespace Kubernetes")] string? @namespace = null,
        [Description("Имя контейнера")]
        string? container = null,
        [Description("Количество строк с конца")]
        int? tailLines = 100,
        CancellationToken cancellationToken = default)
    {
        var ns = ResolveNamespace(@namespace);
        if (!TryGetClient(out var client, out var clientError))
        {
            return clientError;
        }

        try
        {
            await using var logStream = await client.CoreV1.ReadNamespacedPodLogAsync(
                name,
                ns,
                container: container,
                tailLines: tailLines,
                cancellationToken: cancellationToken);

            using var reader = new StreamReader(logStream);
            var logs = await reader.ReadToEndAsync(cancellationToken);

            if (string.IsNullOrWhiteSpace(logs))
            {
                return $"Логи pod '{name}' в namespace '{ns}' пустые.";
            }

            return logs;
        }
        catch (Exception ex)
        {
            return FormatError("get_pod_logs", ns, ex, name);
        }
    }

    private string ResolveNamespace(string? @namespace)
    {
        return string.IsNullOrWhiteSpace(@namespace) ? _defaultNamespace : @namespace;
    }

    private static string BuildClientInitializationError()
    {
        return "Kubernetes клиент не инициализирован. Проверьте Kubernetes:KubeconfigPath или in-cluster окружение (KUBERNETES_SERVICE_HOST/KUBERNETES_SERVICE_PORT).";
    }

    private bool TryGetClient(out IKubernetes client, out string error)
    {
        if (_client is null)
        {
            client = null!;
            var details = string.IsNullOrWhiteSpace(_clientInitializationError)
                ? string.Empty
                : $" Детали: {_clientInitializationError}";
            error = BuildClientInitializationError() + details;
            return false;
        }

        client = _client;
        error = string.Empty;
        return true;
    }

    private static string FormatError(string toolName, string @namespace, Exception exception, string? resourceName = null)
    {
        var resourcePart = string.IsNullOrWhiteSpace(resourceName) ? string.Empty : $", resource='{resourceName}'";

        if (exception is HttpOperationException httpException)
        {
            var statusCode = httpException.Response?.StatusCode;
            var reason = httpException.Response?.ReasonPhrase;
            var body = string.IsNullOrWhiteSpace(httpException.Response?.Content)
                ? "-"
                : httpException.Response!.Content;

            return $"Ошибка Kubernetes в tool '{toolName}' (namespace='{@namespace}'{resourcePart}): status={(int?)statusCode ?? 0} {reason}, details={body}";
        }

        return $"Ошибка Kubernetes в tool '{toolName}' (namespace='{@namespace}'{resourcePart}): {exception.GetType().Name}: {exception.Message}";
    }
}