using System;
using System.Collections.Generic;
using Codely.Newtonsoft.Json.Linq;
using UnityTcp.Editor.Helpers;
using UnityTcp.Editor.Tools.Jobs;

namespace UnityTcp.Editor.Tools
{
    /// <summary>
    /// [EXPERIMENTAL] Handles Unity Package Manager (UPM) operations.
    /// Supports installing, removing, and querying packages.
    /// Compatible with Unity 2022.3 LTS.
    ///
    /// Every action runs as a <see cref="StepJob"/> and answers only when the operation has
    /// actually finished — see <see cref="UpmJob"/> for why installing and removing cannot be
    /// tracked any other way (UPM reloads the domain, which used to destroy the in-flight request
    /// and its update callback and strand the job as Pending).
    /// </summary>
    public static class ManagePackage
    {
        // UPM resolution reloads the domain, so the whole operation runs as a StepJob and answers
        // once it has actually finished. 300s covers a registry fetch plus the reload it triggers.
        private const int DefaultTimeoutSeconds = 300;

        private static object Run(StepJob job, JObject @params)
            => StepJobRunner.Start(
                CommandContext.RequestId, CommandContext.CommandType, job,
                @params["timeoutSeconds"]?.ToObject<int?>() ?? DefaultTimeoutSeconds);

        private static readonly Dictionary<string, Func<JObject, object>> ActionHandlers =
            new Dictionary<string, Func<JObject, object>>
            {
                { "install_package", InstallPackage },
                { "remove_package", RemovePackage },
                { "list_packages", p => Run(new ListPackagesJob(), p) },
            };

        public static object HandleCommand(JObject @params)
            => ActionRouter.Route(@params, ActionHandlers);

        private static object InstallPackage(JObject @params)
        {
            string idOrUrl = @params["id_or_url"]?.ToString();
            string version = @params["version"]?.ToString();

            // "com.unity.package" + "1.2.3" -> "com.unity.package@1.2.3"
            if (!string.IsNullOrEmpty(version) &&
                !string.IsNullOrEmpty(idOrUrl) &&
                !idOrUrl.Contains("@") &&
                !idOrUrl.StartsWith("http"))
            {
                idOrUrl = $"{idOrUrl}@{version}";
            }

            return Run(new UpmJob
            {
                Remove = false,
                Target = idOrUrl,
                PackageName = UpmJob.RegistryNameOf(idOrUrl),
            }, @params);
        }

        private static object RemovePackage(JObject @params)
        {
            string packageName = @params["package_name"]?.ToString();
            return Run(new UpmJob
            {
                Remove = true,
                Target = packageName,
                PackageName = packageName,
            }, @params);
        }
    }
}