using System;
using UnityEngine;
using Vanguard.Api.Contracts;
using Vanguard.Board3D;
using Vanguard.Shared.Protocol;

namespace Vanguard.UI.Overlays
{
    /// <summary>
    /// Один стек экранов поверх боя: список карт → детали карты.
    /// Возврат из деталей всегда ведёт обратно в тот же список.
    /// </summary>
    public sealed class OverlayNavigationService
    {
        private readonly RectTransform _root;
        private readonly CardListView _list;
        private readonly CardDetailOverlay _detail;
        private CardListRequest _currentRequest;

        public OverlayNavigationService(
            Transform parent,
            Func<string, CardCatalogItemDto> catalog)
        {
            _root = UiKit.CreatePanel(parent, "BattleOverlays", Color.clear);
            _root.gameObject.SetActive(false);

            _list = new CardListView(_root, catalog);
            _detail = new CardDetailOverlay(_root, catalog);
        }

        public bool IsOpen => _root.gameObject.activeSelf;

        public event Action<bool> OpenChanged;

        public void OpenZone(PlayerView player, int viewer, BoardZone zone)
        {
            OpenList(CardZoneContent.Build(player, viewer, zone));
        }

        public void OpenList(CardListRequest request)
        {
            if (request == null)
                return;

            _currentRequest = request;
            _detail.Hide();
            _list.Show(request, OpenDetail, CloseAll);
            _root.SetAsLastSibling();
            var wasOpen = _root.gameObject.activeSelf;
            _root.gameObject.SetActive(true);
            if (!wasOpen)
                OpenChanged?.Invoke(true);
        }

        public void OpenCardDetail(CardListEntry entry)
        {
            if (entry == null)
                return;

            _currentRequest = null;
            _list.Hide();
            _detail.Show(entry, CloseAll);
            _root.SetAsLastSibling();
            var wasOpen = _root.gameObject.activeSelf;
            _root.gameObject.SetActive(true);
            if (!wasOpen)
                OpenChanged?.Invoke(true);
        }

        private void OpenDetail(CardListEntry entry)
        {
            _list.Hide();
            _detail.Show(entry, BackToList);
            _root.SetAsLastSibling();
            _root.gameObject.SetActive(true);
        }

        private void BackToList()
        {
            _detail.Hide();
            if (_currentRequest == null)
            {
                CloseAll();
                return;
            }

            _list.Show(_currentRequest, OpenDetail, CloseAll);
        }

        public void CloseAll()
        {
            var wasOpen = _root != null && _root.gameObject.activeSelf;
            _list?.Hide();
            _detail?.Hide();
            _root.gameObject.SetActive(false);
            _currentRequest = null;
            if (wasOpen)
                OpenChanged?.Invoke(false);
        }

        public void Dispose()
        {
            if (_root == null)
                return;

            if (Application.isPlaying)
                UnityEngine.Object.Destroy(_root.gameObject);
            else
                UnityEngine.Object.DestroyImmediate(_root.gameObject);
        }
    }
}