using System;
using UnityEngine;
using UnityEngine.UI;

namespace Vanguard.UI
{
    public enum CommunityTab
    {
        Guides,
        Decks,
        Tickets,
    }

    /// <summary>
    /// Сцена Community: вкладки гайдов, публичных колод и тикетов. Пока это
    /// каркас — серверных данных для разделов нет.
    /// </summary>
    public sealed class CommunityView
    {
        public const string RootName = "CommunityScreen";

        private static readonly Color PanelFill = new Color(0.024f, 0.058f, 0.15f, 0.92f);
        private static readonly Color Border = new Color(0.18f, 0.49f, 1f, 0.55f);
        private static readonly Color BorderStrong = new Color(0.34f, 0.72f, 1f, 0.9f);
        private static readonly Color TextPrimary = new Color(0.88f, 0.93f, 1f);
        private static readonly Color TextDim = new Color(0.44f, 0.55f, 0.75f);

        private readonly RectTransform _root;
        private readonly RectTransform[] _contents;
        private readonly Button[] _tabs;

        public CommunityView(Transform parent, Action onBack)
        {
            _root = UiKit.CreatePanel(parent, RootName, new Color(0f, 0f, 0f, 0f));
            _root.GetComponent<Image>().raycastTarget = false;

            var top = Surface(_root, "TopBar", new Color(0.012f, 0.03f, 0.08f, 0.94f), 0);
            top.anchorMin = new Vector2(0f, 1f);
            top.anchorMax = new Vector2(1f, 1f);
            top.pivot = new Vector2(0.5f, 1f);
            top.sizeDelta = new Vector2(0f, 88f);
            top.anchoredPosition = Vector2.zero;

            var back = UiKit.CreateButton(top, "Back", "← Назад", () => onBack(), 18);
            var backRect = back.GetComponent<RectTransform>();
            backRect.anchorMin = new Vector2(0f, 0.5f);
            backRect.anchorMax = new Vector2(0f, 0.5f);
            backRect.pivot = new Vector2(0f, 0.5f);
            backRect.sizeDelta = new Vector2(150f, 44f);
            backRect.anchoredPosition = new Vector2(24f, 0f);
            ApplyFill(back.GetComponent<Image>(), new Color(0.06f, 0.12f, 0.24f, 0.95f), Border);

            var title = UiKit.CreateText(
                top,
                "Title",
                "Сообщество",
                30,
                TextPrimary,
                TextAnchor.MiddleLeft);
            title.fontStyle = FontStyle.Bold;
            var titleRect = title.rectTransform;
            titleRect.anchorMin = new Vector2(0f, 0.5f);
            titleRect.anchorMax = new Vector2(0f, 0.5f);
            titleRect.pivot = new Vector2(0f, 0.5f);
            titleRect.sizeDelta = new Vector2(420f, 44f);
            titleRect.anchoredPosition = new Vector2(196f, 0f);

            var hint = UiKit.CreateText(
                top,
                "Hint",
                "Гайды, колоды и обратная связь",
                15,
                TextDim,
                TextAnchor.MiddleRight);
            var hintRect = hint.rectTransform;
            hintRect.anchorMin = new Vector2(1f, 0.5f);
            hintRect.anchorMax = new Vector2(1f, 0.5f);
            hintRect.pivot = new Vector2(1f, 0.5f);
            hintRect.sizeDelta = new Vector2(420f, 30f);
            hintRect.anchoredPosition = new Vector2(-24f, 0f);

            var tabs = NewRect(_root, "Tabs");
            tabs.anchorMin = new Vector2(0f, 1f);
            tabs.anchorMax = new Vector2(0f, 1f);
            tabs.pivot = new Vector2(0f, 1f);
            tabs.sizeDelta = new Vector2(900f, 56f);
            tabs.anchoredPosition = new Vector2(24f, -104f);

            _tabs = new Button[3];
            _contents = new RectTransform[3];
            for (var i = 0; i < 3; i++)
            {
                var index = i;
                var label = TabTitle((CommunityTab)i);
                var tab = UiKit.CreateButton(tabs, "Tab" + i, label, () => SelectTab((CommunityTab)index), 17);
                var rect = tab.GetComponent<RectTransform>();
                rect.anchorMin = new Vector2(0f, 0.5f);
                rect.anchorMax = new Vector2(0f, 0.5f);
                rect.pivot = new Vector2(0f, 0.5f);
                rect.sizeDelta = new Vector2(250f, 52f);
                rect.anchoredPosition = new Vector2(i * 266f, 0f);
                _tabs[i] = tab;
            }

            var body = Surface(_root, "Body", PanelFill, 16);
            body.anchorMin = new Vector2(0f, 0f);
            body.anchorMax = new Vector2(1f, 1f);
            body.offsetMin = new Vector2(24f, 24f);
            body.offsetMax = new Vector2(-24f, -180f);

            for (var i = 0; i < 3; i++)
            {
                var tab = (CommunityTab)i;
                _contents[i] = StubUi.Panel(
                    body,
                    "Content" + i,
                    TabTitle(tab),
                    TabNote(tab));
            }

            SelectTab(CommunityTab.Guides);
            _root.gameObject.SetActive(false);
        }

        public CommunityTab Current { get; private set; }

        public void Show() => UiKit.SetActive(_root, true);

        public void Hide() => UiKit.SetActive(_root, false);

        public void SelectTab(CommunityTab tab)
        {
            Current = tab;
            for (var i = 0; i < 3; i++)
            {
                var active = (CommunityTab)i == tab;
                _contents[i].gameObject.SetActive(active);
                ApplyFill(
                    _tabs[i].GetComponent<Image>(),
                    active
                        ? new Color(0.16f, 0.40f, 0.80f, 0.95f)
                        : new Color(0.05f, 0.10f, 0.22f, 0.9f),
                    active ? BorderStrong : Border);
            }
        }

        private static string TabTitle(CommunityTab tab)
        {
            switch (tab)
            {
                case CommunityTab.Decks:
                    return "Колоды";
                case CommunityTab.Tickets:
                    return "Тикеты";
                default:
                    return "Гайды";
            }
        }

        private static string TabNote(CommunityTab tab)
        {
            switch (tab)
            {
                case CommunityTab.Decks:
                    return "Публичные колоды появятся позже. Сейчас колодой можно поделиться по коду в редакторе.";
                case CommunityTab.Tickets:
                    return "Отправка сообщений о багах и улучшениях появится позже: нужен серверный раздел тикетов.";
                default:
                    return "Разборы карт, колод и механик появятся позже. Материалы будут открываться прямо здесь.";
            }
        }

        private static RectTransform NewRect(Transform parent, string name)
        {
            var go = new GameObject(name, typeof(RectTransform));
            var rect = (RectTransform)go.transform;
            rect.SetParent(parent, false);
            return rect;
        }

        private static RectTransform Surface(Transform parent, string name, Color fill, int radius)
        {
            var go = new GameObject(name, typeof(RectTransform), typeof(Image));
            var rect = (RectTransform)go.transform;
            rect.SetParent(parent, false);

            var image = go.GetComponent<Image>();
            image.sprite = NeonUi.BodySliced(radius, fill, Border, 1);
            image.type = Image.Type.Sliced;
            image.color = Color.white;
            image.raycastTarget = false;
            return rect;
        }

        private static void ApplyFill(Image image, Color fill, Color border)
        {
            image.sprite = NeonUi.BodySliced(12, fill, border, 1);
            image.type = Image.Type.Sliced;
            image.color = Color.white;
        }
    }
}