using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace TKS.OutGame
{
    /// <summary>
    /// 편성(img08 · 기획 S12 v3) — 프리셋 3 · 전열 3(윗줄)·후열 2(아랫줄) 자리 = 영웅 목록 카드(축소) · 하단 보유 목록(장수 ▼ 전환 · 같은 카드 4열 · 출전) ·
    /// 탭(자리 고르기 → 카드 탭 = 넣기 · 같은 자리 두 번 = 빼기 · 다른 자리 = 맞바꾸기) · 끌기(자리 ↔ 자리 · 카드 → 자리) · 저장 = 그 프리셋을 출전 편성으로.
    /// 빈 칸 허용 · 최소 1 · 편성 제약 없음(D4).
    /// </summary>
    public class FormationScreen : OutGameScreen
    {
        int preset;
        readonly List<string> work = new List<string>();
        bool dirty;
        int selected = -1;
        bool soldiers;

        readonly List<Button> presetBtns = new List<Button>();
        readonly List<RectTransform> slots = new List<RectTransform>();
        RectTransform list;
        ScrollRect scroll;
        RectTransform ghost;

        public IList<string> Working
        {
            get { return work; }
        }

        public int Preset
        {
            get { return preset; }
        }

        public bool Dirty
        {
            get { return dirty; }
        }

        // 자리 카드 = 영웅 목록 카드(320×431) × SeatScale · 보유 목록 카드 × ListScale(PD 2026-11-09 「변경된 영웅 리스트 반영 · 편성 유닛 정보를 목록·상세 UI 참고해 깔끔하게」)
        const float SeatScale = 0.70f;
        const float ListScale = 0.72f;
        const float SeatGap = 24f;
        const float BoardTop = 122f;
        const float BoardH = 680f;
        Text countText;
        Text filterText;

        public override void Build()
        {
            int n = Root.Battle.Config.playerSpawnPoints.Length;
            int front = Mathf.Clamp(S.Db.Economy.FormationFront, 0, n);
            // 바탕 = 영웅 목록과 같음(진남 + 재화 바 뒤 띠) · 헤더 오른쪽 사선 칸 = 출전 n / 칸 수
            UiKit.Paint(UiKit.Fill("ListBg", Rt), UiKit.Col("list_bg", UiKit.Bg), false);
            UiKit.Paint(UiKit.TopBand("ListTop", Rt, 0f, OutGameRoot.TopBarH), UiKit.Col("band_top", UiKit.Bg), false);
            var head = Header("편성", "", true); // 부제 삭제(설계서 §2-5)
            var ob = UiKit.Rect("Oblique", head, new Vector2(1f, 0.5f), new Vector2(1f, 0.5f), Vector2.zero, new Vector2(239f, OutGameRoot.HeaderH - 7f));
            UiKit.Skin(ob, "oblique", UiKit.Col("oblique", UiKit.White));
            countText = UiKit.Title(UiKit.Label(ob, "", 40, UiKit.Col("count_text", UiKit.Dark), TextAnchor.MiddleCenter, new Vector2(0.5f, 0.5f), new Vector2(0.5f, 0.5f), new Vector2(12f, 0f), new Vector2(220f, 80f)));
            countText.horizontalOverflow = HorizontalWrapMode.Overflow;
            var body = Body();

            // 프리셋 3(팩 서브탭) + 제약 칩
            for (int i = 0; i < S.Save.presets.Count; i++)
            {
                int k = i;
                presetBtns.Add(SubTab("Preset" + i, body, "프리셋 " + (i + 1), new Vector2(24f + i * 226f, -18f), new Vector2(210f, 84f), () => LoadPreset(k)));
            }
            var chip = UiKit.Skin(UiKit.Rect("Free", body, new Vector2(1f, 1f), new Vector2(1f, 1f), new Vector2(-24f, -24f), new Vector2(270f, 72f)), "chip", UiKit.Col("chip_dark", UiKit.Dark));
            UiKit.Title(UiKit.FillLabel(chip.transform, "편성 제약 없음", 30, UiKit.White), false);

            // 자리 판 = 전열(윗줄) · 후열(아랫줄) · 자리 = 목록과 같은 카드
            float sw = CollectionCards.CellSize.x * SeatScale, sh = CollectionCards.CellSize.y * SeatScale;
            var board = UiKit.TopBand("Board", body, BoardTop, BoardH, 24f, 24f);
            UiKit.Skin(board, "card", UiKit.Col("formation_field", UiKit.Paper));
            Pill(board, "전열", UiKit.Col("row_front", UiKit.Red), -(20f + sh / 2f));
            Pill(board, "후열", UiKit.Col("row_back", UiKit.Dark), -(20f + sh + 20f + sh / 2f));
            UiKit.Label(board, "탭·드래그 = 자리 교체 · 같은 자리 두 번 탭 = 빼기", 24, UiKit.InkSoft, TextAnchor.MiddleLeft, new Vector2(0f, 0f), new Vector2(0f, 0f), new Vector2(24f, 2f), new Vector2(900f, 34f), false);
            for (int i = 0; i < n; i++)
            {
                bool f = i < front;
                int col = f ? i : i - front;
                int cnt = f ? front : n - front;
                float x = 60f + (col - (cnt - 1) / 2f) * (sw + SeatGap);
                float y = f ? -20f : -(20f + sh + 20f);
                var s = UiKit.Rect("Slot" + i, board, new Vector2(0.5f, 1f), new Vector2(0.5f, 1f), new Vector2(x, y), new Vector2(sw, sh));
                var hit = s.gameObject.AddComponent<Image>();
                hit.color = Color.clear;
                hit.raycastTarget = true;
                var td = s.gameObject.AddComponent<TapDrag>();
                td.AnyDirection = true;
                int k = i;
                td.OnTap = () => TapSlot(k);
                td.OnDragStart = e => StartGhost(work[k], e);
                td.OnDragMove = MoveGhost;
                td.OnDragEnd = e => DropFromSlot(k, e);
                slots.Add(s);
            }

            // 보유 목록 머리 = 제목 · 「장수 ▼」(영웅 목록과 같은 전환) · 저장
            var row = UiKit.TopBand("ListHead", body, BoardTop + BoardH + 16f, 74f, 24f, 24f);
            UiKit.Title(UiKit.Label(row, "보유 영웅", 40, UiKit.White, TextAnchor.MiddleLeft, new Vector2(0f, 0.5f), new Vector2(0f, 0.5f), new Vector2(4f, 0f), new Vector2(300f, 70f)), true);
            var pick = UiKit.Rect("Filter", row, new Vector2(1f, 0.5f), new Vector2(1f, 0.5f), new Vector2(-244f, 0f), new Vector2(220f, 74f));
            pick.gameObject.AddComponent<Image>().color = Color.clear;
            pick.gameObject.AddComponent<Button>().onClick.AddListener(() =>
            {
                soldiers = !soldiers;
                Refresh();
            });
            filterText = UiKit.Title(UiKit.Label(pick, "", 38, UiKit.InkSoft, TextAnchor.MiddleRight, new Vector2(1f, 0.5f), new Vector2(1f, 0.5f), new Vector2(-50f, 2f), new Vector2(160f, 70f)));
            UiKit.DropShadow(UiKit.Icon(pick, "arrow_down", new Vector2(1f, 0.5f), new Vector2(1f, 0.5f), new Vector2(-6f, 0f), 38f), 3f);
            UiKit.Btn("Save", row, "저장", 34, UiKit.Red, UiKit.White, new Vector2(1f, 0.5f), new Vector2(1f, 0.5f), Vector2.zero, new Vector2(210f, 76f), SaveNow);
            var cell = CollectionCards.CellSize * ListScale;
            float side = (OutGameRoot.Reference.x - cell.x * 4f - 17f * 3f) / 2f;
            list = UiKit.ScrollGrid("List", body, side, side, BoardTop + BoardH + 100f, 0f, cell, new Vector2(17f, 16f), 4, out scroll);
        }

        /// <summary>서브탭(팩 Button_Round10 + 윗면 광택 · 선택 = 붉은 옻칠).</summary>
        static Button SubTab(string name, Transform parent, string label, Vector2 pos, Vector2 size, System.Action onClick)
        {
            var img = UiKit.Skin(UiKit.Rect(name, parent, new Vector2(0f, 1f), new Vector2(0f, 1f), pos, size), UISkin.Has("subtab") ? "subtab" : "button", UiKit.Col("subtab_off", UiKit.Paper), true);
            var b = img.gameObject.AddComponent<Button>();
            b.onClick.AddListener(() => onClick());
            UiKit.Title(UiKit.FillLabel(img.transform, label, 34, UiKit.White, TextAnchor.MiddleCenter, true, 8f), true);
            return b;
        }

        static void Pill(RectTransform board, string label, Color c, float y)
        {
            // 전열·후열 라벨 = 평행사변형 칩(설계서 §3③)
            var p = UISkin.Has("para_orange")
                ? UiKit.Skin(UiKit.Rect("Row_" + label, board, new Vector2(0f, 1f), new Vector2(0f, 0.5f), new Vector2(20f, y), new Vector2(140f, 62f)), "para_orange", c)
                : UiKit.Box("Row_" + label, board, new Vector2(0f, 1f), new Vector2(0f, 0.5f), new Vector2(20f, y), new Vector2(140f, 62f), c);
            UiKit.Title(UiKit.FillLabel(p.transform, label, 32, UiKit.White), true);
        }

        public override void OnShow()
        {
            LoadPreset(S.Save.presetIdx, true);
        }

        public override bool OnBack()
        {
            if (dirty) Root.Toast("저장하지 않은 편성 변경은 취소됩니다");
            dirty = false;
            return false;
        }

        public void LoadPreset(int idx, bool quiet = false)
        {
            if (dirty && !quiet) Root.Toast("저장하지 않은 변경 취소");
            preset = Mathf.Clamp(idx, 0, S.Save.presets.Count - 1);
            work.Clear();
            work.AddRange(S.Save.presets[preset].slots);
            dirty = false;
            selected = -1;
            Refresh();
        }

        int Filled()
        {
            int n = 0;
            foreach (var id in work)
                if (!string.IsNullOrEmpty(id)) n++;
            return n;
        }

        public void TapSlot(int i)
        {
            if (selected < 0)
            {
                selected = i;
            }
            else if (selected == i)
            {
                if (!string.IsNullOrEmpty(work[i]))
                {
                    if (Filled() > 1)
                    {
                        work[i] = "";
                        dirty = true;
                    }
                    else Root.Toast("최소 1명은 출전해야 합니다");
                }
                selected = -1;
            }
            else
            {
                Swap(selected, i);
                selected = -1;
            }
            Refresh();
        }

        public void TapCard(string id)
        {
            int at = work.IndexOf(id);
            if (at >= 0)
            {
                if (Filled() > 1)
                {
                    work[at] = "";
                    dirty = true;
                }
                else Root.Toast("최소 1명은 출전해야 합니다");
            }
            else
            {
                int target = selected >= 0 ? selected : work.IndexOf("");
                if (target < 0) Root.Toast("빈 자리가 없습니다 — 자리를 먼저 탭해 고른 뒤 카드를 탭(교체)");
                else
                {
                    work[target] = id;
                    dirty = true;
                }
            }
            selected = -1;
            Refresh();
        }

        /// <summary>id 를 자리 slot 에 넣는다(이미 다른 자리에 있으면 맞바꿈).</summary>
        public void Place(string id, int slot)
        {
            if (slot < 0 || slot >= work.Count || string.IsNullOrEmpty(id)) return;
            int at = work.IndexOf(id);
            if (at >= 0) Swap(at, slot);
            else
            {
                work[slot] = id;
                dirty = true;
            }
            Refresh();
        }

        public void Swap(int a, int b)
        {
            if (a == b) return;
            var t = work[a];
            work[a] = work[b];
            work[b] = t;
            dirty = true;
        }

        public void SaveNow()
        {
            var why = S.SavePreset(preset, work);
            if (why != null)
            {
                Root.Toast(why);
                return;
            }
            dirty = false;
            Root.Toast("프리셋 " + (preset + 1) + " 저장 · 출전 편성으로 지정");
            Refresh();
        }

        // ---------- 끌기 ----------

        void StartGhost(string id, PointerEventData e)
        {
            if (string.IsNullOrEmpty(id)) return;
            if (ghost != null) Object.Destroy(ghost.gameObject);
            ghost = UiKit.Portrait("Ghost", Root.TopRoot, S.Def(id), new Vector2(0.5f, 0.5f), new Vector2(0.5f, 0.5f), Vector2.zero, new Vector2(170f, 170f), true, 2.1f, UiKit.Red);
            ghost.gameObject.name = "Ghost_" + id;
            MoveGhost(e);
        }

        void MoveGhost(PointerEventData e)
        {
            if (ghost == null) return;
            Vector2 lp;
            if (RectTransformUtility.ScreenPointToLocalPointInRectangle(Root.TopRoot, e.position, Root.Cam, out lp)) ghost.anchoredPosition = lp;
        }

        int SlotAt(Vector2 screen)
        {
            for (int i = 0; i < slots.Count; i++)
                if (RectTransformUtility.RectangleContainsScreenPoint(slots[i], screen, Root.Cam)) return i;
            return -1;
        }

        void DropFromSlot(int from, PointerEventData e)
        {
            EndGhost();
            int to = SlotAt(e.position);
            if (to < 0 || to == from) return;
            Swap(from, to);
            selected = -1;
            Refresh();
        }

        void DropCard(string id, PointerEventData e)
        {
            EndGhost();
            int to = SlotAt(e.position);
            if (to >= 0) Place(id, to);
        }

        void EndGhost()
        {
            if (ghost == null) return;
            ghost.gameObject.SetActive(false);
            Object.Destroy(ghost.gameObject);
            ghost = null;
        }

        // ---------- 그리기 ----------

        public override void Refresh()
        {
            for (int i = 0; i < presetBtns.Count; i++)
            {
                bool on = i == preset;
                presetBtns[i].GetComponent<Image>().color = on ? UiKit.Red : UiKit.Col("subtab_off", UiKit.Paper);
                var t = UiKit.LabelOf(presetBtns[i]);
                t.color = UiKit.White;
                t.text = "프리셋 " + (i + 1) + (i == S.Save.presetIdx ? " <size=22>출전</size>" : "") + (on && dirty ? "*" : "");
            }
            countText.text = "출전 " + Filled() + "/" + work.Count;

            // 자리 = 목록과 같은 카드(배율) · 빈 자리 = 빈 카드 · 고른 자리 = 노란 테두리
            for (int i = 0; i < slots.Count; i++)
            {
                var s = slots[i];
                UiKit.Clear(s);
                var id = i < work.Count ? work[i] : "";
                var h = S.Def(id);
                if (i == selected) UiKit.Layer(s, "Select", "card_border", UiKit.Col("select_line", UiKit.Star), -7f, -7f, -7f, -7f);
                if (h != null) CollectionCards.CardIn(s, S, h, false, null, SeatScale);
                else
                {
                    CollectionCards.EmptyIn(s, SeatScale);
                    UiKit.Title(UiKit.Label(s, "+ 빈 자리", 28, UiKit.InkSoft, TextAnchor.MiddleCenter, new Vector2(0.5f, 0.5f), new Vector2(0.5f, 0.5f), new Vector2(0f, 24f), new Vector2(200f, 50f)));
                }
            }

            // 보유 목록 = 영웅 목록 카드(배율 · 레벨 높은 순 · 출전 = 이 편성에 든 영웅)
            filterText.text = soldiers ? "병사" : "장수";
            UiKit.Clear(list);
            var owned = new List<HeroDb.Hero>(S.Owned(soldiers));
            owned.Sort((a, b) =>
            {
                int la = S.Save.Level(a.id) != null ? S.Save.Level(a.id).lv : 1, lb = S.Save.Level(b.id) != null ? S.Save.Level(b.id).lv : 1;
                return lb.CompareTo(la);
            });
            var cellSize = CollectionCards.CellSize * ListScale;
            foreach (var h in owned)
            {
                var id = h.id;
                var holder = UiKit.Rect("C_" + id, list, new Vector2(0.5f, 0.5f), new Vector2(0.5f, 0.5f), Vector2.zero, cellSize);
                var card = CollectionCards.CardIn(holder, S, h, work.Contains(id), null, ListScale);
                var td = card.gameObject.AddComponent<TapDrag>();
                td.OnTap = () => TapCard(id);
                td.OnDragStart = e => StartGhost(id, e);
                td.OnDragMove = MoveGhost;
                td.OnDragEnd = e => DropCard(id, e);
            }
        }
    }
}