using UnityEngine;

namespace TKS
{
    /// <summary>씬에 하나만 두면 카메라·전장·전투 관리자·HUD·입력을 코드로 구성하고 첫 스테이지를 시작한다.</summary>
    public class GameBootstrap : MonoBehaviour
    {
        public BalanceConfig Config;
        public bool AutoStart = true;
        public int StartStageIndex = 0;

        public BattleManager Battle { get; private set; }
        public CameraController CameraCtrl { get; private set; }

        void Awake()
        {
            if (Config == null) Config = Resources.Load<BalanceConfig>("BalanceConfig");
            if (Config == null)
            {
                Debug.LogError("[TKS] BalanceConfig 자산이 없습니다. 메뉴 TKS/Setup Project 를 실행하세요.");
                return;
            }

            var cam = Camera.main;
            if (cam == null)
            {
                var cgo = new GameObject("Main Camera");
                cgo.tag = "MainCamera";
                cam = cgo.AddComponent<Camera>();
            }
            cam.orthographic = true;
            cam.clearFlags = CameraClearFlags.SolidColor;
            cam.backgroundColor = new Color(0.07f, 0.09f, 0.11f);
            cam.transform.position = new Vector3(0f, 0f, -10f);
            cam.nearClipPlane = 0.1f;
            cam.farClipPlane = 100f;
            // 탑다운: 같은 정렬 순서의 스프라이트는 y 가 큰(멀리 있는) 유닛이 뒤에 그려진다
            cam.transparencySortMode = TransparencySortMode.CustomAxis;
            cam.transparencySortAxis = Vector3.up;

            var board = new GameObject("Board").AddComponent<Board>();
            board.Build(Config.boardSize);

            CameraCtrl = cam.GetComponent<CameraController>();
            if (CameraCtrl == null) CameraCtrl = cam.gameObject.AddComponent<CameraController>();
            CameraCtrl.Init(board, Config.cameraViewHeight, Config.cameraMinViewHeight, Config.cameraMaxViewHeight);

            Battle = new GameObject("BattleManager").AddComponent<BattleManager>();
            Battle.Configure(Config, board);

            var hud = new GameObject("HUD").AddComponent<BattleHUD>();
            hud.Build(Battle, cam, CameraCtrl);
            Battle.Hud = hud;

            var input = new GameObject("SlingshotInput").AddComponent<SlingshotInput>();
            input.Init(Battle, cam, hud, CameraCtrl);
            Battle.Sling = input;

            // 카메라 연동: 행동 중인 유닛 추적 · 아군 턴 시작 시 아군 쪽으로
            var camCtrl = CameraCtrl;
            var battle = Battle;
            battle.UnitActing += u => camCtrl.Follow(u.transform);
            battle.PhaseChanged += phase =>
            {
                if (phase == BattlePhase.PlayerTurn) camCtrl.FocusOn(PlayerFocusPoint(battle));
                else if (phase == BattlePhase.StageClear || phase == BattlePhase.Defeat) camCtrl.StopFollow();
            };
            battle.StageStarted += () => camCtrl.SnapTo(PlayerFocusPoint(battle));

            if (AutoStart) Battle.StartStage(StartStageIndex);
        }

        /// <summary>아군 무게중심에서 적 쪽으로 조금 올린 지점.</summary>
        static Vector2 PlayerFocusPoint(BattleManager battle)
        {
            var players = battle.AliveUnits(Faction.Player);
            if (players.Count == 0) return Vector2.zero;
            Vector2 sum = Vector2.zero;
            foreach (var p in players) sum += p.Position;
            return sum / players.Count + new Vector2(0f, battle.Config.cameraViewHeight * 0.2f);
        }
    }
}