using System;
using System.Collections;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UnityEngine.UI;
using UObject = UnityEngine.Object;

namespace XGame
{
    public class CharacterSwitchController : MonoBehaviour
    {
        private const string ConfigResourcePath = "Config/CharacterConfig";
        private const string SelectedCharacterKey = "CharacterSwitch.SelectedCharacterId";
        private const string PrefabPath = "Assets/Game/Art/UI/Prefab/UI_CharacterSwitch.prefab";

        private CharacterConfigData config;
        private CharacterConfigItem currentConfig;
        private GameObject currentCharacter;
        private Transform characterRoot;
        private string errorText;

        // UGUI 引用（替换原 IMGUI 绘制）
        private GameObject uiPanel;            // 实例化的 UI 根
        private GameObject selectPanel;        // Panel_Select
        private Transform listChars;           // List_Chars
        private GameObject itemTemplate;       // Item_Char
        private TMP_Text errorLabel;           // Txt_Error
        private TMP_Text toggleLabel;          // Txt_Toggle
        private readonly List<Button> itemButtons = new List<Button>();
        private readonly List<string> itemIds = new List<string>();

        public string CurrentCharacterId
        {
            get { return currentConfig == null ? string.Empty : currentConfig.id; }
        }

        private void Start()
        {
            LoadConfig();
            EnsureRoot();
            LoadInitialSelection();
            StartCoroutine(LoadUIAsync());
        }

        public void SwitchTo(string characterId)
        {
            if (config == null)
            {
                LoadConfig();
            }

            CharacterConfigItem next = config == null ? null : config.Find(characterId);
            if (next == null)
            {
                errorText = "Character not found: " + characterId;
                Debug.LogWarning(errorText);
                return;
            }

            SwitchTo(next);
        }

        private void LoadConfig()
        {
            TextAsset textAsset = Resources.Load<TextAsset>(ConfigResourcePath);
            if (textAsset == null)
            {
                errorText = "Missing character config: Resources/" + ConfigResourcePath + ".json";
                Debug.LogError(errorText);
                return;
            }

            try
            {
                config = JsonUtility.FromJson<CharacterConfigData>(textAsset.text);
            }
            catch (Exception ex)
            {
                errorText = "Parse character config failed: " + ex.Message;
                Debug.LogError(errorText);
                config = null;
            }

            if (config == null || config.characters == null || config.characters.Count == 0)
            {
                errorText = "Character config is empty.";
                Debug.LogError(errorText);
                config = null;
            }
        }

        private void EnsureRoot()
        {
            if (characterRoot != null)
            {
                return;
            }

            GameObject rootObject = GameObject.Find("CharacterRoot");
            if (rootObject == null)
            {
                rootObject = new GameObject("CharacterRoot");
            }

            characterRoot = rootObject.transform;
            if (characterRoot.parent != transform)
            {
                characterRoot.SetParent(transform, true);
            }
        }

        private void LoadInitialSelection()
        {
            if (config == null)
            {
                return;
            }

            string selectedId = PlayerPrefs.GetString(SelectedCharacterKey, string.Empty);
            CharacterConfigItem item = config.Find(selectedId) ?? config.GetDefault();
            if (item != null)
            {
                currentConfig = item;
                PlayerPrefs.SetString(SelectedCharacterKey, item.id);
                PlayerPrefs.Save();
            }
        }

        private void SwitchTo(CharacterConfigItem item)
        {
            if (currentCharacter != null)
            {
                Destroy(currentCharacter);
                currentCharacter = null;
            }

            currentConfig = item;
            errorText = string.Empty;

            PlayerPrefs.SetString(SelectedCharacterKey, item.id);
            PlayerPrefs.Save();
            RefreshLobbyAvatar();
        }

        private void RefreshLobbyAvatar()
        {
            LobbyWorldController lobby = FindObjectOfType<LobbyWorldController>();
            if (lobby != null)
            {
                lobby.RefreshSelectedFigure();
            }
        }

        // ---------------- UGUI ----------------

        // 异步加载 UI 预设：按需从 CDN 下载，避免同步加载读到旧 APK 底包。
        private IEnumerator LoadUIAsync()
        {
            string prefabPath = PrefabPath;
            if (prefabPath.StartsWith("Assets/"))
            {
                prefabPath = prefabPath.Substring(7);
            }

            UObject asset = null;
            yield return XResLoader.coLoadRes(prefabPath, typeof(GameObject), o => asset = o);
            GameObject prefab = asset as GameObject;
            if (prefab == null)
            {
                Debug.LogError("Load UI_CharacterSwitch failed: " + PrefabPath);
                yield break;
            }

            uiPanel = Instantiate(prefab);
            // 角色切换是普通功能界面 → 挂到 UIRoot/Normal 层（见 UI 挂载规则）
            UIManager.AttachTo(UILayer.Normal, uiPanel);

            CacheUI();
            BuildCharacterButtons();
        }

        private void CacheUI()
        {
            if (uiPanel == null)
            {
                return;
            }

            Transform sel = uiPanel.transform.FindTransform("Panel_Select");
            selectPanel = sel == null ? null : sel.gameObject;
            listChars = uiPanel.transform.FindTransform("List_Chars");
            Transform item = uiPanel.transform.FindTransform("Item_Char");
            itemTemplate = item == null ? null : item.gameObject;
            Transform err = uiPanel.transform.FindTransform("Txt_Error");
            errorLabel = err == null ? null : err.GetComponent<TMP_Text>();
            Transform tog = uiPanel.transform.FindTransform("Txt_Toggle");
            toggleLabel = tog == null ? null : tog.GetComponent<TMP_Text>();

            Transform toggleBtn = uiPanel.transform.FindTransform("Btn_Toggle");
            if (toggleBtn != null)
            {
                Button b = toggleBtn.GetComponent<Button>();
                if (b != null)
                {
                    b.onClick.RemoveListener(OnToggleClicked);
                    b.onClick.AddListener(OnToggleClicked);
                }
            }

            if (selectPanel != null)
            {
                selectPanel.SetActive(false);
            }
            UpdateToggleLabel();
        }

        private void BuildCharacterButtons()
        {
            itemButtons.Clear();
            itemIds.Clear();
            if (itemTemplate == null || listChars == null || config == null || config.characters == null)
            {
                return;
            }

            for (int i = 0; i < config.characters.Count; i++)
            {
                CharacterConfigItem item = config.characters[i];
                if (item == null)
                {
                    continue;
                }

                GameObject row = Instantiate(itemTemplate, listChars);
                row.name = "Item_Char_" + item.id;
                row.SetActive(true);

                Transform label = row.transform.FindTransform("Txt_Char");
                if (label != null)
                {
                    TMP_Text t = label.GetComponent<TMP_Text>();
                    if (t != null)
                    {
                        t.text = string.IsNullOrEmpty(item.displayName) ? item.id : item.displayName;
                    }
                }

                Button btn = row.GetComponent<Button>();
                if (btn != null)
                {
                    string captured = item.id;
                    btn.onClick.RemoveAllListeners();
                    btn.onClick.AddListener(() => OnCharClicked(captured));
                    itemButtons.Add(btn);
                    itemIds.Add(item.id);
                }
            }

            RefreshSelection();
            RefreshError();
        }

        private void OnToggleClicked()
        {
            if (selectPanel == null)
            {
                return;
            }
            selectPanel.SetActive(!selectPanel.activeSelf);
        }

        private void OnCharClicked(string characterId)
        {
            SwitchTo(characterId);
            RefreshSelection();
            RefreshError();
            UpdateToggleLabel();
            if (selectPanel != null)
            {
                selectPanel.SetActive(false);
            }
        }

        // 高亮当前选中项（当前项绿色加粗，其余白色）
        private void RefreshSelection()
        {
            for (int i = 0; i < itemButtons.Count; i++)
            {
                Button btn = itemButtons[i];
                if (btn == null)
                {
                    continue;
                }
                bool selected = currentConfig != null && currentConfig.id == itemIds[i];
                TMP_Text t = btn.GetComponentInChildren<TMP_Text>(true);
                if (t != null)
                {
                    t.color = selected ? new Color(0.34f, 0.84f, 0.55f, 1f) : new Color(0.96f, 0.97f, 1f, 1f);
                    t.fontStyle = selected ? FontStyles.Bold : FontStyles.Normal;
                }
            }
        }

        private void RefreshError()
        {
            if (errorLabel == null)
            {
                return;
            }
            errorLabel.text = errorText ?? string.Empty;
            errorLabel.gameObject.SetActive(!string.IsNullOrEmpty(errorText));
        }

        private void UpdateToggleLabel()
        {
            if (toggleLabel == null)
            {
                return;
            }
            toggleLabel.text = string.IsNullOrEmpty(CurrentCharacterId) ? "角色" : "角色: " + CurrentCharacterId;
        }
    }
}