using System;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

namespace BaseGames.Editor
{
    /// <summary>
    /// 详情区顶部标题行：显示资产名称，双击或按 ✏ 进入行内重命名。
    /// </summary>
    public class DetailHeader : VisualElement
    {
        // ── 事件 ─────────────────────────────────────────────────────────────
        /// <summary>用户确认重命名时触发，参数为新名称字符串。</summary>
        public event Action<string> RenameRequested;

        // ── 私有字段 ──────────────────────────────────────────────────────────
        private Label     _nameLabel;
        private TextField _renameField;
        private bool      _renaming;

        // ── 构造 ─────────────────────────────────────────────────────────────

        public DetailHeader()
        {
            style.flexDirection     = FlexDirection.Row;
            style.alignItems        = Align.Center;
            style.paddingLeft       = 12;
            style.paddingRight      = 8;
            style.paddingTop        = 10;
            style.paddingBottom     = 10;
            style.borderBottomWidth = 1;
            style.borderBottomColor = new StyleColor(new Color(0.5f, 0.5f, 0.5f, 0.2f));

            // 名称 Label
            _nameLabel = new Label("(未选中)");
            _nameLabel.style.flexGrow             = 1;
            _nameLabel.style.fontSize             = 15;
            _nameLabel.style.unityFontStyleAndWeight = FontStyle.Bold;
            _nameLabel.RegisterCallback<MouseDownEvent>(e =>
            {
                if (e.clickCount == 2) BeginRename();
            });
            Add(_nameLabel);

            // 重命名输入框（默认隐藏）
            _renameField = new TextField();
            _renameField.style.flexGrow  = 1;
            _renameField.style.fontSize  = 15;
            _renameField.style.display   = DisplayStyle.None;
            _renameField.RegisterCallback<KeyDownEvent>(e =>
            {
                if (e.keyCode == KeyCode.Return || e.keyCode == KeyCode.KeypadEnter)
                {
                    e.StopPropagation();
                    CommitRename();
                }
                else if (e.keyCode == KeyCode.Escape)
                {
                    e.StopPropagation();
                    CancelRename();
                }
            });
            _renameField.RegisterCallback<FocusOutEvent>(_ => CommitRename());
            Add(_renameField);

            // 编辑按钮
            var btnEdit = new Button(BeginRename) { text = "✏", tooltip = "重命名（双击名称也可触发）" };
            btnEdit.style.width          = 24;
            btnEdit.style.height         = 24;
            btnEdit.style.marginLeft     = 6;
            btnEdit.style.paddingLeft    = 0;
            btnEdit.style.paddingRight   = 0;
            btnEdit.style.fontSize       = 13;
            Add(btnEdit);
        }

        // ── 公共 API ──────────────────────────────────────────────────────────

        /// <summary>绑定新资产，更新标题显示。</summary>
        public void SetAsset(UnityEngine.Object asset)
        {
            CancelRename();
            _nameLabel.text = asset != null ? asset.name : "(未选中)";
        }

        // ── 内部逻辑 ──────────────────────────────────────────────────────────

        private void BeginRename()
        {
            if (_renaming) return;
            _renaming = true;
            _renameField.value           = _nameLabel.text;
            _nameLabel.style.display     = DisplayStyle.None;
            _renameField.style.display   = DisplayStyle.Flex;
            schedule.Execute(() =>
            {
                _renameField.Focus();
                _renameField.SelectAll();
            });
        }

        private void CommitRename()
        {
            if (!_renaming) return;
            _renaming = false;
            _nameLabel.style.display   = DisplayStyle.Flex;
            _renameField.style.display = DisplayStyle.None;

            var newName = _renameField.value.Trim();
            if (!string.IsNullOrEmpty(newName) && newName != _nameLabel.text)
                RenameRequested?.Invoke(newName);
        }

        private void CancelRename()
        {
            if (!_renaming) return;
            _renaming = false;
            _nameLabel.style.display   = DisplayStyle.Flex;
            _renameField.style.display = DisplayStyle.None;
        }
    }
}