#if UNITY_EDITOR

using UnityEditor;
using UnityEngine;

namespace GraphicsCat
{
    [CustomPropertyDrawer(typeof(LabelAttribute))]
    public class LabelDrawer : PropertyDrawer
    {
        private const float Spacing = 2f;

        public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
        {
            float h0 = EditorGUIUtility.singleLineHeight;
            float h1 = EditorGUI.GetPropertyHeight(property, label, true);
            return h0 + Spacing + h1;
        }

        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
        {
            var attr = (LabelAttribute)attribute;

            GUIStyle style = ResolveStyle(attr.Style);

            Rect labelRect = new Rect(
                position.x,
                position.y,
                position.width,
                EditorGUIUtility.singleLineHeight
            );

            EditorGUI.LabelField(labelRect, attr.Text, style);

            Rect fieldRect = new Rect(
                position.x,
                position.y + EditorGUIUtility.singleLineHeight + Spacing,
                position.width,
                EditorGUI.GetPropertyHeight(property, label, true)
            );

            EditorGUI.PropertyField(fieldRect, property, label, true);
        }

        private GUIStyle ResolveStyle(LabelStyle style)
        {
            switch (style)
            {
                case LabelStyle.Bold:
                    return EditorStyles.boldLabel;
                case LabelStyle.Italic:
                    return EditorStyles.label.WithFontStyle(FontStyle.Italic);
                case LabelStyle.BoldItalic:
                    return EditorStyles.label.WithFontStyle(FontStyle.BoldAndItalic);
                default:
                    return EditorStyles.label;
            }
        }
    }

    internal static class GUIStyleExtensions
    {
        public static GUIStyle WithFontStyle(this GUIStyle style, FontStyle fontStyle)
        {
            GUIStyle s = new GUIStyle(style);
            s.fontStyle = fontStyle;
            return s;
        }
    }
}

#endif