using UnityEditor;
using UnityEngine;

namespace Dialogue.Editor
{
    /// <summary>
    /// Custom property drawer for DialogueContent that displays either text or image fields based on content type
    /// </summary>
    [CustomPropertyDrawer(typeof(DialogueContent))]
    public class DialogueContentDrawer : PropertyDrawer
    {
        // Height constants
        private const float TypeSelectorHeight = 20f;
        private const float PropertySpacing = 2f;
        private const float TextFieldHeight = 40f; // Taller for multi-line text
        private const float ImageFieldHeight = 18f;
        private const float PreviewHeight = 64f;
        
        public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
        {
            var contentTypeProperty = property.FindPropertyRelative("_contentType");
            var height = TypeSelectorHeight + PropertySpacing;
            
            // Add height based on content type
            if (contentTypeProperty.enumValueIndex == (int)DialogueContentType.Text)
            {
                height += TextFieldHeight;
            }
            else // Image
            {
                height += ImageFieldHeight;
                
                // Add preview height if an image is assigned
                var imageProperty = property.FindPropertyRelative("_image");
                if (imageProperty.objectReferenceValue != null)
                {
                    height += PropertySpacing + PreviewHeight;
                }
            }
            
            return height;
        }
        
        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
        {
            EditorGUI.BeginProperty(position, label, property);
            
            // Create a property field and indent it
            var contentRect = EditorGUI.PrefixLabel(position, GUIUtility.GetControlID(FocusType.Passive), label);
            var indent = EditorGUI.indentLevel;
            EditorGUI.indentLevel = 0;
            
            // Get properties
            var contentTypeProperty = property.FindPropertyRelative("_contentType");
            var textProperty = property.FindPropertyRelative("_text");
            var imageProperty = property.FindPropertyRelative("_image");
            
            // Calculate rects
            var typeRect = new Rect(contentRect.x, contentRect.y, contentRect.width, TypeSelectorHeight);
            var contentFieldRect = new Rect(
                contentRect.x, 
                contentRect.y + TypeSelectorHeight + PropertySpacing,
                contentRect.width, 
                contentTypeProperty.enumValueIndex == (int)DialogueContentType.Text ? TextFieldHeight : ImageFieldHeight);
            
            // Draw the content type dropdown
            EditorGUI.PropertyField(typeRect, contentTypeProperty, GUIContent.none);
            
            // Draw the appropriate field based on content type
            if (contentTypeProperty.enumValueIndex == (int)DialogueContentType.Text)
            {
                // Create a custom style with word wrap enabled
                GUIStyle wordWrapStyle = new GUIStyle(EditorStyles.textArea);
                wordWrapStyle.wordWrap = true;
                
                // Text field with word wrap for multi-line input
                textProperty.stringValue = EditorGUI.TextArea(contentFieldRect, textProperty.stringValue, wordWrapStyle);
            }
            else // Image
            {
                // Draw the image field
                EditorGUI.PropertyField(contentFieldRect, imageProperty, GUIContent.none);
                
                // Draw a preview if an image is assigned
                if (imageProperty.objectReferenceValue != null)
                {
                    var sprite = imageProperty.objectReferenceValue as Sprite;
                    if (sprite != null)
                    {
                        var previewRect = new Rect(
                            contentRect.x, 
                            contentFieldRect.y + contentFieldRect.height + PropertySpacing,
                            contentRect.width, 
                            PreviewHeight);
                        
                        // Draw the preview with preserved aspect ratio
                        DrawSpritePreview(previewRect, sprite);
                    }
                }
            }
            
            EditorGUI.indentLevel = indent;
            EditorGUI.EndProperty();
        }
        
        private void DrawSpritePreview(Rect position, Sprite sprite)
        {
            if (sprite == null || sprite.texture == null) return;
            
            // Calculate aspect-preserved rect
            float aspectRatio = sprite.rect.width / sprite.rect.height;
            float targetWidth = Mathf.Min(position.width, position.height * aspectRatio);
            float targetHeight = targetWidth / aspectRatio;
            
            // Center the preview
            Rect previewRect = new Rect(
                position.x + (position.width - targetWidth) * 0.5f,
                position.y + (position.height - targetHeight) * 0.5f,
                targetWidth,
                targetHeight
            );
            
            // Draw the sprite preview
            EditorGUI.DrawPreviewTexture(previewRect, sprite.texture, null, ScaleMode.ScaleToFit);
            
            // Draw a border around the preview
            GUI.Box(previewRect, GUIContent.none);
        }
    }
}