using UnityEngine;
using UnityEditor;
using UnityEngine.Rendering;
using BadDog.Rendering.AreaLight;

namespace BadDog.Rendering.AreaLight.Editor
{
    [CustomEditor(typeof(BGAreaLight))]
    [CanEditMultipleObjects]
    public class BGAreaLightEditor : UnityEditor.Editor
    {
        private SerializedProperty m_CastShadows;
        private SerializedProperty m_UseCustomShadow;
        private SerializedProperty m_CustomShadowResolution;
        private SerializedProperty m_ShadowCone;
        private SerializedProperty m_ShadowStrength;
        private SerializedProperty m_ShadowNormalBias;
        private SerializedProperty m_ShadowDepthBias;
        private SerializedProperty m_ShadowNearPlane;
        private SerializedProperty m_RenderingLayerMask;

        private void OnEnable()
        {
            m_CastShadows = serializedObject.FindProperty("m_CastShadows");
            m_UseCustomShadow = serializedObject.FindProperty("m_UseCustomShadow");
            m_CustomShadowResolution = serializedObject.FindProperty("m_CustomShadowResolution");
            m_ShadowCone = serializedObject.FindProperty("m_ShadowCone");
            m_ShadowStrength = serializedObject.FindProperty("m_ShadowStrength");
            m_ShadowNormalBias = serializedObject.FindProperty("m_ShadowNormalBias");
            m_ShadowDepthBias = serializedObject.FindProperty("m_ShadowDepthBias");
            m_ShadowNearPlane = serializedObject.FindProperty("m_ShadowNearPlane");
            m_RenderingLayerMask = serializedObject.FindProperty("m_RenderingLayerMask");
        }

        public override void OnInspectorGUI()
        {
            serializedObject.Update();

            // Cast Shadows toggle
            EditorGUILayout.PropertyField(m_CastShadows, new GUIContent("Cast Shadows", "Enable shadow casting for this area light."));

            EditorGUILayout.Space();

            // Disable all shadow settings if Cast Shadows is off
            EditorGUI.BeginDisabledGroup(!m_CastShadows.boolValue);

            EditorGUILayout.PropertyField(m_UseCustomShadow, new GUIContent("Custom Shadow", "Enable custom shadow settings for this area light."));

            EditorGUILayout.Space();

            EditorGUI.indentLevel++;

            if (!m_UseCustomShadow.boolValue)
            {
                m_CustomShadowResolution.intValue = 0;
                m_ShadowCone.floatValue = AreaShadowUtils.k_DefaultAreaLightShadowCone;
                m_ShadowStrength.floatValue = 1f;
                m_ShadowNormalBias.floatValue = 0.0f;
                m_ShadowDepthBias.floatValue = 0.05f;
                m_ShadowNearPlane.floatValue = 0.05f;
            }

            EditorGUI.BeginDisabledGroup(!m_UseCustomShadow.boolValue);
            EditorGUILayout.PropertyField(m_CustomShadowResolution);
            EditorGUILayout.PropertyField(m_ShadowCone);
            EditorGUILayout.PropertyField(m_ShadowStrength);
            EditorGUILayout.PropertyField(m_ShadowNormalBias);
            EditorGUILayout.PropertyField(m_ShadowDepthBias);
            EditorGUILayout.PropertyField(m_ShadowNearPlane);
            EditorGUI.EndDisabledGroup();

            EditorGUI.indentLevel--;

            EditorGUI.EndDisabledGroup(); // End Cast Shadows disabled group

            EditorGUILayout.Space();
            DrawRenderingLayersField();

            serializedObject.ApplyModifiedProperties();
        }

        private void DrawRenderingLayersField()
        {
            EditorGUI.showMixedValue = m_RenderingLayerMask.hasMultipleDifferentValues;
            EditorGUI.BeginChangeCheck();
            uint mask = m_RenderingLayerMask.uintValue;
            mask = EditorGUILayout.RenderingLayerMaskField(
                new GUIContent("Rendering Layers", "Rendering Layer Mask used for area light lighting/shadow filtering."),
                mask);
            if (EditorGUI.EndChangeCheck())
            {
                m_RenderingLayerMask.uintValue = mask;
            }
            EditorGUI.showMixedValue = false;
        }
    }
}