// Unity C# reference source
// Copyright (c) Unity Technologies. For terms of use, see
// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using System;
using System.Collections.Generic;
using UnityEngine.Bindings;
using UnityEngine.Rendering;
using UnityEngine.Scripting;

namespace UnityEngine
{
    // List of changes done to the terrain for OnTerrainChanged
    // OnTerrainChanged is called with a bitfield of these items telling it what was changed.
    [Flags]
    public enum TerrainChangedFlags
    {
        Heightmap = 1,
        TreeInstances = 2,
        DelayedHeightmapUpdate = 4,
        FlushEverythingImmediately = 8,
        RemoveDirtyDetailsImmediately = 16,
        WillBeDestroyed = 256,
    }

    [Flags]
    public enum TerrainRenderFlags
    {
        [Obsolete("TerrainRenderFlags.heightmap is obsolete, use TerrainRenderFlags.Heightmap instead. (UnityUpgradable) -> Heightmap")]
        heightmap = 1,

        [Obsolete("TerrainRenderFlags.trees is obsolete, use TerrainRenderFlags.Trees instead. (UnityUpgradable) -> Trees")]
        trees = 2,

        [Obsolete("TerrainRenderFlags.details is obsolete, use TerrainRenderFlags.Details instead. (UnityUpgradable) -> Details")]
        details = 4,

        [Obsolete("TerrainRenderFlags.all is obsolete, use TerrainRenderFlags.All instead. (UnityUpgradable) -> All")]
        all = All,

        Heightmap = 1,
        Trees = 2,
        Details = 4,
        All = Heightmap | Trees | Details
    }

    [UsedByNativeCode]
    [NativeHeader("Modules/Terrain/Public/Terrain.h")]
    [NativeHeader("Runtime/Interfaces/ITerrainManager.h")]
    [NativeHeader("TerrainScriptingClasses.h")]
    [StaticAccessor("GetITerrainManager()", StaticAccessorType.Arrow)]
    public sealed partial class Terrain : Behaviour
    {
        public enum MaterialType
        {
            BuiltInStandard = 0,
            BuiltInLegacyDiffuse,
            BuiltInLegacySpecular,
            Custom
        }

        extern public TerrainData terrainData { get; set; }

        extern public float treeDistance { get; set; }

        extern public float treeBillboardDistance { get; set; }

        extern public float treeCrossFadeLength { get; set; }

        extern public int treeMaximumFullLODCount { get; set; }

        extern public float detailObjectDistance { get; set; }

        extern public float detailObjectDensity { get; set; }

        extern public float heightmapPixelError { get; set; }

        extern public int heightmapMaximumLOD { get; set; }

        extern public float basemapDistance { get; set; }

        [Obsolete("splatmapDistance is deprecated, please use basemapDistance instead. (UnityUpgradable) -> basemapDistance", true)]
        public float splatmapDistance
        {
            get { return basemapDistance; }
            set { basemapDistance = value; }
        }

        [NativeProperty("StaticLightmapIndexInt")]
        extern public int lightmapIndex { get; set; }

        [NativeProperty("DynamicLightmapIndexInt")]
        extern public int realtimeLightmapIndex { get; set; }

        [NativeProperty("StaticLightmapST")]
        extern public Vector4 lightmapScaleOffset { get; set; }

        [NativeProperty("DynamicLightmapST")]
        extern public Vector4 realtimeLightmapScaleOffset { get; set; }

        [NativeProperty("GarbageCollectRenderers")]
        extern public bool freeUnusedRenderingResources { get; set; }

        extern public bool castShadows { get; set; }

        extern public ReflectionProbeUsage reflectionProbeUsage { get; set; }

        extern public void GetClosestReflectionProbes(List<ReflectionProbeBlendInfo> result);

        extern public Terrain.MaterialType materialType { get; set; }

        extern public Material materialTemplate { get; set; }

        extern public Color legacySpecular { get; set; }

        extern public float legacyShininess { get; set; }

        extern public bool drawHeightmap { get; set; }

        extern public bool drawTreesAndFoliage { get; set; }

        extern public Vector3 patchBoundsMultiplier { get; set; }

        extern public float SampleHeight(Vector3 worldPosition);

        extern public void ApplyDelayedHeightmapModification();

        extern public void AddTreeInstance(TreeInstance instance);

        extern public void SetNeighbors(Terrain left, Terrain top, Terrain right, Terrain bottom);

        extern public float treeLODBiasMultiplier { get; set; }

        extern public bool collectDetailPatches { get; set; }

        extern public TerrainRenderFlags editorRenderFlags { get; set; }

        extern public Vector3 GetPosition();

        extern public void Flush();

        extern internal void RemoveTrees(Vector2 position, float radius, int prototypeIndex);

        [NativeMethod("CopySplatMaterialCustomProps")]
        extern public void SetSplatMaterialPropertyBlock(MaterialPropertyBlock properties);

        public void GetSplatMaterialPropertyBlock(MaterialPropertyBlock dest)
        {
            if (dest == null)
                throw new ArgumentNullException("dest");

            Internal_GetSplatMaterialPropertyBlock(dest);
        }

        [NativeMethod("GetSplatMaterialCustomProps")]
        extern private void Internal_GetSplatMaterialPropertyBlock(MaterialPropertyBlock dest);

        extern public bool bakeLightProbesForTrees { get; set; }

        extern public static Terrain activeTerrain { get; }

        [NativeProperty("ActiveTerrainsScriptingArray")]
        extern public static Terrain[] activeTerrains { get; }

        [UsedByNativeCode]
        extern public static GameObject CreateTerrainGameObject(TerrainData assignTerrain);
    }

    public static partial class TerrainExtensions
    {
        public static void UpdateGIMaterials(this Terrain terrain)
        {
            if (terrain.terrainData == null)
                throw new ArgumentException("Invalid terrainData.");

            UpdateGIMaterialsForTerrain(terrain.GetInstanceID(), new Rect(0, 0, 1, 1));
        }

        public static void UpdateGIMaterials(this Terrain terrain, int x, int y, int width, int height)
        {
            if (terrain.terrainData == null)
                throw new ArgumentException("Invalid terrainData.");

            float alphamapWidth = terrain.terrainData.alphamapWidth;
            float alphamapHeight = terrain.terrainData.alphamapHeight;
            UpdateGIMaterialsForTerrain(terrain.GetInstanceID(), new Rect(x / alphamapWidth, y / alphamapHeight, width / alphamapWidth, height / alphamapHeight));
        }

        [FreeFunction]
        [NativeConditional("INCLUDE_DYNAMIC_GI && ENABLE_RUNTIME_GI")]
        extern internal static void UpdateGIMaterialsForTerrain(int terrainInstanceID, Rect uvBounds);
    }

    [NativeHeader("Modules/Terrain/Public/Tree.h")]
    public sealed partial class Tree : Component
    {
        [NativeProperty("TreeData")]
        extern public ScriptableObject data { get; set; }

        extern public bool hasSpeedTreeWind
        {
            [NativeMethod("HasSpeedTreeWind")]
            get;
        }
    }

    // This class has no public scripting API. It is only here so that adding UnityEngine.SpeedTreeWindAsset to
    // link.xml will actually whitelist it from being stripped, which requires the class name to exist in managed land (case 773309)
    internal sealed partial class SpeedTreeWindAsset : Object
    {
        private SpeedTreeWindAsset() {}
    }
}
