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

namespace Ironspore
{
    public sealed class WorldLighting : MonoBehaviour
    {
        readonly List<Light> fixtures = new List<Light>(2);
        WorldLightingProfile profile;
        Material sky;
        ReflectionProbe environment;
        Camera observer;
        bool ownsProfile;
        int shadowBudget;
        bool captureQueued, capturing;
        float captureAfter;
        public bool ReflectionReady { get; private set; }

        public void Initialize(WorldLightingProfile settings, bool hangar)
        {
            profile = settings;
            if (!profile)
            {
                profile = ScriptableObject.CreateInstance<WorldLightingProfile>();
                ownsProfile = true;
            }
            int level = QualitySettings.GetQualityLevel();
            shadowBudget = level <= 1 ? 0 : level >= 4 ? 2 : 1;
            RenderSettings.ambientMode = AmbientMode.Trilight;
            RenderSettings.ambientSkyColor = profile.ambientSky;
            RenderSettings.ambientEquatorColor = profile.ambientEquator;
            RenderSettings.ambientGroundColor = profile.ambientGround;
            RenderSettings.fog = !hangar;
            RenderSettings.fogMode = FogMode.Linear;
            RenderSettings.fogColor = profile.fogColor;
            RenderSettings.fogStartDistance = profile.fogStart;
            RenderSettings.fogEndDistance = profile.fogEnd;
            RenderSettings.reflectionIntensity = profile.reflectionIntensity;
            var sourceSky = RenderSettings.skybox;
            sky = sourceSky ? new Material(sourceSky) : new Material(Shader.Find("Skybox/Procedural"));
            sky.name = "RuntimeDaySky";
            if (sky.HasProperty("_Exposure")) sky.SetFloat("_Exposure", profile.skyExposure);
            RenderSettings.skybox = sky;
            var sunObject = new GameObject("Sun");
            sunObject.transform.SetParent(transform, false);
            sunObject.transform.rotation = Quaternion.Euler(profile.sunEuler);
            var sun = sunObject.AddComponent<Light>();
            sun.type = LightType.Directional;
            sun.color = profile.sunColor;
            sun.intensity = hangar ? profile.hangarSunIntensity : profile.sunIntensity;
            sun.renderMode = LightRenderMode.ForcePixel;
            sun.shadows = level <= 1 ? LightShadows.Hard : LightShadows.Soft;
            sun.shadowStrength = 1;
            sun.shadowBias = profile.bias;
            sun.shadowNormalBias = profile.normalBias;
            sun.shadowNearPlane = profile.shadowNearPlane;
            sun.shadowCustomResolution = level <= 1 ? 1024 : level >= 4 ? 4096 : 2048;
            RenderSettings.sun = sun;
        }

        public void CompleteEnvironment(Camera camera, bool hangar)
        {
            observer = camera;
            if (hangar)
            {
                WorldFactory.Box("HangarWorkFixture", new Vector3(2, 8.2f, 1), new Vector3(2, .18f, .65f), new Color(.8f, .87f, 1), transform, false, true);
                AddSpot("HangarWorkLight", new Vector3(2, 8, 1), new Vector3(2, 1, 2), new Color(.82f, .9f, 1), profile.hangarIntensity, 17, 84);
            }
            else
            {
                WorldFactory.Box("NavigationWorkFixture", new Vector3(0, 3.4f, 22.7f), new Vector3(1.2f, .16f, .4f), new Color(.55f, 1, .85f), transform, false, true);
                AddSpot("NavigationWorkLight", new Vector3(0, 3.25f, 22.3f), new Vector3(0, 0, 20.6f), new Color(.65f, 1, .85f), profile.navigationIntensity, 11, 78);
                WorldFactory.Box("ExtractionLampPost", new Vector3(-22.4f, 3.1f, -8), new Vector3(.16f, 6.2f, .16f), new Color(.2f, .25f, .28f), transform, false);
                WorldFactory.Box("ExtractionLampArm", new Vector3(-20.7f, 6.1f, -8), new Vector3(3.5f, .15f, .18f), new Color(.2f, .25f, .28f), transform, false);
                WorldFactory.Box("ExtractionWorkFixture", new Vector3(-19, 6, -8), new Vector3(1, .18f, .6f), new Color(1, .77f, .45f), transform, false, true);
                AddSpot("ExtractionWorkLight", new Vector3(-19, 5.8f, -8), new Vector3(-19, 0, -8), new Color(1, .8f, .55f), profile.extractionIntensity, 13, 76);
            }
            var probeObject = new GameObject("EnvironmentReflection");
            probeObject.transform.SetParent(transform, false);
            probeObject.transform.position = hangar ? new Vector3(2, 3, 2) : new Vector3(0, 3, 8);
            environment = probeObject.AddComponent<ReflectionProbe>();
            environment.mode = ReflectionProbeMode.Realtime;
            environment.refreshMode = ReflectionProbeRefreshMode.ViaScripting;
            environment.timeSlicingMode = ReflectionProbeTimeSlicingMode.IndividualFaces;
            environment.resolution = QualitySettings.GetQualityLevel() >= 4 ? 256 : 128;
            environment.hdr = true;
            environment.boxProjection = true;
            environment.blendDistance = 5;
            environment.size = hangar ? new Vector3(66, 18, 45) : new Vector3(74, 20, 104);
            // The captured environment must not freeze actors, transient props or world labels.
            environment.cullingMask = ~((1 << 8) | (1 << 9) | (1 << 10) | (1 << 11));
            environment.nearClipPlane = .2f;
            environment.farClipPlane = 150;
            environment.intensity = profile.reflectionIntensity;
            SelectLights();
            StartCoroutine(CaptureEnvironment());
        }

        void AddSpot(string name, Vector3 position, Vector3 target, Color color, float intensity, float range, float angle)
        {
            var obj = new GameObject(name);
            obj.transform.SetParent(transform, false);
            obj.transform.position = position;
            obj.transform.LookAt(target);
            var light = obj.AddComponent<Light>();
            light.type = LightType.Spot;
            light.renderMode = LightRenderMode.ForcePixel;
            light.color = color;
            light.intensity = intensity;
            light.range = range;
            light.spotAngle = angle;
            light.innerSpotAngle = angle * .65f;
            light.shadows = LightShadows.Soft;
            light.shadowCustomResolution = 1024;
            light.shadowBias = profile.bias;
            light.shadowNormalBias = profile.normalBias;
            light.shadowNearPlane = profile.shadowNearPlane;
            light.enabled = false;
            fixtures.Add(light);
        }

        void LateUpdate()
        {
            SelectLights();
            if (environment && captureQueued && !capturing && Time.unscaledTime >= captureAfter)
                StartCoroutine(CaptureEnvironment());
        }

        void SelectLights()
        {
            if (!observer)
                return;
            Vector3 position = observer.transform.position;
            float limit = profile.localLightCullDistance * profile.localLightCullDistance;
            Light nearest = null;
            float distance = limit;
            foreach (var light in fixtures)
            {
                float candidate = (light.transform.position - position).sqrMagnitude;
                if (candidate < distance) { distance = candidate; nearest = light; }
            }
            foreach (var light in fixtures)
            {
                bool active = shadowBudget > 0 && (light == nearest || shadowBudget > 1 && (light.transform.position - position).sqrMagnitude < limit);
                if (light.enabled == active)
                    continue;
                light.enabled = active;
                captureQueued = true;
            }
        }

        IEnumerator CaptureEnvironment()
        {
            capturing = true;
            captureQueued = false;
            yield return null;
            DynamicGI.UpdateEnvironment();
            int render = environment.RenderProbe();
            while (environment && !environment.IsFinishedRendering(render))
                yield return null;
            ReflectionReady = environment != null;
            capturing = false;
            captureAfter = Time.unscaledTime + 8;
        }

        void OnDestroy()
        {
            if (sky)
            {
                if (RenderSettings.skybox == sky) RenderSettings.skybox = null;
                Destroy(sky);
            }
            if (ownsProfile && profile) Destroy(profile);
        }
    }
}