using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using TMPro;

public class PlanetSelector : MonoBehaviour
{
    [SerializeField] private Material skyboxMaterial;
    [SerializeField] private TextMeshProUGUI planetNameText;
    [SerializeField] private Button leftButton;
    [SerializeField] private Button rightButton;
    [SerializeField] private Light sunLight;
    [SerializeField] private ParticleSystem atmosphereParticles;
    [SerializeField] private ParticleSystem starsParticles;

    private int _currentIndex = 0;
    private Coroutine _transitionCoroutine;
    private PlanetData[] _planets;

    public struct PlanetData
    {
        public string name;
        public float gravity;
        public float atmosphereDensity;
        public Color skyTint;
        public Color groundColor;
        public float atmosphereThickness;
        public float sunSize;
        public float exposure;
        public Color sunLightColor;
        public float sunLightIntensity;
        public bool hasFog;
        public float fogDensity;
        public Color fogColor;
        public Color atmosParticleColor;
        public float atmosParticleRate;
        public Color starsColor;
        public float starsRate;
        public float starsSize;
    }

    private static Color H(string hex)
    {
        ColorUtility.TryParseHtmlString(hex, out Color c);
        return c;
    }

    private void Awake()
    {
        _planets = new PlanetData[]
        {
            new PlanetData {
                name = "Земля",
                gravity = 9.8f, atmosphereDensity = 1.0f,
                skyTint = H("#3A7BD5"),
                groundColor = H("#1A3A0A"),
                atmosphereThickness = 1.0f, sunSize = 0.04f, exposure = 1.3f,
                sunLightColor = H("#FFF8DC"),
                sunLightIntensity = 1.2f,
                hasFog = true, fogDensity = 0.0008f,
                fogColor = H("#B0CCEE"),
                atmosParticleColor = new Color(0.70f, 0.85f, 1.0f, 0.45f),
                atmosParticleRate = 80f,
                starsColor = new Color(0.95f, 0.97f, 1.0f, 0.55f),
                starsRate = 60f, starsSize = 0.035f
            },
            new PlanetData {
                name = "Марс",
                gravity = 3.7f, atmosphereDensity = 0.01f,
                skyTint = H("#C99A72"),
                groundColor = H("#6B3A1A"),
                atmosphereThickness = 0.12f, sunSize = 0.028f, exposure = 0.90f,
                sunLightColor = H("#FFD4A0"),
                sunLightIntensity = 0.95f,
                hasFog = true, fogDensity = 0.003f,
                fogColor = H("#D4A87A"),
                atmosParticleColor = new Color(0.78f, 0.55f, 0.32f, 0.65f),
                atmosParticleRate = 120f,
                starsColor = new Color(1.0f, 0.90f, 0.75f, 0.40f),
                starsRate = 30f, starsSize = 0.025f
            },
            new PlanetData {
                name = "Місяць",
                gravity = 1.6f, atmosphereDensity = 0f,
                skyTint = H("#000008"),
                groundColor = H("#323030"),
                atmosphereThickness = 0f, sunSize = 0.042f, exposure = 1.7f,
                sunLightColor = H("#FFFFFF"),
                sunLightIntensity = 1.9f,
                hasFog = false, fogDensity = 0f, fogColor = Color.black,
                atmosParticleColor = new Color(0f, 0f, 0f, 0f),
                atmosParticleRate = 0f,
                starsColor = new Color(1.0f, 1.0f, 1.0f, 1.0f),
                starsRate = 580f, starsSize = 0.065f
            },
            new PlanetData {
                name = "Венера",
                gravity = 8.87f, atmosphereDensity = 90f,
                skyTint = H("#D4922A"),
                groundColor = H("#6B3A08"),
                atmosphereThickness = 3.2f, sunSize = 0.09f, exposure = 1.0f,
                sunLightColor = H("#FF9B20"),
                sunLightIntensity = 1.1f,
                hasFog = true, fogDensity = 0.008f,
                fogColor = H("#C8842A"),
                atmosParticleColor = new Color(0.90f, 0.65f, 0.20f, 0.75f),
                atmosParticleRate = 200f,
                starsColor = new Color(1.0f, 0.85f, 0.50f, 0.05f),
                starsRate = 2f, starsSize = 0.015f
            },
            new PlanetData {
                name = "Юпітер",
                gravity = 24.8f, atmosphereDensity = 50f,
                skyTint = H("#5A7A9E"),
                groundColor = H("#7A5535"),
                atmosphereThickness = 2.5f, sunSize = 0.016f, exposure = 0.80f,
                sunLightColor = H("#E8C080"),
                sunLightIntensity = 0.85f,
                hasFog = true, fogDensity = 0.005f,
                fogColor = H("#8A7050"),
                atmosParticleColor = new Color(0.75f, 0.60f, 0.35f, 0.60f),
                atmosParticleRate = 180f,
                starsColor = new Color(0.90f, 0.88f, 0.75f, 0.15f),
                starsRate = 10f, starsSize = 0.016f
            },
            new PlanetData {
                name = "Сатурн",
                gravity = 10.4f, atmosphereDensity = 20f,
                skyTint = H("#DFC87A"),
                groundColor = H("#A08540"),
                atmosphereThickness = 1.8f, sunSize = 0.014f, exposure = 0.85f,
                sunLightColor = H("#FFF0C0"),
                sunLightIntensity = 0.90f,
                hasFog = true, fogDensity = 0.002f,
                fogColor = H("#D4BC70"),
                atmosParticleColor = new Color(0.90f, 0.80f, 0.50f, 0.50f),
                atmosParticleRate = 100f,
                starsColor = new Color(1.0f, 0.97f, 0.82f, 0.20f),
                starsRate = 15f, starsSize = 0.020f
            },
            new PlanetData {
                name = "Меркурій",
                gravity = 3.7f, atmosphereDensity = 0f,
                skyTint = H("#050404"),
                groundColor = H("#4A4038"),
                atmosphereThickness = 0f, sunSize = 0.12f, exposure = 2.4f,
                sunLightColor = H("#FFFCF0"),
                sunLightIntensity = 2.4f,
                hasFog = false, fogDensity = 0f, fogColor = Color.black,
                atmosParticleColor = new Color(0f, 0f, 0f, 0f),
                atmosParticleRate = 0f,
                starsColor = new Color(1.0f, 1.0f, 0.97f, 0.92f),
                starsRate = 500f, starsSize = 0.058f
            },
            new PlanetData {
                name = "Уран",
                gravity = 8.7f, atmosphereDensity = 5f,
                skyTint = H("#72E0DC"),
                groundColor = H("#2A9090"),
                atmosphereThickness = 1.2f, sunSize = 0.010f, exposure = 1.0f,
                sunLightColor = H("#A0F0F8"),
                sunLightIntensity = 0.95f,
                hasFog = true, fogDensity = 0.0015f,
                fogColor = H("#60D0D0"),
                atmosParticleColor = new Color(0.42f, 0.88f, 0.86f, 0.55f),
                atmosParticleRate = 90f,
                starsColor = new Color(0.70f, 0.95f, 1.0f, 0.50f),
                starsRate = 100f, starsSize = 0.038f
            },
            new PlanetData {
                name = "Нептун",
                gravity = 11.2f, atmosphereDensity = 8f,
                skyTint = H("#1535C8"),
                groundColor = H("#080F50"),
                atmosphereThickness = 1.5f, sunSize = 0.007f, exposure = 0.80f,
                sunLightColor = H("#6080FF"),
                sunLightIntensity = 0.75f,
                hasFog = true, fogDensity = 0.003f,
                fogColor = H("#1828A0"),
                atmosParticleColor = new Color(0.18f, 0.28f, 1.0f, 0.60f),
                atmosParticleRate = 130f,
                starsColor = new Color(0.70f, 0.80f, 1.0f, 0.48f),
                starsRate = 75f, starsSize = 0.036f
            },
            new PlanetData {
                name = "Плутон",
                gravity = 0.62f, atmosphereDensity = 0.001f,
                skyTint = H("#0A0318"),
                groundColor = H("#504870"),
                atmosphereThickness = 0.03f, sunSize = 0.005f, exposure = 0.50f,
                sunLightColor = H("#A090E0"),
                sunLightIntensity = 0.45f,
                hasFog = false, fogDensity = 0f, fogColor = Color.black,
                atmosParticleColor = new Color(0.50f, 0.40f, 0.70f, 0.08f),
                atmosParticleRate = 0f,
                starsColor = new Color(0.88f, 0.82f, 1.0f, 0.92f),
                starsRate = 650f, starsSize = 0.072f
            }
        };
    }

    private void Start()
    {
        if (leftButton != null) leftButton.onClick.AddListener(PrevPlanet);
        if (rightButton != null) rightButton.onClick.AddListener(NextPlanet);

        if (starsParticles != null)
        {
            var shape = starsParticles.shape;
            shape.shapeType = ParticleSystemShapeType.Hemisphere;
            shape.radius = 80f;
        }

        ApplyPlanet(0);
    }

    private void ApplyPlanet(int index)
    {
        if (_transitionCoroutine != null)
            StopCoroutine(_transitionCoroutine);
        _transitionCoroutine = StartCoroutine(TransitionToPlanet(_planets[index]));

        if (planetNameText != null)
            planetNameText.text = _planets[index].name;

        if (leftButton != null) leftButton.interactable = index > 0;
        if (rightButton != null) rightButton.interactable = index < _planets.Length - 1;
    }

    private IEnumerator TransitionToPlanet(PlanetData p)
    {
        float t = 0f;
        float duration = 1.8f;

        Color startSkyTint = skyboxMaterial.GetColor("_SkyTint");
        Color startGroundColor = skyboxMaterial.GetColor("_GroundColor");
        float startAtmosphere = skyboxMaterial.GetFloat("_AtmosphereThickness");
        float startSunSize = skyboxMaterial.GetFloat("_SunSize");
        float startExposure = skyboxMaterial.GetFloat("_Exposure");
        Color startFogColor = RenderSettings.fogColor;
        float startFogDensity = RenderSettings.fogDensity;
        Color startLightColor = sunLight != null ? sunLight.color : Color.white;
        float startLightIntensity = sunLight != null ? sunLight.intensity : 1f;

        while (t < 1f)
        {
            t += Time.deltaTime / duration;
            float s = Mathf.SmoothStep(0f, 1f, t);

            if (skyboxMaterial != null)
            {
                skyboxMaterial.SetColor("_SkyTint", Color.Lerp(startSkyTint, p.skyTint, s));
                skyboxMaterial.SetColor("_GroundColor", Color.Lerp(startGroundColor, p.groundColor, s));
                skyboxMaterial.SetFloat("_AtmosphereThickness", Mathf.Lerp(startAtmosphere, p.atmosphereThickness, s));
                skyboxMaterial.SetFloat("_SunSize", Mathf.Lerp(startSunSize, p.sunSize, s));
                skyboxMaterial.SetFloat("_Exposure", Mathf.Lerp(startExposure, p.exposure, s));
            }

            RenderSettings.fog = p.hasFog;
            if (p.hasFog)
            {
                RenderSettings.fogMode = FogMode.Exponential;
                RenderSettings.fogColor = Color.Lerp(startFogColor, p.fogColor, s);
                RenderSettings.fogDensity = Mathf.Lerp(startFogDensity, p.fogDensity, s);
            }

            if (sunLight != null)
            {
                sunLight.color = Color.Lerp(startLightColor, p.sunLightColor, s);
                sunLight.intensity = Mathf.Lerp(startLightIntensity, p.sunLightIntensity, s);
            }

            DynamicGI.UpdateEnvironment();
            yield return null;
        }

        if (atmosphereParticles != null)
        {
            var main = atmosphereParticles.main;
            main.startColor = p.atmosParticleColor;
            var emission = atmosphereParticles.emission;
            emission.rateOverTime = p.atmosParticleRate;
            if (p.atmosParticleRate > 0f && !atmosphereParticles.isPlaying)
                atmosphereParticles.Play();
            else if (p.atmosParticleRate == 0f)
                atmosphereParticles.Stop();
        }

        if (starsParticles != null)
        {
            var main = starsParticles.main;
            main.startColor = p.starsColor;
            main.startSize = new ParticleSystem.MinMaxCurve(p.starsSize * 0.5f, p.starsSize);
            var emission = starsParticles.emission;
            emission.rateOverTime = p.starsRate;
            if (p.starsRate > 0f && !starsParticles.isPlaying)
                starsParticles.Play();
            else if (p.starsRate == 0f)
                starsParticles.Stop();
        }
    }

    private void NextPlanet()
    {
        if (_currentIndex < _planets.Length - 1)
        {
            _currentIndex++;
            ApplyPlanet(_currentIndex);
        }
    }

    private void PrevPlanet()
    {
        if (_currentIndex > 0)
        {
            _currentIndex--;
            ApplyPlanet(_currentIndex);
        }
    }

    public void RestoreCurrentPlanet()
    {
        if (_transitionCoroutine != null)
            StopCoroutine(_transitionCoroutine);
        _transitionCoroutine = StartCoroutine(TransitionToPlanet(_planets[_currentIndex]));
    }

    public PlanetData GetCurrentPlanet() => _planets[_currentIndex];
}