using UnityEngine;
using UnityEditor;
using System.IO;

public class MercuryTextureGenerator : EditorWindow
{
    public Texture2D sourceTexture;
    public string outputFolder = "Assets/Textures/Mercury";

    [MenuItem("Tools/Mercury Texture Generator")]
    public static void ShowWindow()
    {
        GetWindow<MercuryTextureGenerator>("Mercury Texture Generator");
    }

    void OnGUI()
    {
        GUILayout.Label("Генератор текстур Меркурія", EditorStyles.boldLabel);
        sourceTexture = (Texture2D)EditorGUILayout.ObjectField("Текстура Меркурія", sourceTexture, typeof(Texture2D), false);
        outputFolder = EditorGUILayout.TextField("Папка збереження", outputFolder);
        EditorGUILayout.Space(10);

        if (GUILayout.Button("Згенерувати -- Екзосфера (метеорити + вітер)", GUILayout.Height(35)))
        {
            if (sourceTexture == null) { EditorUtility.DisplayDialog("Помилка", "Перетягни текстуру!", "OK"); return; }
            GenerateAllTextures("Mercury", GenerateTextureMercury);
        }
    }

    Texture2D GenerateTextureMercury(Texture2D source, float alive)
    {
        int width = source.width;
        int height = source.height;
        Texture2D result = new Texture2D(width, height, TextureFormat.RGB24, false);

        Color[] pixels = source.GetPixels();
        Color[] output = new Color[pixels.Length];

        Color craterDark = new Color(0.25f, 0.22f, 0.20f);
        Color heatSide = new Color(0.65f, 0.35f, 0.15f);
        Color coldSide = new Color(0.30f, 0.32f, 0.40f);
        Color burnedOut = new Color(0.18f, 0.15f, 0.12f);
        Color finalDead = new Color(0.10f, 0.08f, 0.07f);

        System.Random rng = new System.Random(42);

        for (int p = 0; p < pixels.Length; p++)
        {
            int x = p % width;
            int y = p / width;

            float u = (float)x / width;
            float v = (float)y / height;

            Color col = pixels[p];
            Color result_col = col;

            if (alive < 1.0f)
            {
                float t = Mathf.Clamp01((1.0f - alive) / 0.3f);
                float noise = (float)rng.NextDouble();
                if (noise < 0.03f * t)
                    result_col = Color.Lerp(result_col, craterDark, t * 0.8f);
            }

            if (alive < 0.7f)
            {
                float t = Mathf.Clamp01((0.7f - alive) / 0.2f);
                float heatInfluence = Mathf.Clamp01(1f - u * 2f);
                float coldInfluence = Mathf.Clamp01(u * 2f - 1f);
                result_col = Color.Lerp(result_col, heatSide, heatInfluence * t * 0.6f);
                result_col = Color.Lerp(result_col, coldSide, coldInfluence * t * 0.4f);
            }

            if (alive < 0.5f)
            {
                float t = Mathf.Clamp01((0.5f - alive) / 0.2f);
                result_col = Color.Lerp(result_col, burnedOut, t * 0.7f);
                float noise = (float)rng.NextDouble();
                if (noise < 0.06f * t)
                    result_col = Color.Lerp(result_col, craterDark, 0.9f);
            }

            if (alive < 0.3f)
            {
                float t = Mathf.Clamp01((0.3f - alive) / 0.3f);
                result_col = Color.Lerp(result_col, finalDead, t);
            }

            output[p] = result_col;
        }

        result.SetPixels(output);
        result.Apply();
        return result;
    }

    void GenerateAllTextures(string prefix, System.Func<Texture2D, float, Texture2D> generator)
    {
        if (!Directory.Exists(outputFolder))
            Directory.CreateDirectory(outputFolder);

        MakeTextureReadable(sourceTexture);

        float[] levels = { 1.0f, 0.7f, 0.5f, 0.3f, 0.0f };
        string[] names = { "100", "70", "50", "30", "0" };

        for (int i = 0; i < levels.Length; i++)
        {
            EditorUtility.DisplayProgressBar("Генерація", prefix + "_" + names[i], (float)i / levels.Length);
            Texture2D result = generator(sourceTexture, levels[i]);
            SaveTexture(result, outputFolder + "/" + prefix + "_" + names[i] + ".png");
        }

        EditorUtility.ClearProgressBar();
        AssetDatabase.Refresh();
        EditorUtility.DisplayDialog("Готово!", "Текстури збережено в " + outputFolder, "OK");
    }

    void SaveTexture(Texture2D tex, string path)
    {
        byte[] bytes = tex.EncodeToPNG();
        File.WriteAllBytes(path, bytes);
    }

    void MakeTextureReadable(Texture2D tex)
    {
        string path = AssetDatabase.GetAssetPath(tex);
        TextureImporter importer = AssetImporter.GetAtPath(path) as TextureImporter;
        if (importer != null && !importer.isReadable)
        {
            importer.isReadable = true;
            importer.SaveAndReimport();
        }
    }
}