using Godot;
using System;

public enum DebugType
{
    None,
    Slope,
    Height,
    Temperature,
    Moisture
}

[Tool]
public partial class World : Node2D
{
    [Export]
    public Texture2D HeightMapTexture;

    [Export]
    public int MapWidth
    {
        get => _mapWidth;
        set
        {
            _mapWidth = value;
            SetupShader();
        }
    }
    private int _mapWidth = 3072;

    [Export]
    public float RockThreshold
    {
        get => _rockThreshold;
        set
        {
            _rockThreshold = value;
            UpdateShaderParameters();
        }
    }
    private float _rockThreshold = 0.05f;

    [Export]
    public float SnowHeightThreshold
    {
        get => _snowHeightThreshold;
        set
        {
            _snowHeightThreshold = value;
            UpdateShaderParameters();
        }
    }
    private float _snowHeightThreshold = 0.8f;

    [Export]
    public float WaterThreshold
    {
        get => _waterThreshold;
        set
        {
            _waterThreshold = value;
            UpdateShaderParameters();
        }
    }
    private float _waterThreshold = 0.0f;

    [Export]
    public float DesertTemperatureThreshold
    {
        get => _desertTemperatureThreshold;
        set
        {
            _desertTemperatureThreshold = value;
            UpdateShaderParameters();
        }
    }
    private float _desertTemperatureThreshold = 0.7f;

    [Export]
    public float DesertMoistureThreshold
    {
        get => _desertMoistureThreshold;
        set
        {
            _desertMoistureThreshold = value;
            UpdateShaderParameters();
        }
    }
    private float _desertMoistureThreshold = 0.3f;

    [Export]
    public float TemperatureNoiseFrequency
    {
        get => _temperatureNoiseFrequency;
        set
        {
            _temperatureNoiseFrequency = value;
            UpdateShaderParameters();
        }
    }
    private float _temperatureNoiseFrequency = 0.01f;

    [Export]
    public float MoistureNoiseFrequency
    {
        get => _moistureNoiseFrequency;
        set
        {
            _moistureNoiseFrequency = value;
            UpdateShaderParameters();
        }
    }
    private float _moistureNoiseFrequency = 0.01f;

    [Export]
    public float TemperatureNoiseAmplitude
    {
        get => _temperatureNoiseAmplitude;
        set
        {
            _temperatureNoiseAmplitude = value;
            UpdateShaderParameters();
        }
    }
    private float _temperatureNoiseAmplitude = 0.1f;

    [Export]
    public float MoistureNoiseAmplitude
    {
        get => _moistureNoiseAmplitude;
        set
        {
            _moistureNoiseAmplitude = value;
            UpdateShaderParameters();
        }
    }
    private float _moistureNoiseAmplitude = 0.1f;

    [Export]
    public DebugType DebugType
    {
        get => _debugType;
        set
        {
            _debugType = value;
            UpdateShaderParameters();
        }
    }
    private DebugType _debugType = DebugType.None;

    private Sprite2D _terrainSprite;
    private ShaderMaterial _shaderMaterial;

    public override void _Ready()
    {
        // If the height map image is not assigned, log an error and return
        if (HeightMapTexture == null)
        {
            GD.PrintErr("Height map texture is not assigned.");
            return;
        }

        SetupShader();
    }

    private void SetupShader()
    {
        // Don't run during initialization if not ready
        if (HeightMapTexture == null) return;

        // Clear any existing terrain sprite
        if (_terrainSprite != null)
        {
            _terrainSprite.QueueFree();
            _terrainSprite = null;
        }

        // Load the shader
        Shader terrainShader = GD.Load<Shader>("res://Shaders/terrain.gdshader");
        if (terrainShader == null)
        {
            GD.PrintErr("Failed to load terrain shader.");
            return;
        }

        // Create shader material
        _shaderMaterial = new ShaderMaterial();
        _shaderMaterial.Shader = terrainShader;

        // Get heightmap dimensions
        Image heightImage = HeightMapTexture.GetImage();
        if (heightImage == null)
        {
            GD.PrintErr("Failed to get image from HeightMapTexture.");
            return;
        }

        Vector2I heightMapSize = new Vector2I(heightImage.GetWidth(), heightImage.GetHeight());

        // Calculate output resolution
        // Height is always calculated based on heightmap aspect ratio
        int outputWidth = MapWidth;
        float aspectRatio = (float)heightMapSize.Y / heightMapSize.X;
        int outputHeight = (int)(outputWidth * aspectRatio);

        // Create a sprite to display the shader
        _terrainSprite = new Sprite2D();
        _terrainSprite.Material = _shaderMaterial;
        _terrainSprite.TextureFilter = TextureFilterEnum.Nearest;

        // Create a white texture with the desired output size
        // The shader will render over this
        Image whiteImage = Image.CreateEmpty(outputWidth, outputHeight, false, Image.Format.Rgba8);
        whiteImage.Fill(Colors.White);
        _terrainSprite.Texture = ImageTexture.CreateFromImage(whiteImage);

        // Center the sprite
        _terrainSprite.Centered = false;

        AddChild(_terrainSprite);

        // Update all shader parameters
        UpdateShaderParameters();
    }

    private void UpdateShaderParameters()
    {
        if (_shaderMaterial == null)
        {
            GD.PrintErr("ShaderMaterial is null, cannot update parameters");
            return;
        }

        if (HeightMapTexture == null)
        {
            GD.PrintErr("HeightMapTexture is null, cannot update parameters");
            return;
        }

        GD.Print($"Setting height_map texture: {HeightMapTexture.ResourcePath}");

        // Set the heightmap texture
        _shaderMaterial.SetShaderParameter("height_map", HeightMapTexture);

        // Set all threshold parameters
        _shaderMaterial.SetShaderParameter("water_threshold", WaterThreshold);
        _shaderMaterial.SetShaderParameter("rock_threshold", RockThreshold);
        _shaderMaterial.SetShaderParameter("snow_height_threshold", SnowHeightThreshold);
        _shaderMaterial.SetShaderParameter("desert_temperature_threshold", DesertTemperatureThreshold);
        _shaderMaterial.SetShaderParameter("desert_moisture_threshold", DesertMoistureThreshold);

        // Set noise parameters
        _shaderMaterial.SetShaderParameter("temperature_noise_frequency", TemperatureNoiseFrequency);
        _shaderMaterial.SetShaderParameter("temperature_noise_amplitude", TemperatureNoiseAmplitude);
        _shaderMaterial.SetShaderParameter("moisture_noise_frequency", MoistureNoiseFrequency);
        _shaderMaterial.SetShaderParameter("moisture_noise_amplitude", MoistureNoiseAmplitude);

        // Set debug mode
        _shaderMaterial.SetShaderParameter("debug_type", (int)DebugType);

        GD.Print("Shader parameters updated successfully");
    }
}