using Godot;
using FileAccess = Godot.FileAccess;

namespace Polonium.DataStructures;

/// <summary>
/// Represents a complete set of textures for UI button states.
/// Automatically loads textures for Normal, Pressed, Disabled, Hover, and Focused states from a directory.
/// </summary>
public class TextureSet
{
    /// <summary>
    /// Initializes a new instance of the <see cref="TextureSet"/> class by loading textures from the specified path.
    /// </summary>
    /// <param name="path">The base path where texture files are located.</param>
    public TextureSet(string path)
    {
        Normal = LoadTexture($"{path}/Normal");
        Pressed = LoadTexture($"{path}/Pressed");
        Disabled = LoadTexture($"{path}/Disabled");
        Hover = LoadTexture($"{path}/Hover");
        Focused = LoadTexture($"{path}/Focused");
    }
    
    /// <summary>
    /// Gets the texture for the normal button state.
    /// </summary>
    public Texture2D Normal { get; init; }
    
    /// <summary>
    /// Gets the texture for the pressed button state.
    /// </summary>
    public Texture2D Pressed { get; init; }
    
    /// <summary>
    /// Gets the texture for the hover button state.
    /// </summary>
    public Texture2D Hover { get; init; }
    
    /// <summary>
    /// Gets the texture for the disabled button state.
    /// </summary>
    public Texture2D Disabled { get; init; }
    
    /// <summary>
    /// Gets the texture for the focused button state.
    /// </summary>
    public Texture2D Focused { get; init; }

    /// <summary>
    /// Loads a texture from the specified path, supporting both static PNG files and animated texture directories.
    /// </summary>
    /// <param name="path">The path to the texture file or directory.</param>
    /// <returns>The loaded texture, or an empty texture if not found.</returns>
    private static Texture2D LoadTexture(string path)
    {
        Texture2D res = new();
        if(FileAccess.FileExists($"{path}.png"))
            res = ResourceLoader.Load<Texture2D>($"{path}.png");
        else if(DirAccess.DirExistsAbsolute($"{path}.at_dir"))
            res = Utils.LoadAnimatedTextureFromDirectory($"{path}.at_dir");
        return res;
    }
}