#ifndef SURFACE_TEXTURE_CLASS
#define SURFACE_TEXTURE_CLASS

#include <glm/glm.hpp>

#include "shaderClass.h"
#include "texture.h"

// How one game element wears a texture. Texture is the shared image, this is per element,
// so the same image can be stretched on one thing and tiled on another.
class SurfaceTexture {
public:
    enum class Mode {
        Stretch,   // the image fills each face once, whatever size it is
        Tile       // the image repeats every tileSize, so it keeps its size as the element grows
    };

    Texture* texture = nullptr;
    Mode mode = Mode::Stretch;
    float tileSize = 1.0f;                  // world units on meshes, pixels on gui
    glm::vec2 offset = glm::vec2(0.0f);     // slides the image, in repeats of it

    SurfaceTexture() {}

    static SurfaceTexture Stretched(Texture* texture) {
        SurfaceTexture surface;
        surface.texture = texture;
        return surface;
    }

    static SurfaceTexture Tiled(Texture* texture, float tileSize) {
        SurfaceTexture surface;
        surface.texture = texture;
        surface.mode = Mode::Tile;
        surface.tileSize = tileSize;
        return surface;
    }

    // Binds the image and sets the uv uniforms. size is the element's size, with the shader active.
    void Apply(Shader& shader, GLuint unit, const glm::vec3& size) const {
        glActiveTexture(GL_TEXTURE0 + unit);
        shader.SetInt("tex", unit);
        if (texture == nullptr) {
            glBindTexture(GL_TEXTURE_2D, 0);
            shader.SetInt("useTexture", 0);
            return;
        }

        glBindTexture(GL_TEXTURE_2D, texture->ID);
        shader.SetInt("useTexture", 1);
        shader.SetInt("uvMode", mode == Mode::Tile ? 1 : 0);
        shader.Set3F("tileScale", size / glm::max(tileSize, 0.0001f));
        shader.Set2F("uvOffset", offset);
    }
};

#endif