#include "opengl_texture.h"
#include <iostream>

namespace Donut
{
    OpenGLTexture2D::OpenGLTexture2D(uint32_t width, uint32_t height)
        : m_width(width), m_height(height)
    {
        m_internal_format = GL_RGBA8;
        m_data_format     = GL_RGBA;

        glCreateTextures(GL_TEXTURE_2D,  1, &m_renderer_id);
        glTextureStorage2D(m_renderer_id, 1, m_internal_format, m_width, m_height);

        glTextureParameteri(m_renderer_id, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTextureParameteri(m_renderer_id, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        glTextureParameteri(m_renderer_id, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTextureParameteri(m_renderer_id, GL_TEXTURE_WRAP_T, GL_REPEAT);
    }

    OpenGLTexture2D::OpenGLTexture2D(const std::string& path)
        : m_path(path)
    {
        m_width          = 1;
        m_height         = 1;
        m_internal_format = GL_RGBA8;
        m_data_format     = GL_RGBA;

        glCreateTextures(GL_TEXTURE_2D,  1, &m_renderer_id);
        glTextureStorage2D(m_renderer_id, 1, m_internal_format, m_width, m_height);

        glTextureParameteri(m_renderer_id, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTextureParameteri(m_renderer_id, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        glTextureParameteri(m_renderer_id, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTextureParameteri(m_renderer_id, GL_TEXTURE_WRAP_T, GL_REPEAT);

        uint32_t white_pixel = 0xFFFFFFFF;
        glTextureSubImage2D(m_renderer_id, 0, 0, 0, m_width, m_height, m_data_format, GL_UNSIGNED_BYTE, &white_pixel);

        std::cout << "Created default texture (stb_image not available for loading: " << path << ")" << std::endl;
    }

    OpenGLTexture2D::~OpenGLTexture2D()
    {
        glDeleteTextures(1, &m_renderer_id);
    }

    void OpenGLTexture2D::set_data(void* data, uint32_t size)
    {
        uint32_t bpp = m_data_format == GL_RGBA ? 4 : 3;
        if (size != m_width * m_height * bpp)
        {
            std::cout << "Data must be entire texture!" << std::endl;
            return;
        }
        
        glTextureSubImage2D(m_renderer_id, 0, 0, 0, m_width, m_height, m_data_format, GL_UNSIGNED_BYTE, data);
    }

    void OpenGLTexture2D::bind(uint32_t slot) const
    {
        glBindTextureUnit(slot, m_renderer_id);
    }

    void OpenGLTexture2D::bind_as_image(uint32_t slot, bool read_only) const
    {
        GLenum access = read_only ? GL_READ_ONLY : GL_WRITE_ONLY;
        glBindImageTexture(slot, m_renderer_id, 0, GL_FALSE, 0, access, m_internal_format);
    }
};