#include "cbt/opengl/texture.hpp"

#include "glad/glad.h"

namespace cbt::opengl {

texture::texture() {
    glGenTextures(1, &m_id);
}

texture::texture(texture_target target)
    : m_target(target) {
    glGenTextures(1, &m_id);
}

texture::~texture() {
    if (m_id) {
        glDeleteTextures(1, &m_id);
    }
}

texture::texture(texture&& other) noexcept
    : m_id(other.m_id)
    , m_target(other.m_target) {
    other.m_id = 0;
}

texture& texture::operator=(texture&& other) noexcept {
    if (this != &other) {
        if (m_id) {
            glDeleteTextures(1, &m_id);
        }
        m_id = other.m_id;
        m_target = other.m_target;
        other.m_id = 0;
    }
    return *this;
}

auto texture::bind(GLuint unit) -> void {
    glActiveTexture(GL_TEXTURE0 + unit);
    glBindTexture(static_cast<GLenum>(m_target), m_id);
}

auto texture::unbind() -> void {
    glBindTexture(static_cast<GLenum>(m_target), 0);
}

auto texture::upload(void const* data, int width, int height, texture_format format, texture_type type) -> void {
    bind();
    glTexImage2D(static_cast<GLenum>(m_target), 0,
                 static_cast<GLenum>(format), width, height, 0,
                 static_cast<GLenum>(format), static_cast<GLenum>(type), data);
    unbind();
}

auto texture::set_filter(GLenum min_filter, GLenum mag_filter) -> void {
    bind();
    glTexParameteri(static_cast<GLenum>(m_target), GL_TEXTURE_MIN_FILTER, min_filter);
    glTexParameteri(static_cast<GLenum>(m_target), GL_TEXTURE_MAG_FILTER, mag_filter);
    unbind();
}

auto texture::set_wrap(GLenum wrap_s, GLenum wrap_t) -> void {
    bind();
    glTexParameteri(static_cast<GLenum>(m_target), GL_TEXTURE_WRAP_S, wrap_s);
    glTexParameteri(static_cast<GLenum>(m_target), GL_TEXTURE_WRAP_T, wrap_t);
    unbind();
}

auto texture::generate_mipmaps() -> void {
    bind();
    glGenerateMipmap(static_cast<GLenum>(m_target));
    unbind();
}

auto texture::id() const -> GLuint {
    return m_id;
}

auto texture::valid() const -> bool {
    return m_id != 0;
}

}