#include "pch.h"
#include "log.h"
#include "texture.h"
#include "util.h"
#include "app.h"
#include "renderer_gl/opengl_capabilities.h"

#include <cstdint>

namespace {

[[nodiscard]] GLenum texture_2d_target() noexcept
{
    return static_cast<GLenum>(pp::renderer::gl::texture_2d_target());
}

[[nodiscard]] GLenum texture_cube_map_target() noexcept
{
    return static_cast<GLenum>(pp::renderer::gl::texture_cube_map_target());
}

[[nodiscard]] GLenum framebuffer_target() noexcept
{
    return static_cast<GLenum>(pp::renderer::gl::framebuffer_target());
}

[[nodiscard]] GLenum draw_framebuffer_binding_query() noexcept
{
    return static_cast<GLenum>(pp::renderer::gl::draw_framebuffer_binding_query());
}

}

std::map<uint16_t, Texture2D> TextureManager::m_textures;
std::array<int, 6> TextureCube::m_faces_map {
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(0U)),
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(1U)),
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(2U)),
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(3U)),
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(4U)),
    static_cast<int>(pp::renderer::gl::cube_face_texture_target(5U)),
};

TextureCube::TextureCube(TextureCube&& other) noexcept
{
    other.m_faces = std::move(other.m_faces); 
    m_cubetex_id = other.m_cubetex_id;      other.m_cubetex_id = 0;
    m_resolution = other.m_resolution;      other.m_resolution = 0;
}

TextureCube::~TextureCube()
{
    destroy();
}

void TextureCube::operator=(TextureCube&& other) noexcept
{
    other.m_faces = std::move(other.m_faces);
    m_cubetex_id = other.m_cubetex_id;      other.m_cubetex_id = 0;
    m_resolution = other.m_resolution;      other.m_resolution = 0;
}

bool TextureCube::create(int resolution) noexcept
{
    App::I->render_task([this, resolution]
    {
        destroy();
        m_resolution = resolution;
        glGenTextures(1, &m_cubetex_id);

        if (!m_cubetex_id)
            return;

        glBindTexture(texture_cube_map_target(), m_cubetex_id);
        const auto format = pp::renderer::gl::texture_format_for_channel_count(4U);
        const auto component_type = static_cast<GLenum>(pp::renderer::gl::unsigned_byte_component_type());
        for (GLuint i = 0; i < 6; i++)
        {
            glTexImage2D(
                static_cast<GLenum>(pp::renderer::gl::cube_map_allocation_face_texture_target(i)),
                0,
                static_cast<GLint>(format.internal_format),
                m_resolution,
                m_resolution,
                0,
                static_cast<GLenum>(format.pixel_format),
                component_type,
                nullptr);
        }
    });
    return m_cubetex_id != 0;
}

void TextureCube::destroy() noexcept
{
    if (m_cubetex_id)
    {
        App::I->render_task([f=m_faces, id=m_cubetex_id]
        {
            glDeleteTextures(static_cast<GLsizei>(f.size()), f.data());
            glDeleteTextures(1, &id);
        });
        m_cubetex_id = 0;
        m_faces.fill(0);
        m_resolution = 0;
    }
}

void TextureCube::bind() const noexcept
{
    assert(App::I->is_render_thread());
    glBindTexture(texture_cube_map_target(), m_cubetex_id);
}

bool TextureManager::load(const char* path, bool generate_mipmaps)
{
    uint16_t id = const_hash(path);
    auto t = m_textures.find(id);
    if (t == m_textures.end() || !m_textures[id].ready())
    {
        if (!m_textures[id].load(path))
            return false;
    }
    if (generate_mipmaps && !m_textures[id].has_mips)
        m_textures[id].create_mipmaps();
    return true;
}

void TextureManager::assign(uint16_t id, GLuint tex, int w, int h, GLuint internal_format, GLuint format)
{
    m_textures[id].assign(tex, w, h, internal_format, format);
}

void TextureManager::assign(uint16_t id, GLuint tex, int w, int h)
{
    assign(
        id,
        tex,
        w,
        h,
        pp::renderer::gl::rgba8_internal_format(),
        pp::renderer::gl::rgba_pixel_format());
}

Texture2D& TextureManager::get(uint16_t id)
{
    return m_textures[id];
}

void TextureManager::invalidate()
{
    for (auto& t : m_textures)
    {
        t.second.destroy();
    }
    m_textures.clear();
}

Image Texture2D::get_image() const noexcept
{
    Image ret;
    ret.create(m_width, m_height);
    App::I->render_task([&]
    {
        bind();
        
        GLuint fboID;
        glGenFramebuffers(1, &fboID);
        if (fboID == 0)
            return;

        GLint oldFboID;
        glGetIntegerv(draw_framebuffer_binding_query(), &oldFboID);

        glBindFramebuffer(framebuffer_target(), fboID);
        glFramebufferTexture2D(
            framebuffer_target(),
            static_cast<GLenum>(pp::renderer::gl::framebuffer_color_attachment()),
            texture_2d_target(),
            m_tex,
            0);
        GLenum status = glCheckFramebufferStatus(framebuffer_target());
        if (status == static_cast<GLenum>(pp::renderer::gl::framebuffer_complete_status()))
        {
            const auto readback = pp::renderer::gl::rgba8_readback_format();
            glReadPixels(
                0,
                0,
                m_width,
                m_height,
                static_cast<GLenum>(readback.pixel_format),
                static_cast<GLenum>(readback.component_type),
                ret.m_data.get());
        }
        else
        {
            LOG("Texture2D::get_image() failed because: %s",
                pp::renderer::gl::framebuffer_status_name(static_cast<std::uint32_t>(status)));
        }
        
        glBindFramebuffer(framebuffer_target(), oldFboID);
        glDeleteFramebuffers(1, &fboID);
    });
    return ret;
}

Texture2D::Texture2D(Texture2D&& other) noexcept
{
    m_tex = other.m_tex;
    m_width = other.m_width;
    m_height = other.m_height;
    m_format = other.m_format;
    m_iformat = other.m_iformat;
    has_mips = other.has_mips;
    other.m_tex = false;
}

void Texture2D::operator=(Texture2D&& other) noexcept
{
    m_tex = other.m_tex;
    m_width = other.m_width;
    m_height = other.m_height;
    m_format = other.m_format;
    m_iformat = other.m_iformat;
    has_mips = other.has_mips;
    other.m_tex = false;
}

bool Texture2D::create(int width, int height)
{
    return create(
        width,
        height,
        static_cast<GLint>(pp::renderer::gl::rgba8_internal_format()),
        static_cast<GLint>(pp::renderer::gl::rgba_pixel_format()));
}

bool Texture2D::create(int width, int height, GLint internal_format)
{
    return create(
        width,
        height,
        internal_format,
        static_cast<GLint>(pp::renderer::gl::rgba_pixel_format()));
}

bool Texture2D::create(int width, int height, GLint internal_format, GLint format, const uint8_t* data)
{
    App::I->render_task([=]
    {
        destroy();
        m_width = width;
        m_height = height;
        m_format = format;
        m_iformat = internal_format;
        glGenTextures(1, &m_tex);
        //LOG("TEX create %d", m_tex);
        bind();
        const auto ifmt = static_cast<GLenum>(
            pp::renderer::gl::texture_upload_type_for_internal_format(static_cast<std::uint32_t>(internal_format)));
        glTexImage2D(texture_2d_target(), 0, internal_format, width, height, 0, format, ifmt, data);
        unbind();
    });
    return true;
}
bool Texture2D::create(const Image& img)
{
    const auto format = pp::renderer::gl::texture_format_for_channel_count(static_cast<std::uint32_t>(img.comp));
    if (format.channel_count == 0U)
        return false;

    return create(
        img.width,
        img.height,
        static_cast<GLint>(format.internal_format),
        static_cast<GLint>(format.pixel_format),
        img.data());
}

void Texture2D::create_mipmaps()
{
    App::I->render_task([this]
    {
        bind();
        glGenerateMipmap(texture_2d_target());
        unbind();
        has_mips = true;
    });
}

void Texture2D::assign(GLuint tex, int w, int h, GLuint internal_format, GLuint format)
{
    m_tex = tex;
    m_width = w;
    m_height = h;
    m_format = format;
    m_iformat = internal_format;
}

void Texture2D::assign(GLuint tex, int w, int h)
{
    assign(
        tex,
        w,
        h,
        pp::renderer::gl::rgba8_internal_format(),
        pp::renderer::gl::rgba_pixel_format());
}

bool Texture2D::load(std::string filename)
{
    LOG("load texture %s", filename.c_str());
    Image img;
    if (!img.load(filename))
        return false;
    return create(img);
}

bool Texture2D::load_file(std::string filename)
{
    LOG("load texture %s", filename.c_str());
    Image img;
    if (!img.load_file(filename))
        return false;
    return create(img);
}

void Texture2D::destroy()
{
    if (m_tex)
    {
        App::I->render_task_async([id = m_tex] 
        {
            glDeleteTextures(1, &id); 
        });
        m_tex = 0;
    }
}

void Texture2D::bind() const
{
    assert(App::I->is_render_thread());
    glBindTexture(texture_2d_target(), m_tex);
}

void Texture2D::unbind() const
{
    assert(App::I->is_render_thread());
    glBindTexture(texture_2d_target(), 0);
}

void Texture2D::update(const uint8_t* data)
{
    App::I->render_task([this, data]
    {
        bind();
        glTexSubImage2D(
            texture_2d_target(),
            0,
            0,
            0,
            m_width,
            m_height,
            m_format,
            static_cast<GLenum>(pp::renderer::gl::unsigned_byte_component_type()),
            data);
    });
}

glm::vec2 Texture2D::size() const
{
    return { m_width, m_height };
}

Texture2D::~Texture2D()
{
    destroy();
}

bool Sampler::create(GLint filter, GLint wrap)
{
    bool ret = false;
    App::I->render_task([this, &ret, filter, wrap]
    {
#if USE_SAMPLER
        glGenSamplers(1, &id);
#endif // USE_SAMPLER
        if (id == 0)
        {
            ret = false;
            return;
        }
        set(filter, wrap);
        ret = true;
    });
    return ret;
}

bool Sampler::create()
{
    return create(
        static_cast<GLint>(pp::renderer::gl::linear_texture_filter()),
        static_cast<GLint>(pp::renderer::gl::clamp_to_edge_texture_wrap()));
}

bool Sampler::create(GLint filter)
{
    return create(filter, static_cast<GLint>(pp::renderer::gl::clamp_to_edge_texture_wrap()));
}

void Sampler::set(GLint filter, GLint wrap)
{
    App::I->render_task([=]
    {
#if USE_SAMPLER
        for (const auto parameter : pp::renderer::gl::sampler_parameters_for_filter_wrap(
                 static_cast<std::uint32_t>(filter),
                 static_cast<std::uint32_t>(wrap)))
        {
            glSamplerParameteri(id, static_cast<GLenum>(parameter.name), static_cast<GLint>(parameter.value));
        }
#endif // USE_SAMPLER
    });
}

void Sampler::set()
{
    set(
        static_cast<GLint>(pp::renderer::gl::linear_texture_filter()),
        static_cast<GLint>(pp::renderer::gl::clamp_to_edge_texture_wrap()));
}

void Sampler::set(GLint filter)
{
    set(filter, static_cast<GLint>(pp::renderer::gl::clamp_to_edge_texture_wrap()));
}

void Sampler::set_filter(GLint filter_min, GLint filter_mag)
{
    App::I->render_task([=]
    {
#if USE_SAMPLER
        for (const auto parameter : pp::renderer::gl::sampler_filter_parameters(
                 static_cast<std::uint32_t>(filter_min),
                 static_cast<std::uint32_t>(filter_mag)))
        {
            glSamplerParameteri(id, static_cast<GLenum>(parameter.name), static_cast<GLint>(parameter.value));
        }
#endif // USE_SAMPLER
    });
}
void Sampler::set_border(glm::vec4 rgba)
{
    App::I->render_task([this, rgba]
    {
#if USE_SAMPLER && !defined(__GLES__)
        glSamplerParameterfv(
            id,
            static_cast<GLenum>(pp::renderer::gl::sampler_border_color_parameter_name()),
            glm::value_ptr(rgba));
#endif // USE_SAMPLER
    });
}
void Sampler::bind(int unit) const
{
    assert(App::I->is_render_thread());
    current_unit = unit;
#if USE_SAMPLER
    glBindSampler(unit, id);
#endif // USE_SAMPLER
}
void Sampler::unbind()
{
    assert(App::I->is_render_thread());
#if USE_SAMPLER
    glBindSampler(current_unit, 0);
#endif // USE_SAMPLER
}