#pragma once

#include <cstddef>
#include <cstdint>
#include <memory>
#include <span>
#include <vector>

#include "glm/glm.hpp"

namespace cbt::gfx {

enum class primitive_type {
    triangles
};

enum class index_type {
    uint16,
    uint32
};

struct attribute_desc {
    std::uint32_t location = 0;
    std::uint32_t num_components = 3;
    std::uint32_t offset = 0;
};

struct pipeline_desc {
    std::span<std::byte const> vertex_data{};
    std::span<std::byte const> index_data{};
    std::vector<attribute_desc> attributes{};
    std::uint32_t vertex_stride = 0;
    char const* vertex_shader_src = nullptr;
    char const* fragment_shader_src = nullptr;
    bool depth_test = true;
    primitive_type primitive = primitive_type::triangles;
    index_type index_type_ = index_type::uint32;
};

class pipeline {
public:
    pipeline();
    explicit pipeline(pipeline_desc const& desc);
    pipeline(pipeline const&) = delete;
    pipeline(pipeline&& other) noexcept;
    auto operator=(pipeline const&) -> pipeline& = delete;
    auto operator=(pipeline&& other) noexcept -> pipeline&;
    ~pipeline();

    auto valid() const -> bool;
    auto draw(glm::mat4 const& model, glm::mat4 const& view, glm::mat4 const& proj) const -> void;
    auto bind_texture(char const* sampler_name, std::uint32_t texture_id, std::uint32_t unit = 0) const -> void;
    auto bind_vec3(char const* name, glm::vec3 const& v) const -> void;
    auto bind_float(char const* name, float v) const -> void;

private:
    struct impl;
    std::unique_ptr<impl> m_impl;
};

class render_target {
public:
    explicit render_target(int width, int height);
    render_target(render_target const&) = delete;
    render_target(render_target&& other) noexcept;
    auto operator=(render_target const&) -> render_target& = delete;
    auto operator=(render_target&& other) noexcept -> render_target&;
    ~render_target();

    auto bind() const -> void;
    auto unbind() const -> void;
    auto color_id() const -> std::uint32_t;
    auto width() const -> int;
    auto height() const -> int;
    auto valid() const -> bool;
    auto resize(int width, int height) -> void;

private:
    struct impl;
    std::unique_ptr<impl> m_impl;
};

} // namespace cbt::gfx