#include "client/world/block.hh"

namespace client {
namespace world {

struct glvert_args {
    glm::vec3 translate;
    float rotate_degrees;
    glm::vec3 rotate_axis;
    glm::vec3 texture_offset;
};
static block::glface_t make_glface(const glvert_args& args) noexcept {
    static constexpr block::glface_t glverts = {
        block::glvert{{-0.5f, -0.5f, 0.0f}, {0.0f, 1.0f, 0.0f}},
        block::glvert{{0.5f, -0.5f, 0.0f}, {1.0f, 1.0f, 0.0f}},
        block::glvert{{0.5f, 0.5f, 0.0f}, {1.0f, 0.0f, 0.0f}},
        block::glvert{{0.5f, 0.5f, 0.0f}, {1.0f, 0.0f, 0.0f}},
        block::glvert{{-0.5f, 0.5f, 0.0f}, {0.0f, 0.0f, 0.0f}},
        block::glvert{{-0.5f, -0.5f, 0.0f}, {0.0f, 1.0f, 0.0f}}};

    // We have to be careful here not to rotate/translate a zero vector.
    constexpr auto zero = glm::vec3{};
    const glm::mat4 mtranslate =
        args.translate == zero
            ? glm::mat4{1.0f}
            : glm::translate(glm::mat4{1.0f}, args.translate);
    const glm::mat4 mrotate =
        args.rotate_axis == zero
            ? glm::mat4{1.0f}
            : glm::rotate(glm::mat4{1.0f}, glm::radians(args.rotate_degrees),
                          args.rotate_axis);

    block::glface_t ret;
    std::ranges::transform(glverts, std::begin(ret), [&](auto f) {
        f.vertice =
            glm::vec3(mtranslate * mrotate * glm::vec4{f.vertice, 1.0f});
        f.texture += args.texture_offset;
        return f;
    });
    return ret;
}

static const block::glfaces_t& get_shrub_faces() noexcept {
    static block::glfaces_t faces{
        make_glface({.translate = {0.0f, 0.0f, 0.0f},
                     .rotate_degrees = 45.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 0.0f}}),
        make_glface({.translate = {0.0f, 0.0f, 0.0f},
                     .rotate_degrees = 135.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 0.0f}}),
        make_glface({.translate = {0.0f, 0.0f, 0.0f},
                     .rotate_degrees = 225.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 0.0f}}),
        make_glface({.translate = {0.0f, 0.0f, 0.0f},
                     .rotate_degrees = 315.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 0.0f}})};
    return faces;
}

static const block::glfaces_t& get_cube_faces() noexcept {
    static block::glfaces_t faces{
        make_glface({.translate = {0.0f, 0.0f, 0.5f},
                     .rotate_degrees = 0.0f,
                     .rotate_axis = {0.0f, 0.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 0.0f}}),
        make_glface({.translate = {0.5f, 0.0f, 0.0f},
                     .rotate_degrees = 90.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 1.0f}}),
        make_glface({.translate = {0.0f, 0.0f, -0.5f},
                     .rotate_degrees = 180.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 2.0f}}),
        make_glface({.translate = {-0.5f, 0.0f, 0.0f},
                     .rotate_degrees = 270.0f,
                     .rotate_axis = {0.0f, 1.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 3.0f}}),
        make_glface({.translate = {0.0f, 0.5f, 0.0f},
                     .rotate_degrees = -90.0f,
                     .rotate_axis = {1.0f, 0.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 4.0f}}),
        make_glface({.translate = {0.0f, -0.5f, 0.0f},
                     .rotate_degrees = 90.0f,
                     .rotate_axis = {1.0f, 0.0f, 0.0f},
                     .texture_offset = {0.0f, 0.0f, 5.0f}}),
    };
    return faces;
}

enum block::draw_type
block::get_draw_type(const enum block::type& type) noexcept {
    using t = enum shared::world::block::type;
    switch (type) {
    case t::dead_shrub:
    case t::shrub:
    case t::snowy_shrub:
        return draw_type::custom;
    default:
        return draw_type::block;
    }
}

const block::glfaces_t&
block::get_glfaces(const enum block::type& type) noexcept {
    const auto draw_type = get_draw_type(type);
    if (draw_type == block::draw_type::custom) {
        return get_shrub_faces();
    }
    return get_cube_faces();
}

} // namespace world
} // namespace client