#include "renderer.hpp"
#include "config.hpp"

#include <raylib.h>
#include <raymath.h>
#include <rlgl.h>

#ifdef TRACY
#include <tracy/Tracy.hpp>
#endif

auto renderer::update_texture_sizes() -> void
{
    if (!IsWindowResized()) {
        return;
    }

    UnloadRenderTexture(render_target);
    UnloadRenderTexture(klotski_target);
    UnloadRenderTexture(menu_target);

    const int width = GetScreenWidth() / 2;
    const int height = GetScreenHeight() - MENU_HEIGHT;

    render_target = LoadRenderTexture(width, height);
    klotski_target = LoadRenderTexture(width, height);
    menu_target = LoadRenderTexture(width * 2, MENU_HEIGHT);
}

auto renderer::draw_mass_springs(const std::vector<Vector3>& masses) -> void
{
    #ifdef TRACY
    ZoneScoped;
    #endif

    if (masses.size() != state.get_state_count()) {
        // Because the physics run in a different thread, it might need time to catch up
        return;
    }

    // Prepare connection batching
    {
        #ifdef TRACY
        ZoneNamedN(prepare_masses, "PrepareConnectionsBatching", true);
        #endif

        connections.clear();
        connections.reserve(state.get_target_count());
        if (input.connect_solutions) {
            for (const size_t& _state : state.get_winning_indices()) {
                const Vector3& current_mass = masses.at(state.get_current_index());
                const Vector3& winning_mass = masses.at(_state);
                connections.emplace_back(current_mass, winning_mass);
                DrawLine3D(current_mass, winning_mass, Fade(TARGET_BLOCK_COLOR, 0.5));
            }
        }
    }

    // Prepare cube instancing
    {
        #ifdef TRACY
        ZoneNamedN(prepare_masses, "PrepareMassInstancing", true);
        #endif

        if (masses.size() < DRAW_VERTICES_LIMIT) {
            // Don't have to reserve, capacity is already set to DRAW_VERTICES_LIMIT in constructor
            transforms.clear();
            colors.clear();

            size_t mass = 0;
            for (const auto& [x, y, z] : masses) {
                transforms.emplace_back(MatrixTranslate(x, y, z));

                // Normal vertex
                Color c = VERTEX_COLOR;
                if ((input.mark_solutions || input.mark_path) && state.get_winning_indices().contains(mass)) {
                    // Winning vertex
                    c = VERTEX_TARGET_COLOR;
                } else if ((input.mark_solutions || input.mark_path) && state.get_path_indices().contains(mass)) {
                    // Path vertex
                    c = VERTEX_PATH_COLOR;
                } else if (mass == state.get_starting_index()) {
                    // Starting vertex
                    c = VERTEX_START_COLOR;
                } else if (state.get_visit_counts().at(mass) > 0) {
                    // Visited vertex
                    c = VERTEX_VISITED_COLOR;
                }
                // Current vertex is drawn as individual cube to increase its size

                colors.emplace_back(c);
                ++mass;
            }
        }

        rlUpdateVertexBuffer(color_vbo_id, colors.data(), colors.size() * sizeof(Color), 0);
    }

    BeginTextureMode(render_target);
    ClearBackground(RAYWHITE);
    BeginMode3D(camera.camera);

    // Draw springs (batched)
    {
        #ifdef TRACY
        ZoneNamedN(draw_springs, "DrawSprings", true);
        #endif

        rlBegin(RL_LINES);
        for (const auto& [from, to] : state.get_links()) {
            if (masses.size() > from && masses.size() > to) {
                const auto& [ax, ay, az] = masses.at(from);
                const auto& [bx, by, bz] = masses.at(to);
                rlColor4ub(EDGE_COLOR.r, EDGE_COLOR.g, EDGE_COLOR.b, EDGE_COLOR.a);
                rlVertex3f(ax, ay, az);
                rlVertex3f(bx, by, bz);
            }
        }
        rlEnd();
    }

    // Draw masses (instanced)
    {
        #ifdef TRACY
        ZoneNamedN(draw_masses, "DrawMasses", true);
        #endif

        if (masses.size() < DRAW_VERTICES_LIMIT) {
            // NOTE: I don't know if drawing all this inside a shader would make it
            //       much faster... The amount of data sent to the GPU would be
            //       reduced (just positions instead of matrices), but is this
            //       noticable for < 100000 cubes?
            DrawMeshInstanced(cube_instance, vertex_mat, transforms.data(), masses.size()); // NOLINT(*-narrowing-conversions)
        }
    }

    // Connect current to winning states (batched)
    const auto [r, g, b, a] = Fade(VERTEX_CURRENT_COLOR, 0.3);
    rlBegin(RL_LINES);
    for (const auto& [from, to] : connections) {
        const auto& [ax, ay, az] = from;
        const auto& [bx, by, bz] = to;
        rlColor4ub(r, g, b, a);
        rlVertex3f(ax, ay, az);
        rlVertex3f(bx, by, bz);
    }
    rlEnd();

    // Mark current state
    const size_t current_index = state.get_current_index();
    if (masses.size() > current_index) {
        const Vector3& current_mass = masses.at(current_index);
        DrawCube(current_mass, VERTEX_SIZE * 2, VERTEX_SIZE * 2, VERTEX_SIZE * 2, VERTEX_CURRENT_COLOR);
    }

    EndMode3D();
    EndTextureMode();
}

auto renderer::draw_klotski() const -> void
{
    #ifdef TRACY
    ZoneScoped;
    #endif

    BeginTextureMode(klotski_target);
    ClearBackground(RAYWHITE);

    gui.draw_puzzle_board();

    EndTextureMode();
}

auto renderer::draw_menu() const -> void
{
    #ifdef TRACY
    ZoneScoped;
    #endif

    BeginTextureMode(menu_target);
    ClearBackground(RAYWHITE);

    gui.draw_main_menu();

    EndTextureMode();
}

auto renderer::draw_textures(const int fps, const int ups, const size_t mass_count,
                             const size_t spring_count) const -> void
{
    BeginDrawing();

    DrawTextureRec(menu_target.texture, Rectangle(0, 0, menu_target.texture.width, -menu_target.texture.height),
                   Vector2(0, 0), WHITE);
    DrawTextureRec(klotski_target.texture,
                   Rectangle(0, 0, klotski_target.texture.width, -klotski_target.texture.height),
                   Vector2(0, MENU_HEIGHT), WHITE);
    DrawTextureRec(render_target.texture, Rectangle(0, 0, render_target.texture.width, -render_target.texture.height),
                   Vector2(GetScreenWidth() / 2.0f, MENU_HEIGHT), WHITE);

    // Draw borders
    DrawRectangleLinesEx(Rectangle(0, 0, GetScreenWidth(), MENU_HEIGHT), 1.0f, BLACK);
    DrawRectangleLinesEx(Rectangle(0, MENU_HEIGHT, GetScreenWidth() / 2.0f, GetScreenHeight() - MENU_HEIGHT), 1.0f,
                         BLACK);
    DrawRectangleLinesEx(Rectangle(GetScreenWidth() / 2.0f, MENU_HEIGHT, GetScreenWidth() / 2.0f,
                                   GetScreenHeight() - MENU_HEIGHT), 1.0f, BLACK);

    gui.draw_graph_overlay(fps, ups, mass_count, spring_count);
    gui.draw_save_preset_popup();
    gui.update();

    EndDrawing();
}

auto renderer::render(const std::vector<Vector3>& masses, const int fps, const int ups, const size_t mass_count,
                      const size_t spring_count) -> void
{
    update_texture_sizes();

    draw_mass_springs(masses);
    draw_klotski();
    draw_menu();
    draw_textures(fps, ups, mass_count, spring_count);
}