#pragma once

#include "engine/prefabs/includes.h"
#include "entities/song.h"
#include "rapidjson/filereadstream.h"
#include "background.h"
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <string>
#include <unordered_set>
#include <vector>

namespace
{
constexpr int LANE_COUNT = 12;
constexpr int OCTAVE_COUNT = 2;
constexpr int MAX_GAMEPADS = 4;
constexpr int MAX_INSTRUMENT_TYPES = MAX_GAMEPADS;
constexpr float RECEPTOR_HEIGHT = 150.0f;
constexpr float HIT_ZONE_MARGIN = 20.0f;
constexpr float SIMULTANEOUS_NOTE_Y_TOLERANCE = 2.0f;
constexpr float SCROLL_PX_PER_SEC = 350.0f;
constexpr float LEAD_OFFSET_SECONDS = 3.0f;

const int GAMEPAD_BUTTONS[LANE_COUNT] = {
    GAMEPAD_BUTTON_LEFT_FACE_LEFT, // Left
    GAMEPAD_BUTTON_LEFT_FACE_UP, // Up
    GAMEPAD_BUTTON_LEFT_FACE_RIGHT, // Right
    GAMEPAD_BUTTON_LEFT_FACE_DOWN, // Down
    GAMEPAD_BUTTON_RIGHT_FACE_LEFT, // X
    GAMEPAD_BUTTON_RIGHT_FACE_UP, // Y
    GAMEPAD_BUTTON_RIGHT_FACE_RIGHT, // B
    GAMEPAD_BUTTON_RIGHT_FACE_DOWN, // A
    GAMEPAD_BUTTON_LEFT_TRIGGER_2, // LT
    GAMEPAD_BUTTON_LEFT_TRIGGER_1, // LB
    GAMEPAD_BUTTON_RIGHT_TRIGGER_1, // RB
    GAMEPAD_BUTTON_RIGHT_TRIGGER_2, // RT
};

const char* const GAMEPAD_BUTTON_LABELS[LANE_COUNT] = {
    "<", "^", ">", "v", "X", "Y", "B", "A", "LT", "LB", "RB", "RT",
};

constexpr int COMBO_TIER_COUNT = 20;
constexpr int COMBO_DISPLAY_THRESHOLD = 5;
constexpr int COMBO_NOTES_PER_TIER = 10;
const char* const COMBO_TIER_LABELS[COMBO_TIER_COUNT] = {
    "Cool!", "Awesome!", "Radical!", "Amazing!", "Incredible!",
    "Fantastic!", "Excellent!", "Outstanding!", "Perfect!", "Brilliant!",
    "Superb!", "Magnificent!", "Phenomenal!", "Splendid!", "Terrific!",
    "Stellar!", "Legendary!", "Epic!", "Divine!", "Godlike!",
};

const int KEY_KEYS[LANE_COUNT] = {
    KEY_Q,
    KEY_W,
    KEY_E,
    KEY_R,
    KEY_A,
    KEY_S,
    KEY_D,
    KEY_F,
    KEY_Z,
    KEY_X,
    KEY_C,
    KEY_V,
};

/* One color per track (track index % MAX_INSTRUMENT_TYPES). */
const Color INSTRUMENT_COLORS[MAX_INSTRUMENT_TYPES] = {
    {220, 100, 100, 255}, // red
    {100, 160, 255, 255}, // blue
    {100, 220, 120, 255}, // green
    {255, 200, 80, 255}, // yellow
};

const char* const INSTRUMENT_LANE_WAV[MAX_INSTRUMENT_TYPES][LANE_COUNT * OCTAVE_COUNT] {
    { // Instrument 0
        "assets/sounds/genesis_bass/genesis_bass_024.wav", "assets/sounds/genesis_bass/genesis_bass_025.wav",
        "assets/sounds/genesis_bass/genesis_bass_026.wav", "assets/sounds/genesis_bass/genesis_bass_027.wav",
        "assets/sounds/genesis_bass/genesis_bass_028.wav", "assets/sounds/genesis_bass/genesis_bass_029.wav",
        "assets/sounds/genesis_bass/genesis_bass_030.wav", "assets/sounds/genesis_bass/genesis_bass_031.wav",
        "assets/sounds/genesis_bass/genesis_bass_032.wav", "assets/sounds/genesis_bass/genesis_bass_033.wav",
        "assets/sounds/genesis_bass/genesis_bass_034.wav", "assets/sounds/genesis_bass/genesis_bass_035.wav",
        "assets/sounds/genesis_bass/genesis_bass_036.wav", "assets/sounds/genesis_bass/genesis_bass_037.wav",
        "assets/sounds/genesis_bass/genesis_bass_038.wav", "assets/sounds/genesis_bass/genesis_bass_039.wav",
        "assets/sounds/genesis_bass/genesis_bass_040.wav", "assets/sounds/genesis_bass/genesis_bass_041.wav",
        "assets/sounds/genesis_bass/genesis_bass_042.wav", "assets/sounds/genesis_bass/genesis_bass_043.wav",
        "assets/sounds/genesis_bass/genesis_bass_044.wav", "assets/sounds/genesis_bass/genesis_bass_045.wav",
        "assets/sounds/genesis_bass/genesis_bass_046.wav", "assets/sounds/genesis_bass/genesis_bass_047.wav"
    },
    { // Instrument 1
        "assets/sounds/genesis_bass/genesis_bass_024.wav", "assets/sounds/genesis_bass/genesis_bass_025.wav",
        "assets/sounds/genesis_bass/genesis_bass_026.wav", "assets/sounds/genesis_bass/genesis_bass_027.wav",
        "assets/sounds/genesis_bass/genesis_bass_028.wav", "assets/sounds/genesis_bass/genesis_bass_029.wav",
        "assets/sounds/genesis_bass/genesis_bass_030.wav", "assets/sounds/genesis_bass/genesis_bass_031.wav",
        "assets/sounds/genesis_bass/genesis_bass_032.wav", "assets/sounds/genesis_bass/genesis_bass_033.wav",
        "assets/sounds/genesis_bass/genesis_bass_034.wav", "assets/sounds/genesis_bass/genesis_bass_035.wav",
        "assets/sounds/genesis_bass/genesis_bass_036.wav", "assets/sounds/genesis_bass/genesis_bass_037.wav",
        "assets/sounds/genesis_bass/genesis_bass_038.wav", "assets/sounds/genesis_bass/genesis_bass_039.wav",
        "assets/sounds/genesis_bass/genesis_bass_040.wav", "assets/sounds/genesis_bass/genesis_bass_041.wav",
        "assets/sounds/genesis_bass/genesis_bass_042.wav", "assets/sounds/genesis_bass/genesis_bass_043.wav",
        "assets/sounds/genesis_bass/genesis_bass_044.wav", "assets/sounds/genesis_bass/genesis_bass_045.wav",
        "assets/sounds/genesis_bass/genesis_bass_046.wav", "assets/sounds/genesis_bass/genesis_bass_047.wav"
    },
    { // Instrument 2
        "assets/sounds/genesis_bass/genesis_bass_024.wav", "assets/sounds/genesis_bass/genesis_bass_025.wav",
        "assets/sounds/genesis_bass/genesis_bass_026.wav", "assets/sounds/genesis_bass/genesis_bass_027.wav",
        "assets/sounds/genesis_bass/genesis_bass_028.wav", "assets/sounds/genesis_bass/genesis_bass_029.wav",
        "assets/sounds/genesis_bass/genesis_bass_030.wav", "assets/sounds/genesis_bass/genesis_bass_031.wav",
        "assets/sounds/genesis_bass/genesis_bass_032.wav", "assets/sounds/genesis_bass/genesis_bass_033.wav",
        "assets/sounds/genesis_bass/genesis_bass_034.wav", "assets/sounds/genesis_bass/genesis_bass_035.wav",
        "assets/sounds/genesis_bass/genesis_bass_036.wav", "assets/sounds/genesis_bass/genesis_bass_037.wav",
        "assets/sounds/genesis_bass/genesis_bass_038.wav", "assets/sounds/genesis_bass/genesis_bass_039.wav",
        "assets/sounds/genesis_bass/genesis_bass_040.wav", "assets/sounds/genesis_bass/genesis_bass_041.wav",
        "assets/sounds/genesis_bass/genesis_bass_042.wav", "assets/sounds/genesis_bass/genesis_bass_043.wav",
        "assets/sounds/genesis_bass/genesis_bass_044.wav", "assets/sounds/genesis_bass/genesis_bass_045.wav",
        "assets/sounds/genesis_bass/genesis_bass_046.wav", "assets/sounds/genesis_bass/genesis_bass_047.wav"
    },
    { // Instrument 3
        "assets/sounds/genesis_bass/genesis_bass_024.wav", "assets/sounds/genesis_bass/genesis_bass_025.wav",
        "assets/sounds/genesis_bass/genesis_bass_026.wav", "assets/sounds/genesis_bass/genesis_bass_027.wav",
        "assets/sounds/genesis_bass/genesis_bass_028.wav", "assets/sounds/genesis_bass/genesis_bass_029.wav",
        "assets/sounds/genesis_bass/genesis_bass_030.wav", "assets/sounds/genesis_bass/genesis_bass_031.wav",
        "assets/sounds/genesis_bass/genesis_bass_032.wav", "assets/sounds/genesis_bass/genesis_bass_033.wav",
        "assets/sounds/genesis_bass/genesis_bass_034.wav", "assets/sounds/genesis_bass/genesis_bass_035.wav",
        "assets/sounds/genesis_bass/genesis_bass_036.wav", "assets/sounds/genesis_bass/genesis_bass_037.wav",
        "assets/sounds/genesis_bass/genesis_bass_038.wav", "assets/sounds/genesis_bass/genesis_bass_039.wav",
        "assets/sounds/genesis_bass/genesis_bass_040.wav", "assets/sounds/genesis_bass/genesis_bass_041.wav",
        "assets/sounds/genesis_bass/genesis_bass_042.wav", "assets/sounds/genesis_bass/genesis_bass_043.wav",
        "assets/sounds/genesis_bass/genesis_bass_044.wav", "assets/sounds/genesis_bass/genesis_bass_045.wav",
        "assets/sounds/genesis_bass/genesis_bass_046.wav", "assets/sounds/genesis_bass/genesis_bass_047.wav"
    }
};

struct Glyph
{
    float time = 0.0f;
    int lane = 0;
    int instrument_slot = 0;
    int octave = 0;

    float y_position(float song_time, float hit_line_y) const
    {
        return hit_line_y - (time - song_time) * SCROLL_PX_PER_SEC;
    }
};

std::vector<Glyph> chart_from_song(const Song& song)
{
    std::vector<Glyph> glyphs;
    int ppq = song.header.ppq > 0 ? song.header.ppq : 480;
    float bpm = song.header.bpm > 0.0f ? song.header.bpm : 120.0f;
    float ticks_per_sec = ppq * (bpm / 60.0f);

    std::vector<std::pair<size_t, size_t>> track_note_counts;
    for (size_t i = 0; i < song.tracks.size(); i++)
        track_note_counts.push_back({i, song.tracks[i].notes.size()});

    std::sort(track_note_counts.begin(), track_note_counts.end(),
              [](const auto& a, const auto& b) { return a.second > b.second; });

    size_t n_used = std::min(static_cast<size_t>(MAX_INSTRUMENT_TYPES), track_note_counts.size());
    for (size_t slot = 0; slot < n_used; slot++)
    {
        size_t track_idx = track_note_counts[slot].first;
        size_t note_count = track_note_counts[slot].second;
        const Track& track = song.tracks[track_idx];
        std::printf("Instrument %zu: \"%s\" (family=%s number=%d) %zu notes\n",
                    slot, track.name.c_str(), track.instrument.family.c_str(),
                    track.instrument.number, note_count);
        int instrument_slot = static_cast<int>(slot);
        for (const Note& note : track.notes)
        {
            if (note.midi < 0 || note.midi > 127)
                continue;
            float time_sec = note.ticks / ticks_per_sec;
            int lane = note.midi % LANE_COUNT;
            int octave = note.midi % (LANE_COUNT * OCTAVE_COUNT);
            glyphs.push_back(Glyph{time_sec, lane, instrument_slot, octave});
        }
    }
    std::sort(glyphs.begin(), glyphs.end(),
              [](const Glyph& a, const Glyph& b) {
                  if (a.time != b.time)
                      return a.time < b.time;
                  return a.lane < b.lane;
              });
    return glyphs;
}

std::vector<Glyph> load_chart(const char* path)
{
    std::vector<Glyph> empty;
    std::FILE* fp = std::fopen(path, "rb");
    if (!fp)
        return empty;
    char read_buf[65536];
    rapidjson::FileReadStream is(fp, read_buf, sizeof(read_buf));
    rapidjson::Document doc;
    if (!doc.ParseStream(is).HasParseError())
    {
        Song song = parseSong(doc);
        std::fclose(fp);
        return chart_from_song(song);
    }
    std::fclose(fp);
    return empty;
}

} // namespace

extern std::string SELECTED_SONG_PATH;
extern int INSTRUMENT_GAMEPAD_INDEX[MAX_INSTRUMENT_TYPES];
extern int INSTRUMENT_PHYSICAL_GAMEPAD[MAX_INSTRUMENT_TYPES];

class GHHBScene : public Scene
{
public:
    Font font = {0};
    Music music = {0};
    bool music_loaded = false;
    std::vector<Glyph> chart;
    std::vector<Glyph*> spawned;
    std::unordered_set<Glyph*> completed_notes;
    float song_time = 0.0f;
    float chart_time_offset = 0.0f;
    int score = 0;
    int combo = 0;
    float upper_bar_y = 0.0f;
    float hit_line_y = 0.0f;
    float lane_width = 0.0f;
    float screen_width = 0.0f;
    float screen_height = 0.0f;
    Sound note_sounds[MAX_INSTRUMENT_TYPES][LANE_COUNT * OCTAVE_COUNT] = {{0}};
    bool note_sounds_loaded[MAX_INSTRUMENT_TYPES][LANE_COUNT * OCTAVE_COUNT] = {{false}};
    static constexpr float PRESS_FLASH_DURATION = 0.12f;
    static constexpr float MISS_FLASH_DURATION = 0.15f;
    float press_flash_timer[LANE_COUNT] = {0};
    float hit_flash_timer[LANE_COUNT] = {0};
    float miss_flash_timer[LANE_COUNT] = {0};
    bool game_ended = false;
    bool dev_auto_hit_mode = false;
    static constexpr float RESULTS_DELAY_AFTER_LAST_NOTE = 1.0f;
    std::shared_ptr<Background> background;

    void on_enter() override
    {
        chart = load_chart(SELECTED_SONG_PATH.c_str());
        float first_note_time = 0.0f;
        if (!chart.empty())
        {
            first_note_time = chart.front().time;
            float lead_seconds = (hit_line_y - 60.0f) / SCROLL_PX_PER_SEC;
            chart_time_offset = lead_seconds + LEAD_OFFSET_SECONDS - first_note_time;
        }
        song_time = 0.0f;
        score = 0;
        combo = 0;
        game_ended = false;
        dev_auto_hit_mode = false;
        spawned.clear();
        completed_notes.clear();
        for (int i = 0; i < LANE_COUNT; i++)
        {
            press_flash_timer[i] = 0.0f;
            hit_flash_timer[i] = 0.0f;
            miss_flash_timer[i] = 0.0f;
        }
        if (music_loaded)
        {
            StopMusicStream(music);
            PlayMusicStream(music);
            if (chart_time_offset < 0.0f)
            {
                SeekMusicStream(music, -chart_time_offset);
            }
        }
    }

    void on_exit() override
    {
        if (music_loaded)
        {
            StopMusicStream(music);
        }
    }

    ~GHHBScene() override
    {
        if (music_loaded)
        {
            StopMusicStream(music);
            UnloadMusicStream(music);
        }
        for (int slot = 0; slot < MAX_INSTRUMENT_TYPES; slot++)
        {
            for (int lane = 0; lane < LANE_COUNT * OCTAVE_COUNT; lane++)
            {
                if (note_sounds_loaded[slot][lane])
                {
                    UnloadSound(note_sounds[slot][lane]);
                }
            }
        }
    }

    void init_services() override {
        add_service<TextureService>();
    }

    void init() override
    {
        auto font_manager = game->get_manager<FontManager>();
        font = font_manager->get_font("Roboto");
        update_layout();
        for (int slot = 0; slot < MAX_INSTRUMENT_TYPES; slot++)
        {
            for (int lane = 0; lane < LANE_COUNT * OCTAVE_COUNT; lane++)
            {
                const char* path = INSTRUMENT_LANE_WAV[slot][lane];
                if (FileExists(path))
                {
                    note_sounds[slot][lane] = LoadSound(path);
                    note_sounds_loaded[slot][lane] = true;
                }
            }
        }
        background = add_game_object<Background>();
        background->add_tag("background");
    }

    float lane_center_x(int lane) const
    {
        return (lane + 0.5f) * lane_width;
    }

    bool is_lane_pressed(int lane) const
    {
        if (IsKeyPressed(KEY_KEYS[lane]))
        {
            return true;
        }
        for (int i = 0; i < MAX_GAMEPADS; i++)
        {
            if (IsGamepadAvailable(i) && IsGamepadButtonPressed(i, GAMEPAD_BUTTONS[lane]))
            {
                return true;
            }
        }
        return false;
    }

    bool lane_pressed_by_instrument_owner(int lane, int instrument_slot) const
    {
        int physical_id = INSTRUMENT_PHYSICAL_GAMEPAD[instrument_slot];
        if (physical_id < 0)
        {
            for (int i = 0; i < MAX_GAMEPADS; i++)
            {
                if (IsGamepadAvailable(i) && IsGamepadButtonPressed(i, GAMEPAD_BUTTONS[lane]))
                    return true;
            }
            return false;
        }
        return IsGamepadAvailable(physical_id) &&
               IsGamepadButtonPressed(physical_id, GAMEPAD_BUTTONS[lane]);
    }

    bool is_menu_pressed() const
    {
        if (IsKeyPressed(KEY_ENTER))
        {
            return true;
        }
        for (int i = 0; i < MAX_GAMEPADS; i++)
        {
            if (IsGamepadAvailable(i) && IsGamepadButtonPressed(i, GAMEPAD_BUTTON_MIDDLE_RIGHT))
            {
                return true;
            }
        }
        return false;
    }

    bool is_select_pressed() const
    {
        for (int i = 0; i < MAX_GAMEPADS; i++)
        {
            if (IsGamepadAvailable(i) && IsGamepadButtonPressed(i, GAMEPAD_BUTTON_MIDDLE_LEFT))
            {
                return true;
            }
        }
        return false;
    }

    float glyph_y(const Glyph& n) const
    {
        return hit_line_y - (n.time + chart_time_offset - song_time) * SCROLL_PX_PER_SEC;
    }

    bool is_note_hittable(const Glyph& n) const
    {
        float y = glyph_y(n);
        return y >= upper_bar_y - HIT_ZONE_MARGIN && y <= hit_line_y + HIT_ZONE_MARGIN;
    }

    void consume_note(Glyph* n)
    {
        auto it = std::find_if(spawned.begin(), spawned.end(), [n](Glyph* p) { return p == n; });
        if (it != spawned.end())
        {
            hit_flash_timer[n->lane] = PRESS_FLASH_DURATION;
            spawned.erase(it);
            completed_notes.insert(n);
            printf("note lane: %d, note octave: %d\n", n->lane, n->octave);
            if (note_sounds_loaded[n->instrument_slot][n->octave])
                PlaySound(note_sounds[n->instrument_slot][n->octave]);
            float y_n = glyph_y(*n);
            for (auto it2 = spawned.begin(); it2 != spawned.end();)
            {
                Glyph* other = *it2;
                if (other != n && other->lane == n->lane && other->instrument_slot == n->instrument_slot &&
                    fabsf(glyph_y(*other) - y_n) <= SIMULTANEOUS_NOTE_Y_TOLERANCE)
                {
                    completed_notes.insert(other);
                    it2 = spawned.erase(it2);
                }
                else
                {
                    ++it2;
                }
            }
        }
        combo++;
        score += 100 + std::min(combo * 10, 50);
    }

    void update_layout()
    {
        screen_width = static_cast<float>(GetScreenWidth());
        screen_height = static_cast<float>(GetScreenHeight());
        upper_bar_y = screen_height - RECEPTOR_HEIGHT;
        hit_line_y = screen_height - RECEPTOR_HEIGHT / 2.0f;
        lane_width = screen_width / LANE_COUNT;
    }

    void update(float delta_time) override
    {
        update_layout();
        if (is_select_pressed())
        {
            dev_auto_hit_mode = !dev_auto_hit_mode;
        }
        if (game_ended)
        {
            if (is_menu_pressed())
            {
                game->go_to_scene("title");
            }
            return;
        }

        if (music_loaded)
        {
            UpdateMusicStream(music);
            song_time = GetMusicTimePlayed(music);
        }
        else
        {
            song_time += delta_time;
        }

        float last_note_time = 0.0f;
        for (const auto& n : chart)
        {
            float t = n.time + chart_time_offset;
            if (t > last_note_time)
            {
                last_note_time = t;
            }
        }
        float note_exit_seconds = (hit_line_y - upper_bar_y) / SCROLL_PX_PER_SEC;
        if (song_time >= last_note_time + note_exit_seconds + RESULTS_DELAY_AFTER_LAST_NOTE)
        {
            game_ended = true;
            return;
        }

        float lead_seconds = (hit_line_y - 60.0f) / SCROLL_PX_PER_SEC;
        for (auto& n : chart)
        {
            if (completed_notes.count(&n) != 0)
            {
                continue;
            }
            bool already = std::find_if(spawned.begin(), spawned.end(),
                                       [&n](Glyph* p) { return p == &n; }) != spawned.end();
            if (!already && song_time >= n.time + chart_time_offset - lead_seconds)
            {
                spawned.push_back(&n);
            }
        }

        for (auto it = spawned.begin(); it != spawned.end();)
        {
            Glyph* n = *it;
            float y = glyph_y(*n);
            if (y > hit_line_y + HIT_ZONE_MARGIN)
            {
                miss_flash_timer[n->lane] = MISS_FLASH_DURATION;
                completed_notes.insert(n);
                it = spawned.erase(it);
                combo = 0;
            }
            else
            {
                ++it;
            }
        }

        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            press_flash_timer[lane] -= delta_time;
            if (press_flash_timer[lane] < 0.0f)
            {
                press_flash_timer[lane] = 0.0f;
            }
            hit_flash_timer[lane] -= delta_time;
            if (hit_flash_timer[lane] < 0.0f)
            {
                hit_flash_timer[lane] = 0.0f;
            }
            miss_flash_timer[lane] -= delta_time;
            if (miss_flash_timer[lane] < 0.0f)
            {
                miss_flash_timer[lane] = 0.0f;
            }
        }

        if (dev_auto_hit_mode)
        {
            std::vector<Glyph*> to_consume;
            for (Glyph* n : spawned)
            {
                if (is_note_hittable(*n))
                {
                    to_consume.push_back(n);
                }
            }
            for (Glyph* n : to_consume)
            {
                consume_note(n);
            }
        }
        else
        {
        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            bool pressed = is_lane_pressed(lane);
            if (pressed)
                press_flash_timer[lane] = PRESS_FLASH_DURATION;
            if (!pressed)
            {
                continue;
            }
            Glyph* best = nullptr;
            float best_dist = 1e9f;
            for (Glyph* n : spawned)
            {
                if (n->lane != lane)
                {
                    continue;
                }
                if (!is_note_hittable(*n))
                {
                    continue;
                }
                if (!lane_pressed_by_instrument_owner(lane, n->instrument_slot))
                {
                    continue;
                }
                float y = glyph_y(*n);
                float d = fabsf(y - hit_line_y);
                if (d < best_dist)
                {
                    best_dist = d;
                    best = n;
                }
            }
            if (best != nullptr)
            {
                consume_note(best);
            }
            else
            {
                combo = 0;
                score = std::max(0, score - 25);
            }
        }
        }

        if (is_menu_pressed())
        {
            game->go_to_scene("title");
        }
    }

    void draw_scene() override
    {
        if (background)
        {
            background->draw_object();
        }
        draw();
    }

    void draw() override
    {
        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            float cx = lane_center_x(lane);
            DrawLineEx(Vector2{cx, 0}, Vector2{cx, screen_height}, 2.0f, Color{70, 70, 90, 255});
        }

        DrawRectangle(0,
                      static_cast<int>(upper_bar_y),
                      static_cast<int>(screen_width),
                      static_cast<int>(RECEPTOR_HEIGHT),
                      Color{60, 60, 100, 255});
        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            if (hit_flash_timer[lane] > 0.0f)
            {
                float alpha = 180.0f * (hit_flash_timer[lane] / PRESS_FLASH_DURATION);
                DrawRectangle(static_cast<int>(lane * lane_width),
                              static_cast<int>(upper_bar_y),
                              static_cast<int>(lane_width),
                              static_cast<int>(RECEPTOR_HEIGHT),
                              Color{80, 255, 120, static_cast<unsigned char>(alpha)});
            }
            else if (press_flash_timer[lane] > 0.0f)
            {
                float alpha = 180.0f * (press_flash_timer[lane] / PRESS_FLASH_DURATION);
                DrawRectangle(static_cast<int>(lane * lane_width),
                              static_cast<int>(upper_bar_y),
                              static_cast<int>(lane_width),
                              static_cast<int>(RECEPTOR_HEIGHT),
                              Color{255, 255, 255, static_cast<unsigned char>(alpha)});
            }
            if (miss_flash_timer[lane] > 0.0f)
            {
                float alpha = 200.0f * (miss_flash_timer[lane] / MISS_FLASH_DURATION);
                DrawRectangle(static_cast<int>(lane * lane_width),
                              static_cast<int>(upper_bar_y),
                              static_cast<int>(lane_width),
                              static_cast<int>(RECEPTOR_HEIGHT),
                              Color{255, 80, 80, static_cast<unsigned char>(alpha)});
            }
        }
        DrawLineEx(Vector2{0, upper_bar_y}, Vector2{screen_width, upper_bar_y}, 3.0f, WHITE);
        DrawLineEx(Vector2{0, hit_line_y}, Vector2{screen_width, hit_line_y}, 3.0f, WHITE);

        const float button_label_font_size = 28.0f;
        const float button_label_y = hit_line_y + 18.0f;
        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            const char* label = GAMEPAD_BUTTON_LABELS[lane];
            float label_w = MeasureTextEx(font, label, button_label_font_size, 1).x;
            float cx = lane_center_x(lane);
            DrawTextEx(font, label,
                       {cx - label_w / 2.0f, button_label_y},
                       button_label_font_size, 1, Color{220, 220, 240, 255});
        }

        std::vector<std::vector<Glyph*>> by_lane(static_cast<size_t>(LANE_COUNT));
        for (Glyph* n : spawned)
        {
            float y = glyph_y(*n);
            if (y < -40.0f || y > screen_height + 40.0f)
            {
                continue;
            }
            by_lane[static_cast<size_t>(n->lane)].push_back(n);
        }
        for (int lane = 0; lane < LANE_COUNT; lane++)
        {
            std::vector<Glyph*>& list = by_lane[static_cast<size_t>(lane)];
            std::sort(list.begin(), list.end(),
                     [this](Glyph* a, Glyph* b) { return glyph_y(*a) < glyph_y(*b); });
            float left_base = lane * lane_width;
            for (size_t i = 0; i < list.size();)
            {
                size_t j = i;
                float y0 = glyph_y(*list[i]);
                while (j < list.size() &&
                       glyph_y(*list[j]) - y0 <= SIMULTANEOUS_NOTE_Y_TOLERANCE)
                {
                    j++;
                }
                std::vector<Glyph*> group(list.begin() + static_cast<std::ptrdiff_t>(i),
                                         list.begin() + static_cast<std::ptrdiff_t>(j));
                std::sort(group.begin(), group.end(),
                          [](Glyph* a, Glyph* b) { return a->instrument_slot < b->instrument_slot; });
                int instrument_count = 0;
                for (size_t g = 0; g < group.size(); g++)
                {
                    if (g == 0 || group[g]->instrument_slot != group[g - 1]->instrument_slot)
                    {
                        instrument_count++;
                    }
                }
                float slice_width = lane_width / static_cast<float>(instrument_count);
                float glyph_height = lane_width / 2.0f;
                int column = 0;
                for (size_t g = 0; g < group.size();)
                {
                    int slot = group[g]->instrument_slot;
                    float left = left_base + column * slice_width;
                    Glyph* n = group[g];
                    float y = glyph_y(*n);
                    float top = y - glyph_height / 2.0f;
                    Color fill = INSTRUMENT_COLORS[n->instrument_slot];
                    Color edge = Color{
                        static_cast<unsigned char>(std::min(255, fill.r + 35)),
                        static_cast<unsigned char>(std::min(255, fill.g + 50)),
                        static_cast<unsigned char>(std::min(255, fill.b + 50)), 255};
                    DrawRectangle(static_cast<int>(left), static_cast<int>(top),
                                  static_cast<int>(slice_width),
                                  static_cast<int>(glyph_height), fill);
                    DrawRectangleLinesEx(
                        Rectangle{left, top, slice_width, glyph_height}, 2.0f, edge);
                    while (g < group.size() && group[g]->instrument_slot == slot)
                    {
                        g++;
                    }
                    column++;
                }
                i = j;
            }
        }

        std::string score_text = "Score: " + std::to_string(score);
        DrawTextEx(font, score_text.c_str(), {20, 16}, 28, 1, WHITE);

        if (combo >= COMBO_DISPLAY_THRESHOLD)
        {
            int tier_index = std::min(COMBO_TIER_COUNT - 1,
                                     (combo - COMBO_DISPLAY_THRESHOLD) / COMBO_NOTES_PER_TIER);
            int size_tier = (combo - COMBO_DISPLAY_THRESHOLD) / COMBO_NOTES_PER_TIER;
            std::string combo_popup = std::string(COMBO_TIER_LABELS[tier_index]) + " " + std::to_string(combo);
            const float combo_font_size = 72.0f + size_tier * 6.0f;
            float combo_w = MeasureTextEx(font, combo_popup.c_str(), combo_font_size, 1).x;
            const float combo_margin = 24.0f;
            DrawTextEx(font, combo_popup.c_str(),
                       {screen_width - combo_w - combo_margin, combo_margin},
                       combo_font_size, 1, Color{255, 220, 100, 255});
        }

        DrawTextEx(font, "Arrows / D-pad / X Y A B / LB LT RB RT: hit when note is between the two white lines",
                  {20, upper_bar_y - 28}, 18, 1, Color{200, 200, 200, 255});

        if (game_ended)
        {
            DrawRectangle(0, 0, static_cast<int>(screen_width), static_cast<int>(screen_height),
                          Color{0, 0, 0, 200});
            const char* title_text = "Song complete!";
            const float title_font_size = 42.0f;
            float title_w = MeasureTextEx(font, title_text, title_font_size, 1).x;
            DrawTextEx(font, title_text,
                       {screen_width / 2.0f - title_w / 2.0f, screen_height / 2.0f - 80},
                       title_font_size, 1, WHITE);
            std::string final_score_text = "Final score: " + std::to_string(score);
            const float score_font_size = 32.0f;
            float score_w = MeasureTextEx(font, final_score_text.c_str(), score_font_size, 1).x;
            DrawTextEx(font, final_score_text.c_str(),
                       {screen_width / 2.0f - score_w / 2.0f, screen_height / 2.0f - 20},
                       score_font_size, 1, Color{220, 220, 255, 255});
            const char* prompt = "Press Enter to return to menu";
            const float prompt_font_size = 20.0f;
            float prompt_w = MeasureTextEx(font, prompt, prompt_font_size, 1).x;
            DrawTextEx(font, prompt,
                       {screen_width / 2.0f - prompt_w / 2.0f, screen_height / 2.0f + 40},
                       prompt_font_size, 1, Color{180, 180, 200, 255});
        }
    }
};