nntv/docs/codebase-summary.md

Codebase Summary - Night Ninja: Twilight Voyage

Overview

NNTV is a turn-based stealth puzzle game built with Svelte 5 and Vite 6.x. The codebase separates pure JS game engine (classes in lib/game/) from Svelte rendering (scenes + components). State flows one-way: game classes mutate internally, then renderVersion++ triggers Svelte re-derivation.

Module Inventory

Entry Point

• src/main.js — Mounts App.svelte into #app

Scene Router

• src/App.svelte — {#key currentScene} with transition:fade, passes navigate function as prop to all scenes

Scenes (src/scenes/)

File	Purpose
MainMenu.svelte	Start game, level select, settings, guide
StoryIntro.svelte	Scrolling narrative with skip button
LevelIntro.svelte	Level name + story text + continue
LevelSelect.svelte	4x3 grid of level buttons (locked/unlocked/completed)
Game.svelte	Main gameplay: state owner, input, turn loop, rendering
GameOver.svelte	Loss/twist screen, retry/menu
Settings.svelte	Language toggle (EN/VI)
Guide.svelte	Rules, controls, enemy types

Components (src/components/)

File	Purpose
Button.svelte	Reusable styled button
GameBoard.svelte	CSS grid of cells, each rendering a pixel-art tile
GameHud.svelte	Level, lives (pixel hearts), turns, pixel-icon action buttons
PlayerSprite.svelte	Pixel-art ninja rabbit sprite
GuardSprite.svelte	Pixel-art veggie sprite dispatched by guard.type + direction indicator
DetectionPopup.svelte	"Detected!" overlay with retry
LevelCompletePopup.svelte	Star rating, best moves, next-level action
PauseMenu.svelte	Resume / restart / main menu
ControlsOverlay.svelte	Keyboard / tap / swipe reference overlay

Game Engine (src/lib/game/) — Pure JS, no Svelte

File	Purpose
grid-system.js	GridSystem class: cell state, walls, goals, lighting
player.js	Player class: position, movement validation
guards.js	Guard base + 6 subclasses (Static, Rotating, Blinking, Mirror, Patrolling, Chaser)
turn-manager.js	TurnManager: turn cycle, guard updates, detection
level-manager.js	loadLevel(): GUARD_REGISTRY factory pattern for guard instantiation
level-solver.js	BFS solvability checker (test-only); reuses runtime AI via capture()/apply()
game-history.js	GameHistory class: undo/redo snapshots (Z/Y keys)
princess-mechanic.js	Princess detection logic: escalating light rings on level 12
touch-controls.js	TouchControls class: pointer gesture detection (legacy; no mobile support claim)

Level Data (src/lib/levels/)

File	Purpose
levels.js	LEVELS array: 12 level definitions (grid, guards, walls, goals); L1-L11 solvable, L12 intentionally unsolvable
levels.solvability.test.js	CI-enforced invariants: each L1-L11 solvable, L12 unsolvable, no wall/light overlaps, exactly 12 levels

Pixel-Art Pipeline (src/lib/pixel/)

File	Purpose
Pixel.svelte	SVG renderer: string-art + palette → run-length-merged <rect>s
palette.js	NNTV color constants (mirrors theme.css guard colors; extended atmosphere palette)
art-characters.js	32×32 sprites: rabbit, princess, 6 guard veggies + GUARD_SPRITES map
art-tiles.js	16×16 board tiles: empty, wall, goal, lit, mirror, preview
art-ui.js	Heart (full/empty), moon, logo, pixel icons (undo/redo/eye/pause/settings/lang/arrow)
art-scenes.js	80×N act backdrops + SCENE_BY_LEVEL mapping (garden/walls/fortress/underground/palace/chamber)

Audio System (src/lib/)

File	Purpose
audio.js	Web Audio API procedural sound: playTone, playMoveSound, playDetectionSound, playCompleteSound, toggleMute

Utilities (src/lib/)

File	Purpose
localization.js	getText/setLanguage/getLanguage/initLanguage
progress.js	getProgress/completeLevel via localStorage

Localization (src/lib/locales/)

File	Keys	Purpose
en.json	~55	English translations
vi.json	~55	Vietnamese translations

Styles (src/styles/)

File	Purpose
theme.css	CSS variables: colors, fonts, guard colors, grid colors

Class Hierarchy

Guard Inheritance

Guard (abstract base: grid, row, col, type, direction, isOn)
├── StaticGuard     — lights fixed litCells array
├── RotatingGuard   — rotates beam 90°/turn, castBeam with mirror bounce
├── BlinkingGuard   — toggles isOn, lights litCells when on
├── MirrorGuard     — lights own cell, stores reflectDirection (cw/ccw)
├── PatrollingGuard — follows path array, lights front + right cells
└── ChaserGuard     — BFS pathfinding to player, detectionRadius range

Key Data Structures

Level Definition

{
  id: 1, name: "Garden Path", storyKey: "level1Story",
  grid: { rows: 6, cols: 6 },
  player: { row: 0, col: 0 },
  goal: { row: 5, col: 5 },
  walls: [{ row: 1, col: 1 }, ...],
  guards: [
    { type: "static", position: { row: 2, col: 4 }, litCells: [...] },
    { type: "rotating", position: { row: 3, col: 3 }, startDirection: 0 },
    { type: "blinking", position: {...}, litCells: [...], startState: true },
    { type: "mirror", position: {...}, reflectDirection: "cw" },
    { type: "patrolling", startPosition: {...}, path: [...] },
  ],
  isFinalLevel: false
}

Cell State

{ isWall: boolean, isGoal: boolean, isLight: boolean }

Progress (localStorage)

{ maxLevel: 1, completedLevels: [1, 2, 3] }

Public API Summary

GridSystem

new GridSystem(rows, cols, cellSize)
.isValidPosition(row, col), .isWall(row, col), .setWall(row, col, value)
.isGoal(row, col), .setGoal(row, col, value)
.isLight(row, col), .setLight(row, col, value)
.clearAllLight(), .getAllCells() → [{row, col, isWall, isGoal, isLight}]

Player

new Player(grid, row, col)
.move(direction) → boolean, .moveTo(row, col) → boolean
.isInLitCell() → boolean, .isAtGoal() → boolean

Guards

All: .updateLight(allGuards?), .onTurnChange(allGuards?)
All: .capture() → state, .apply(state)   # dynamic-state snapshot for undo/preview
RotatingGuard: .castBeam(dir, fromRow, fromCol, range, allGuards, depth)
PatrollingGuard: .checkIfCircularPath(), path traversal with reversing
MirrorGuard: .reflectDirection ('cw' or 'ccw')
ChaserGuard: .bfsNextStep(targetRow, targetCol), hunting/returning state

PrincessMechanic

new PrincessMechanic()
.update(grid, player, goalRow, goalCol) → { showMessage, detected }
.lightRing(grid, goalRow, goalCol, radius)
.capture() → { alerted, alertRadius, messageShown }, .apply(state)
.reset()

GameHistory

new GameHistory()
.createSnapshot(player, guards, turnCount, princessState) → snapshot
.pushSnapshot(snap), .undo(...), .redo(...)
.canUndo(), .canRedo(), .reset()

TurnManager

new TurnManager()
.nextTurn(grid, player, guards) → { detected, levelComplete }
.reset()

Dependencies

Package	Version	Purpose
svelte	5.x	UI framework (runes mode)
vite	6.3.6	Build tool, dev server
@sveltejs/vite-plugin-svelte	6.x	Svelte compiler for Vite

File Dependency Map

main.js → App.svelte
App.svelte → all scenes

Game.svelte (central hub)
  ├── lib/game/level-manager.js → grid-system, player, guards, levels
  ├── lib/game/turn-manager.js
  ├── lib/game/game-history.js, princess-mechanic.js, touch-controls.js
  ├── lib/audio.js, lib/progress.js, lib/localization.js
  ├── lib/pixel/Pixel.svelte, lib/pixel/art-scenes.js (act backdrop)
  ├── components/GameBoard, PlayerSprite, GuardSprite, GameHud
  ├── components/DetectionPopup, LevelCompletePopup, PauseMenu, ControlsOverlay
  └── renderVersion pattern for reactivity

LevelSelect.svelte → level-manager.getTotalLevels(), progress.js, localization.js
LevelIntro.svelte → levels.js, lib/pixel/art-scenes.js, localization.js
MainMenu.svelte → lib/pixel/{Pixel, art-ui, art-characters}
Pixel components (PlayerSprite/GuardSprite/GameBoard/GameHud) → lib/pixel/Pixel + art-*
All scenes → localization.js (for UI text)

Statistics

Metric	Value
Total Source Files	~36 (8 scenes + 9 components + 8 engine + 6 pixel + audio + utils)
Number of Classes	10 (GridSystem, Player, Guard + 6 subclasses, TurnManager, GameHistory, TouchControls)
Number of Levels	12 (across 6 acts)
Guard Types	6 (Static, Rotating, Blinking, Mirror, Patrolling, Chaser)
Localization Keys	~67 per language
Max Grid Size	10x10
Max Guards/Level	8