Functional Design Plan - Nokia Snake Game

Unit Context

Unit Name: Nokia Snake Game (Monolithic)
Type: Single monolithic web application
Scope: Complete Nokia Snake game implementation

Functional Design Plan Steps

Step 1: Analyze Unit Context

• 1.1 Review Unit Definition

  • Read aidlc-docs/inception/application-design/unit-of-work.md
  • Understand unit responsibilities and boundaries
  • Review development sequence and timeline

• 1.2 Review Application Design

  • Read aidlc-docs/inception/application-design/components.md
  • Read aidlc-docs/inception/application-design/component-methods.md
  • Read aidlc-docs/inception/application-design/services.md
  • Understand component interfaces and responsibilities

• 1.3 Review Requirements

  • Read aidlc-docs/inception/requirements/requirements.md
  • Identify functional requirements to be implemented
  • Map requirements to business logic areas

Step 2: Business Logic Modeling

• 2.1 Core Game Logic

  • Define game state transitions
  • Define collision detection algorithms
  • Define game rule enforcement
  • Define scoring algorithms

• 2.2 Game Mechanics

  • Define snake movement logic
  • Define food generation logic
  • Define power-up mechanics
  • Define game difficulty progression

• 2.3 State Management Logic

  • Define state persistence logic
  • Define state serialization/deserialization
  • Define state validation rules
  • Define state transition validation

Step 3: Domain Model Design

• 3.1 Core Entities

  • Define Snake entity with properties and behaviors
  • Define Food entity with types and effects
  • Define Game entity with state and rules
  • Define Player entity with score and progress
  • Define Power-up entity for special abilities

• 3.2 Value Objects

  • Define Position (x, y coordinates)
  • Define Direction (enum: up, down, left, right)
  • Define GameSettings (difficulty, speed, etc.)
  • Define Score (value, multiplier, timestamp)

• 3.3 Entity Relationships

  • Define relationships between entities
  • Define aggregation and composition
  • Define entity lifecycles
  • Define entity state transitions
  • Define validation rules for entities

Step 4: Business Rules Definition

• 4.1 Game Rules

  • Define collision rules (snake-self, snake-wall, snake-food)
  • Define movement rules (direction changes, boundary handling)
  • Define scoring rules (points per food, multipliers, combos)
  • Define game over conditions

• 4.2 Validation Rules

  • Define input validation rules
  • Define state validation rules
  • Define game rule validation
  • Define boundary condition rules

• 4.3 Business Logic Rules

  • Define power-up activation rules
  • Define difficulty adjustment rules
  • Define game progression rules
  • Define achievement rules

Step 5: Data Flow Design

• 5.1 Game Loop Data Flow

  • Define input processing flow
  • Define game state update flow
  • Define rendering data flow
  • Define score update flow

• 5.2 State Persistence Flow

  • Define save game flow
  • Define load game flow
  • Define high score persistence flow
  • Define settings persistence flow

Step 6: Frontend Components Design

• 6.1 UI Component Structure

  • Define component hierarchy
  • Define component props and state
  • Define component interactions
  • Define component lifecycle

• 6.2 User Interaction Flows

  • Define game start flow
  • Define game pause/resume flow
  • Define game over flow
  • Define menu navigation flow

• 6.3 Form Validation Rules

  • Define settings form validation
  • Define control mapping validation
  • Define game state validation

Step 7: Questions for User Input

Question 1: Game Difficulty Progression

How should game difficulty progress as the player advances?

A) Fixed difficulty - same speed and rules throughout B) Gradual speed increase - snake gets faster as it grows C) Level-based - discrete levels with increasing difficulty D) Adaptive - difficulty adjusts based on player performance

Question 2: Scoring System Details

What specific scoring rules should we implement?

A) Simple - fixed points per food (10 points) B) Progressive - more points for consecutive food without dying C) Combo-based - multiplier for speed, length, or special food D) Achievement-based - bonus points for specific accomplishments

Question 3: Power-up Mechanics

What power-up mechanics should we implement?

A) Speed boost - temporary increase in snake speed B) Invincibility - temporary protection from collisions C) Score multiplier - temporary point multiplier D) All of the above with different durations and effects

Question 4: Game State Persistence Details

What exactly should be saved in game state persistence?

A) Minimal - only high scores and settings B) Basic - current game state (snake, food, score) C) Comprehensive - full game state including power-ups, timers, etc. D) Checkpoint - save at specific points for continue functionality

Question 5: Input Validation Rules

What input validation rules should we enforce?

A) Basic - prevent opposite direction changes (can't go right when moving left) B) Advanced - validate all input against game state and rules C) Lenient - allow any input, game handles invalid states D) Strict - validate and sanitize all input with error handling

Question 6: Error Handling Strategy

How should we handle errors and exceptional conditions?

A) Silent fail - log errors but continue game if possible B) User notification - show error messages to user C) Graceful degradation - fallback to safe state D) Comprehensive - different strategies for different error types

Question 7: Frontend Component Granularity

How granular should frontend components be?

A) Coarse - few large components (GameScreen, MenuScreen, etc.) B) Moderate - logical component grouping (SnakeComponent, FoodComponent, etc.) C) Fine - many small, reusable components D) Hybrid - mix based on complexity and reusability

Step 8: Generate Functional Design Artifacts

• Generate business-logic-model.md with game logic design
• Generate business-rules.md with detailed business rules
• Generate domain-entities.md with domain model
• Generate frontend-components.md with UI component design

Step 9: Validate Functional Design

• Validate business logic completeness
• Validate domain model consistency
• Validate business rule correctness
• Validate frontend component design

Step 10: Security Compliance Check

• Verify SECURITY-05 (Input Validation) compliance in business rules
• Verify SECURITY-15 (Exception Handling) compliance in error handling
• Document security considerations in functional design

Follow-up Questions

Follow-up to Question 4: Game State Persistence Consistency

In the application design phase, you selected "Full game state persistence (save/load games)". Now you've selected "Minimal - only high scores and settings". Which approach should we use?

A) Stick with minimal (only high scores and settings) - simpler B) Use basic (current game state: snake, food, score) - balanced C) Use comprehensive (full state including power-ups, timers) - as originally planned D) Hybrid: Save high scores always, optional full game state save

Follow-up to Question 6: Error Handling Details

You selected "Silent fail - log errors but continue game if possible". For a game, some errors might require user notification. Could you clarify?

A) Silent fail for all errors (log only) B) User notification for critical errors (game-breaking) C) Graceful degradation with user feedback D) Different strategies based on error severity

Follow-up to Question 3: Power-up Duration

You selected "Speed boost" power-up. How long should power-ups last?

A) Fixed duration (e.g., 5 seconds) B) Duration based on snake length or score C) Until next food collection D) Other (please describe)