You have a persistent profile and a dynamic menu from the previous lesson. As a quick reminder, the profile now updates after each run and survives reloads. In this lesson, you will focus on the final assembly and performance polish:

• Drive the real-time game loop safely with React hooks.
• Add visual feedback with a dedicated ShopView.
• Finish the reducer logic for difficulty, auto-serve, and end conditions.
• Tie everything together in the menu and action panels with a clean UI.

By the end, the game will feel responsive, readable, and production-ready.

src/components/GameScreen.jsx

Explanation:

• The effect sets a 1-second interval that dispatches TICK only while playing and not paused. This avoids wasted work and keeps timing stable.
• Cleanup clears the interval to prevent memory leaks.
• The End Shift button dispatches END_SHIFT, moving to results immediately.

src/components/ShopView.jsx

Explanation:

• Translates state into friendly labels: mood (by satisfaction), queue status (by length), and supply status (beans/milk thresholds).
• The emoji “visual” reacts to queue length, giving instant, lightweight feedback.

src/reducers/gameReducer.js

Explanation:

• Constants and getInitialState define the "Day 0" shape of our world.
• Helper functions like getDifficultySettings and updateGameTime keep the reducer lean and focused on state transitions rather than math.

src/reducers/gameReducer.js

src/components/MenuScreen.jsx

Explanation:

• Shows lifetime stats pulled from the persistent profile.
• Difficulty buttons adjust game parameters via SET_DIFFICULTY before starting.

src/components/GameActions.jsx

Explanation:

• Each card is a declarative source of truth for costs and logic.
• Buttons use the enabled flag to visually communicate constraints (like not enough money or beans).

Great work. You:

• Drove the real-time loop with a clean, safe interval.
• Added a responsive ShopView with clear, immediate feedback.
• Finalized the reducer for difficulty, auto-serving, satisfaction, and end states.
• Polished the menu and actions so stats and controls feel cohesive.

You are ready to practice and make these patterns second nature. Let’s put the finishing touches into action.