🍎 Switch-On Diet

A fully offline-first 28-day structured diet tracking mobile application built with Flutter (iOS + Android).

This app is designed to help users follow a strict 28-day diet program with daily meal tracking, automated reminders, and progress visualization — all without any backend server.

---

📱 Overview

Switch-On Diet is a minimal yet structured habit-tracking app focused on consistency and discipline over 28 days.

The app runs completely offline and stores all user data locally on the device.

Key Concept

"Start once, stay consistent for 28 days."

---

✨ Features

📆 28-Day Program System

• Automatically calculates current day (Day N)
• Based on user-defined start date
• Fixed 28-day cycle

---

🚀 Onboarding Flow

• Welcome screen on first launch
• "Start" button initializes program
• Saves startDate locally
• Skips onboarding on future launches

---

🍽️ Daily Meal Tracking

Each day includes:

• Breakfast
• Lunch
• Snack
• Dinner

Users can check off meals as completed.

---

📊 Diet Rules System

Dynamic weekly diet rules:

• Days 1–3: vegetables, tofu, yogurt only
• Day 4+: expanded diet (eggs, fish, meat, etc.)

---

🔔 Smart Local Notifications

• When a meal is checked:

  • Reminder notification after 5h 45m
  • Follow-up reminder after 6h 30m if incomplete

Fully implemented using local notification system only (no backend)

---

🎉 Daily Completion Reward

• Confetti / fireworks animation when all meals are completed
• Positive reinforcement for consistency

---

⚙️ Settings

• Simple notification toggle (ON / OFF only)
• Minimal configuration by design

---

📦 Offline Data Management

• Fully offline-first architecture
• Export user data as JSON file
• Import data to restore or transfer to another device

---

🏗️ Architecture

The app follows a clean, scalable Flutter architecture:

lib/
 ├── core/          # utilities, constants, helpers
 ├── data/          # local storage, models
 ├── domain/        # business logic
 ├── presentation/  # UI screens

Design Principles

• Offline-first
• Separation of concerns
• Feature-based modular structure

---

🧠 State Management

• Recommended: Riverpod / Provider / Bloc
• Local state persists using SQLite / Hive

---

🔔 Notification Strategy

• Uses flutter_local_notifications

• Schedule-based reminder system:

  • Trigger 1: +5h 45m after check
  • Trigger 2: +6h 30m fallback reminder

⚠️ Designed with iOS background limitations in mind.

---

🛠 Tech Stack

• Flutter
• Dart
• Hive / SQLite
• flutter_local_notifications
• Lottie / Confetti
• File system API (JSON export/import)

---

📂 Data Model (Simplified)

{
  "startDate": "2026-01-01",
  "days": [
    {
      "day": 1,
      "meals": {
        "breakfast": true,
        "lunch": false,
        "snack": true,
        "dinner": true
      }
    }
  ]
}

---

⚠️ Edge Cases & Considerations

• App reinstall resets local data unless exported
• iOS may delay scheduled notifications
• Timezone changes may affect Day calculation
• 28-day overflow must be handled safely
• Background execution is limited on mobile OS

---

🎯 Why This Project Matters

This project demonstrates:

• Offline-first mobile architecture
• Local persistence strategy
• Time-based scheduling logic
• Clean Flutter project structuring
• Real-world product thinking

---

🚀 Future Improvements

• Apple Health / Google Fit integration
• Cloud sync (optional)
• Habit streak system
• Dark mode
• AI diet suggestions

---

👨‍💻 Author

Portfolio project showcasing Flutter architecture and offline-first mobile system design.

---

📌 License

For educational and portfolio use.