Code Structure

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Project Overview

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Directory Layout

vitu/
├── lib/
│   └── main.dart              # Complete app implementation (6,698 lines)
├── android/                   # Android platform configuration
├── ios/                       # iOS platform configuration
├── windows/                   # Windows platform configuration
├── linux/                     # Linux platform configuration
├── macos/                     # macOS platform configuration
├── web/                       # Web platform configuration
├── assets/                    # App assets and images
│   └── WhatsApp Image 2026-02-16 at 12.16.07 PM.jpeg
├── test/                      # Test files
├── pubspec.yaml               # Dependencies and configuration
├── analysis_options.yaml      # Linter configuration
└── README.md                  # Project documentation

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main.dart Structure

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1. Imports and Configuration (Lines 1-20)

• Core Flutter imports (Material, Cupertino, Services)
• Third-party dependencies (image_picker, geolocator, sensors_plus, fl_chart, hive_flutter, google_generative_ai)
• Platform-specific imports (dart:io, dart:async, dart:convert, dart:math, dart:ui)

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2. Application Entry Point (Lines 21-54)

• Initializes Flutter bindings
• Opens Hive boxes for data persistence:
  • users - User profile data
  • user_settings - App preferences
  • daily_exercise - Exercise tracking
  • hydration_logs - Water intake logs
  • daily_hydration_summary - Daily summaries
• Sets immersive UI mode
• Launches MyApp widget

• Material App configuration
• Lime color scheme with Material 3
• Routes to SplashScreen

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3. Data Models (Lines 56-200)

• Properties: nombre, apellido, genero, edad, altura, peso, correo, contrasena
• UI settings: brightness, seedColor, fontFamily, followLocation
• Serialization: toMap() and fromMap() methods

• Theme preferences (brightness, seedColor, fontFamily)
• Location tracking (followLocation)
• Hydration goal (metaHydratationMl)

• _Receta: Recipe data (nombre, tiempo, dificultad, ingredientes, nutricion)
• _Ingrediente: Ingredient information
• _Nutricion: Nutritional data (kcal, proteinas, carbohidratos, grasas)

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4. Data Persistence Layer (Lines 127-268)

• getCurrentUserEmail() (lib/main.dart:132-136)
• getUserByEmail() (lib/main.dart:138-142)
• getCurrentUser() (lib/main.dart:144-148)
• saveCurrentUser() (lib/main.dart:150-153)
• verifyLogin() (lib/main.dart:155-159)
• getSettingsForUser() (lib/main.dart:211-215)
• saveSettings() (lib/main.dart:217-219)
• addHydrationMl() (lib/main.dart:224-268)
• computeDailyHydrationGoalMl() (lib/main.dart:202-209)

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5. Main Navigation (Lines 319-420)

• Bottom navigation with 5 tabs:
  • Home (Nutrition)
  • Exercise
  • Hydration
  • Sleep
  • Settings
• Theme management (brightness, seed color, font family)
• IndexedStack for tab switching

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6. UI Components

• Reusable button with scale animation
• Provides tactile feedback on press

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7. Feature Screens

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HomeScreen (Lines 448-1630)

• Purpose: Food analysis using Gemini AI
• Key Features:
  • Camera/gallery image picker
  • AI-powered nutritional analysis
  • Recipe recommendations
  • PieChart visualization (fl_chart)
  • Photo gallery management
• Key Methods:
  • _takePhoto() (lib/main.dart:529-532)
  • _analizarConGemini() (lib/main.dart:629-789)
  • _cargarRecetasRecomendadas() (lib/main.dart:1285-1309)
  • _parseRecetas() (lib/main.dart:1311-1393)
  • _macroSections() (lib/main.dart:1587-1629)

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ExerciseScreen (Lines 1632-2431)

• Purpose: Step tracking and activity detection
• Key Features:
  • Real-time step counting
  • Activity recognition (walking, running, vehicle, stationary)
  • Geolocator for speed tracking
  • Accelerometer for step detection
  • Weekly activity bar chart
  • Workout routine suggestions (Strength, Yoga, Stretching)
• Key Methods:
  • _ensurePermissionAndStart() (lib/main.dart:1739-1769)
  • _onAccel() (lib/main.dart:1806-1848)
  • _persistSteps() (lib/main.dart:1712-1722)
  • _weeklyBarChart() (lib/main.dart:2344-2430)
• Activity Detection:
  • Vehicle: Speed > 15 km/h (steps not counted)
  • Walking: Speed < 6 km/h, magnitude > 0.9
  • Running: Speed < 12 km/h, magnitude > 1.4
  • Stationary: Speed < 0.5 km/h

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RoutineSuggestionScreen (Lines 2433-2816)

• Purpose: AI-generated workout routines
• Features:
  • Personalized exercise suggestions via Gemini
  • JSON parsing of workout data
  • Exercise detail screens

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HydrationScreen (Lines ~3000-4500)

• Purpose: Water intake tracking
• Key Features:
  • Quick-add buttons (+100ml, +250ml, +500ml)
  • Daily goal calculation based on weight (35ml/kg)
  • Circular progress indicator
  • Weekly hydration chart
  • Persistent storage in Hive

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SleepScreen (Lines ~4500-5500)

• Purpose: Sleep tracking via screen state
• Key Features:
  • Automatic sleep detection (19:00-07:00)
  • Screen state monitoring
  • Sleep quality rating (editable)
  • Weekly sleep chart
  • Duration calculation

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SettingsScreen (Lines ~5500-6698)

• Purpose: App configuration and user profile
• Key Features:
  • Theme switching (light/dark)
  • Custom seed color picker
  • Font family selection
  • Personal data management
  • Password change
  • Logout functionality
  • Hydration goal customization

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Platform Folders

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android/

• Build configuration (build.gradle)
• Manifest permissions (camera, location, sensors)
• Minimum SDK: Configured for AGP 8+
• Removed incompatible activity_recognition_flutter plugin

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ios/

• Info.plist with permission descriptions
• Camera usage description
• Location usage description
• Photo library usage description

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windows/, linux/, macos/

• Native build files
• Platform channels (if needed)
• App icons and resources

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web/

• index.html entry point
• Web-specific assets
• Service worker configuration

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Assets Folder

• App icon: WhatsApp Image 2026-02-16 at 12.16.07 PM.jpeg
• Used for launcher icons across all platforms
• Configured in pubspec.yaml with flutter_launcher_icons

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Key Classes and Widgets

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File Organization Rationale

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Why Single-File Architecture?

1. Simplicity: All code in one place makes it easy to search and understand data flow
2. Rapid Prototyping: Fast iteration without managing multiple files
3. Self-Contained: No complex module dependencies or import chains
4. Educational: Clear progression from app entry to UI to data

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Trade-offs

• Easy to navigate with IDE search (Ctrl+F)
• No file organization decisions needed
• Clear mental model of app structure
• Fast compile times (single compilation unit)

• Large file can be overwhelming
• Limited code reusability across projects
• Difficult for team collaboration (merge conflicts)
• IDE performance may degrade with large files
• Testing individual components is harder

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When to Refactor

• Team size grows beyond 2-3 developers
• Features become independent products
• Need to share code across multiple apps
• File size exceeds 10,000 lines
• IDE performance degrades noticeably

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Code Organization Best Practices

1. Top-down flow: Global utilities → Models → Widgets → Screens
2. Grouped by feature: Each screen has its state, methods, and UI together
3. Consistent naming: Private methods prefixed with _
4. Clear separation: Data layer (Hive) separate from UI layer
5. Type safety: Strong typing throughout (User, UserSettings, etc.)

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Navigation Structure

SplashScreen
    ↓
LoginScreen / RegisterScreen
    ↓
VidaPlusApp (Bottom Navigation)
    ├── HomeScreen (Index 0)
    ├── ExerciseScreen (Index 1)
    │   └── RoutineSuggestionScreen
    │       └── SessionDetailScreen
    ├── HydrationScreen (Index 2)
    ├── SleepScreen (Index 3)
    └── SettingsScreen (Index 4)