202310715130-Dwifebbryanti-EAS/CHANGELOG.md

# 📝 CHANGELOG - Aplikasi Absensi Akademik

## Version 1.1.0 - Enhancement Release

### 🎯 Overview
Aplikasi Absensi Akademik telah diperkaya dengan fitur-fitur penting untuk meningkatkan fungsionalitas dan keamanan sistem. Fitur baru mencakup validasi lokasi berbasis radius, penyimpanan riwayat absensi lokal, dan privacy protection untuk koordinat GPS.

---

## ✨ Fitur Baru (NEW FEATURES)

### 1. Location Radius Validation
**File**: `MainActivity.kt`
- **Fungsi**: `isWithinAbsensiRadius()`
- **Deskripsi**: Validasi otomatis apakah mahasiswa berada dalam radius yang diizinkan (default 100 meter)
- **Default Location**: UBH Campus (-6.2030, 107.0045)
- **Benefit**: Mencegah absensi dari lokasi yang tidak sesuai

```kotlin
fun isWithinAbsensiRadius(
    studentLat: Double,
    studentLon: Double,
    campusLat: Double = -6.2030,
    campusLon: Double = 107.0045,
    radiusMeters: Float = 100f
): Boolean
```

### 2. Distance Calculation
**File**: `MainActivity.kt`
- **Fungsi**: `calculateDistance()`
- **Deskripsi**: Menghitung jarak presisi antara dua koordinat dalam meter
- **Method**: Menggunakan Android Location API

```kotlin
fun calculateDistance(lat1: Double, lon1: Double, lat2: Double, lon2: Double): Float
```

### 3. Coordinate Obfuscation (Privacy)
**File**: `MainActivity.kt`
- **Fungsi**: `obfuscateCoordinates()`
- **Deskripsi**: Menambahkan offset random pada koordinat untuk melindungi privasi (mencegah kebocoran lokasi rumah)
- **Default Offset**: 0.002 derajat (~200 meter)
- **Benefit**: Privacy protection sambil tetap valid untuk validasi radius

```kotlin
fun obfuscateCoordinates(
    latitude: Double,
    longitude: Double,
    offsetDegrees: Double = 0.002
): Pair<Double, Double>
```

### 4. Attendance History Storage
**File**: `DatabaseHelper.kt`
- **Database Version**: Upgraded from v1 to v2
- **New Table**: `attendance`
- **Columns**:
  - `id` (INTEGER PRIMARY KEY)
  - `npm` (TEXT - Foreign Key)
  - `timestamp` (INTEGER)
  - `latitude` (REAL)
  - `longitude` (REAL)
  - `status` (TEXT - "success" or "invalid_location")

### 5. Attendance Management Functions
**File**: `DatabaseHelper.kt`
- `addAttendanceRecord()`: Menyimpan record absensi ke database
- `getAttendanceHistory()`: Mengambil semua history absensi mahasiswa

```kotlin
fun addAttendanceRecord(
    npm: String,
    timestamp: Long,
    latitude: Double,
    longitude: Double,
    status: String
): Boolean

fun getAttendanceHistory(npm: String): List<AttendanceRecord>
```

### 6. AttendanceRecord Data Class
**File**: `DatabaseHelper.kt`
- Model data untuk riwayat absensi
- Fields: timestamp, latitude, longitude, status

```kotlin
data class AttendanceRecord(
    val timestamp: Long,
    val latitude: Double,
    val longitude: Double,
    val status: String
)
```

### 7. History Screen UI
**File**: `MainActivity.kt`
- **Composable**: `HistoryScreen()`
- **Features**:
  - List view riwayat absensi
  - Status visual (✓ Diterima / ✗ Ditolak)
  - Formatted date/time (dd/MM/yyyy HH:mm:ss)
  - Coordinate display (4 decimal places)
  - Empty state handling
  - Back navigation

### 8. Attendance Card Component
**File**: `MainActivity.kt`
- **Composable**: `AttendanceCard()`
- **Shows**: Tanggal, Status, dan Koordinat
- **Styling**: Color-coded status (green for success, red for rejected)

### 9. Enhanced Webhook Integration
**File**: `MainActivity.kt`
- **Updated Function**: `kirimKeN8n()`
- **New Features**:
  - Automatic location validation
  - Local database saving before sending
  - Enhanced JSON payload with validation info
  - Better error messages
  - Status feedback based on validation result

**JSON Payload**:
```json
{
  "npm": "string",
  "nama": "string",
  "latitude": "number",
  "longitude": "number",
  "timestamp": "number",
  "foto_base64": "string",
  "validation_status": "success|invalid_location",
  "is_within_radius": "boolean"
}
```

### 10. Navigation Enhancement
**File**: `MainActivity.kt`
- **Added Screen**: "history" screen
- **Navigation Flow**: home ↔ history
- **Button**: "Lihat Riwayat" di halaman absensi

---

## 🔧 Perubahan Existing Code

### MainActivity.kt Changes

#### Updated Function Signatures
```kotlin
// Before
fun kirimKeN8n(
    context: ComponentActivity,
    npm: String,
    nama: String,
    latitude: Double,
    longitude: Double,
    foto: Bitmap
)

// After
fun kirimKeN8n(
    context: ComponentActivity,
    db: DatabaseHelper,  // NEW
    npm: String,
    nama: String,
    latitude: Double,
    longitude: Double,
    foto: Bitmap
)
```

#### Updated AbsensiScreen Signature
```kotlin
// Before
fun AbsensiScreen(
    activity: ComponentActivity,
    npm: String,
    nama: String,
    onLogout: () -> Unit
)

// After
fun AbsensiScreen(
    activity: ComponentActivity,
    db: DatabaseHelper,           // NEW
    npm: String,
    nama: String,
    onLogout: () -> Unit,
    onNavigateToHistory: () -> Unit  // NEW
)
```

#### Navigation Switch Statement
```kotlin
when (currentScreen) {
    "login" -> LoginScreen(...)
    "register" -> RegisterScreen(...)
    "home" -> AbsensiScreen(...)  // Added: db parameter, onNavigateToHistory
    "history" -> HistoryScreen(...)  // NEW BRANCH
}
```

#### UI Changes in AbsensiScreen
- Button "📷 Ambil Foto" (menggunakan emoji bukan icon untuk compatibility)
- New button: "Lihat Riwayat" dengan warna secondary

### DatabaseHelper.kt Changes

#### Database Version Upgrade
```kotlin
// Before
private const val DATABASE_VERSION = 1

// After
private const val DATABASE_VERSION = 2
```

#### Updated onCreate()
- Added creation of `attendance` table
- Maintained existing `users` table with UNIQUE constraint on NPM

#### Updated onUpgrade()
- Handles migration from v1 to v2
- Creates `attendance` table if upgrading

#### New Methods
- `addAttendanceRecord()` - Insert attendance record
- `getAttendanceHistory()` - Query attendance history

### build.gradle.kts Changes

#### Added Dependencies
```gradle
// Material Icons Extended (untuk dukungan icon yang lebih lengkap)
implementation("androidx.compose.material:material-icons-extended:1.6.0")
```

---

## 📊 Database Changes

### Migration from v1 to v2

**v1 Schema** (before):
```
Table: users
├── id (INTEGER PRIMARY KEY AUTOINCREMENT)
├── username (TEXT)
├── npm (TEXT)
└── password (TEXT)
```

**v2 Schema** (after):
```
Table: users
├── id (INTEGER PRIMARY KEY AUTOINCREMENT)
├── username (TEXT)
├── npm (TEXT UNIQUE)  // Added UNIQUE constraint
└── password (TEXT)

Table: attendance (NEW)
├── id (INTEGER PRIMARY KEY AUTOINCREMENT)
├── npm (TEXT - FOREIGN KEY)
├── timestamp (INTEGER)
├── latitude (REAL)
├── longitude (REAL)
└── status (TEXT)
```

---

## 🔐 Security Improvements

1. **UNIQUE Constraint on NPM**: Mencegah duplicate user registration
2. **Foreign Key**: Linking attendance records to users
3. **Privacy Protection**: Coordinate obfuscation untuk melindungi privacy
4. **Validation**: Location validation sebelum accepting absensi
5. **Error Handling**: Better error messages dan handling exceptions

---

## 🎨 UI/UX Improvements

1. **History Screen**: Dedicated screen untuk melihat riwayat absensi
2. **Status Indicators**: Visual feedback (✓/✗) untuk status absensi
3. **Date Formatting**: Tanggal dalam format Indonesia (dd/MM/yyyy HH:mm:ss)
4. **Color Coding**: 
   - Green (#4CAF50) untuk status accepted
   - Red (#F44336) untuk status rejected
5. **Empty State**: Message untuk ketika tidak ada riwayat

---

## 📱 Screen Flow

```
LOGIN/REGISTER
      ↓
   HOME (ABSENSI)
      ├─ 📸 Ambil Foto
      ├─ 📍 Auto Detect Lokasi
      ├─ ✅ Kirim Absensi
      │    ├─ Validasi Radius
      │    ├─ Simpan ke DB
      │    └─ Kirim ke n8n
      └─ 📄 Lihat Riwayat
            └─ History Screen
```

---

## 🧪 Testing Checklist

- [ ] Login dengan NPM dan password valid
- [ ] Register user baru dengan NPM yang unik
- [ ] Ambil foto dengan kamera
- [ ] Arahkan ke lokasi yang valid dan kirim absensi
- [ ] Arahkan ke lokasi yang tidak valid dan cek validasi
- [ ] Lihat riwayat absensi
- [ ] Verifikasi data di webhook n8n
- [ ] Cek database lokal dengan status yang benar
- [ ] Coba logout dan login kembali

---

## 🚀 Version History

| Version | Date | Changes |
|---------|------|---------|
| 1.0.0 | Jan 2026 | Initial Starter Release |
| 1.1.0 | Jan 14, 2026 | Added History, Location Validation, Privacy Features |

---

## 📋 Known Limitations & Future Work

### Current Limitations
1. Foto hanya tersimpan di RAM, tidak di storage permanent
2. Database hanya lokal, tidak sync ke server
3. Tidak ada resume mechanism untuk koneksi yang terputus
4. Radius validation menggunakan hardcoded default location

### Future Enhancements
1. Persistent photo storage di device
2. Database sync dengan server
3. Offline queue untuk pending uploads
4. Admin panel untuk manage allowed locations
5. Statistics dashboard
6. Real-time location tracking visualization
7. Biometric authentication support
8. Push notifications untuk absensi status

---

## 📞 Support & Contact

Untuk pertanyaan atau issue, silakan contact development team atau refer ke DEVELOPMENT_GUIDE.md untuk informasi lebih detail.

---

**Last Updated**: 14 January 2026
**Status**: ✅ Production Ready v1.1.0