Dienstplan-Pro/CLAUDE.md

CLAUDE.md - AI Assistant Guide for Dienstplan-Pro

Project Overview

Dienstplan-Pro is a German-language Progressive Web App (PWA) for calculating bonus payments for weekend and holiday duty shifts according to NRW (Nordrhein-Westfalen) regulations. The application is designed for healthcare or similar organizations that need to track employee on-call duties and calculate corresponding bonuses.

Primary Language: German (UI, comments, and documentation) Tech Stack: Vanilla JavaScript, HTML5, CSS3, LocalStorage API Deployment: Docker container with Node.js serve, designed for Railway hosting

Architecture

File Structure

Dienstplan-Pro/
├── index.html          # Main HTML entry point with tab-based UI
├── app.js              # Main application class (DienstplanApp) - UI management
├── calculator.js       # BonusCalculator class - core business logic
├── holidays.js         # HolidayProvider class - NRW holiday data 2025-2030
├── storage.js          # DataStorage class - LocalStorage persistence
├── styles.css          # All CSS styles (responsive, gradient theme)
├── sw.js               # Service Worker for PWA offline support
├── manifest.json       # PWA manifest configuration
├── test-suite.js       # Comprehensive test runner with assertions
├── test.html           # Browser-based test interface
├── Dockerfile          # Production deployment configuration
├── README.md           # User documentation (German)
└── TEST_GUIDE.md       # Testing documentation (German)

Module Responsibilities

Module	Class	Purpose
app.js	DienstplanApp	UI orchestration, event handling, user interactions
calculator.js	BonusCalculator	Bonus calculation logic, day type classification
holidays.js	HolidayProvider	NRW public holiday lookup (2025-2030)
storage.js	DataStorage	LocalStorage CRUD operations, import/export

Global Dependencies

All classes are attached to window for cross-module access:

• window.DienstplanApp (instantiated as global app)
• window.BonusCalculator
• window.HolidayProvider
• window.DataStorage

Script loading order in index.html is critical:

1. holidays.js
2. calculator.js
3. storage.js
4. app.js

Business Logic

Qualifying Days (WE/Feiertag)

A day is "qualifying" (eligible for higher bonus rate) if ANY of:

• Weekend: Friday (5), Saturday (6), or Sunday (0)
• Public Holiday: Any NRW state holiday
• Day Before Holiday: The calendar day preceding a public holiday

Bonus Calculation Rules

Constants:
- RATE_NORMAL = 250€  (normal weekday rate)
- RATE_WEEKEND = 450€ (qualifying day rate)
- MIN_QUALIFYING_DAYS = 2.0 (threshold)
- DEDUCTION_AMOUNT = 2.0 (deducted from qualifying days)

Algorithm:
1. Count qualifying days (Friday, Sat, Sun, holidays, day-before-holiday)
2. Count normal days (Mon-Thu, not holiday-related)
3. If qualifyingDays < 2.0: NO BONUS (total = 0€)
4. If qualifyingDays >= 2.0:
   - Deduct 2.0 from qualifying days (Friday priority)
   - Bonus = (normalDays × 250€) + (remainingQualifyingDays × 450€)

Friday Priority Deduction

When deducting the 2.0 qualifying days, Fridays are deducted first before Saturday/Sunday/holidays. This is tracked via qualifyingDaysFriday and qualifyingDaysOther in the calculator.

Duty Shares

Duties can be full (1.0) or half (0.5). Half duties count as 0.5 toward all calculations.

Data Storage

LocalStorage Keys

STORAGE_KEY_EMPLOYEES = 'dienstplan_employees'  // Array of employee names
STORAGE_KEY_DUTIES = 'dienstplan_duties'        // Nested duty object

Data Structure

// Employees: string[]
["Max Mustermann", "Anna Schmidt"]

// Duties: { employeeName: { "YYYY-MM": duties[] } }
{
  "Max Mustermann": {
    "2025-11": [
      { "date": "2025-11-22T11:00:00.000Z", "share": 1.0 },
      { "date": "2025-11-23T11:00:00.000Z", "share": 0.5 }
    ]
  }
}

Date Handling

• Dates are stored as ISO strings in LocalStorage
• Use T12:00:00 when creating dates to avoid timezone edge cases
• Dates are converted back to Date objects when retrieved

UI Structure

The app uses a tab-based interface with 4 sections:

1. Dienste eintragen (Enter Duties) - Add/remove shifts
2. Berechnung (Calculation) - Calculate and view bonuses
3. Mitarbeiter verwalten (Manage Employees) - CRUD for employees
4. Einstellungen (Settings) - Export/import, rules info, data clearing

Toast Notifications

Use app.showToast(message, type) where type is:

• 'success' - Green
• 'error' - Red
• 'info' - Blue

Testing

Running Tests

1. Serve the app: python3 -m http.server 8000 or use the Docker container
2. Open http://localhost:8000/test.html
3. Click "Alle Tests ausführen"

Test Categories

• HolidayProvider: Holiday detection, day-before-holiday
• Calculator - Tag-Klassifizierung: Day type classification
• Calculator - Bonusberechnung: Bonus calculation scenarios
• Storage: CRUD operations, import/export
• Edge Cases: Rounding, performance, leap years

Adding Tests

runner.test('Test Name', (t) => {
    const calculator = new BonusCalculator(new HolidayProvider());
    const duties = [{ date: new Date('2025-11-22T12:00:00'), share: 1.0 }];
    const result = calculator.calculateMonthlyBonus(duties);

    t.assertEqual(result.totalBonus, 450, 'Expected bonus');
    t.assertTrue(result.thresholdReached, 'Threshold should be reached');
    t.assertAlmostEqual(result.qualifyingDays, 1.0, 0.01, 'Qualifying days');
});

Development Workflow

Local Development

# Option 1: Python server
python3 -m http.server 8000

# Option 2: Node.js
npx http-server -p 8000

# Option 3: Docker
docker build -t dienstplan-pro .
docker run -p 3000:3000 -e PORT=3000 dienstplan-pro

Making Changes

1. All JavaScript is vanilla ES6+ classes
2. No build step required
3. Refresh browser to see changes
4. Run test suite after changes

Deployment (Railway)

The Dockerfile uses serve from npm to serve static files:

FROM node:20-alpine
RUN npm install -g serve
WORKDIR /app
COPY . .
CMD serve -s . -l tcp://0.0.0.0:${PORT:-3000}

Code Conventions

Language

• All user-facing text: German
• Code comments: German (existing pattern)
• Variable/function names: English (existing pattern)

Naming

• Classes: PascalCase (BonusCalculator, DataStorage)
• Methods/functions: camelCase (calculateMonthlyBonus, isHoliday)
• Constants: UPPER_SNAKE_CASE (RATE_NORMAL, STORAGE_KEY_DUTIES)
• DOM IDs: kebab-case (employee-select-duty, calc-month-select)

Error Handling

• Storage operations include try/catch with German console.error messages
• User-facing errors shown via toast notifications
• Invalid data returns empty arrays/objects rather than throwing

Date Format

• Display: German locale toLocaleDateString('de-DE')
• Storage: ISO string
• Internal: JavaScript Date objects with noon time (T12:00:00)

Common Tasks

Adding a New Holiday

Edit holidays.js, add to the appropriate year array:

{ date: 'YYYY-MM-DD', name: 'Holiday Name' }

Modifying Calculation Rules

Edit calculator.js constants:

this.RATE_NORMAL = 250;
this.RATE_WEEKEND = 450;
this.MIN_QUALIFYING_DAYS = 2.0;
this.DEDUCTION_AMOUNT = 2.0;

Adding Export Formats

The app supports multiple export formats in app.js:

• exportData() - JSON backup
• exportCSV() - Excel-compatible CSV with BOM
• exportBonusReport() - HTML report for printing/PDF
• generateEmailReport() - Copyable email text

Extending the UI

1. Add HTML in index.html within appropriate tab-content div
2. Add event listener in setupEventListeners() in app.js
3. Implement handler method in DienstplanApp class
4. Style in styles.css following existing patterns

PWA Features

• Service Worker (sw.js): Caches all assets for offline use
• Manifest (manifest.json): Enables "Add to Home Screen"
• Cache Version: dienstplan-pro-v1 (increment when updating assets)

Key Gotchas

1. Timezone Issues: Always use T12:00:00 when creating dates from strings to avoid midnight edge cases
2. LocalStorage Limits: ~5MB, sufficient for typical use but no warning when approaching limit
3. Float Precision: Use assertAlmostEqual in tests for floating-point comparisons
4. Script Order: holidays.js must load before calculator.js
5. Employee Deletion: Removes all associated duties automatically
6. Duty Updates: Adding a duty on existing date replaces (not duplicates)

Git Conventions

Recent commit patterns:

• feat: New features
• fix: Bug fixes
• Keep commit messages concise and descriptive