Calendar/CLAUDE.md

# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Development Commands

### Build and Development
- **Build TypeScript:** `npm run build` - Compiles TypeScript sources to JavaScript using esbuild
- **Watch mode:** `npm run watch` - Continuously compiles TypeScript on file changes
- **Clean build:** `npm run clean` - Removes compiled JavaScript files (uses PowerShell on Windows)
- **Start server:** `dotnet run` - Starts the ASP.NET Core server on http://localhost:8000

### Typical Development Workflow
1. Install dependencies: `npm install`
2. Build TypeScript: `npm run build`
3. Start server: `dotnet run`
4. For active development, run `npm run watch` in a separate terminal

## Architecture Overview

Calendar Plantempus is an event-driven calendar application with the following architecture:

### Core Principles
- **Event-driven communication**: All components communicate via DOM CustomEvents through a central EventBus
- **No global state**: Each manager maintains its own state
- **Manager-based architecture**: Each manager has a specific responsibility
- **Pure DOM manipulation**: No external JavaScript frameworks (React, Vue, etc.)
- **TypeScript with esbuild**: Modern build tooling for fast compilation

### Key Components

#### EventBus (src/core/EventBus.ts)
Central event dispatcher using DOM CustomEvents. All inter-component communication flows through this:
```typescript
// Example event emission
eventBus.emit('calendar:view-changed', { view: 'week' });

// Example event subscription
eventBus.on('calendar:view-changed', (event) => { /* handle */ });
```

#### Manager Pattern
Each manager is instantiated via ManagerFactory in `src/index.ts` and handles a specific domain:
- **CalendarManager**: Main coordinator, initializes other managers
- **ViewManager**: Handles day/week/month view switching
- **NavigationManager**: Prev/next/today navigation
- **EventManager**: CRUD operations for calendar events
- **EventRenderer**: Visual rendering of events in the grid
- **GridManager**: Creates and maintains the calendar grid structure
- **ScrollManager**: Handles scroll position and time indicators
- **DragDropManager**: Drag & drop functionality for events

### Project Structure
```
src/
├── constants/     # Enums and constants (CoreEvents)
├── core/          # Core functionality (EventBus, CalendarConfig)
├── factories/     # ManagerFactory for dependency injection
├── interfaces/    # TypeScript interfaces
├── managers/      # Manager classes (one per domain)
├── renderers/     # Event rendering services
├── strategies/    # View strategy pattern implementations
├── types/         # TypeScript type definitions
└── utils/         # Utility functions (DateUtils, PositionUtils)

wwwroot/
├── css/          # Modular CSS files
├── js/           # Compiled JavaScript output
└── index.html    # Main HTML entry point
```

### CSS Architecture
Modular CSS structure without external frameworks:
- `calendar-base-css.css`: CSS custom properties and base styles
- `calendar-components-css.css`: UI components
- `calendar-events-css.css`: Event styling and colors
- `calendar-layout-css.css`: Grid and layout
- `calendar-popup-css.css`: Popup and modal styles
- `calendar-month-css.css`: Month view specific styles

### Event System
The application uses CoreEvents enum for type-safe event handling. Events follow the pattern `category:action`:
- `calendar:*` - General calendar events
- `grid:*` - Grid-related events
- `event:*` - Event data changes
- `navigation:*` - Navigation actions
- `view:*` - View changes

Core events are centralized in `src/constants/CoreEvents.ts` to maintain consistency across the application.

### Configuration System
CalendarConfig singleton (`src/core/CalendarConfig.ts`) manages:
- Grid settings (hour height, snap intervals, time boundaries)
- View configurations (day/week/month settings)
- Work week presets (standard, compressed, midweek, weekend, fullweek)
- Resource-based calendar mode support

### TypeScript Configuration
- Target: ES2020
- Module: ESNext
- Strict mode enabled
- Source maps enabled
- Output directory: `wwwroot/js`

### Build System
Uses esbuild for fast TypeScript compilation:
- Entry point: `src/index.ts`
- Output: `wwwroot/js/calendar.js` (single bundled file)
- Platform: Browser
- Format: ESM
- Source maps: Inline for development