# Go Controller Implementation Summary

## Overview

The Go controller logic has been successfully moved from the example application into the lofigui library, making it extensible and customizable for all users.

## What Was Done

### 1. Created Library Controller (`controller.go`)

A new `controller.go` file was added to the library root with:

- **ControllerConfig struct**: Flexible configuration for template paths, refresh times, display URLs, and custom contexts
- **Two constructor functions**:
  - `NewController(config ControllerConfig)`: Full configuration control
  - `NewControllerFromDir(dir, name, refreshTime)`: Convenience function
- **Action management methods**: `StartAction()`, `EndAction()`, `IsActionRunning()`, `SetRefreshTime()`
- **Template context**: `StateDict(r *http.Request)` generates template context with current state
- **Route helpers**: `HandleRoot()` and `HandleDisplay()` reduce boilerplate
- **http.Handler interface**: `ServeHTTP()` allows controller to be used directly as a handler
- **Advanced methods**: `RenderTemplate()`, `GetTemplate()`, `ReloadTemplate()` for custom use cases

### 2. Updated Go Example (`examples/01_hello_world/go/main.go`)

Simplified from ~90 lines to ~45 lines by using the library controller:

**Before:**
```go
type Controller struct {
    template      *pongo2.Template
    actionRunning bool
}

func NewController() *Controller {
    tmpl, err := pongo2.FromFile("../templates/hello.html")
    if err != nil {
        log.Fatalf("Failed to load template: %v", err)
    }
    return &Controller{template: tmpl, actionRunning: false}
}
// ... many more methods ...
```

**After:**
```go
ctrl, err := lofigui.NewController(lofigui.ControllerConfig{
    TemplatePath: "../templates/hello.html",
    RefreshTime:  1,
    DisplayURL:   "/display",
})
if err != nil {
    log.Fatal(err)
}
```

### 3. Created Simplified Example (`examples/01_hello_world/go/hello_simple.go`)

Demonstrates the simplest usage pattern with `NewControllerFromDir()` and direct use of `ServeHTTP`.

### 4. Added Comprehensive Tests (`controller_test.go`)

11 test functions covering:
- Controller creation with various configurations
- Action state management
- Refresh time updates
- State dictionary generation
- Route handler helpers
- Custom context usage
- Error handling

All tests pass successfully.

### 5. Updated Dependencies

Added `github.com/flosch/pongo2/v6` to `go.mod` for template rendering support.

### 6. Created Documentation (`GO_CONTROLLER_GUIDE.md`)

Comprehensive guide covering:
- Quick start examples
- Customization options
- Complete API reference
- Advanced patterns
- Framework integration examples
- Migration guide
- Best practices

## Key Features

### Extensibility

The controller is now fully extensible with:

1. **Customizable Template Locations**: Not restricted to default "templates/" directory
   ```go
   TemplatePath: "../custom/path/template.html"
   ```

2. **Configurable Refresh Behavior**: Adjust auto-refresh timing
   ```go
   RefreshTime: 2  // seconds
   ```

3. **Custom Display URLs**: Control where actions redirect
   ```go
   DisplayURL: "/status"
   ```

4. **Isolated Contexts**: Use separate buffer contexts per controller
   ```go
   Context: lofigui.NewContext()
   ```

### Backward Compatibility

Existing code patterns still work - this is purely additive functionality.

### Clean Separation of Concerns

- **Library**: Contains reusable controller logic
- **Examples**: Show usage patterns, not implementation details
- **Tests**: Ensure reliability and document expected behavior

## Usage Examples

### Basic Usage
```go
ctrl, _ := lofigui.NewController(lofigui.ControllerConfig{
    TemplatePath: "../templates/hello.html",
})

http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    ctrl.HandleRoot(w, r, model, true)
})

http.HandleFunc("/display", func(w http.ResponseWriter, r *http.Request) {
    ctrl.HandleDisplay(w, r, nil)
})
```

### Simplified Usage
```go
ctrl, _ := lofigui.NewControllerFromDir("../templates", "hello.html", 1)

http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    ctrl.HandleRoot(w, r, model, true)
})

http.HandleFunc("/display", ctrl.ServeHTTP)  // Direct handler!
```

### Custom Context
```go
extra := pongo2.Context{
    "title": "My Page",
    "user":  currentUser,
}

ctrl.HandleDisplay(w, r, extra)
```

## Files Created/Modified

### Created
- `controller.go` - Main controller implementation
- `controller_test.go` - Comprehensive test suite
- `GO_CONTROLLER_GUIDE.md` - Complete documentation
- `GO_CONTROLLER_SUMMARY.md` - This file
- `examples/01_hello_world/go/hello_simple.go` - Simple example

### Modified
- `go.mod` - Added pongo2/v6 dependency
- `examples/01_hello_world/go/main.go` - Updated to use library controller

## Test Results

All controller tests pass:
```
✓ TestNewController (4 subtests)
✓ TestNewControllerFromDir
✓ TestActionManagement
✓ TestSetRefreshTime
✓ TestStateDict (2 subtests)
✓ TestHandleRoot
✓ TestHandleDisplay
✓ TestHandleDisplayWithExtraContext
✓ TestServeHTTP
✓ TestCustomContext
```

## Benefits

1. **DRY Principle**: Controller logic in one place, not duplicated in every app
2. **Easier Updates**: Bug fixes and improvements benefit all users
3. **Better Testing**: Comprehensive test coverage in the library
4. **Simpler Examples**: Examples focus on usage, not implementation
5. **Flexibility**: Users can customize behavior without modifying library code
6. **Discoverability**: Well-documented API with examples and tests

## Next Steps for Users

1. **Migrate existing apps**: Replace custom controller code with library version
2. **Customize as needed**: Use ControllerConfig to adjust behavior
3. **Refer to guide**: See GO_CONTROLLER_GUIDE.md for complete documentation
4. **Check examples**: Look at updated examples for usage patterns

## Conclusion

The Go controller is now a first-class library feature that provides the same extensibility and customization as the Python version, while maintaining Go's simplicity and type safety. Users can now build lofigui applications with minimal boilerplate while retaining full control over template locations, refresh behavior, and routing patterns.
