track-gopher/examples/main.go

package main

import (
	"bufio"
	"context"
	"flag"
	"fmt"
	"os"
	"os/signal"
	"strings"
	"sync"
	"syscall"
	"time"

	"log/slog"
	"track-gopher/derby"
	"track-gopher/web"
)

func main() {
	// Create logger
	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
		Level: slog.LevelInfo,
	}))

	// Use the logger
	logger.Info("Starting derby race application")

	// Parse command line flags
	portName := flag.String("port", "/dev/ttyACM0", "Serial port for the derby clock")
	baudRate := flag.Int("baud", 19200, "Baud rate for the serial port")
	webPort := flag.Int("web-port", 8080, "Port for the web server")
	dbPath := flag.String("db", "./data/derby.db", "Path to SQLite database file")
	noWeb := flag.Bool("no-web", false, "Disable web interface")
	noTerminal := flag.Bool("no-terminal", false, "Disable terminal interface")
	flag.Parse()

	// Create a new derby clock connection
	clock, err := derby.NewDerbyClock(*portName, *baudRate)
	if err != nil {
		fmt.Printf("Error opening derby clock: %v\n", err)
		os.Exit(1)
	}
	defer clock.Close()

	// Set up signal handling for clean shutdown
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)

	var wg sync.WaitGroup

	// Create multiple event channels for fan-out
	terminalEvents := make(chan derby.Event, 10)
	webEvents := make(chan derby.Event, 10)

	// Start the event broadcaster with fan-out to multiple channels
	go func() {
		for event := range clock.Events() {
			// Clone the event to both channels
			terminalEvents <- event
			webEvents <- event
		}
		close(terminalEvents)
		close(webEvents)
	}()

	// Create a context for graceful shutdown
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Start web interface if enabled
	if !*noWeb {
		wg.Add(1)
		go func() {
			defer wg.Done()
			startWebInterface(clock, webEvents, *webPort, *dbPath, ctx)
		}()
	}

	// Start terminal interface if enabled
	if !*noTerminal {
		wg.Add(1)
		go func() {
			defer wg.Done()
			startTerminalInterface(clock, terminalEvents, ctx)
		}()
	}

	// Wait for signal to exit
	<-sigChan
	fmt.Println("Shutting down...")

	// Cancel context to signal all components to shut down
	cancel()

	// Give a moment for any pending operations to complete
	time.Sleep(500 * time.Millisecond)

	// Wait for all interfaces to shut down
	wg.Wait()
}

// startWebInterface initializes and runs the web interface
func startWebInterface(clock *derby.DerbyClock, events <-chan derby.Event, webPort int, dbPath string, ctx context.Context) {
	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
		Level: slog.LevelInfo,
	}))

	// Create and start the web server
	server, err := web.NewServer(clock, events, dbPath, webPort, logger)
	if err != nil {
		logger.Error("Error creating web server", "error", err)
		return
	}

	fmt.Printf("Web interface available at http://localhost:%d\n", webPort)

	// Start the web server
	if err := server.Start(); err != nil {
		logger.Error("Web server error", "error", err)
		return
	}

	// Wait for context cancellation
	<-ctx.Done()

	// Gracefully shut down the server
	if err := server.Shutdown(ctx); err != nil {
		logger.Error("Error shutting down web server", "error", err)
	}
}

// startTerminalInterface initializes and runs the terminal interface
func startTerminalInterface(clock *derby.DerbyClock, events <-chan derby.Event, ctx context.Context) {
	fmt.Println("Terminal interface started")

	// Reset the clock to start fresh
	if err := clock.Reset(); err != nil {
		fmt.Printf("Error resetting clock: %v\n", err)
		return
	}
	fmt.Println("Clock reset. Ready to start race.")

	// Print instructions
	fmt.Println("\nCommands:")
	fmt.Println("  r - Reset the clock")
	fmt.Println("  f - Force end the race")
	fmt.Println("  q - Quit the program")
	fmt.Println("  ? - Show this help message")

	// Process events from the clock
	go func() {
		raceResults := make([]*derby.Result, 0)
		for {
			select {
			case event, ok := <-events:
				if !ok {
					return
				}
				switch event.Type {
				case derby.EventRaceStart:
					fmt.Println("\n🏁 Race started!")

				case derby.EventLaneFinish:
					result := event.Result
					fmt.Printf("🚗 Lane %d finished in place %d with time %.4f seconds\n",
						result.Lane, result.FinishPlace, result.Time)
					raceResults = append(raceResults, result)

				case derby.EventRaceComplete:
					fmt.Println("\n🏆 Race complete! Final results:")
					for _, result := range raceResults {
						fmt.Printf("Place %d: Lane %d - %.4f seconds\n",
							result.FinishPlace, result.Lane, result.Time)
					}
					fmt.Println("\nEnter command (r/f/q/?):")
					raceResults = nil
				}
			case <-ctx.Done():
				return
			}
		}
	}()

	// Handle keyboard input
	reader := bufio.NewReader(os.Stdin)
	for {
		select {
		case <-ctx.Done():
			return
		default:
			fmt.Print("Enter command (r/f/q/?): ")
			input, err := reader.ReadString('\n')
			if err != nil {
				fmt.Printf("Error reading input: %v\n", err)
				continue
			}

			// Trim whitespace and convert to lowercase
			command := strings.TrimSpace(strings.ToLower(input))

			switch command {
			case "r":
				fmt.Println("Resetting clock...")
				if err := clock.Reset(); err != nil {
					fmt.Printf("Error resetting clock: %v\n", err)
				} else {
					fmt.Println("Clock reset. Ready to start race.")
				}

			case "f":
				fmt.Println("Forcing race to end...")
				if err := clock.ForceEnd(); err != nil {
					fmt.Printf("Error forcing race end: %v\n", err)
				}

			case "q":
				fmt.Println("Quitting...")
				return

			case "?":
				fmt.Println("\nCommands:")
				fmt.Println("  r - Reset the clock")
				fmt.Println("  f - Force end the race")
				fmt.Println("  q - Quit the program")
				fmt.Println("  ? - Show this help message")

			default:
				if command != "" {
					fmt.Println("Unknown command. Type ? for help.")
				}
			}
		}
	}
}