treewide: refactor; defer cli handling to cobra

cmd/root.go

@@ -0,0 +1,91 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/spf13/cobra"
+	"notashelf.dev/tct/internal/tct"
+)
+
+var (
+	url         string
+	maxRequests int
+	delay       time.Duration
+	Version     string // will be set by main package
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "tct",
+	Short: "TCP Connection Timer - find optimal parallel request count",
+	Long:  `A tool to measure and find the optimal number of parallel TCP requests for a given URL.`,
+	Run:   run,
+}
+
+func Execute() {
+	if Version != "" {
+		rootCmd.Version = Version
+	}
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func init() {
+	rootCmd.Flags().StringVarP(&url, "url", "u", "http://example.com", "URL to fetch")
+	rootCmd.Flags().IntVarP(&maxRequests, "max", "m", 100, "Maximum number of parallel requests")
+	rootCmd.Flags().DurationVarP(&delay, "delay", "d", 0, "Delay between requests")
+}
+
+func run(cmd *cobra.Command, args []string) {
+	client := tct.NewClient()
+
+	// Context that listens for the interrupt signal
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	optimal := 0
+	minTime := time.Duration(0)
+
+	for i := 1; i <= maxRequests; i++ {
+		// Check for cancellation before starting the loop
+		if ctx.Err() != nil {
+			break
+		}
+
+		start := time.Now()
+		wg := &sync.WaitGroup{}
+		wg.Add(i)
+
+		for range i {
+			go func() {
+				defer wg.Done()
+				select {
+				case <-ctx.Done():
+					fmt.Println("Operation cancelled.")
+					return
+				default:
+					time.Sleep(delay)
+					client.MakeRequest(url)
+				}
+			}()
+		}
+
+		wg.Wait()
+		duration := time.Since(start)
+		fmt.Printf("Parallel Requests: %d, Time Taken: %s\n", i, duration)
+
+		if minTime == 0 || duration < minTime {
+			minTime = duration
+			optimal = i
+		}
+	}
+
+	fmt.Printf("\nOptimal Number of Parallel TCP Requests: %d\n", optimal)
+}