package net

import (
	"fmt"
	"net"
	"os"
	"sync"
)

// Start Starts the TCP server on the specified address.
func Start(addr string, stopChan <-chan struct{}, wg *sync.WaitGroup) {
	defer wg.Done()

	// Start listening on the specified address
	listener, err := net.Listen("tcp", addr)
	if err != nil {
		_, err := fmt.Fprintf(os.Stderr, "Error starting TCP server: %v", err)
		if err != nil {
			return
		}
		return
	}

	// Close the listener when the application closes.
	defer func(listener net.Listener) {
		err := listener.Close()
		if err != nil {
			return
		}
	}(listener)

	fmt.Printf("TCP server listening on %s\n", addr)

	// Listen for an incoming connection in a goroutine.
	go func() {
		for {
			conn, err := listener.Accept()
			if err != nil {
				select {
				case <-stopChan:
					return // Safe exit if stop has been signalled
				default:
					fmt.Fprintf(os.Stderr, "Error accepting connection: %v", err)
				}
				continue
			}

			// Handle connections in a new goroutine.
			go handleRequest(conn)
		}
	}()

	// Block until we receive a stop signal
	<-stopChan
}

// handleRequest handles incoming requests.
func handleRequest(conn net.Conn) {
	// Close the connection when you're done with it.
	defer conn.Close()

	// Make a buffer to hold incoming data.
	buf := make([]byte, 1024)

	// Read the incoming connection into the buffer.
	_, err := conn.Read(buf)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error reading: %v", err)
		return
	}

	// Send a response back to person contacting us.
	conn.Write([]byte("Hello, World!\n"))
}