package main

import (
	"bufio"
	"fmt"
	"os"
	"time"
	"iptcp/pkg/ipstack"
	"strings"
	
)

func main() {
	if len(os.Args) != 2 {
		fmt.Printf("Usage:  %s <configFile>\n", os.Args[0])
		os.Exit(1)
	}

	fileName := os.Args[1]

	go ipstack.Initialize(fileName)

	// TODO @ MICHAEL: Dont know why its not running instantly
	go func() {
		for {
			ipstack.RequestRip()
			time.Sleep(5 * time.Second)
		}
	}()
	
	// TODO @ MICHEAL
	// go ipstack.CheckAndUpdateRoutingTable()

	scanner := bufio.NewScanner(os.Stdin)

	for scanner.Scan() {
		line := scanner.Text()
		switch line {
		case "li":
			fmt.Println("Name\tAddr/Prefix\tState")
			ipstack.SprintInterfaces()
		case "ln":
			fmt.Println("Iface\tVIP\tUDPAddr")
			ipstack.SprintNeighbors()
		case "lr":
			fmt.Println("T\tPrefix\tNext Hop\tCost")
			ipstack.SprintRoutingTable()
		case "q":
			ipstack.CleanUp()
			os.Exit(0)
		default:
			if len(line) > 4 {
				if line[:4] == "down" {
					ifaceName := line[5:]
					ipstack.InterfaceDownREPL(ifaceName)
				}

				if line[:4] == "send" {
					// get IP address and message that follows it
					IPAndMessage := strings.Split(line, " ")
					ipAddr := IPAndMessage[1]
					message := IPAndMessage[2:]

					// combine message into one string
					messageToSend := strings.Join(message, " ")
					messageToSendBytes := []byte(messageToSend)
					
					// check if ipAddr is in neighbor table
					iface, err := ipstack.GetNeighborByIP(ipAddr)
					if err != nil {
						fmt.Println(err)

						// check if ipAddr is in routing table
						iface, err = ipstack.GetRouteByIP(ipAddr)
						if err != nil {
							fmt.Println(err)
							continue
						}

						// get the interface to send from
						for _, interfaces := range ipstack.GetInterfaces() {
							if interfaces.Name == iface.Name {
								err = ipstack.SendIP(interfaces, iface, 0, messageToSendBytes, ipAddr)
								if err != nil {
									fmt.Println(err)
								}
								break
							}
						}
						continue
					}
					// neighbor was found, send to neighbor
					for _, interfaces := range ipstack.GetInterfaces() {
							if interfaces.Name == iface.Name {
								err = ipstack.SendIP(interfaces, iface, 0, messageToSendBytes, ipAddr)
								if err != nil {
									fmt.Println(err)
								}
								break
						}
					}
					continue
				}
			}
			if len(line) > 2 {
				if line[:2] == "up" {
					// get interface name
					ifaceName := line[3:]
					ipstack.InterfaceUpREPL(ifaceName)
				}
			}
			continue
		}
	}
}