/*
Description: Tool to check alive URLs.
Auth0r: sml@lacashita.com

Use it only as educational purpose.
*/

package main

import (
	"bufio"
	"flag"
	"fmt"
	"net/http"
	"os"
	"sync"
	"time"
)

// Func to check if URL works.
func checkUrl(page string, client http.Client, wg *sync.WaitGroup) {
	defer wg.Done()
	request, err := http.NewRequest("GET", page, nil)
	if err != nil {
		fmt.Printf("Error requesting url.\n")
	}
	response, err := client.Do(request)
	if err != nil {
		// Shows the errors in requests.
		fmt.Printf("Error in the URL: %v with the error %v\n", page, err)
	} else {
		if response.StatusCode == 200 {
			// Uncomment the following line to check what pages are OK (Status 200).
			// fmt.Printf("Page %v OK\n",page)
			defer response.Body.Close()
		} else {
			// Shows URLs with errors (Status != 200).
			fmt.Printf("Page %v with errors.\n",page)
		}
	}
}

var wg sync.WaitGroup

func lanomalie() {
fmt.Println(`
   __ _               _              
  / _| |             | |             
 | |_| |__  _ __ ___ | | _____ _ __  
 |  _| '_ \| '__/ _ \| |/ / _ \ '_ \ 
 | | | |_) | | | (_) |   <  __/ | | |
 |_| |_.__/|_|  \___/|_|\_\___|_| |_|
=====================================
[-] Checking alive URLs...

 `)
}

func main() {
	var page string
	fichero := flag.String("f", "", "File with urls")
	web := flag.String("u", "", "Only one url")
	flag.Parse()
	client := http.Client{Timeout: 10 * time.Second}
	// Check there are at least 2 args.
	if len(os.Args) < 2 {
		fmt.Println(`
Parameters:
-f File with URLs to check.
-u URL to check.

Examples to check file with URLs:
fbroken -f urls.txt 

Example to check URL:
fbroken -u https://domain.xxx
		`)
		os.Exit(1)
	}

	switch os.Args[1] {
	case "-f":
		lanomalie()
		// Open file and check URLs
		file, err := os.Open(*fichero)
		if err != nil {
			fmt.Print("Error opening the file")
		}
		defer file.Close()
		scanner := bufio.NewScanner(file)
		for scanner.Scan() {
			page = scanner.Text()
			go checkUrl(page, client, &wg)
			wg.Add(1)
		}

	case "-u":
		lanomalie()
		// Check directly the URL.
		go checkUrl(*web, client, &wg)
		wg.Add(1)
	default:
		fmt.Println("-f or -u expected")
		os.Exit(1)
	}
	wg.Wait()

}