/*
==========
Cariddi
==========

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see http://www.gnu.org/licenses/.

	@Repository:  https://github.com/edoardottt/cariddi

	@Author:      edoardottt, https://www.edoardoottavianelli.it


* Disclaimer *: Code partially taken from:
https://github.com/gocolly/colly/blob/v1.2.0/extensions/random_user_agent.go

*/

package crawler

import (
	"fmt"
	"math/rand"
	"time"
)

var ffVersions = []float32{
	58.0,
	57.0,
	56.0,
	52.0,
	48.0,
	40.0,
	35.0,
}

var chromeVersions = []string{
	"65.0.3325.146",
	"64.0.3282.0",
	"41.0.2228.0",
	"40.0.2214.93",
	"37.0.2062.124",
}

var osStrings = []string{
	"Macintosh; Intel Mac OS X 10_10",
	"Windows NT 10.0",
	"Windows NT 5.1",
	"Windows NT 6.1; WOW64",
	"Windows NT 6.1; Win64; x64",
	"X11; Linux x86_64",
}

//genFirefoxUA generates a random Firefox User Agent
func genFirefoxUA() string {
	rand.Seed(time.Now().UnixNano())
	version := ffVersions[rand.Intn(len(ffVersions))]
	os := osStrings[rand.Intn(len(osStrings))]
	return fmt.Sprintf("Mozilla/5.0 (%s; rv:%.1f) Gecko/20100101 Firefox/%.1f", os, version, version)
}

//genChromeUA generates a random Chrome User Agent
func genChromeUA() string {
	rand.Seed(time.Now().UnixNano())
	version := chromeVersions[rand.Intn(len(chromeVersions))]
	os := osStrings[rand.Intn(len(osStrings))]
	return fmt.Sprintf("Mozilla/5.0 (%s) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%s Safari/537.36", os, version)
}

//GenerateRandomUserAgent generates a random user agent
//(can be Chrome or Firefox).
func GenerateRandomUserAgent() string {
	rand.Seed(time.Now().UnixNano())
	var ua string
	decision := rand.Intn(100)
	if decision%2 == 0 {
		ua = genChromeUA()
	} else {
		ua = genFirefoxUA()
	}
	return ua
}