cariddi/utils/urls.go

/*
==========
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

	@License: https://github.com/edoardottt/cariddi/blob/main/LICENSE

*/

package utils

import (
	"errors"
	"net/url"
	"strings"
)

//GetHost takes as input a string and
//tries to parse it as url, if it's a
//well formatted url this function returns
//the host (the domain if you prefer)
func GetHost(input string) string {
	u, err := url.Parse(input)
	if err != nil {
		return ""
	}
	return u.Host
}

//GetProtocol takes as input a string and
//tries to parse it as url, if it's a
//well formatted url this function returns
//the protocol (the scheme if you prefer)
func GetProtocol(input string) string {
	u, err := url.Parse(input)
	if err != nil {
		return ""
	}
	return u.Scheme
}

//GetRootHost takes as input a string and
//tries to parse it as url, if it's a
//well formatted url this function returns
//the second level domain
func GetRootHost(input string) (string, error) {
	u, err := url.Parse(input)
	if err != nil {
		return "", err
	}
	//divide host and port, then split by dot
	parts := strings.Split(strings.Split(u.Host, ":")[0], ".")
	//return the last two parts
	if len(parts) > 1 {
		return parts[len(parts)-2] + "." + parts[len(parts)-1], nil
	}
	return "", errors.New("domain formatted in a bad way")
}

//HasProtocol takes as input a string and
//checks if it has a protocol ( like in a
//URI/URL)
func HasProtocol(input string) bool {
	res := strings.Index(input, "://")
	return res >= 0
}

//RemoveProtocol removes the protocol from
//the input string (something://...)
//If it's not present it returns the input
func RemoveProtocol(input string) string {
	res := strings.Index(input, "://")
	if res >= 0 {
		return input[res+3:]
	}
	return input
}

//RemovePort removes port from the input string
//If it's not present it returns the input
func RemovePort(input string) string {
	res := strings.Index(input, ":")
	if res >= 0 {
		return input[:res]
	}
	return input
}

//RetrieveParameters takes as input a string and
//if it's correctly url-formatted returns a slice
//of strings that are the parameters of the URL
func RetrieveParameters(input string) []string {
	var result []string
	u, err := url.Parse(input)
	if err != nil {
		return result
	}
	m, _ := url.ParseQuery(u.RawQuery)
	for k := range m {
		result = append(result, k)
	}
	return result
}

//AbsoluteURL takes as input a protocol, a domain and a path
//and returns the absolute URL with protocol + domain + path
func AbsoluteURL(protocol string, target string, path string) string {
	// if the path variable starts with a scheme, it means that the
	// path is itself an absolute path.
	if HasProtocol(path) {
		return path
	}
	if len(path) != 0 && path[0] == '/' {
		return protocol + "://" + target + path
	}
	return protocol + "://" + target + "/" + path
}

//SameDomain checks if two urls have the same domain
func SameDomain(url1 string, url2 string) bool {
	u1, err := url.Parse(url1)
	if err != nil {
		return false
	}
	u2, err := url.Parse(url2)
	if err != nil {
		return false
	}
	if u1.Host == "" || u2.Host == "" {
		return false
	}
	return u1.Host == u2.Host
}

//GetPath returns the path of the input string
//(if correctly URL-formatted)
func GetPath(input string) (string, error) {
	u, err := url.Parse(input)
	if err != nil {
		return "", err
	}
	return u.Path, nil
}

//IsEmailURL checks if the input string is a mail URL.
func IsEmailURL(input string) (bool, string) {
	if input[:7] == "mailto:" {
		return true, input[7:]
	}
	return false, ""
}