client.go

package pixie

import (
	"encoding/xml"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"regexp"
	"strings"
)

//Client contains the API credentials
type Client struct {
	Username            string
	Password            string
	StandardCountryCode string
}

//New returns a client used for requests to the Pixie API
func New(username string, password string) Client {
	return Client{
		Username: username,
		Password: password,
	}
}

/*
Send an SMS via the Pixie API

- `sender` is the name that shows up on the receivers' phone.

- `to` is the phonenumber to which the SMS should be sent to,
multiple phonenumbers should be separated with commas (,).

- `message` is the message to send, use `\n` for newline.
*/
func (c Client) Send(sender, to, message string) error {
	//Make sure the arguments are not empty strings
	if sender == "" {
		return errors.New("the specified `sender` is not valid")
	} else if to == "" {
		return errors.New("the specified `to` is not valid")
	} else if message == "" {
		return errors.New("the specified `message` is not valid")
	}

	//Replace all invalid characters in the recipients string
	reg, err := regexp.Compile("[^,+0-9]+")
	if err != nil {
		return fmt.Errorf("failed to compile regexp: %v", err.Error())
	}
	to = reg.ReplaceAllString(to, "")

	//Use the standard country code if specified
	if c.StandardCountryCode != "" {
		var standardCountryCode = c.StandardCountryCode
		if standardCountryCode[0:1] != "+" {
			standardCountryCode = "+" + standardCountryCode
		}

		if to[0:1] == "0" {
			//First character in phone number is a zero, replace it with the standard country code
			var n []rune
			p := []rune(to)
			for i := 1; i < len(p); i++ {
				n = append(n, p[i])
			}

			to = standardCountryCode + string(n)
		}

		to = strings.ReplaceAll(to, ",0", ","+standardCountryCode)
	}

	//Send GET request to the Pixie SMS Server
	resp, err := http.DefaultClient.Get(
		fmt.Sprintf(
			"http://smsserver.pixie.se/sendsms.asp?account=%s&pwd=%s&receivers=%s&sender=%s&message=%s",
			url.QueryEscape(c.Username),
			url.QueryEscape(c.Password),
			url.QueryEscape(to),
			url.QueryEscape(sender),
			url.QueryEscape(message),
		),
	)
	if err != nil {
		return fmt.Errorf("failed to GET: %v", err.Error())
	}

	//Read response body
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("failed to read response body: %v", err.Error())
	}

	//Unmarshal xml
	var response struct {
		XMLName     xml.Name `xml:"response"`
		Code        string   `xml:"code,attr"`
		Description string   `xml:"description,attr"`
	}
	err = xml.Unmarshal(body, &response)
	if err != nil {
		return fmt.Errorf("failed to unmarshal xml: %v", err.Error())
	} else if response.Code != "0" {
		return errors.New(response.Description)
	}

	//No errors occurred
	return nil
}