academy-chauffeurs - emails.go

     1  package main
     2  
     3  import (
     4  	"crypto/tls"
     5  	"io"
     6  	"net"
     7  	"net/http"
     8  	"net/smtp"
     9  	"net/url"
    10  	"strings"
    11  	"text/template"
    12  )
    13  
    14  var (
    15  	compiledEmailTemplate *template.Template
    16  	emailServer           string
    17  	emailTLS              bool
    18  	emailFrom             string
    19  	emailAuth             smtp.Auth
    20  )
    21  
    22  func setEmailVars(server, username, password, templateT string) error {
    23  	// smtp://host:port or smtps://host:port for TLS
    24  	u, err := url.Parse(server)
    25  	if err != nil {
    26  		return err
    27  	}
    28  	t, err := template.New("email").Parse(templateT)
    29  	if err != nil {
    30  		return err
    31  	}
    32  	compiledEmailTemplate = t
    33  	emailServer = u.Hostname()
    34  	emailTLS = u.Scheme == "smtps"
    35  	if p := u.Port(); p == "" {
    36  		if emailTLS {
    37  			emailServer = u.Hostname() + ":465"
    38  		} else {
    39  			emailServer = u.Hostname() + ":25"
    40  		}
    41  	} else {
    42  		emailServer = u.Hostname() + ":" + p
    43  	}
    44  	emailAuth = smtp.PlainAuth("", username, password, emailServer)
    45  	emailFrom = username
    46  	return nil
    47  }
    48  
    49  func (c *Calls) PrepareEmail(eventID int64, md *MessageData) error {
    50  	return c.prepareMessage(compiledEmailTemplate, eventID, md)
    51  }
    52  
    53  func (c *Calls) SendEmail(md MessageData, e *string) error {
    54  	message := md.Message
    55  	headers := make([]byte, 0, len(message)+3)
    56  	for {
    57  		i := strings.Index(message, "\n")
    58  		if i < 0 {
    59  			break
    60  		}
    61  		line := message[:i]
    62  		message = message[i+1:]
    63  		line = strings.TrimRight(line, "\r")
    64  		if line == "" {
    65  			headers = append(headers, "\r\n"...)
    66  			break
    67  		}
    68  		i = strings.Index(line, ":")
    69  		canHeader := http.CanonicalHeaderKey(line[:i])
    70  		if i > 0 && len(line) > i+1 && (canHeader == "Subject" || canHeader == "Mime-Version" || canHeader == "Content-Type") {
    71  			headers = append(headers, canHeader...)
    72  			headers = append(headers, ": "...)
    73  			headers = append(headers, strings.TrimSpace(line[i+1:])...)
    74  			headers = append(headers, "\r\n"...)
    75  		} else {
    76  			message = line + "\n" + message
    77  			break
    78  		}
    79  	}
    80  
    81  	headers = append(headers, "\r\n"...)
    82  
    83  	var (
    84  		event  Event
    85  		client Client
    86  	)
    87  	err := c.GetEvent(md.ID, &event)
    88  	if err != nil {
    89  		return err
    90  	}
    91  	err = c.GetClient(event.ClientID, &client)
    92  	if err != nil {
    93  		return err
    94  	}
    95  	var conn net.Conn
    96  	if emailTLS {
    97  		conn, err = tls.Dial("tcp", emailServer, nil)
    98  	} else {
    99  		conn, err = net.Dial("tcp", emailServer)
   100  	}
   101  	if err != nil {
   102  		return err
   103  	}
   104  	cl, err := smtp.NewClient(conn, emailServer)
   105  	if err == nil {
   106  		err = cl.Auth(emailAuth)
   107  		if err == nil {
   108  			err = cl.Mail(emailFrom)
   109  			if err == nil {
   110  				err = cl.Rcpt(client.Email)
   111  				if err == nil {
   112  					var wr io.WriteCloser
   113  					wr, err = cl.Data()
   114  					if err == nil {
   115  						_, err = wr.Write(append(headers, message...))
   116  						if err == nil {
   117  							err = wr.Close()
   118  							if err == nil {
   119  								err = cl.Quit()
   120  							}
   121  						}
   122  					}
   123  				}
   124  			}
   125  		}
   126  	}
   127  	if err != nil {
   128  		*e = err.Error()
   129  	} else {
   130  		_, err = c.statements[MessageSent].Exec(md.ID)
   131  		if err != nil {
   132  			return err
   133  		}
   134  	}
   135  	return nil
   136  }
   137