SMTP sync/async deduplication

Deduplicate synchronous and asynchronous code with the multisync pragma.
Pass address and port at connect rather than ``new(Async)Smtp``.

lib/pure/smtp.nim

@@ -20,7 +20,8 @@
 ##   var msg = createMessage("Hello from Nim's SMTP",
 ##                           "Hello!.\n Is this awesome or what?",
 ##                           @["foo@gmail.com"])
-##   var smtpConn = connect("smtp.gmail.com", Port 465, true, true)
+##   let smtpConn = newSmtp(useSsl = true, debug=true)
+##   smtpConn.connect("smtp.gmail.com", Port 465)
 ##   smtpConn.auth("username", "password")
 ##   smtpConn.sendmail("username@gmail.com", @["foo@gmail.com"], $msg)
 ##
@@ -34,10 +35,6 @@ import asyncnet, asyncdispatch
 export Port
 
 type
-  Smtp* = object
-    sock: Socket
-    debug: bool
-
   Message* = object
     msgTo: seq[string]
     msgCc: seq[string]
@@ -47,37 +44,29 @@ type
 
   ReplyError* = object of IOError
 
-  AsyncSmtp* = ref object
+  SmtpBase[SocketType] = ref object
-    sock: AsyncSocket
+    sock: SocketType
-    address: string
-    port: Port
-    useSsl: bool
     debug: bool
 
+  Smtp* = SmtpBase[Socket]
+  AsyncSmtp* = SmtpBase[AsyncSocket]
+
 {.deprecated: [EInvalidReply: ReplyError, TMessage: Message, TSMTP: Smtp].}
 
-proc debugSend(smtp: Smtp, cmd: string) =
+proc debugSend(smtp: Smtp | AsyncSmtp, cmd: string) {.multisync.} =
   if smtp.debug:
     echo("C:" & cmd)
-  smtp.sock.send(cmd)
+  await smtp.sock.send(cmd)
-
-proc debugRecv(smtp: var Smtp): TaintedString =
-  var line = TaintedString""
-  smtp.sock.readLine(line)
 
+proc debugRecv(smtp: Smtp | AsyncSmtp): Future[TaintedString] {.multisync.} =
+  result = await smtp.sock.recvLine()
   if smtp.debug:
-    echo("S:" & line.string)
+    echo("S:" & result.string)
-  return line
 
 proc quitExcpt(smtp: Smtp, msg: string) =
   smtp.debugSend("QUIT")
   raise newException(ReplyError, msg)
 
-proc checkReply(smtp: var Smtp, reply: string) =
-  var line = smtp.debugRecv()
-  if not line.string.startswith(reply):
-    quitExcpt(smtp, "Expected " & reply & " reply, got: " & line.string)
-
 const compiledWithSsl = defined(ssl)
 
 when not defined(ssl):
@@ -86,63 +75,6 @@ when not defined(ssl):
 else:
   let defaultSSLContext = newContext(verifyMode = CVerifyNone)
 
-proc connect*(address: string, port = Port(25),
-              ssl = false, debug = false,
-              sslContext = defaultSSLContext): Smtp =
-  ## Establishes a connection with a SMTP server.
-  ## May fail with ReplyError or with a socket error.
-  result.sock = newSocket()
-  if ssl:
-    when compiledWithSsl:
-      sslContext.wrapSocket(result.sock)
-    else:
-      raise newException(ESystem,
-                         "SMTP module compiled without SSL support")
-  result.sock.connect(address, port)
-  result.debug = debug
-
-  result.checkReply("220")
-  result.debugSend("HELO " & address & "\c\L")
-  result.checkReply("250")
-
-proc auth*(smtp: var Smtp, username, password: string) =
-  ## Sends an AUTH command to the server to login as the `username`
-  ## using `password`.
-  ## May fail with ReplyError.
-
-  smtp.debugSend("AUTH LOGIN\c\L")
-  smtp.checkReply("334") # TODO: Check whether it's asking for the "Username:"
-                         # i.e "334 VXNlcm5hbWU6"
-  smtp.debugSend(encode(username) & "\c\L")
-  smtp.checkReply("334") # TODO: Same as above, only "Password:" (I think?)
-
-  smtp.debugSend(encode(password) & "\c\L")
-  smtp.checkReply("235") # Check whether the authentification was successful.
-
-proc sendmail*(smtp: var Smtp, fromaddr: string,
-               toaddrs: seq[string], msg: string) =
-  ## Sends `msg` from `fromaddr` to `toaddr`.
-  ## Messages may be formed using ``createMessage`` by converting the
-  ## Message into a string.
-
-  smtp.debugSend("MAIL FROM:<" & fromaddr & ">\c\L")
-  smtp.checkReply("250")
-  for address in items(toaddrs):
-    smtp.debugSend("RCPT TO:<" & address & ">\c\L")
-    smtp.checkReply("250")
-
-  # Send the message
-  smtp.debugSend("DATA " & "\c\L")
-  smtp.checkReply("354")
-  smtp.debugSend(msg & "\c\L")
-  smtp.debugSend(".\c\L")
-  smtp.checkReply("250")
-
-proc close*(smtp: Smtp) =
-  ## Disconnects from the SMTP server and closes the socket.
-  smtp.debugSend("QUIT\c\L")
-  smtp.sock.close()
-
 proc createMessage*(mSubject, mBody: string, mTo, mCc: seq[string],
                 otherHeaders: openarray[tuple[name, value: string]]): Message =
   ## Creates a new MIME compliant message.
@@ -178,81 +110,94 @@ proc `$`*(msg: Message): string =
   result.add("\c\L")
   result.add(msg.msgBody)
 
-proc newAsyncSmtp*(address: string, port: Port, useSsl = false,
+proc newSmtp*(useSsl = false, debug=false,
+              sslContext = defaultSslContext): Smtp =
+  ## Creates a new ``Smtp`` instance.
+  new result
+  result.debug = debug
+
+  result.sock = newSocket()
+  if useSsl:
+    when compiledWithSsl:
+      sslContext.wrapSocket(result.sock)
+    else:
+      raise newException(SystemError,
+                         "SMTP module compiled without SSL support")
+
+proc newAsyncSmtp*(useSsl = false, debug=false,
                    sslContext = defaultSslContext): AsyncSmtp =
   ## Creates a new ``AsyncSmtp`` instance.
   new result
-  result.address = address
+  result.debug = debug
-  result.port = port
-  result.useSsl = useSsl
 
   result.sock = newAsyncSocket()
   if useSsl:
     when compiledWithSsl:
       sslContext.wrapSocket(result.sock)
     else:
-      raise newException(ESystem,
+      raise newException(SystemError,
                          "SMTP module compiled without SSL support")
 
 proc quitExcpt(smtp: AsyncSmtp, msg: string): Future[void] =
   var retFuture = newFuture[void]()
-  var sendFut = smtp.sock.send("QUIT")
+  var sendFut = smtp.debugSend("QUIT")
   sendFut.callback =
     proc () =
       # TODO: Fix this in async procs.
       raise newException(ReplyError, msg)
   return retFuture
 
-proc checkReply(smtp: AsyncSmtp, reply: string) {.async.} =
+proc checkReply(smtp: Smtp | AsyncSmtp, reply: string) {.multisync.} =
-  var line = await smtp.sock.recvLine()
+  var line = await smtp.debugRecv()
-  if not line.string.startswith(reply):
+  if not line.startswith(reply):
-    await quitExcpt(smtp, "Expected " & reply & " reply, got: " & line.string)
+    await quitExcpt(smtp, "Expected " & reply & " reply, got: " & line)
 
-proc connect*(smtp: AsyncSmtp) {.async.} =
+proc connect*(smtp: Smtp | AsyncSmtp,
+              address: string, port: Port) {.multisync.} =
   ## Establishes a connection with a SMTP server.
   ## May fail with ReplyError or with a socket error.
-  await smtp.sock.connect(smtp.address, smtp.port)
+  await smtp.sock.connect(address, port)
 
   await smtp.checkReply("220")
-  await smtp.sock.send("HELO " & smtp.address & "\c\L")
+  await smtp.debugSend("HELO " & address & "\c\L")
   await smtp.checkReply("250")
 
-proc auth*(smtp: AsyncSmtp, username, password: string) {.async.} =
+proc auth*(smtp: Smtp | AsyncSmtp, username, password: string) {.multisync.} =
   ## Sends an AUTH command to the server to login as the `username`
   ## using `password`.
   ## May fail with ReplyError.
 
-  await smtp.sock.send("AUTH LOGIN\c\L")
+  await smtp.debugSend("AUTH LOGIN\c\L")
   await smtp.checkReply("334") # TODO: Check whether it's asking for the "Username:"
                                # i.e "334 VXNlcm5hbWU6"
-  await smtp.sock.send(encode(username) & "\c\L")
+  await smtp.debugSend(encode(username) & "\c\L")
   await smtp.checkReply("334") # TODO: Same as above, only "Password:" (I think?)
 
-  await smtp.sock.send(encode(password) & "\c\L")
+  await smtp.debugSend(encode(password) & "\c\L")
   await smtp.checkReply("235") # Check whether the authentification was successful.
 
-proc sendMail*(smtp: AsyncSmtp, fromAddr: string,
+proc sendMail*(smtp: Smtp | AsyncSmtp, fromAddr: string,
-               toAddrs: seq[string], msg: string) {.async.} =
+               toAddrs: seq[string], msg: string) {.multisync.} =
   ## Sends ``msg`` from ``fromAddr`` to the addresses specified in ``toAddrs``.
   ## Messages may be formed using ``createMessage`` by converting the
   ## Message into a string.
 
-  await smtp.sock.send("MAIL FROM:<" & fromAddr & ">\c\L")
+  await smtp.debugSend("MAIL FROM:<" & fromAddr & ">\c\L")
   await smtp.checkReply("250")
   for address in items(toAddrs):
-    await smtp.sock.send("RCPT TO:<" & address & ">\c\L")
+    await smtp.debugSend("RCPT TO:<" & address & ">\c\L")
     await smtp.checkReply("250")
 
   # Send the message
-  await smtp.sock.send("DATA " & "\c\L")
+  await smtp.debugSend("DATA " & "\c\L")
   await smtp.checkReply("354")
   await smtp.sock.send(msg & "\c\L")
-  await smtp.sock.send(".\c\L")
+  await smtp.debugSend(".\c\L")
   await smtp.checkReply("250")
 
-proc close*(smtp: AsyncSmtp) {.async.} =
+proc close*(smtp: Smtp | AsyncSmtp) {.multisync.} =
   ## Disconnects from the SMTP server and closes the socket.
-  await smtp.sock.send("QUIT\c\L")
+  await smtp.debugSend("QUIT\c\L")
   smtp.sock.close()
 
 when not defined(testing) and isMainModule:
@@ -278,25 +223,24 @@ when not defined(testing) and isMainModule:
 
   proc async_test() {.async.} =
     let client = newAsyncSmtp(
-      conf["smtphost"],
+      conf["use_tls"].parseBool,
-      conf["port"].parseInt.Port,
+      debug=true
-      conf["use_tls"].parseBool
     )
-    await client.connect()
+    await client.connect(conf["smtphost"], conf["port"].parseInt.Port)
     await client.auth(conf["username"], conf["password"])
     await client.sendMail(conf["sender"], @[conf["recipient"]], $msg)
     await client.close()
     echo "async email sent"
 
   proc sync_test() =
-    var smtpConn = connect(
+    var smtpConn = newSmtp(
-      conf["smtphost"],
-      conf["port"].parseInt.Port,
       conf["use_tls"].parseBool,
-      true, # debug
+      debug=true
     )
+    smtpConn.connect(conf["smtphost"], conf["port"].parseInt.Port)
     smtpConn.auth(conf["username"], conf["password"])
-    smtpConn.sendmail(conf["sender"], @[conf["recipient"]], $msg)
+    smtpConn.sendMail(conf["sender"], @[conf["recipient"]], $msg)
+    smtpConn.close()
     echo "sync email sent"
 
   waitFor async_test()