Improve Gammu SMS Receiver

This as a rewrite of `gammu_get_unread_sms.py` script that adds:
- Support for long SMS
- Added proper CLI interface (see --help)
- Added optional --delete parameter which deletes SMS after printing them as JSON
- Added optional --show-read parameter which shows all not Unread marked SMS
- Added logging and --debug option
- Retain retrocompatibility with earlier versions of this script
- Retain retrocompatibility with Python 2.7+ (hopefully)

Fixes #181.
Btw, the interface with RaspiSMS could be improved with a temporary JSON file, using stdout seems lossy.

bin/gammu_get_unread_sms.py

@@ -1,56 +1,225 @@
 #!/usr/bin/env python3
 # -*- coding: UTF-8 -*-
 # vim: expandtab sw=4 ts=4 sts=4:
-#
+
+# (C) 2003 - 2018 Michal Čihař <michal@cihar.com> - python-gammu
+# (C) 2015 - 2021 Raspian France <raspbianfrance@gmail.com> - RaspianFrance/raspisms
+# (C) 2022 Orsiris de Jong <orsiris.dejong@netperfect.fr> - NetInvent SASU
+
 
 from __future__ import print_function
+
+
+__intname__ = "gammu_get_unread_sms.py"
+__author__ = "Orsiris de Jong - <orsiris.dejong@netperfect.fr>"
+__version__ = "2.0.0"
+__build__ = "2022102001"
+__compat__ = "python2.7+"
+
+
+import os
 import gammu
-import sys
 import json
+import logging
+from logging.handlers import RotatingFileHandler
+import tempfile
+from argparse import ArgumentParser
+import subprocess
+import re
 
-def main():
+LOG_FILE = "/var/log/{}.log".format(__intname__)
+_DEBUG = os.environ.get("_DEBUG", False)
+logger = logging.getLogger(__name__)
+
+
+def get_logger(log_file):
+    try:
+        try:
+            filehandler = RotatingFileHandler(
+                log_file, mode="a", encoding="utf-8", maxBytes=1048576, backupCount=3
+            )
+        except OSError:
+            try:
+                temp_log_file = tempfile.gettempdir() + os.sep + __name__ + ".log"
+                filehandler = RotatingFileHandler(
+                    temp_log_file,
+                    mode="a",
+                    encoding="utf-8",
+                    maxBytes=1048576,
+                    backupCount=3,
+                )
+            except OSError as exc:
+                print("Cannot create log file: %s" % exc.__str__())
+                return None
+
+        _logger = logging.getLogger()
+        if _DEBUG:
+            _logger.setLevel(logging.DEBUG)
+        else:
+            _logger.setLevel(logging.INFO)
+        _logger.addHandler(filehandler)
+        _logger.addHandler(logging.StreamHandler())
+        return _logger
+    except Exception as exc:
+        print("Cannot create logger instance: %s" % exc.__str__())
+
+
+def get_gammu_version():
+    # Quite badly coded, i'd use command_runner but I try to not have dependencies here
+    try:
+        proc = subprocess.Popen(
+            ["LC_ALL=C gammu", "--version"], shell=True, stdout=subprocess.PIPE
+        )
+        stdout, _ = proc.communicate()
+        version = re.search(r"Gammu version ([0-9]+)\.([0-9]+)\.([0-9]+)", str(stdout))
+        # dont' bother to return version[0] since it's the whole match
+        return (int(version[1]), int(version[2]), int(version[3]))
+    except Exception as exc:
+        logger.error("Cannot get gammu version: %s" % exc.__str__())
+        return None
+
+
+def get_gammu_handle(config_file):
     state_machine = gammu.StateMachine()
-    
-    if len(sys.argv) < 2:
-        sys.exit(1)
-    else :
-        state_machine.ReadConfig(Filename=sys.argv[1])
-        del sys.argv[1]
 
+    if config_file:
+        state_machine.ReadConfig(Filename=config_file)
+    else:
+        state_machine.Readconfig()
     state_machine.Init()
 
+    return state_machine
+
+
+def load_sms_from_gammu(state_machine):
+    """
+    The actual function that retrieves SMS via GAMMU from your modem / phone
+    Also concatenates multiple SMS into single long SMS
+    """
     status = state_machine.GetSMSStatus()
 
-    remain = status['SIMUsed'] + status['PhoneUsed'] + status['TemplatesUsed']
+    remaining_sms = status["SIMUsed"] + status["PhoneUsed"] + status["TemplatesUsed"]
-
+    logger.debug("Found %s sms" % remaining_sms)
-    start = True
+    sms_list = []
 
     try:
-        while remain > 0:
+        is_first_message = True
-            if start:
+        while remaining_sms > 0:
-                sms = state_machine.GetNextSMS(Start=True, Folder=0)
+            if is_first_message:
-                start = False
+                sms = state_machine.GetNextSMS(Start=is_first_message, Folder=0)
+                is_first_message = False
             else:
-                sms = state_machine.GetNextSMS(
+                sms = state_machine.GetNextSMS(Location=sms[0]["Location"], Folder=0)
-                    Location=sms[0]['Location'], Folder=0
+            remaining_sms = remaining_sms - len(sms)
-                )
+            sms_list.append(sms)
-            remain = remain - len(sms)
 
-            for m in sms :
+        # Concat multiSMS into list of sms that go together
-                if m['State'] != 'UnRead' :
-                    continue
-
-                print(json.dumps({
-                    'number': m['Number'],
-                    'at': str(m['DateTime']),
-                    'status': m['State'],
-                    'text': m['Text'],
-                }))
 
     except gammu.ERR_EMPTY:
-        #do noting
+        logger.debug("Finished reading all messages")
-        return True
+
+    return gammu.LinkSMS(sms_list)
 
 
-if __name__ == '__main__':
+def render_sms_as_json(state_machine, sms_list, delete_sms, show_read_sms):
-    main()
+    """
+    Provided sms_list is a list of lists of sms, eg
+    sms_list = [
+                   [sms],
+                   [sms1, sms2],  #  When two sms are in the same list, they form a long sms
+                   [sms],
+               ]
+
+    Concatenate long SMS from multiple sends and print them as JSON on stdout
+    """
+
+    for sms in sms_list:
+        if sms[0]["State"] == "UnRead" or show_read_sms:
+            sms_text = ""
+            for to_concat_sms in sms:
+                sms_text += to_concat_sms["Text"]
+            print(
+                json.dumps(
+                    {
+                        "number": sms[0]["Number"],
+                        "at": str(sms[0]["DateTime"]),
+                        "status": sms[0]["State"],
+                        "text": sms_text,
+                    }
+                )
+            )
+
+            if delete_sms:
+                for to_concat_sms in sms:
+                    try:
+                        state_machine.DeleteSMS(
+                            to_concat_sms["Folder"], to_concat_sms["Location"]
+                        )
+                    except Exception as exc:
+                        logger.error("Cannot delete sms: %s" % exc.__str__())
+
+
+def main(config_file, delete_sms, show_read):
+    # type: (bool, bool) -> None
+    try:
+        # Mandatory modem config file
+        # config_file = sys.argv[1]
+
+        state_machine = get_gammu_handle(config_file)
+
+        sms_list = load_sms_from_gammu(state_machine)
+        render_sms_as_json(state_machine, sms_list, delete_sms, show_read)
+
+    except Exception as exc:
+        logger.error("Could not retrieve SMS from Gammu: %s" % exc.__str__())
+        logger.debug("Trace:", exc_info=True)
+
+
+if __name__ == "__main__":
+    parser = ArgumentParser("Gammu SMS retriever")
+    parser.add_argument(
+        "gammu_config_file", type=str, nargs="?", help="Gammu config file"
+    )
+    parser.add_argument("--debug", action="store_true", help="Activate debugging")
+    parser.add_argument(
+        "-l",
+        "--log-file",
+        type=str,
+        dest="log_file",
+        default=None,
+        help="Optional path to log file, defaults to /var/log",
+    )
+    parser.add_argument(
+        "--delete", action="store_true", help="Delete messages after they've been read"
+    )
+    parser.add_argument(
+        "--show-read", action="store_true", help="Also show already read messages"
+    )
+
+    args = parser.parse_args()
+
+    config_file = args.gammu_config_file
+
+    if args.log_file:
+        LOG_FILE = args.log_file
+
+    if args.debug:
+        _DEBUG = args.debug
+
+    _logger = get_logger(LOG_FILE)
+    if _logger:
+        logger = _logger
+
+    delete = False
+    if args.delete:
+        # We need to check if we have gammu >= 1.42.0 since deleting sms with lower versions fail with:
+        # Cannot delete sms: {'Text': 'The type of memory is not available or has been disabled.', 'Where': 'DeleteSMS', 'Code': 81}
+        # see https://github.com/gammu/gammu/issues/460
+        gammu_version = get_gammu_version()
+        if gammu_version[0] >= 1 and gammu_version[1] >= 42:
+            delete = True
+        else:
+            logger.warning("Cannot delete SMS. You need gammu >= 1.42.0.")
+
+    show_read = args.show_read
+    main(config_file, delete, show_read)