# -*- coding: utf-8 -*-

"""
List the logged (executed) cron jobs and their commands (uses journald/logfile)
NOTE: If using journald, the log level for cron.service should be at least 2 
(default is 1). This can be changed with `sudo systemctl edit cron --full`, 
and ammend `-L 2` to the ExecStart command.
TODO: also output a list of scheduled (future) jobs
"""

from systemd import journal
import datetime

from logparse import config
from logparse.formatting import *
from logparse.load_parsers import Parser
from logparse.parsers.cron import CronCommand


class CronJournald(Parser):

    def __init__(self):
        super().__init__()
        self.name = "cron_journald"
        self.info = "List the logged (executed) cron jobs and their commands " \
                "(uses journald module)"

    def parse_log(self):

        logger.debug("Starting cron section")
        section = Section("cron")

        # Initiate journald reader
        j = journal.Reader()
        j.this_machine()
        j.log_level(journal.LOG_INFO)
        j.add_match(_COMM="cron")
        j.seek_realtime(section.period.startdate)

        logger.info("Obtaining cron logs")

        records = [entry for entry in j
                if "MESSAGE" in entry and " CMD " in entry["MESSAGE"]]

        if len(records) == 0:
            logger.warning("Couldn't find any cron commands")
            return 1

        logger.info("Found {0} log records".format(len(records)))

        logger.debug("Analysing cron commands for each user")
        command_objects = []
        users = {}
        for record in records:
            if record["_SOURCE_REALTIME_TIMESTAMP"] < section.period.startdate:
                logger.warning("Discarding log record from {0} - was "
                        "seek_realtime set properly?".format(
                            record["_SOURCE_REALTIME_TIMESTAMP"]))
                continue
            try:
                cmd_obj = CronCommand(record)
                if config.prefs.getboolean("cron", "truncate-commands"):
                    cmd_obj.truncate() 
                if not (cmd_obj.match_user(config.prefs.get("cron", "users")
                    .split()) and cmd_obj.match_cmd(config.prefs.get(
                        "cron", "commands").split())):
                    logger.debug("Ignoring cron session by {0} with command "
                        "{1} due to config".format(cmd_obj.user, cmd_obj.cmd))
                    continue
                command_objects.append(cmd_obj)
                if not cmd_obj.user in users:
                    users[cmd_obj.user] = []
                users[cmd_obj.user].append(cmd_obj.cmd)
            except Exception as e:
                logger.warning("Malformed cron log message: {0}. "
                    "Error message: {1}".format(record["MESSAGE"], str(e)))
                continue

        logger.info("Found {0} valid cron sessions".format(len(command_objects)))

        if config.prefs.getboolean("cron", "summary"):
            summary_data = Data()
            summary_data.subtitle = "Total of " + plural("cron session",
                    len(command_objects)) + " for " + plural("user",
                            len(users))
            summary_data.items = ["{}: `{}`".format(c.user, c.cmd) 
                    for c in command_objects]
            summary_data.orderbyfreq()
            summary_data.truncl(config.prefs.getint("logparse", "maxcmd"))
            section.append_data(summary_data)

        if config.prefs.getboolean("cron", "list-users"):
            for user, cmdlist in users.items():
                user_data = Data()
                user_data.subtitle = plural("session", len(cmdlist)) \
                        + " for " + user + (" (" + plural("unique command",
                            len(set(cmdlist))) + ")" if len(set(cmdlist)) > 1
                            else "")
                user_data.items = ["`{0}`".format(cmd) for cmd in cmdlist]
                user_data.orderbyfreq()
                user_data.truncl(config.prefs.getint("logparse", "maxcmd"))
                section.append_data(user_data)
                logger.debug("Found {0} cron sessions for user {1} "
                        "({2} unique commands): {3}".format(
                            len(cmdlist), user, 
                            len(set(cmdlist)), user_data.items))


        logger.info("Finished cron section")

        return section