"""
The `singleCleaner` class is a timer-driven thread that cleans data structures
to free memory, resends messages when a remote node doesn't respond, and
sends pong messages to keep connections alive if the network isn't busy.

It cleans these data structures in memory:
  - inventory (moves data to the on-disk sql database)
  - inventorySets (clears then reloads data out of sql database)

It cleans these tables on the disk:
  - inventory (clears expired objects)
  - pubkeys (clears pubkeys older than 4 weeks old which we have not used
    personally)
  - knownNodes (clears addresses which have not been online for over 3 days)

It resends messages when there has been no response:
  - resends getpubkey messages in 5 days (then 10 days, then 20 days, etc...)
  - resends msg messages in 5 days (then 10 days, then 20 days, etc...)

"""

import gc
import os
import time

import knownnodes
import queues
import shared
import state
import tr
from bmconfigparser import BMConfigParser
from helper_sql import sqlQuery, sqlExecute
from inventory import Inventory
from network import BMConnectionPool, StoppableThread


class singleCleaner(StoppableThread):
    """The singleCleaner thread class"""
    name = "singleCleaner"
    cycleLength = 300
    expireDiscoveredPeers = 300

    def run(self):  # pylint: disable=too-many-branches
        gc.disable()
        timeWeLastClearedInventoryAndPubkeysTables = 0
        try:
            shared.maximumLengthOfTimeToBotherResendingMessages = (
                float(BMConfigParser().get(
                    'bitmessagesettings', 'stopresendingafterxdays'))
                * 24 * 60 * 60
            ) + (
                float(BMConfigParser().get(
                    'bitmessagesettings', 'stopresendingafterxmonths'))
                * (60 * 60 * 24 * 365) / 12)
        except:
            # Either the user hasn't set stopresendingafterxdays and
            # stopresendingafterxmonths yet or the options are missing
            # from the config file.
            shared.maximumLengthOfTimeToBotherResendingMessages = float('inf')

        # initial wait
        if state.shutdown == 0:
            self.stop.wait(singleCleaner.cycleLength)

        while state.shutdown == 0:
            queues.UISignalQueue.put((
                'updateStatusBar',
                'Doing housekeeping (Flushing inventory in memory to disk...)'
            ))
            Inventory().flush()
            queues.UISignalQueue.put(('updateStatusBar', ''))

            # If we are running as a daemon then we are going to fill up the UI
            # queue which will never be handled by a UI. We should clear it to
            # save memory.
            # FIXME redundant?
            if shared.thisapp.daemon or not state.enableGUI:
                queues.UISignalQueue.queue.clear()
            if timeWeLastClearedInventoryAndPubkeysTables < \
                    int(time.time()) - 7380:
                timeWeLastClearedInventoryAndPubkeysTables = int(time.time())
                Inventory().clean()
                queues.workerQueue.put(('sendOnionPeerObj', ''))
                # pubkeys
                sqlExecute(
                    "DELETE FROM pubkeys WHERE time<? AND usedpersonally='no'",
                    int(time.time()) - shared.lengthOfTimeToHoldOnToAllPubkeys)

                # Let us resend getpubkey objects if we have not yet heard
                # a pubkey, and also msg objects if we have not yet heard
                # an acknowledgement
                queryreturn = sqlQuery(
                    "SELECT toaddress, ackdata, status FROM sent"
                    " WHERE ((status='awaitingpubkey' OR status='msgsent')"
                    " AND folder='sent' AND sleeptill<? AND senttime>?)",
                    int(time.time()), int(time.time())
                    - shared.maximumLengthOfTimeToBotherResendingMessages
                )
                for row in queryreturn:
                    if len(row) < 2:
                        self.logger.error(
                            'Something went wrong in the singleCleaner thread:'
                            ' a query did not return the requested fields. %r',
                            row
                        )
                        self.stop.wait(3)
                        break
                    toAddress, ackData, status = row
                    if status == 'awaitingpubkey':
                        self.resendPubkeyRequest(toAddress)
                    elif status == 'msgsent':
                        self.resendMsg(ackData)

            try:
                # Cleanup knownnodes and handle possible severe exception
                # while writing it to disk
                knownnodes.cleanupKnownNodes()
            except Exception as err:
                # pylint: disable=protected-access
                if "Errno 28" in str(err):
                    self.logger.fatal(
                        '(while writing knownnodes to disk)'
                        ' Alert: Your disk or data storage volume is full.'
                    )
                    queues.UISignalQueue.put((
                        'alert',
                        (tr._translate("MainWindow", "Disk full"),
                         tr._translate(
                             "MainWindow",
                             'Alert: Your disk or data storage volume'
                             ' is full. Bitmessage will now exit.'),
                         True)
                    ))
                    if shared.thisapp.daemon or not state.enableGUI:
                        os._exit(1)

            # inv/object tracking
            for connection in BMConnectionPool().connections():
                connection.clean()

            # discovery tracking
            exp = time.time() - singleCleaner.expireDiscoveredPeers
            reaper = (k for k, v in state.discoveredPeers.items() if v < exp)
            for k in reaper:
                try:
                    del state.discoveredPeers[k]
                except KeyError:
                    pass
            # ..todo:: cleanup pending upload / download

            gc.collect()

            if state.shutdown == 0:
                self.stop.wait(singleCleaner.cycleLength)

    def resendPubkeyRequest(self, address):
        """Resend pubkey request for address"""
        self.logger.debug(
            'It has been a long time and we haven\'t heard a response to our'
            ' getpubkey request. Sending again.'
        )
        try:
            # We need to take this entry out of the neededPubkeys structure
            # because the queues.workerQueue checks to see whether the entry
            # is already present and will not do the POW and send the message
            # because it assumes that it has already done it recently.
            del state.neededPubkeys[address]
        except:
            pass

        queues.UISignalQueue.put((
            'updateStatusBar',
            'Doing work necessary to again attempt to request a public key...'
        ))
        sqlExecute(
            '''UPDATE sent SET status='msgqueued' WHERE toaddress=?''',
            address)
        queues.workerQueue.put(('sendmessage', ''))

    def resendMsg(self, ackdata):
        """Resend message by ackdata"""
        self.logger.debug(
            'It has been a long time and we haven\'t heard an acknowledgement'
            ' to our msg. Sending again.'
        )
        sqlExecute(
            '''UPDATE sent SET status='msgqueued' WHERE ackdata=?''',
            ackdata)
        queues.workerQueue.put(('sendmessage', ''))
        queues.UISignalQueue.put((
            'updateStatusBar',
            'Doing work necessary to again attempt to deliver a message...'
        ))