#  D-STAR Link Management Program
#    Provides for disconnect of inactive links after a configurable # secs
#    Provides for automatic reconnect attempts of links that fail
#    Provides for periodic (configurable) announcements that link is up and
#       connected to [callsign - module].
#    Provides a mechanism for playing general announcements in a friendly
#       manner (waits for quiet channel).
#    This is installed as a 'service' and runs in the background.
#    Program actions can be monitored via /var/log/monlink.log
#
#
#    Author:  Ken Adkisson, WB4FAY
#
#
#  CHANGE LOG:
#  --------------------------------------------------------------------
#  01/01/2011 - Version 0.4c
#               Corrected errors in link timeout clocking and
#                 link disconnects at the appropriate time.
#
#  12/29/2011 - Version 0.4b
#               Corrected error which caused link announcements to
#                 not wait for quiet channel in some cases immediately
#                 following link connection.
#               Made modifications so support modules 'D' and 'E' as
#                 supported by dplus version 2.2h.   Timeout values can
#                 be set for D and E, etc.
#               Corrected code in handling of default link definitions.
#                 The error occurred when multiple time slots were
#                 defined a single module connecting to the same remote
#                 system (e.g. 0000-0600 and also 1800-2359).
#
#  12/21/2011 - Version 0.4a
#               Added code to handle the new dplus.log format that
#                 is generated by D-Star Plus Version 2.2h.
#
#  10/25/2011 - version 0.3j
#               Corrected bug which caused link timeout functions to not
#                 disconnect properly when a default link is also defined.
#               Added code so that a default link is not reestablished for
#                 10 minutes since the last disconnect OR 2 minutes after
#                 the last local transmit -- whichever occurs LAST.
#                 In earlier versions, only the 10 minutes since the last
#                 disconnect was required.
#
#  10/05/2011 - version 0.3i
#               Corrected bug which in some cases would cause monlink
#                 to not properly disconnect a link which had timed out.
#
#  04/13/2010 - Version 0.3d
# 		    Added logic to check for new dvtool files and download.
#               Added logic to check for new version of monlink.  If a new
#                 version is available, monlink will write msgs to log file.
#               Added ability to define link default for module(s).
#                  for example:  DefaultLink=B,1-5,0600,1800,REF030C
#                 A maximum of thirty (30) default definitions may be supplied
#                 in the 'monlink.conf' file.   However, default definitions
#                 are not allowed to overlap times for the same D-STAR module.
#                 If the specified module is not connected, and a default is
#                 specified, monlink will attempt to maintain a the link.
#                 Timeout timers are suspended when a 'default' is linked.
#                 If a user unlinks the module during the default interval,
#                 monlink will then wait for ten (10) minutes with no connection
#                 before attempting to reestablish the default link.  (This gives
#                 the user time to link to another destination of their choice.)
#
#
#
#  08/26/2009 - Version 0.2e
#               Corrected error in processing of link reconnect which
#                  causes multiple reconnect attemps in rapid succession.
#               Changed delay before initial reconnect attempt from 10
#                  to 15 seconds.
#               Added Timeout Processing suspension configuration ability
#                  within the monlink.conf file.  Now all timeout process-
#                  ing can be skipped (e.g. during a net where locally
#                  there may be long periods of listing.
#                  "TOBlock=C,0,2000,2130 #block Mod C, Sunday, 2000-2130"
#
#
#  08/13/2009 - Version 0.2c
#               Corrected minor logic errors in link reconnect logic
#               and added new functionality to manage playing of 'general
#               announcements' (e.g. club message reminders, net reminders,
#               etc.).  The configuration file specifies when to play the
#               messages and on which modules (e.g. Module C, Mon-Fri,
#               0600 to 2200).  There is also a mechanism to completely
#               block any general announcements during specific times
#               (e.g. during a net).  Messages are played only if:
#                 1. the module has been inactive for a minimum of 60 seconds
#                 2. no other general announcement has been played
#                      within 10 minutes
#                 3. this particular announcement has not been played for
#                      60 minutes.  (Multiple announcements may be defined
#                      but a single message will not be repeated for 1 hour.)
#
#  08/10/2009 - Version 0.2a
#               Added delay logic to not try and make any announcment if
#               the particular module has been active within the previous
#               30 seconds.
#
#  08/09/2009 - Version 0.1d
#               Added "No link established" message to be announced when
#               an RF user requests an announcement when no link up.
#               Corrected issue with handling link management after
#               dplus is restarted.
#
#  08/08/2009 - Version 0.1c
#               Added ability for a local RF user to request an announcement
#               of the ID of the far end of a link connection.  The user
#               must set URCALL to the repeater callsign and "LI" in the
#               7th and 8th position.  If no link is active, the request
#               to announce is ignored.
#
#  08/07/2009 - Version 0.1b
#		Initial version of the program