//
//   Copyright 2019  SenX S.A.S.
//
//   This program is free software: you can redistribute it and/or modify it
//   under the terms of the GNU Affero General Public License as published
//   by the Free Software Foundation, version 3.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty
//   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
//   See the GNU Affero General Public License for more details.
//
//   You should have received a copy of the GNU Affero General Public License
//   along with this program. If not, see <https://www.gnu.org/licenses/>
//

<%
  SAVE '.context' STORE
    'lastarchive.attr' '.lastarchive' MACROCONFIGDEFAULT '.lastarchive' CSTORE
    'lastpurge.attr' '.lastpurge' MACROCONFIGDEFAULT '.lastpurge' CSTORE

    [ 'RTOKEN' 'WTOKEN' 'CLASS_SELECTOR' 'LABELS_SELECTOR' 'ARCHIVE_MACRO' 'PURGE_MACRO' 'MIN_DELAY' ] STORE

    // Add the lastarchive selector to the labels selectors
    $LABELS_SELECTOR '~.*' $.lastarchive PUT DROP

    // FIND the GTS

    [ $RTOKEN $CLASS_SELECTOR $LABELS_SELECTOR ] FIND

    // Stop now if there are no matching GTS
    DUP SIZE 0 == <% STOP %> IFT

    //
    // Retrieve GTS to archive and extract the oldest archived period
    //
    () SWAP
    <%
      ATTRIBUTES
      $.lastarchive GET
      +!
    %> FOREACH
    SET-> LSORT 0 GET

    'lastarchive' STORE

    //
    // Compute the next archival period
    //
    $lastarchive @senx/arch/period
    [ NULL NULL 'nextperiod' 'prevperiod' ] STORE
    $nextperiod @senx/arch/period
    [ 'start' 'end' NULL NULL ] STORE

    //
    // FETCH data to archive - we only select those with the oldest lastarchive attribute value
    //

    [ $RTOKEN $CLASS_SELECTOR $LABELS_SELECTOR $lastarchive $.lastarchive PUT ] FIND

    // Iterate over GTS to archive
    <%
      <%
        'gts' STORE

        // Extract last purge
        $gts ATTRIBUTES $.lastpurge GET 'lastpurge' STORE

        // Extract selector
        $gts TOSELECTOR 'sel' STORE

        // Fetch data to archive
        {
          'token' $RTOKEN
          'selector' $sel
          'start' $start
          'end' $end
        } FETCH  

        'fetched' STORE
  
        //
        // Only proceed if the last archived period was also purged
        // and if the minimum delay has elapsed since the end of the
        // period to archive
        //

        // Keep track of the last archived period
        $lastarchive 'lastarchived' STORE

        // Only archive if the last archived period was also purged
        // This ensures that we do not have colliding archive/purge operations
        $lastpurge $lastarchive ==
        // if less then $MIN_DELAY has elapsed since the end of the period to archive, bailout
        NOW $end - $MIN_DELAY >= AND
        <%
          //
          // Archive the data using the provided macro
          // We pass the GTS to archive and the archival period
          //
          $fetched SIZE 1 ==
          <%
            $fetched 0 GET $nextperiod $ARCHIVE_MACRO EVAL
          %>
          IFT
  
          // Update metadata to update the lastarchive attribute
          $gts { $.lastarchive $nextperiod } SETATTRIBUTES
          // Update $gts so we have the correct attributes when marking the purge
          'gts' STORE $gts
          $WTOKEN
          META

          // Update the last archived period
          $nextperiod 'lastarchived' STORE
        %> IFT

        //
        // Perform the purge if nextpurge is <= lastarchived
        // This and the test before archiving ensures there is no archive/purge collision
        //
        $lastpurge @senx/arch/period [ NULL NULL 'nextpurge' NULL ] STORE
        $nextpurge $lastarchived <=
        <%
          $gts $nextpurge $PURGE_MACRO EVAL

          // Update metadata to update the lastpurge attribute
          $gts { $.lastpurge $nextpurge } SETATTRIBUTES
          $WTOKEN
          META
        %> IFT
      %> <% %> <% %> TRY // We wrap the handling of each GTS in a TRY call so we do not abort the whole process for a single GTS failure
    %> FOREACH

  $.context RESTORE
%>