//
//   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
    'period' STORE

    //
    // Compute the bounds of the archive period
    // and the name of the previous and next periods
    //

    $period SIZE
    <% DUP 4 == %> // YYYY
    <%
      DROP $period '-01-01T00:00:00Z' TOTIMESTAMP 'start' STORE
      $start 1 ADDYEARS 1 - 'end' STORE
      $end 1 + ISO8601 0 4 SUBSTRING 'nextperiod' STORE
      $start -1 ADDYEARS ISO8601 0 4 SUBSTRING 'prevperiod' STORE
    %>
    <% DUP 6 == %> // YYYYMM
    <%
      DROP $period 0 4 SUBSTRING '-' + $period 4 2 SUBSTRING + '-01T00:00:00Z' + TOTIMESTAMP 'start' STORE
      $start 1 ADDMONTHS 1 - 'end' STORE
      $end 1 + ISO8601 0 7 SUBSTRING '-' '' REPLACE 'nextperiod' STORE
      $start -1 ADDMONTHS ISO8601 0 7 SUBSTRING '-' '' REPLACE 'prevperiod' STORE
    %>
    <% DUP 8 == %> // YYYYMMDD
    <%
      DROP $period 0 4 SUBSTRING '-' + $period 4 2 SUBSTRING + $period 6 2 SUBSTRING + 'T00:00:00Z' + TOTIMESTAMP 'start' STORE
      $start 1 ADDDAYS 1 - 'end' STORE
      $end 1 + ISO8601 0 10 SUBSTRING '-' '' REPLACEALL 'nextperiod' STORE
      $start -1 ADDDAYS ISO8601 0 10 SUBSTRING '-' '' REPLACEALL 'prevperiod' STORE
    %>
    <% 'Invalid archival period specification, expected YYYY, YYYYMM or YYYYMMDD' MSGFAIL %>
    3 SWITCH

    $start $end $nextperiod $prevperiod

  $.context RESTORE
%>