#! /bin/sh
#
#  @configure_input@
#
#  $Id: dst.in 0.09 2000/03/24 00:00:09 tom Exp $
#
#  dst.in:  Uses `dst[.awk|.pl]' for processing ZONEINFO files and saves the
#             dates at which Daylight-Saving Times take place converted to the
#             Gcal fixed date format in a resource file.
#
#           Usage: dst --help | --version
#           Usage: dst [--debug] [--before=DAYS] [--after=DAYS] ZONEINFO-FILE...
#
#           `--debug':        Turn on shell debugging.
#           `--before=DAYS':  Display the fixed date up to number DAYS
#                               before the Daylight-Saving Time is active.
#                               If this option is not given, `--before=0'
#                               is used by default.
#           `--after=DAYS':   Display the fixed date up to number DAYS
#                               after the Daylight-Saving Time is active.
#                               If this option is not given, `--after=0'
#                               is used by default.
#
#  UN*X solution.
#
#  Needs `test', `echo', `eval', `set', `sed', `mv', `rm',
#    `zdump', and `perl' or `awk' for processing!
#
#  Returns 0 if any fixed dates are created (returned by AWK/Perl script
#            if neither `--help' nor `--version' option was specified).
#  Returns 1 in case no fixed dates are created (returned by AWK/Perl script).
#  Returns 2 if neither Zdump, or neither Perl nor AWK are present for
#            further processing.
#
#  Copyright (c) 1998, 2000  Thomas Esken      <esken@uni-muenster.de>
#                            Im Hagenfeld 84
#                            D-48147 M"unster
#                            GERMANY
#
#  This software doesn't claim completeness, correctness or usability.
#  On principle I will not be liable for ANY damages or losses (implicit
#  or explicit), which result from using or handling my software.
#  If you use this software, you agree without any exception to this
#  agreement, which binds you LEGALLY !!
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the `GNU General Public License' as published by
#  the `Free Software Foundation'; either version 3, or (at your option)
#  any later version.
#
#  You should have received a copy of the `GNU General Public License'
#  along with this program; if not, write to the:
#
#
#

#
# Basically used programs.
#
Mv=mv
Rm=rm
Sed=sed
Set=set
Test=test
Echo=echo

#
# Basically used texts.
#
packagedatamiscdir=/usr/local/share/gcal/misc/dst
#
PACKAGE=@PACKAGE@
VERSION=@VERSION@
transform=@program_transform_name@
#
mydefaultname=dst
#
myname=`$Echo "$0" | $Sed -e 's,.*/,,' -e "$transform"`
myversion=0.09
myinternalname="$myname ($PACKAGE $VERSION) $myversion"
#
gcal_resource_file_suffix=.rc
backup_suffix="~"
#
info1="$myname: Processes ZONEINFO files and saves the dates"
info2="$myname: at which Daylight-Saving Times take place in"
info3="$myname: a Gcal resource file by the name \`ZONEINFO-FILE""$gcal_resource_file_suffix'."
info4="$myname:"
usage1="usage: $myname  --help | --version"
usage2="usage: $myname  [--debug] [--before=DAYS] [--after=DAYS] ZONEINFO-FILE..."
usage3="usage: $myname  without \`--before=DAYS' option uses \`--before=0' by default"
usage4="usage: $myname  without \`--after=DAYS'  option uses \`--after=0'  by default"

#
# Some constant values.
#
EXIT_SUCCESS=0
EXIT_FAILURE=1
EXIT_FATAL=2

#
# The used programs.
#
Eval=eval
ThisGcal=/usr/local/bin/gcal
#
Zdump=@ZDUMP@
#
Awk=@AWK@
Awk_script=$mydefaultname"".awk
#
Perl=@PERL@
Perl_script=$mydefaultname"".pl

#
# Let's check for command line arguments.
#
debug=no
FILS=""
previous=""
for option in $*
do
  #
  # If the previous option needs an argument, assign it.
  #
  if $Test -n "$previous";
  then
    $Eval "$previous=\$option"
    previous=""
    continue
  fi

  case "$option" in
    -*=)  optarg="###error###" ;;
    -*=*) optarg=`$Echo "$option" | $Sed 's/[-_a-zA-Z0-9]*=//'` ;;
    *)    optarg="" ;;
  esac

  #
  # Manage the options.
  #
  case "$option" in
    -help=* | -hel=* | -he=* | -h=* | -help | -hel |-he | -h | \
    --help=* | --hel=* | --he=* | --h=* | --help | --hel | --he | --h)
      if $Test -n "$optarg";
      then
        $Echo "$myname: error: option \``$Echo $option | $Sed -e 's/=.*//'`' doesn't allow an argument" 1>&2
        exit $EXIT_FAILURE
      fi
      $Echo "$info1"
      $Echo "$info2"
      $Echo "$info3"
      $Echo "$info4"
      $Echo "$usage1"
      $Echo "$usage2"
      $Echo "$usage3"
      $Echo "$usage4"
      exit $EXIT_SUCCESS ;;

    -version=* | -versio=* | -versi=* | -vers=* | -ver=* | -ve=* | -v=* | \
    -version | -versio | -versi | -vers | -ver | -ve | -v | \
    --version=* | --versio=* | --versi=* | --vers=* | --ver=* | --ve=* | --v=* | \
    --version | --versio | --versi | --vers | --ver | --ve | --v)
      if $Test -n "$optarg";
      then
        $Echo "$myname: error: option \``$Echo $option | $Sed -e 's/=.*//'`' doesn't allow an argument" 1>&2
        exit $EXIT_FAILURE
      fi
      $Echo "$myinternalname"
      exit $EXIT_SUCCESS ;;

    -debug=* | -debu=* | -deb=* | -de=* | -d=* | \
    -debug | -debu | -deb | -de | -d | \
    --debug=* | --debu=* | --deb=* | --de=* | --d=* | \
    --debug | --debu | --deb | --de | --d)
      if $Test -n "$optarg";
      then
        $Echo "$myname: error: option \``$Echo $option | $Sed -e 's/=.*//'`' doesn't allow an argument" 1>&2
        exit $EXIT_FAILURE
      fi
      debug=yes
      shift ;;

    -before | -befor | -befo | -bef | -be | -b | \
    --before | --befor | --befo | --bef | --be | --b)
      previous=before ;;
    -before=* | -befor=* | -befo=* | -bef=* | -be=* | -b=* | \
    --before=* | --befor=* | --befo=* | --bef=* | --be=* | --b=*)
      if $Test -z "$optarg" || $Test "$optarg" = "###error###";
      then
        $Echo "$myname: error: option \``$Echo $option | $Sed -e 's/=//g'`' requires an argument" 1>&2
        exit $EXIT_FAILURE
      fi
      opt_before="$optarg"
      shift ;;

    -after | -afte | -aft | -af | -a | \
    --after | --afte | --aft | --af | --a)
      previous=after ;;
    -after=* | -afte=* | -aft=* | -af=* | -a=* | \
    --after=* | --afte=* | --aft=* | --af=* | --a=*)
      if $Test -z "$optarg" || $Test "$optarg" = "###error###";
      then
        $Echo "$myname: error: option \``$Echo $option | $Sed -e 's/=//g'`' requires an argument" 1>&2
        exit $EXIT_FAILURE
      fi
      opt_after="$optarg"
      shift ;;

    -* | /*)
      $Echo "$myname: error: $option: invalid option, use --help to show usage" 1>&2
      exit $EXIT_FAILURE ;;

    *)
     if $Test -z "$FILS";
     then
       FILS="$option"
     else
       FILS="$FILS $option"
     fi
  esac
done

if $Test -n "$previous";
then
  $Echo "$myname: error: missing argument to --$previous" 1>&2
  exit $EXIT_FAILURE
fi

#
# Enable tracing.
#
if $Test "$debug" = yes;
then
  $Set -x
fi

#
# Let's start processing now.
#
if $Test -n "$Zdump" && ($Test -n "$Awk" || $Test -n "$Perl");
then
  if $Test -z "$FILS";
  then
    $Echo "$info1"
    $Echo "$info2"
    $Echo "$info3"
    $Echo "$info4"
    $Echo "$usage1"
    $Echo "$usage2"
    $Echo "$usage3"
    $Echo "$usage4"
    exit $EXIT_FAILURE
  fi
  ARGS=""
  if $Test -n "$opt_after";
  then
    arg=`$Echo "$opt_after" | $Sed -e 's/[0-9]//g'`
    if $Test -z "$arg";
    then
      ARGS="-a""$opt_after"
    else
      $Echo "$myname: error: invalid option argument \`$opt_after' specified" 1>&2
      $Echo "$myname: use --help to show usage" 1>&2
      exit $EXIT_FAILURE
    fi
  fi
  if $Test -n "$opt_before";
  then
    arg=`$Echo "$opt_before" | $Sed -e 's/[0-9]//g'`
    if $Test -z "$arg";
    then
      ARGS="$ARGS -b""$opt_before"
    else
      $Echo "$myname: error: invalid option argument \`$opt_before' specified" 1>&2
      $Echo "$myname: use --help to show usage" 1>&2
      exit $EXIT_FAILURE
    fi
  fi
  #
  for file in $FILS
  do
    #
    # Design the name of the resulting Gcal resource file.
    #
    outfile="`$Echo $file | $Sed -e 's,.*/,,'`""$gcal_resource_file_suffix"
    #
    if $Test -s "$outfile" && \
       $Test -f "$outfile" && \
       $Test -r "$outfile";
    then
      $Mv $outfile $outfile""$backup_suffix
    fi
    #
    if $Test "$debug" = no;
    then
      trap "$Rm -f $outfile; \
        if $Test -s "$outfile""$backup_suffix" && \
           $Test -f "$outfile""$backup_suffix" && \
           $Test -r "$outfile""$backup_suffix"; \
        then \
           $Mv $outfile""$backup_suffix $outfile; \
        fi;\
        exit $EXIT_FAILURE" 1 2 15
    fi
    #
    # We prefer the use of Perl.
    #
    if $Test -n "$Perl";
    then
      $Echo "$myname: \``$Echo $Zdump | $Sed -e 's,.*/,,'`/$Perl' are working on \`$file' ..." 1>&2
      $Zdump -v $file | $Perl -- $packagedatamiscdir/$Perl_script $ARGS > $outfile
    else
      $Echo "$myname: \``$Echo $Zdump | $Sed -e 's,.*/,,'`/$Awk' are working on \`$file' ..." 1>&2
      $Zdump -v $file | $Awk -f $packagedatamiscdir/$Awk_script $ARGS > $outfile
    fi
    status=$?
    if $Test "$status" -eq "$EXIT_SUCCESS";
    then
      $Echo "$myname: daylight-saving times found, \`$outfile' created" 1>&2
    else
      if $Test "$status" -eq "$EXIT_FAILURE";
      then
        $Echo "$myname: no daylight-saving times found in \`$file'" 1>&2
      else
        if $Test -n "$Perl";
        then
          $Echo "$myinternalname: error: invalid option \`$ARGS' to \`$Perl' given" 1>&2
        else
          $Echo "$myinternalname: error: invalid option \`$ARGS' to \`$Awk' given" 1>&2
        fi
      fi
      $Rm -f $outfile
      if $Test -s "$outfile""$backup_suffix" && \
         $Test -f "$outfile""$backup_suffix" && \
         $Test -r "$outfile""$backup_suffix";
      then
        $Mv $outfile""$backup_suffix $outfile
      fi
    fi
  done
  exit $status
else
  $Echo "$myinternalname: error: neither \`zdump', OR neither \`perl' nor \`awk' available" 1>&2
  exit $EXIT_FATAL
fi