localtxt2ics



#!/usr/bin/perl
# Copyright © 2016 Jonas Smedegaard <dr@jones.dk>
#
# 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.
#
# Description: Create iCalendar file from multiline news chunks
#
# Depends: libdata-ical-perl libdatetime-timezone-perl libdatetime-format-ical-perl

use strict;
use warnings;

use Data::ICal;
use Data::ICal::Entry::Event;
use DateTime::TimeZone;
use DateTime::Format::ICal;

my $data;
my $calendar = Data::ICal->new( rfc_strict => 1, auto_uid => 1 );
my $tz = DateTime::TimeZone->new( name => 'local' );

# warn about resolved timezone
printf STDERR "using timezone %s - set environment variable TZ to override\n",
    $tz->name;

# slurp input
my @lines;
while (<>) {
    chomp;
    $data .= "$_\n";
}

# parse data and serialize as iCalendar events
#  * Events are newline-newline delimited
#  * First line contains date, location, time(s)
#    * String before date (e.g. weekday) is ignored
#    * Date is formatted as DD.MM.YYYY
#    * Times are formatted as either HH or HH:MM
#    * Times are space-hyphen-space delimited
#    * End time (and delimiter) is optional
#    * string after date (e.g. hour keyword) is ignored
#  * Second line is summary
#  * Third and subsequent lines are description
while (
    $data =~ m{
        (\d{1,2})[./](\d{1,2})[./](\d{4}),\h* # date
        ([^\n]+?),?\h* # location
        (\d{1,2})(?::(\d{2}))? # start time
        (?:\h+-\h+(\d{1,2})(?::(\d{2}))?)? # end time
        (?:\h+Uhr)?\h*\n

        ([^\n]+)\h*\n # description

        ([^\n]+(?:\n[^\n]+)*)\h*\n(?:\n|\z) # description
    }gx
) {
    my ( $dtstart, $dtend );
    $dtstart = DateTime->new(
        year      => $3,
        month     => $2,
        day       => $1,
        hour      => $5,
        minute    => $6 || '00',
        time_zone => $tz,
    );
    # Data::ICal does not support named timezones
    $dtstart->set_time_zone( $dtstart->offset() );
    if ( defined($7) ) {
        $dtend = DateTime->new(
            year      => $3,
            month     => $2,
            day       => $1,
            hour      => $7,
            minute    => $8 || '00',
            time_zone => $tz,
        );
        # Data::ICal does not support named timezones
        $dtend->set_time_zone( $dtend->offset() );
    }
    my $location    = $4;
    my $summary     = $9;
    my $description = $10;

    my $vevent = Data::ICal::Entry::Event->new();
    $vevent->add_properties(
        dtstart     => DateTime::Format::ICal->format_datetime($dtstart),
        location    => $location,
        summary     => $summary,
        description => $description,
    );
    $vevent->add_property(
        dtend => DateTime::Format::ICal->format_datetime($dtend) )
        if ($dtend);
    $calendar->add_entry($vevent);
}

print $calendar->as_string;