#!/usr/bin/env perl
#
# Copyright (c) 2020-2023 Lorenzo Salvadore <salvadore@FreeBSD.org>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

use strict;
use warnings;

use Getopt::Std;

# -------------------------------------------------------
# Global variables declaration
# -------------------------------------------------------

# Variables used to compute the time coordinates of the call (see below)
#
# They can be computed based on present date or given on the command line
# through options (see --help).
my $day;
my $month;
my $year;

# Time coordinates of the call
#
# - $quarter is the number of the quarter for which we are sending the
#   calls.
# - $urgency_tag indicates the urgency with which we are requesting the
#   reports. It will be included in the subject of the calling mail. It
#   can be empty, [2 WEEKS LEFT REMINDER] or [LAST OFFICIAL REMINDER].
my $quarter;
my $urgency_tag;

# Variables related to the contacts of the last status reports
#
# $year_last, $month_last_start, %month_last_stop and $quarter_last are
# the year, the initial month, the last month and the number of the
# quarter of the last quarterly status reports. They are used to compute
# $quarter_last_directory, the directory where the reports for last
# quarter can be found.
my $year_last;
my $month_last_start;
my $month_last_stop;
my $quarter_last;
my $quarter_last_directory;

# Variables related to the calls mail we are sending
#
# - $subject is the subject of the mail we send.
# - $send_command is the command we run to send the mail.
# - @bcc_recipients and @cc_recipients are the array of all the addresses
#   we want to put in the BCC and CC field respectively. The To field
#   contains freebsd-status-calls@FreeBSD.org.
my $subject;
my $send_command;
my @bcc_recipients;
my @cc_recipients;

# Other variables
# - %quarter_specific_recipients is a hash that contains lists of
#   addresses. The addresses of each list should be contacted only for the
#   quarter specified by the list's the keys.
# - %template_substitutions is a hash that specifies for each quarter how
#   the variabes in the call.template file should be substituted.
# - %options is a hash used for registering option. See --help to list all
#   available options.
my %quarter_specific_recipients;
my %template_substitutions;
my %options;

# -------------------------------------------------------
# Variables initialization
# -------------------------------------------------------

@bcc_recipients = ();
@cc_recipients = (	'freebsd-current@FreeBSD.org',
			'freebsd-hackers@FreeBSD.org',
			'devsummit@FreeBSD.org'	);

$quarter_specific_recipients{1} = [	'secretary@asiabsdcon.org'	];
$quarter_specific_recipients{2} = [	'info@bsdcan.org',
					'soc-students@FreeBSD.org',
					'soc-mentors@FreeBSD.org'	];
$quarter_specific_recipients{3} = [	'soc-students@FreeBSD.org',
					'soc-mentors@FreeBSD.org'	];
$quarter_specific_recipients{4} = [];

$template_substitutions{1}{'%%START%%'}	=	'January';
$template_substitutions{1}{'%%STOP%%'}	=	'March';
$template_substitutions{1}{'%%START_NUM%%'}	=	'01';
$template_substitutions{1}{'%%STOP_NUM%%'}	=	'03';
$template_substitutions{1}{'%%DEADLINE%%'}	=	'March, 31st';
$template_substitutions{2}{'%%START%%'}	=	'April';
$template_substitutions{2}{'%%STOP%%'}	=	'June';
$template_substitutions{2}{'%%START_NUM%%'}	=	'04';
$template_substitutions{2}{'%%STOP_NUM%%'}	=	'06';
$template_substitutions{2}{'%%DEADLINE%%'}	=	'June, 30th';
$template_substitutions{3}{'%%START%%'}	=	'July';
$template_substitutions{3}{'%%STOP%%'}	=	'September';
$template_substitutions{3}{'%%START_NUM%%'}	=	'07';
$template_substitutions{3}{'%%STOP_NUM%%'}	=	'09';
$template_substitutions{3}{'%%DEADLINE%%'}	=	'September, 30th';
$template_substitutions{4}{'%%START%%'}	=	'October';
$template_substitutions{4}{'%%STOP%%'}	=	'December';
$template_substitutions{4}{'%%DEADLINE%%'}	=	'December, 31st';
$template_substitutions{4}{'%%START_NUM%%'}	=	'10';
$template_substitutions{4}{'%%STOP_NUM%%'}	=	'12';

$main::VERSION = "[not versioned]";
$Getopt::Std::STANDARD_HELP_VERSION = 1;

# -------------------------------------------------------
# Subroutines definition
# -------------------------------------------------------

sub main::HELP_MESSAGE
{
	print <<EOT;
Usage: ./sendcalls [-d day] [-m month] [-y year] [-t] -s signature

Options:
	-d day		Day of the month: [1-31].
	-m month	Month: [1-12].
	-y year		Year: >= 1970
			(I think you are unlikely to send calls before
			the Unix epoch. And I am writing it in 2020.)
	-t		Testing flag. Set it it you want to test the
			script without actually send mails.
	-s signature	Name to use for signing the status reports calls mail.

Example:
	./sendcalls -d 31 -m 2 -y 2000 -s 'Lorenzo Salvadore'
	(Yes, you can send calls even on inexistent days such as
	2020 February, 31st.)
EOT
	exit 1;
}

# -------------------------------------------------------
# Execution starts here
# -------------------------------------------------------
getopts('d:m:y:s:t', \%options);

main::HELP_MESSAGE if(not $options{'s'});

# -------------------------------------------------------
# Compute time coordinates (see global variables declaration)
# -------------------------------------------------------

(undef, undef, undef, $day, $month, $year, undef, undef, undef) = localtime();
$year = $year + 1900;

$day = $options{'d'} if($options{'d'});
$month = $options{'m'} - 1 if($options{'m'});
$year = $options{'y'} if($options{'y'});

die "Choosen date does not seem plausibile: year is $year, month is $month and day is $day"
if(	$day < 1 or
	$day > 31 or
	$month < 1 or
	$month > 12 or
	$year < 1970	);

if($day < 14)
{
	$urgency_tag = '';
}
elsif($day < 23)
{
	$urgency_tag = '[2 WEEKS LEFT REMINDER] ';
}
else
{
	$urgency_tag = '[LAST OFFICIAL REMINDER] ';
}

$quarter = int($month / 3) + 1;

# -------------------------------------------------------
# Compute @bcc_recipients and @cc_recipients
# -------------------------------------------------------
$year_last = $year;
$month_last_start = sprintf("%02d",int((($month - 3) % 12) / 3) * 3 + 1);
$month_last_stop = sprintf("%02d",$month_last_start + 2);
$quarter_last = $quarter - 1;
if($quarter_last == 0)
{
	$year_last = $year_last - 1;
	$quarter_last = 4;
}
$quarter_last_directory =	'../../website/content/en/status/report-'.
				$year_last.
				'-'.
				$month_last_start.
				'-'.
				$year_last.
				'-'.
				$month_last_stop;
foreach(`ls $quarter_last_directory`)
{
	$_ =~ tr/\n//d;
	open(quarterly_report, '<', $quarter_last_directory.'/'.$_) or
	die "Could not open $quarter_last_directory/$_: $!";
	while(<quarterly_report>)
	{
		if($_ =~ m/^Contact:.*(<.*@.*>)/)
		{
			my $address = $1;
			$address =~ tr/<>//d;
			push @bcc_recipients, $address if(not $address =~ m/\@FreeBSD.org$/i);
		}
	}
	close(quarterly_report);
}

{
	my %tmp = map {$_ => 0} @bcc_recipients;
	@bcc_recipients = keys %tmp;
}

push @cc_recipients, @{ $quarter_specific_recipients{$quarter} };

# -------------------------------------------------------
# Compute missing %template_substitutions elements
# -------------------------------------------------------
$template_substitutions{$quarter}{'%%QUARTER%%'} = $quarter;
$template_substitutions{$quarter}{'%%YEAR%%'} = $year;
$template_substitutions{$quarter}{'%%SIGNATURE%%'} = $options{'s'};
$template_substitutions{$quarter}{'%%DEADLINE%%'} =
$template_substitutions{$quarter}{'%%DEADLINE%%'}.' '.$year;

# -------------------------------------------------------
# Generate mail text
# -------------------------------------------------------
open(call_template, '<', 'call.txt.template') or
die "Could not open call.txt.template: $!";
open(call_mail, '>', 'call.txt') or
die "Could not open call.txt: $!";
while(<call_template>)
{
	my $line = $_;
	$line =~ s/$_/$template_substitutions{$quarter}{$_}/g
		foreach(keys %{ $template_substitutions{$quarter} });
	print call_mail $line;
}
close(call_template);
close(call_mail);

# -------------------------------------------------------
# Compute $subject and $send_command
# -------------------------------------------------------
$subject = $urgency_tag."Call for ".$year."Q".$quarter." status reports";

$send_command = "cat call.txt | mail -s \"".$subject."\"";
# @bcc_recipients should never be empty as we have reports with mail
# contacts every quarter, but we test it anyway: we do not want to
# assume that this will be true forever
$send_command = $send_command.' -b '.(join ',', @bcc_recipients) if(@bcc_recipients);
# @cc_recipients should never be empty as we initialize it not empty
# and never remove addresses from there, but we test it anyway: we do
# not want to assume that this will be true forever
$send_command = $send_command.' -c '.(join ',', @cc_recipients) if(@cc_recipients);
$send_command = $send_command.' freebsd-status-calls@FreeBSD.org';

# -------------------------------------------------------
# Send mail or show testing information 
# -------------------------------------------------------
if($options{'t'})
{
	print <<EOT;
send_command: $send_command
subject: $subject
call.txt:
EOT
	open(call_mail, '<', 'call.txt') or
	die "Could not open call.txt: $!";
	print <call_mail>;
	close(call_mail);
}
else
{
	system $send_command;
}

# -------------------------------------------------------
# Clean environment
# -------------------------------------------------------
unlink "call.txt";