#!/usr/bin/perl
#
# /usr/local/sbin/localmarkdown2sms
# Copyright 2009 Jonas Smedegaard <dr@jones.dk>
#
# Send series of messages through Kannel from simplified Markdown files

#  * Lines starting with "#" are "keywords" activating a message series
#    * write only a single word
#    * use each keyword only once across the whole system
#    * use only minuscles (not majuscles, i.e. CAPITAL LETTERS)
#  * Lines starting with "##" express pauses
#    * a pause is a number + a single letter, without spaces between
#    * a pause line can contain multiple pauses, separated by space

# Suggestion for writing style:
#
#  * Write explicitly how to activate next series
#  * pick keywords tied to nex series rather than the previous
#  * use same instruction jargon across all series in the system


use strict;
use warnings;

use Env qw[$debug $info $warn $dummy $nosleep];
use Log::Log4perl qw(:easy);
use File::Spec;
use File::Slurp;
use Time::Duration::Parse;
use Encode;
use LWP::UserAgent;
use URI::Escape;
use Proc::Daemon;

Proc::Daemon::Init unless ($debug);

my $sms_url = $ENV{SMS_URL} || "http://localhost:13013/cgi-bin/sendsms";
my $sms_user = $ENV{SMS_USER} || "tester";
my $sms_pw = $ENV{SMS_PW} || "foobar";
my $sms_phone = $ENV{SMS_PHONE};
my $sms_smsc = $ENV{SMS_SMSC};
my $sms_msgtag = $ENV{SMS_MSGTAG} || "text";

my (%file, %delay, %reply);
my ($path) = shift @ARGV;
my ($phone) = shift @ARGV;
my ($key) = lc (shift @ARGV);

# strip non-word chars from keyword (and use only first chunk of word chars)
$key =~ s/.*?(\w+).*?/$1/;

if ($debug) {
	Log::Log4perl->easy_init($DEBUG);
} elsif ($INFO) {
	Log::Log4perl->easy_init($INFO);
} elsif ($WARN) {
	Log::Log4perl->easy_init($WARN);
} elsif ($ERROR) {
	Log::Log4perl->easy_init($ERROR);
}

foreach my $file (read_dir( $path )) {
    my ($key, $i, $skipkeysection, $skipcontent);
    # suppress repeated warnings for same issue
    my ($warn_nonkey_delay, $warn_nonkey_content);
    next unless ($file =~ /\.mdwn$/);
    foreach my $line (read_file( File::Spec->catfile($path, $file))) {
	chomp $line;
	my $content;
	# headline
	if ($line =~ /^(#+)\s*(.*?)\s*$/) {
		# tidy latest reply
		if (defined($key) and defined($reply{$key}[$i])) {
			$reply{$key}[$i] = &tidymsg($reply{$key}[$i]);
			($reply{$key}[$i]) || delete $reply{$key}[$i];
		}
		my $level = length($1);
		$content = $2;
		# key
		if ($level == 1 and $content =~ /(\w+)/) {
			$key = lc($1);
			$i = 0;
			$skipkeysection = undef;
			$skipcontent = undef;
			if (lc($content) ne $key) {
				WARN "key \"$key\" extracted from fuzzy string \"$content\" in file \"$file\"";
			}
			if (!defined( $delay{$key})) {
				$delay{$key}[0] = 0;
				$warn_nonkey_delay = undef;
				$warn_nonkey_content = undef;
			} else {
				WARN "skipping non-unique key \"$key\" in file \"$file\"";
				$key = undef;
				$skipkeysection = 1;
				$skipcontent = 1;
			}
		# delay
		} elsif ($level == 2 and $content =~ /((\d+[sm]\s?)+)/) {
			$skipcontent = undef;
			if (defined( $key)) {
				my $delay = parse_duration($1);
				if (defined($reply{$key}[$i])) {
					$i++;
					$delay{$key}[$i] = $delay{$key}[$i - 1];
				}
#				$delay{$key}[$i] += $delay; # accumulate: forked replies
				$delay{$key}[$i] = $delay; # simple: queued replies
				if ($content ne $1) {
					WARN "delay (${delay}s) resolved from fuzzy string \"$content\" in file \"$file\"";
				}
			} elsif ($skipkeysection or $warn_nonkey_delay) {
				# skipping - already warned about it...
			} else {
				WARN "ignoring non-key'ed delay line \"$1\" in file \"$file\"";
				$warn_nonkey_delay = 1;
				$skipcontent = 1;
			}
		} else {
			WARN "ignoring non-parsable headline \"$line\" in file \"$file\"";
			$skipcontent = 1;
		}
	# reply
	} else {
		$content = $line . "\n";
		# ikiwiki directives - strip from content and parse for tags
		$content =~ s/(?<!\\)\[\[([^\[\]]*)(?<!\\)\]\]//gs and do {
			my $directive_string = $1;
			my ($directive, $directive_content);
			$directive_string =~ /^\s*\!(tag|taglink)\s*((\s*?\b\w+)+)/ and $file{$file}{'directive'}{'tag'} = [ split /\s+/, $2 ];
		};
		if ( defined( $key ) and not ($skipcontent)) {
			$reply{$key}[$i] .= $content;
		} elsif ($skipkeysection or $skipcontent or $warn_nonkey_content) {
			# skipping - already warned about it...
		} else {
			$content =~ /\S/s && WARN "skipping non-key'ed content \"$line\" in file \"$file\"";
			$warn_nonkey_content = 1;
		}
	}
    }
    # tidy latest reply
    if (defined($key) and defined($reply{$key}[$i])) {
	$reply{$key}[$i] = &tidymsg($reply{$key}[$i]);
	($reply{$key}[$i]) || delete $reply{$key}[$i];
    }
}

sub tidymsg {
	my $msg = shift @_;
	$msg =~ s/^\h*$//g;			# clean virtually empty lines
	$msg =~ s/(\S)\h$/$1/g;			# strip single trailing space
	$msg =~ s/\n\n+/\n\n/g;			# strip excess newlines
	$msg =~ s/(\S)\n([^\n])/$1 $2/g;	# convert newline to space
	$msg =~ s/\h*$//g;			# strip all trailing spaces
	$msg =~ s/^\s*(\w*?.*?)\s*$/$1/s;	# strip surrounding space
	return $msg;
}

sub sendmsg {
	my ($phone, $desc, $msg) = @_;

	unless ($dummy) {
		my $ua = LWP::UserAgent->new(agent => "localmarkdown2sms");
		$ua->timeout(10);
		my $url = $sms_url
			. '?username=' . uri_escape($sms_user)
			. '&password=' . uri_escape($sms_pw)
			. '&to=' . uri_escape($phone);
		$url .= '&from=' . uri_escape($sms_phone) if ($sms_phone);
		$url .= '&smsc=' . uri_escape($sms_smsc) if ($sms_smsc);
		$url .= '&' . $sms_msgtag . '=' . uri_escape(encode("cp1252", $msg));
		my $response = $ua->request(HTTP::Request->new('GET', $url));
		unless ($response->is_success) {
			ERROR $response->status_line;
		}
		DEBUG "Done $desc";
	} else {
		print STDERR "\n --> $phone: $desc\n";
		print STDERR $msg . "\n";
	}
}

my $num_children = $#{ $reply{$key} } + 1;    # How many children we'll create

if (0 == $num_children) {
	&sendmsg($phone, "fallback message", "Sorry, the sms code \"$key\" is unknown.\nPlease send only sms codes to this number.");
	exit;
}

if ($debug) {
	DEBUG "queueing $num_children replies:";
	for my $num ( 0 .. $num_children - 1 ) {
		DEBUG " [" . $delay{$key}[$num] . "s]";
	}
#	DEBUG "\n";
}
for my $num ( 0 .. $num_children - 1 ) {
	sleep($delay{$key}[$num]) unless ($nosleep);
	&sendmsg($phone, "reply #$num [" . $delay{$key}[$num] . "s]", $reply{$key}[$num]);
}

1;