#!/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 $DUMMY $NOSLEEP];
use File::Spec;
use File::Slurp;
use Time::Duration::Parse;
#use Proc::Daemon;
use Proc::Fork;
#use IO::Pipe;

#Proc::Daemon::Init;

my (%delay, %reply);
my ($path) = shift @ARGV;

foreach my $file (read_dir( $path )) {
    my ($key, $i);
    # suppress repeated warnings for same issue
    my ($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*$/) {
		# tidy latest reply (TODO: use sub)
		if (defined($key) and defined($reply{$key}[$i])) {
			$reply{$key}[$i] =~ s/^\s*(\w.*?)\s*$/$1/s || delete $reply{$key}[$i];
		}
		my $level = length($1);
		$content = $2;
		# key
		if ($level == 1 and $content =~ /(\w+)/) {
			$key = lc($1);
			$i = 0;
			if (lc($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\"" );
				$key = undef;
			}
		# delay
		} elsif ($level == 2 and $content =~ /(\d+[sm](\s+|\Z))+/) {
			if (defined( $key)) {
				my $delay = parse_duration($1);
				if (defined($reply{$key}[$i])) {
					$i++;
					$delay{$key}[$i] = $delay{$key}[$i - 1];
				}
				$delay{$key}[$i] += $delay;
				if ($content ne $1) {
					warn( "delay (${delay}s) resolved from fuzzy string \"$content\" in file \"$file\"" );
				}
			} else {
				warn( "ignoring non-key'ed delay line \"$1\" in file \"$file\"" ) unless ($warn_nonkey_delay);
				$warn_nonkey_delay = 1;
			}
		} else {
			warn( "ignoring non-parsable headline \"$line\" in file \"$file\"");
		}
	# reply
	} elsif ( defined( $key )) {
		$content = $reply{$key}[$i] if (defined($reply{$key}[$i]));
		$content .= $line . "\n";
		$content =~ s/^\h*$//g;		# clean virtually empty lines
		$content =~ s/(\S)\h$/$1/g;	# strip single trailing space
		$content =~ s/\n\n+/\n\n/g;	# strip excess newlines
		$content =~ s/(\S)\n([^\n])/$1 $2/g; # convert newline to space
		$content =~ s/\h*$//g;		# strip all trailing spaces
		$reply{$key}[$i] = $content;
	} else {
		warn( "skipping non-key'ed content \"$line\" in file \"$file\"" ) unless ($warn_nonkey_content);
		$warn_nonkey_content = 1;
	}
    }
    # tidy latest reply (TODO: use sub)
    if (defined($key) and defined($reply{$key}[$i])) {
	$reply{$key}[$i] =~ s/^\s*(\w.*?)\s*$/$1/s || delete $reply{$key}[$i];
    }
}

my ($phone) = shift @ARGV;
my ($key) = shift @ARGV;

my $num_children = $#{ $reply{$key} } + 1;    # How many children we'll create
$SIG{CHLD} = 'IGNORE';   # Don't worry about reaping zombies

# Spawn off some children
if ($DEBUG) {
	print STDERR "queueing $num_children replies:";
	for my $num ( 0 .. $num_children - 1 ) {
		print STDERR " [" . $delay{$key}[$num] . "s]";
	}
	print STDERR "\n";
}
for my $num ( 0 .. $num_children - 1 ) {

	run_fork {
		child {
			sleep($delay{$key}[$num]) unless ($NOSLEEP);
			unless ($DUMMY) {
				system {'/usr/share/kannel/contrib/sendsms' } $phone, $reply{$key}[$num];
				print STDERR "Done reply #$num [" . $delay{$key}[$num] . "s]\n" if ($DEBUG);
			} else {
				print STDERR "\n[" . $delay{$key}[$num] . "s]\n";
				print STDERR $reply{$key}[$num] . "\n";
			}
			exit;
		}
		parent {
			if ($DEBUG) {
				my $child_pid = shift;
				waitpid $child_pid, 0;
			}
		}
	}
}

1;