#!/usr/local/bin/perl

# Download Counter - ファイルのダウンロード数をカウントする
# Copyright (C) Takashi Utsunomiya. All Rights Reserved.
# http://uttsu.com/
# 2002.08.17-

# ver 1.00	2002.08.17

# ■init
use strict;

# カウントデータファイルを置くディレクトリ
my $data_path = 'dat/';
# カウントデータファイル
my $data_file = 'count.dat';
# ダウンロードするファイルを置くディレクトリ
my $file_path = '../../work/';

my $target = $ARGV[0] or err('No argument');
my %count;
my $time;

$ENV{TZ} = 'JST-9';
main();
exit;

# ■main
sub main {
	err("Illegal filename: $target") if ($target =~ /\.\./ || $target =~ /^\//);
	not_found() if (!-e "$file_path$target");

	mkdir($data_path) if (!-d $data_path);
	open(FILE, "> $_") if (!-e ($_ = "$data_path$data_file"));
	open(FILE, "+< $_") or die $!;
	eval { flock(FILE, 2); };
	binmode(FILE);
	get_count();
	seek(FILE, 0, 0);

	get_time();
	do_count();
	do_log();
	put_count();
	put_file();

	close(FILE);
}

# ◆get_count
sub get_count {
	foreach (<FILE>) {
		my ($file, $count) = split(/\s/);
		$count{$file} = $count;
	}
}

# ◆put_count
sub put_count {
	foreach (sort keys %count) {
		print FILE "$_\t$count{$_}\n";
	}
}

# ◆get_time
sub get_time {
	my ($sec, $min, $hour, $day, $month, $year) = localtime(time);

	$sec = figure($sec);
	$min = figure($min);
	$hour = figure($hour);
	$day = figure($day);
	$month = figure($month+1);
	$year += 1900;

	$time = "$year.$month.$day $hour:$min:$sec";
}

# ◆figure
sub figure {
	my $num = shift;
	my $figure = (shift || 2);

	$num = substr(('0' x $figure) . $num, -$figure);
	return $num;
}

# ◆do_count
sub do_count {
	$count{$target}++;
}

# ◆do_log
sub do_log {
	my ($ip, $host, $ref);

	$ip = $ENV{REMOTE_ADDR};
	$host = (gethostbyaddr(pack("C4", split(/\./, $ip)), 2) || $ip);
	$ref = $ENV{HTTP_REFERER};

	$_ = $target;
	s/\//_/g;

	open(LOG, ">> $data_path$_\.log") or die $!;
	print LOG "$time $host $ref\n";
	close(LOG);
}

# ◆put_file
sub put_file {
	my $size = -s "$file_path$target";
	$_ = $target;
	s/^(.*)\///g;

	print <<EOF;
Content-Disposition: attachment; filename=$_
Content-Type: application/octet-stream
Content-Length: $size

EOF
	open(IN, "$file_path$target") or err('Cannot open file');
	binmode(IN);
	binmode(STDOUT);
	print $_ while (<IN>);
	close(IN);
}

# ◆not_found
sub not_found {
	print <<EOF;
Status: 404
Content-type: text/html

No such file: $target
EOF
	exit;
}

# ◆err
sub err {
	$_ = shift;
	print "Content-type: text/html\n\n$_\n";
	exit;
}