#!/usr/bin/env perl
use strict;
use warnings FATAL => qw(all);
use LWP::Simple;

use make::configure;

our @modlist;

my %installed;
# $installed{name} = $version

my %modules;
# $modules{$name}{$version} = {
#	url => URL of this version
#	depends => [ 'm_foo 1.2.0-1.3.0', ... ]
#	conflicts => [ ]
#	from => URL of source document
#	mask => Reason for not installing (INSECURE/DEPRECATED)
#	description => some string
# }

my %url_seen;

sub parse_url;

# retrieve and parse entries from sources.list
sub parse_url {
	my $src = shift;
	return if $url_seen{$src};
	$url_seen{$src}++;

	my $doc = get($src);
	die "Could not retrieve $_" unless defined $doc;

	my $mod;
	for (split /\n+/, $doc) {
		s/^\s+//; # ignore whitespace at start
		next if /^#/;
		if (/^module (\S+) (\S+) (\S+)/) {
			my($name, $ver, $url) = ($1,$2,$3);
			if ($modules{$name}{$ver}) {
				my $origsrc = $modules{$name}{$ver}{from};
				warn "Overriding module $name $ver defined from $origsrc with one from $src";
			}
			$mod = {
				from => $src,
				url => $url,
				depends => [],
				conflicts => [],
			};
			$modules{$name}{$ver} = $mod;
		} elsif (/^depends (.*)/) {
			push @{$mod->{depends}}, $1;
		} elsif (/^conflicts (.*)/) {
			push @{$mod->{conflicts}}, $1;
		} elsif (/^description (.*)/) {
			$mod->{description} = $1;
		} elsif (/^mask (.*)/) {
			$mod->{mask} = $1;
		} elsif (m#^source (http://\S+)#) {
			parse_url $1;
		} else {
			print "Unknown line in $src: $_\n";
		}
	}
}

# hash of installed module versions from our mini-database, key (m_foobar) to version (00abacca..).
my %mod_versions;

# useless helper stub
sub getmodversion {
	my ($file) = @_;
	return $mod_versions{$file};
}

# read in installed versions
if (-e '.modulemanager')
{
	open SRC, '.modulemanager' or die ".modulemanager exists but i can't read it: $!";
	while (<SRC>)
	{
		s/\n//;
		(my $mod, my $ver) = split(/ /, $_);
		$mod_versions{$mod} = $ver;
	}
	close SRC;
}

# read in external URL sources
open SRC, 'sources.list' or die "Could not open sources.list: $!";
while (<SRC>) {
	next if /^\s*#/;
	parse_url($_);
}
close SRC;

getmodules(1);

# determine core version
`./src/version.sh` =~ /InspIRCd-([0-9.]+)/ or die "Cannot determine inspircd version";
$installed{core} = $1;
for my $mod (keys %modules) {
	MODVER: for my $mver (keys %{$modules{$mod}}) {
		for my $dep (@{$modules{$mod}{$mver}{depends}}) {
			next unless $dep =~ /^core (.*)/;
			if (!ver_in_range($installed{core}, $1)) {
				delete $modules{$mod}{$mver};
				next MODVER;
			}
		}
	}
	delete $modules{$mod} unless %{$modules{$mod}};
}
$modules{core}{$1} = {
	url => 'NONE',
	depends => [],
	conflicts => [],
	from => 'local file',
};

# set up core module list
for my $modname (@modlist) {
	my $mod = "m_$modname";
	my $modfile = "src/modules/$mod.cpp";
	my $ver = getmodversion($mod) || '0.0';
	$ver =~ s/\$Rev: (.*) \$/$1/; # for storing revision in SVN
	$installed{$mod} = $ver;
	next if $modules{$mod}{$ver};
	$modules{$mod}{$ver} = {
		url => 'NONE',
		depends => [],
		conflicts => [],
		from => 'local file',
	};
}

my %todo = %installed;

sub ver_cmp {
	($a,$b) = @_ if @_;

	if ($a !~ /^[0-9.]+$/ or $b !~ /^[0-9.]+$/)
	{
		# not a valid version number, don't try to sort
		return $a ne $b;
	}

	# else it's probably a numerical type version.. i.e. 1.0
	my @a = split /\./, $a;
	my @b = split /\./, $b;
	push @a, 0 while $#a < $#b;
	push @b, ($_[2] || 0) while $#b < $#a;
	for my $i (0..$#a) {
		my $d = $a[$i] <=> $b[$i];
		return $d if $d;
	}
	return 0;
}

sub ver_in_range {
	my($ver, $range) = @_;
	return 1 unless defined $range;
	my($l,$h) = ($range, $range);
	if ($range =~ /(.*)-(.*)/) {
		($l,$h) = ($1,$2);
	}
	return 0 if $l && ver_cmp($ver, $l) < 0;
	return 0 if $h && ver_cmp($ver, $h, 9999) > 0;
	return 1;
}

sub find_mod_in_range {
	my($mod, $vers, $force) = @_;
	my @versions = keys %{$modules{$mod}};
	@versions = sort { -ver_cmp() } @versions;
	for my $ver (@versions) {
		next if $modules{$mod}{$ver}{mask} && !$force;
		return $ver if ver_in_range($ver, $vers);
	}
	return undef;
}

sub resolve_deps {
	my($trial) = @_;
	my $tries = 100;
	my $changes = 'INIT';
	my $fail = undef;
	while ($changes && $tries) {
		$tries--;
		$changes = '';
		$fail = undef;
		my @modsnow = sort keys %todo;
		for my $mod (@modsnow) {
			my $ver = $todo{$mod};
			my $info = $modules{$mod}{$ver} or die "no dependency information on $mod $ver";
			for my $dep (@{$info->{depends}}) {
				$dep =~ /^(\S+)(?: (\S+))?/ or die "Bad dependency $dep from $info->{from}";
				my($depmod, $depvers) = ($1,$2);
				next if $todo{$depmod} && ver_in_range($todo{$depmod}, $depvers);
				# need to install a dependency
				my $depver = find_mod_in_range($depmod, $depvers);
				if (defined $depver) {
					$todo{$depmod} = $depver;
					$changes .= " $mod-$ver->$depmod-$depver";
				} else {
					$fail ||= "Could not find module $depmod $depvers required by $mod $ver";
				}
			}
			for my $dep (@{$info->{conflicts}}) {
				$dep =~ /^(\S+)(?: (\S+))?/ or die "Bad dependency $dep from $info->{from}";
				my($depmod, $depvers) = ($1,$2);
				next unless $todo{$depmod} && ver_in_range($todo{$depmod}, $depvers);
				# if there are changes this round, maybe the conflict won't come up after they are resolved.
				$fail ||= "Cannot install: module $mod ($ver) conflicts with $depmod version $todo{$depmod}";
			}
		}
	}
	if ($trial) {
		return !($changes || $fail);
	}
	if ($changes) {
		print "Infinite dependency loop:$changes\n";
		exit 1;
	}
	if ($fail) {
		print "$fail\n";
		exit 1;
	}
}

my $action = lc shift @ARGV;

if ($action eq 'install') {
	for my $mod (@ARGV) {
		my $vers = $mod =~ s/=([-0-9.]+)// ? $1 : undef;
		$mod = lc $mod;
		unless ($modules{$mod}) {
			print "Cannot find module $mod\n";
			exit 1;
		}
		my $ver = find_mod_in_range($mod, $vers, $vers ? 1 : 0);
		unless ($ver) {
			print "Cannot find suitable version of $mod\n";
			exit 1;
		}
		$todo{$mod} = $ver;
	}
} elsif ($action eq 'upgrade') {
	my @installed = sort keys %installed;
	for my $mod (@installed) {
		next unless $mod =~ /^m_/;
		my %saved = %todo;
		$todo{$mod} = find_mod_in_range($mod);
		if (!resolve_deps(1)) {
			%todo = %saved;
		}
	}
} elsif ($action eq 'list') {
	my @all = sort keys %modules;
	for my $mod (@all) {
		my @vers = sort { ver_cmp() } keys %{$modules{$mod}};
		my $desc = '';
		for my $ver (@vers) {
			# latest defined description wins
			$desc = $modules{$mod}{$ver}{description} || $desc;
		}
		next if @vers == 1 && $modules{$mod}{$vers[0]}{url} eq 'NONE';
		my $instver = $installed{$mod} || '';
		my $vers = join ' ', map { $_ eq $instver ? "\e[1m$_\e[m" : $_ } @vers;
		print "$mod ($vers) - $desc\n";
	}
} else {
	print <<ENDUSAGE
Use: $0 <action> <args>
Action is one of the following
 install   install new modules
 upgrade   upgrade installed modules
 list      lists available modules

For installing a package, specify its name or name=version to force the
installation of a specific version.
ENDUSAGE
;exit 1;
}

resolve_deps(0);

$| = 1; # immediate print of lines without \n

print "Processing changes for $action...\n";
for my $mod (keys %installed) {
	next if $todo{$mod};
	print "Uninstalling $mod $installed{$mod}\n";
	unlink "src/modules/$mod.cpp";
}

my $count = scalar keys %todo;
print "Checking $count items...\n";
for my $mod (sort keys %todo) {
	my $ver = $todo{$mod};
	my $oldver = $installed{$mod};
	if ($modules{$mod}{$ver}{mask}) {
		print "Module $mod $ver is masked: $modules{$mod}{$ver}{mask}\n";
	}
	next if $oldver && $oldver eq $ver;
	my $url = $modules{$mod}{$ver}{url};
	if ($oldver) {
		print "Upgrading $mod from $oldver to $ver using $url"
	} else {
		print "Installing $mod $ver from $url";
	}
	$mod_versions{$mod} = $ver;

	my $stat = getstore($url, "src/modules/$mod.cpp");
	if ($stat == 200) {
		print " - done\n";
	} else {
		print " - HTTP $stat\n";
	}
}

# write database of installed versions
open SRC, '>.modulemanager' or die "can't write installed versions to .modulemanager, won't be able to track upgrades properly: $!";
foreach my $key (keys %mod_versions)
{
	print SRC "$key $mod_versions{$key}\n";
}
close SRC;

print "Finished!\n";