#
# InspIRCd -- Internet Relay Chat Daemon
#
#   Copyright (C) 2020 Nicole Kleinhoff <ilbelkyr@shalture.org>
#   Copyright (C) 2013-2020 Sadie Powell <sadie@witchery.services>
#   Copyright (C) 2012 Robby <robby@chatbelgie.be>
#   Copyright (C) 2007-2008 Craig Edwards <brain@inspircd.org>
#   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
#
# This file is part of InspIRCd.  InspIRCd is free software: you can
# redistribute it and/or modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#


package make::configure;

use v5.10.0;
use strict;
use warnings FATAL => qw(all);

use Exporter              qw(import);
use File::Basename        qw(basename dirname);
use File::Spec::Functions qw(abs2rel catdir catfile);

use make::common;
use make::console;

use constant CONFIGURE_ROOT          => dirname dirname __FILE__;
use constant CONFIGURE_DIRECTORY     => catdir(CONFIGURE_ROOT, '.configure');
use constant CONFIGURE_CACHE_FILE    => catfile(CONFIGURE_DIRECTORY, 'cache.cfg');
use constant CONFIGURE_CACHE_VERSION => '1';
use constant CONFIGURE_ERROR_PIPE    => $ENV{INSPIRCD_VERBOSE} ? '' : '1>/dev/null 2>/dev/null';

our @EXPORT = qw(CONFIGURE_CACHE_FILE
                 CONFIGURE_CACHE_VERSION
                 CONFIGURE_DIRECTORY
                 cmd_clean
                 cmd_help
                 cmd_update
                 run_test
                 test_file
                 test_header
                 module_expand
                 module_shrink
                 write_configure_cache
                 get_compiler_info
                 find_compiler
                 parse_templates);

sub __get_socketengines {
	my @socketengines;
	foreach (<${\CONFIGURE_ROOT}/src/socketengines/socketengine_*.cpp>) {
		s/src\/socketengines\/socketengine_(\w+)\.cpp/$1/;
		push @socketengines, $1;
	}
	return @socketengines;
}

# TODO: when buildtool is done this can be mostly removed with
#       the remainder being merged into parse_templates.
sub __get_template_settings($$$) {

	# These are actually hash references
	my ($config, $compiler, $version) = @_;

	# Start off by populating with the config
	my %settings = %$config;

	# Compiler information
	while (my ($key, $value) = each %{$compiler}) {
		$settings{'COMPILER_' . $key} = $value;
	}

	# Version information
	while (my ($key, $value) = each %{$version}) {
		$settings{'VERSION_' . $key} = $value;
	}

	# Miscellaneous information
	$settings{CONFIGURE_DIRECTORY} = CONFIGURE_DIRECTORY;
	$settings{CONFIGURE_CACHE_FILE} = CONFIGURE_CACHE_FILE;
	$settings{SYSTEM_NAME} = lc $^O;

	return %settings;
}

sub __test_compiler($) {
	my $compiler = shift;
	return 0 unless run_test("`$compiler`", !system "$compiler -v ${\CONFIGURE_ERROR_PIPE}");
	return 0 unless run_test("`$compiler`", test_file($compiler, 'compiler.cpp', '-fno-rtti'), 'compatible');
	return 1;
}

sub cmd_clean {
	unlink CONFIGURE_CACHE_FILE;
}

sub cmd_help {
	my $SELIST = join ', ', __get_socketengines();
	print <<EOH;
Usage: $0 [options]

When no options are specified, configure runs in interactive mode and you must
specify any required values manually. If one or more options are specified,
non-interactive configuration is started and any omitted values are defaulted.

PATH OPTIONS

  --system                      Automatically set up the installation paths
                                for system-wide installation.
  --prefix=[dir]                The root install directory. If this is set then
                                all subdirectories will be adjusted accordingly.
                                [${\CONFIGURE_ROOT}/run]
  --binary-dir=[dir]            The location where the main server binary is
                                stored.
                                [${\CONFIGURE_ROOT}/run/bin]
  --config-dir=[dir]            The location where the configuration files and
                                SSL certificates are stored.
                                [${\CONFIGURE_ROOT}/run/conf]
  --data-dir=[dir]              The location where the data files, such as the
                                pid file, are stored.
                                [${\CONFIGURE_ROOT}/run/data]
  --example-dir=[dir]           The location where the example configuration files
                                and SQL schemas are stored.
                                [${\CONFIGURE_ROOT}/run/conf/examples]
  --log-dir=[dir]               The location where the log files are stored.
                                [${\CONFIGURE_ROOT}/run/logs]
  --manual-dir=[dir]            The location where the manual files are stored.
                                [${\CONFIGURE_ROOT}/run/manuals]
  --module-dir=[dir]            The location where the loadable modules are
                                stored.
                                [${\CONFIGURE_ROOT}/run/modules]
  --script-dir=[dir]            The location where the scripts, such as the
                                init scripts, are stored.
                                [${\CONFIGURE_ROOT}/run]

EXTRA MODULE OPTIONS

  --enable-extras=[extras]      Enables a comma separated list of extra modules.
  --disable-extras=[extras]     Disables a comma separated list of extra modules.
  --list-extras                 Shows the availability status of all extra
                                modules.

MISC OPTIONS

  --clean                       Remove the configuration cache file and start
                                the interactive configuration wizard.
  --disable-auto-extras         Disables automatically enabling extra modules
                                for which the dependencies are available.
  --disable-interactive         Disables the interactive configuration wizard.
  --distribution-label=[text]   Sets a distribution specific version label in
                                the build configuration.
  --gid=[id|name]               Sets the group to run InspIRCd as.
  --help                        Show this message and exit.
  --socketengine=[name]         Sets the socket engine to be used. Possible
                                values are $SELIST.
  --uid=[id|name]               Sets the user to run InspIRCd as.
  --update                      Updates the build environment with the settings
                                from the cache.


FLAGS

  CXX=[name]                    Sets the C++ compiler to use when building the
                                server. If not specified then the build system
                                will search for c++, g++, clang++ or icpc.

If you have any problems with configuring InspIRCd then visit our IRC channel
at irc.inspircd.org #InspIRCd or create a support discussion at
https://github.com/inspircd/inspircd/discussions.

Packagers: see https://docs.inspircd.org/packaging/ for packaging advice.
EOH
	exit 0;
}

sub cmd_update {
	print_error "You have not run $0 before. Please do this before trying to update the generated files." unless -f CONFIGURE_CACHE_FILE;
	say 'Updating...';
	my %config = read_config_file(CONFIGURE_CACHE_FILE);
	$config{EXAMPLE_DIR} //= catdir $config{CONFIG_DIR}, 'examples';
	$config{RUNTIME_DIR} //= $config{DATA_DIR};
	my %compiler = get_compiler_info($config{CXX});
	my %version = get_version $config{DISTRIBUTION};
	parse_templates(\%config, \%compiler, \%version);
	say 'Update complete!';
	exit 0;
}

sub run_test($$;$) {
	my ($what, $result, $adjective) = @_;
	$adjective //= 'available';
	print_format "Checking whether <|GREEN $what|> is $adjective ... ";
	print_format $result ? "<|GREEN yes|>\n" : "<|RED no|>\n";
	return $result;
}

sub test_file($$;$) {
	my ($compiler, $file, $args) = @_;
	my $status = 0;
	$args //= '';
	$status ||= system "$compiler -o ${\CONFIGURE_ROOT}/__test_$file ${\CONFIGURE_ROOT}/make/test/$file $args ${\CONFIGURE_ERROR_PIPE}";
	$status ||= system "${\CONFIGURE_ROOT}/__test_$file ${\CONFIGURE_ERROR_PIPE}";
	unlink "${\CONFIGURE_ROOT}/__test_$file";
	return !$status;
}

sub test_header($$;$) {
	my ($compiler, $header, $args) = @_;
	$args //= '';
	open(my $fh, "| $compiler -E - $args ${\CONFIGURE_ERROR_PIPE}") or return 0;
	print $fh "#include <$header>";
	close $fh;
	return !$?;
}

sub module_expand($) {
	my $module = shift;
	$module = "m_$module" unless $module =~ /^(?:m|core)_/;
	$module = "$module.cpp" unless $module =~ /\.cpp$/;
	return $module;
}

sub module_shrink($) {
	my $module = basename shift;
	return $module =~ s/(?:^m_|\.cpp$)//gr;
}

sub write_configure_cache(%) {
	unless (-e CONFIGURE_DIRECTORY) {
		print_format "Creating <|GREEN ${\abs2rel CONFIGURE_DIRECTORY, CONFIGURE_ROOT}|> ...\n";
		create_directory CONFIGURE_DIRECTORY, 0750 or print_error "unable to create ${\CONFIGURE_DIRECTORY}: $!";
	}

	print_format "Writing <|GREEN ${\abs2rel CONFIGURE_CACHE_FILE, CONFIGURE_ROOT}|> ...\n";
	my %config = @_;
	write_config_file CONFIGURE_CACHE_FILE, %config;
}

sub get_compiler_info($) {
	my $binary = shift;
	my %info = (NAME => 'Unknown', VERSION => '0.0');
	return %info if system "$binary -o __compiler_info ${\CONFIGURE_ROOT}/make/test/compiler_info.cpp ${\CONFIGURE_ERROR_PIPE}";
	open(my $fh, '-|', './__compiler_info 2>/dev/null');
	while (my $line = <$fh>) {
		$info{$1} = $2 if $line =~ /^([A-Z]+)\s(.+)$/;
	}
	close $fh;
	unlink './__compiler_info';
	return %info;
}

sub find_compiler {
	my @compilers = qw(c++ g++ clang++ icpc);
	foreach my $compiler (shift // @compilers) {
		return $compiler if __test_compiler $compiler;
		return "xcrun $compiler" if $^O eq 'darwin' && __test_compiler "xcrun $compiler";
	}
}

sub parse_templates($$$) {

	# These are actually hash references
	my ($config, $compiler, $version) = @_;

	# Collect settings to be used when generating files
	my %settings = __get_template_settings($config, $compiler, $version);

	# Iterate through files in make/template.
	foreach my $template (<${\CONFIGURE_ROOT}/make/template/*>) {
		print_format "Parsing <|GREEN ${\abs2rel $template, CONFIGURE_ROOT}|> ...\n";
		open(my $fh, $template) or print_error "unable to read $template: $!";
		my (@lines, $mode, @platforms, @targets);

		# First pass: parse template variables and directives.
		while (my $line = <$fh>) {
			chomp $line;

			# Does this line match a variable?
			while ($line =~ /(@(\w+?)(?:\|(\w*))?@)/) {
				my ($variable, $name, $default) = ($1, $2, $3);
				if (defined $settings{$name}) {
					$line =~ s/\Q$variable\E/$settings{$name}/;
				} elsif (defined $default) {
					$line =~ s/\Q$variable\E/$default/;
				} else {
					print_warning "unknown template variable '$name' in $template!";
					last;
				}
			}

			# Does this line match a directive?
			if ($line =~ /^(\s*)%(\w+)\s+(.+)$/) {
				if ($2 eq 'define') {
					if ($settings{$3}) {
						push @lines, "#$1define $3";
					} else {
						push @lines, "#$1undef $3";
					}
				} elsif ($2 eq 'mode') {
					$mode = oct $3;
				} elsif ($2 eq 'platform') {
					push @platforms, $3;
				} elsif ($2 eq 'target') {
					push @targets, catfile CONFIGURE_ROOT, $3;
				} else {
					print_warning "unknown template command '$2' in $template!";
					push @lines, $line;
				}
				next;
			}
			push @lines, $line;
		}
		close $fh;

		# Only proceed if this file should be templated on this platform.
		if ($#platforms < 0 || grep { $_ eq $^O } @platforms) {

			# Add a default target if the template has not defined one.
			unless (@targets) {
				push @targets, catfile(CONFIGURE_DIRECTORY, basename $template);
			}

			# Write the templated files to disk.
			for my $target (@targets) {

				# Create the directory if it doesn't already exist.
				my $directory = dirname $target;
				unless (-e $directory) {
					print_format "Creating <|GREEN ${\abs2rel $directory, CONFIGURE_ROOT}|> ...\n";
					create_directory $directory, 0750 or print_error "unable to create $directory: $!";
				};

				# Write the template file.
				print_format "Writing <|GREEN ${\abs2rel $target, CONFIGURE_ROOT}|> ...\n";
				open(my $fh, '>', $target) or print_error "unable to write $target: $!";
				foreach (@lines) {
					say $fh $_;
				}
				close $fh;

				# Set file permissions.
				if (defined $mode) {
					chmod $mode, $target;
				}
			}
		}
	}
}

1;