#!/bin/perl -w
# 
# preinst maintainer script for the translator package.
#
# summary of how this script can be called:
#        * <new-preinst> `install'
#        * <new-preinst> `install' <old-version>
#        * <new-preinst> `upgrade' <old-version>
#        * <old-preinst> `abort-upgrade' <new-version>
#
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package

use strict;

use File::Copy;
use Debconf::Client::ConfModule ':all';

my $MAIN_DIRECTORY = '/usr/lib/autolatex/mkfiles';
my $CONFIG_FILE = '/etc/autolatex/default.cfg';

#--------------------------------------------------------------
# Print a message if in debug mode (see DEBCONF_DEBUG)
sub printDbg(@) {
	if (($ENV{'DEBCONF_DEBUG'})&&($ENV{'DEBCONF_DEBUG'} eq 'developer')) {
		print STDERR ("AutoLaTeX config: ",@_,"\n");
	}
	1;
}

#--------------------------------------------------------------
# Print an error message
sub printErr(@) {
	print STDERR (@_,"\n");
	1;
}

#--------------------------------------------------------------
# Read a configuration file and replies the data
sub readConfigFile($;$) {
	my $filename = shift;
	my $filterCommentedAttrs = shift;
	local *CFGFILE;
	open(*CFGFILE, "< $filename") or die("$filename: $!\n");
	my $currentsection = undef;
	my %results = ();
	while (my $line = <CFGFILE>) {
		# Remove comments
		$line =~ s/\#[^\#]*$//;

		# Trim
		$line =~ s/^\s+//;
		$line =~ s/\s+$//;

		if ($line) {
			if ($line =~ /^\[([a-zA-Z0-9+_]+)\]$/) {
				$currentsection = lc("$1");
			}
			elsif (($currentsection)&&($line =~ /^;\s*(.*?)\s*=\s*(.*?)$/)) {
				if (!$filterCommentedAttrs) {
					my $keyname = lc("$1");
					my $keyvalue = "$2";
					$results{"$currentsection"}{";$keyname"} = "$keyvalue";
				}
			}
			elsif (($currentsection)&&($line =~ /^(.*?)\s*=\s*(.*?)$/)) {
				my $keyname = lc("$1");
				my $keyvalue = "$2";
				$results{"$currentsection"}{"$keyname"} = "$keyvalue";
			}
		}
	}
	close(*CFGFILE);
	return %results;
}

#--------------------------------------------------------------
# Get installed translators with conflits
sub getInstalledTranslatorsWithConflicts($@) {
	my $dir = shift;
	my %translators = ();
	foreach my $tr (@_) {
		if (!$translators{$tr->{'source'}}) {
			$translators{$tr->{'source'}} = [];
		}
		push @{$translators{$tr->{'source'}}}, $tr;
	}

	local *DIR;
	opendir(*DIR,"$dir") or die("$dir: $!\n");
	while (my $subfile = readdir(*DIR)) {
		if ($subfile =~ /^([a-zA-Z+]+)2([a-zA-Z0-9+]+)(?:_([a-zA-Z0-9_+]+))?.mk$/) {
			my ($source,$target,$variante) = ($1,$2,$3||'');
			my $fullname = $source.'2'.$target.($variante?"_$variante":'');
			if ($target =~ /^(.*)\Q+tex\E$/) {
				$target = "$1+TeX";
				$source = "ltx.$source";
			}

			if (!$translators{"$source"}) {
				$translators{"$source"} = [];
			}

			my $foundinlist = undef;
			foreach my $tr (@{$translators{"$source"}}) {
				if (($tr)&&($tr->{'fullname'} eq "$fullname")) {
					$foundinlist = 1;
					last;
				}
			}

			unless ($foundinlist) {
				push @{$translators{"$source"}}, {
						'source' => "$source",
						'target' => "$target",
						'variante' => "$variante",
						'fullname' => "$fullname",
					};
			}
		}
	}
	closedir(*DIR);

	my %currentConfig = readConfigFile("$CONFIG_FILE",1);

	foreach my $key (keys %translators) {
		if (@{$translators{"$key"}}<=1) {
			delete $translators{"$key"};
		}
		else {
			# Remove the unloaded translators
			my @result = ();
			foreach my $trans (@{$translators{"$key"}}) {
				if ((! exists $currentConfig{$trans->{'fullname'}}{'include module'})||
				    (!$currentConfig{$trans->{'fullname'}}{'include module'})||
				    ($currentConfig{$trans->{'fullname'}}{'include module'} ne 'no')) {

					push @result, $trans;
				}
			}
			if (@result<=1) {
				delete $translators{"$key"};
			}
		}
	}

	return %translators;
}

#--------------------------------------------------------------
# Replace a value if the configuration file
sub replaceInConfig($$$$$$) {
	my $filename = shift;
	my $section = lc(shift);
	my $prefix = shift;
	my $oldattribute = lc(shift);
	my $newattribute = lc(shift);
	my $value = shift;

	local *NEWCFGFILE;
	local *CFGFILE;
	open(*CFGFILE, "< $filename") or die("$filename: $!\n");
	open(*NEWCFGFILE, "> $filename.newtmp") or die("$filename.newtmp: $!\n");
	my $currentsection = undef;
	my $attradded = undef;
	while (my $rline = <CFGFILE>) {
		# Remove comments
		my $line = $rline;
		$line =~ s/\#[^\#]*$//;

		# Trim
		$line =~ s/^\s+//;
		$line =~ s/\s+$//;
		if ($line) {
			if ($attradded) {
				print NEWCFGFILE "$rline";
			}
			elsif ($line =~ /^\[([a-zA-Z0-9+_]+)\]$/) {
				if (($currentsection)&&($currentsection eq $section)) {
					# Add at the end of the section
					print NEWCFGFILE "$newattribute = $value\n\n";
				}
				$currentsection = lc("$1");
				print NEWCFGFILE "$rline";
			}
			elsif (($currentsection)&&($line =~ /^;\s*(.*?)\s*=\s*.*?\s*((?:\#.*)?)$/)) {
				my ($attr,$cmt) = (lc("$1"),$2||'');
				if (($section eq $currentsection)&&
				    ($prefix eq ";")&&
				    ("$attr" eq "$oldattribute")) {
					print NEWCFGFILE "$newattribute = $value".($cmt?" $cmt":'')."\n";
					$attradded = 1;
				}
				else {
					print NEWCFGFILE "$rline";
				}
			}
			elsif (($currentsection)&&($line =~ /^(.*?)\s*=\s*.*?\s*((?:\#.*)?)$/)) {
				my ($attr,$cmt) = (lc("$1"),$2||'');
				if (($section eq $currentsection)&&
				    ($prefix ne ";")&&
				    ("$attr" eq "$oldattribute")) {
					print NEWCFGFILE "$newattribute = $value".($cmt?" $cmt":'')."\n";
					$attradded = 1;
				}
				else {
					print NEWCFGFILE "$rline";
				}
			}
			else {
				print NEWCFGFILE "$rline";
			}
		}
		else {
			print NEWCFGFILE "$rline";
		}
	}

	if (!$attradded) {
		print NEWCFGFILE "\n[$section]\n";
		print NEWCFGFILE "$newattribute = $value\n";
	}

	close(*NEWCFGFILE);
	close(*CFGFILE);

	unlink("$filename") or die("$filename: $!\n");
	move("$filename.newtmp","$filename") or die("$filename.newtmp: $!\n");
}

#--------------------------------------------------------------
# Replace a value if the configuration file
sub replaceConfig($$$;$) {
	my $section = lc(shift);
	my $attribute = lc(shift);
	my $value = lc(shift);
	my $msg = shift || '';

	printDbg($msg) if ($msg);
	printDbg("[",$section,"] ",$attribute," <- ",$value);

	my %config = readConfigFile("$CONFIG_FILE");

	if (exists $config{"$section"}{";$attribute"}) {
		# uncomment the attribute
		replaceInConfig("$CONFIG_FILE","$section",";","$attribute","$attribute","$value");
	}
	else {
		# update the value
		replaceInConfig("$CONFIG_FILE","$section","","$attribute","$attribute","$value");
	}
}

#--------------------------------------------------------------
# Solve a conflict between translators
sub solveConflict(\%) {
	my @ret;
	my $tmp;
	foreach my $source (keys %{$_[0]}) {
		printDbg("Conflict on ",$source," source figures");
		
		# Display the wizard
		my $state = 1;
		my %allanswers = ();
		while (1) {
			if ($state == 0) {
				# Allow the user to backup from image generation selection
				$state = 1;
		                next;
			}
			elsif ($state == 1) {
				# Display the question
				my @translatorlist = ();
				foreach $tmp (@{$_[0]->{"$source"}}) {
					push @translatorlist,
						$tmp->{'source'}." to ".$tmp->{'target'}.
						($tmp->{'variante'} ? (' with '.$tmp->{'variante'}) : '').
						' ('.$tmp->{'fullname'}.')';
				}
		                fset("shared/autolatex-select-translator","seen","false");
				subst("shared/autolatex-select-translator","translatorlist",join(', ',@translatorlist));
				subst("shared/autolatex-select-translator","figuretype",".$source");
				@ret = input("critical","shared/autolatex-select-translator");
				if ($ret[0] != 0) {
					set("shared/autolatex-select-translator","");
				}
			}
			elsif ($state == 2) {
				# Treat the answer
				@ret = get("shared/autolatex-select-translator");
				if ($ret[0] == 0) {
					my $answer = $ret[1];
					$answer =~ /\((.*?)\)$/;
					$answer = "$1";
					foreach $tmp (@{$_[0]->{"$source"}}) {
						my $name = $tmp->{'fullname'};
						$allanswers{"$name"} = ("$name" eq "$answer");
					}
				}
				else {
					printErr("ERROR: unable to get the selected translator for $source from DebConf");
					stop();
					exit(1);
				}
				last;
			}

			@ret = go();
			if ($ret[0]==0) {
				$state ++;
			}
			else {
				$state --;
			}
		}

		# Saving the answer
		while (my ($transname, $includetrans) = each(%allanswers)) {
			replaceConfig("$transname","include module",($includetrans ? 'yes' : 'no'));
		}

	}
}





if ($ARGV[0] eq 'install') {

	printDbg("Running preinst script for translator xxx2xxx with target ",$ARGV[0]);

	if (-f "$CONFIG_FILE") {

		printDbg("Configuration file found.");
		printDbg("Assuming that autolatex-core is already fully installed.");
		printDbg("Check for conflicts");

		my %conflictTranslators = getInstalledTranslatorsWithConflicts("$MAIN_DIRECTORY",
###LOOP WITH , FROM 0###
			{
			'source' => "xxxSOURCExxx",
			'target' => "xxxTARGETxxx",
			'variante' => "xxxVARIANTExxx",
			'fullname' => "xxx2xxx",
			}
###END LOOP###
);

		if (%conflictTranslators) {
			solveConflict(%conflictTranslators);
		}
		else {
			printDbg("No conflict detected.");
		}
	}
	else {
		printDbg("Configuration file not found.");
		printDbg("Assuming that autolatex-core is under installation.");
		printDbg("Return now");
	}

}

exit(0);