#!/usr/bin/perl -w
#
# ProjectBuilder Conf module
# Conf files subroutines brought by the the Project-Builder project
# which can be easily used by wahtever perl project
#
# Copyright B. Cornec 2007-2016
# Eric Anderson's changes are (c) Copyright 2012 Hewlett Packard
# Provided under the GPL v2
#
# $Id$
#

package ProjectBuilder::Conf;

use strict;
use Carp 'confess';
use Data::Dumper;
use ProjectBuilder::Base;
use ProjectBuilder::Version;

# Inherit from the "Exporter" module which handles exporting functions.
 
use vars qw($VERSION $REVISION $PBCONFVER @ISA @EXPORT);
use Exporter;
 
# Export, by default, all the functions into the namespace of
# any code which uses this module.
 
our @ISA = qw(Exporter);
our @EXPORT = qw(pb_conf_init pb_conf_add pb_conf_read pb_conf_read_if pb_conf_write pb_conf_get pb_conf_get_if pb_conf_get_all pb_conf_get_hash pb_conf_cache pb_conf_update_v0);
($VERSION,$REVISION,$PBCONFVER) = pb_version_init();

# Global hash of conf files
# Key is the conf file name
# Value is its rank
my %pbconffiles;

# Global hash of conf file content
# Key is the config keyword
# Value is a hash whose key depends on the nature of the config keyword as documented
# and value is the confguration value
# We consider that values can not change during the life of pb
my $h = ();

=pod

=head1 NAME

ProjectBuilder::Conf, part of the project-builder.org - module dealing with configuration files

=head1 DESCRIPTION

This modules provides functions dealing with configuration files.

=head1 SYNOPSIS

  use ProjectBuilder::Conf;

  #
  # Read hash codes of values from a configuration file and return table of pointers
  #
  my ($k1, $k2) = pb_conf_read_if("$ENV{'HOME'}/.pbrc.yml","key1","key2");
  my ($k) = pb_conf_read("$ENV{'HOME'}/.pbrc.yml","key");

=head1 USAGE

The configuration files are loaded in a specific order from most generic to the most specific 
to allow for overwrite to work:

For recent versions of pb (>= 0.15):
1. /usr/share/pb/pb.yml     - the read-only system conf file provided by install
2. /etc/pb/pb.yml           - the same global conf file given to the sysadmin in order to make system wide modifications
3. /path/to/project.yml     - Configuration file for the project we're building for
4. /vm|vepath/to/.pbrc.yml  - configuration file for VM, VE or RM specific parameters. Cumulative should be orthogonal
5. $HOME/.pbrc.yml          - user's configuration file

For versions of pb up to 0.14:
1. /usr/share/pb/pb.conf    - the read-only system conf file provided by install
2. /etc/pb/pb.conf          - the same global conf file given to the sysadmin in order to make system wide modifications
3. /path/to/project.pb      - Configuration file for the project we're building for
4. /(vm|ve|rm)path/to/.pbrc - configuration file for VM, VE or RM specific parameters. Cumulative should be orthogonal
5. $HOME/.pbrc              - user's configuration file

The format of the configuration file is as follows:

For recent versions of pb (>= 0.15):
YAML format is now used - The version of the configuration files is 

Supposing the file is called "$ENV{'HOME'}/.pbrc.yml", containing the following:

  $ cat $HOME/.pbrc.yml
  ---
    pbver:
      - pb: 3
      - default: 1
    pblist:
      - pb: 12,25

calling it like this:

  my ($k1, $k2) = pb_conf_read_if("$ENV{'HOME'}/.pbrc.yml","pbver","pblist");

will allow to get the mapping:

  $k1->{'pb'} contains 3
  $k1->{'default'} contains 1
  $k2->{'pb'} contains 12,25

For versions of pb up to 0.14:
An own format was used - The version of the configuration files is 0

key tag = value1,value2,...

Supposing the file is called "$ENV{'HOME'}/.pbrc", containing the following:

  $ cat $HOME/.pbrc
  pbver pb = 3
  pbver default = 1
  pblist pb = 12,25

calling it like this:

  my ($k1, $k2) = pb_conf_read_if("$ENV{'HOME'}/.pbrc","pbver","pblist");

will allow to get the mapping:

  $k1->{'pb'}  contains 3
  $k1->{'default'} contains 1
  $k2->{'pb'} contains 12,25

Valid chars for keys and tags are letters, numbers, '-' and '_'.

=over 4

=item B<pb_conf_init>

This function setup the environment PBPROJ for project-builder function usage from other projects.
The first parameter is the project name.
It sets up environment variables (PBPROJ) 

=cut

sub pb_conf_init {

my $proj=shift;

pb_log(1,"Entering pb_conf_init\n");
#
# Check project name
# Could be with env var PBPROJ
# or option -p
# if not defined take the first in conf file
#
if ((defined $ENV{'PBPROJ'}) &&
	(not defined $proj)) {
	pb_log(2,"PBPROJ env var setup ($ENV{'PBPROJ'}) so using it\n");
	$proj = $ENV{'PBPROJ'};
}

if (defined $proj) {
	$ENV{'PBPROJ'} = $proj;
} else {
	$ENV{'PBPROJ'} = "default";
}
pb_log(1,"PBPROJ = $ENV{'PBPROJ'}\n");
}


=item B<pb_conf_cache>

This function caches the configuration file content passed as first parameter into the hash passed in second parameter
It returns the modified hash
Can be used in correlation with the %h hash to store permanently values or not if temporarily.

=cut

sub pb_conf_cache {

my $cf = shift;
my $lh = shift;

my $ldfunc;

# Read the content of the config file and cache it in the %h hash then available for queries
if ($PBCONFVER < 1) {
	open(CONF,$cf) || confess "Unable to open $cf";
	# This is the original conf file format for versions up to 0.14
	while(<CONF>) {
		next if (/^#/);
		if (/^\s*([A-z0-9-_.]+)\s+([[A-z0-9-_.\?\[\]\*\+\\]+)\s*=\s*(.*)$/) {
			pb_log(3,"DEBUG: 1:$1 2:$2 3:$3\n");
			my ($what, $var, $value) = ($1, $2, $3);
			# Add support for multi-lines
			while ($value =~ s/\\\s*$//o) {
				$_ = <CONF>;
				die "Still processing continuations for $what $var at EOF" if (not defined $_);
				s/[\r\n]//go;
				$value .= "\n$_";
			}
			$lh->{$what}->{$var}=$value;
		} elsif ((/^\s*#/o) || (/^\s*$/o)) {
			# ignore
		} else {
			chomp();
			warn "unexpected line '$_' in $cf";
		}
	}
	close(CONF);
} else {
	eval {
		require YAML;
		YAML->import();
	};
	if ($@) {
		eval {
			# No YAML found using a more std but less complete one. Old perl only
			require Module::Build::YAML;
			Module::Build::YAML->import();
		};
		if ($@) {
			die "Unable to handle YAML configuration files without a YAML.pm module\n";
		} else {
			$ldfunc = \&Module::Build::YAML::LoadFile;
		}
	} else {
		$ldfunc = \&YAML::LoadFile;
	}

	pb_log(1,"Loading YAML conf file $cf\n");
	my $lh0 = $ldfunc->($cf);
	foreach my $k (keys %$lh0) {
		if (defined $lh->{$k}) {
			foreach my $k2 (keys %{$lh0->{$k}}) {
				$lh->{$k}->{$k2} = $lh0->{$k}->{$k2};
			}
		} else {
			$lh->{$k} = $lh0->{$k};
		}
	}
}
return($lh);
}

=item B<pb_conf_add>

This function adds the configuration file to the list last, and cache their content in the %h hash

=cut

sub pb_conf_add {

pb_log(2,"DEBUG: pb_conf_add with ".Dumper(@_)."\n");
my $lh;

foreach my $cf (@_) {
	if (! -r $cf) {
		pb_log(0,"WARNING: pb_conf_add can not read $cf\n");
		next;
	}
	# Skip already used conf files
	return($lh) if (defined $pbconffiles{$cf});
	
	# The new conf file overload values already managed
	my $num = keys %pbconffiles;
	pb_log(2,"DEBUG: pb_conf_cache of $cf at position $num\n");
	$pbconffiles{$cf} = $num;

	# Read the content of the config file 
	$lh = pb_conf_cache($cf,$lh);
	# and cache it in the %h hash for further queries but after the previous
	# as we load conf files in reverse order (most precise first)
	pb_conf_add_last_in_hash($lh)
}
}


=item B<pb_conf_read_if>

This function returns a table of pointers on hashes
corresponding to the keys in a configuration file passed in parameter.
If that file doesn't exist, it returns undef.

The file read is forgotten after its usage. If you want permanent caching of the data, use pb_conf_add then pb_conf_get

=cut

sub pb_conf_read_if {

my $conffile = shift;
my @param = @_;

open(CONF,$conffile) || return((undef));
close(CONF);
return(pb_conf_read($conffile,@param));
}

=item B<pb_conf_read>

This function is similar to B<pb_conf_read_if> except that it dies when the file in parameter doesn't exist.

=cut

sub pb_conf_read {

my $conffile = shift;
my @param = @_;
my @ptr;
my $lh;

$lh = pb_conf_cache($conffile,$lh);

foreach my $param (@param) {
	push @ptr,$lh->{$param};
}
return(@ptr);
}

=item B<pb_conf_write>

This function writes in the file passed as first parameter the hash of values passed as second parameter

=cut

sub pb_conf_write {

my $conffile = shift;
my $h = shift;
my $dpfunc;

confess "No configuration file defined to write into !" if (not defined $conffile);
confess "No hash defined to read from !" if (not defined $h);
open(CONF,"> $conffile") || confess "Unable to write into $conffile";

if ($PBCONFVER < 1) {
	# This is the original conf file format for versions up to 0.14
	foreach my $p (sort keys %$h) {
		my $j = $h->{$p};
		foreach my $k (sort keys %$j) {
			print CONF "$p $k = $j->{$k}\n";
		}
	}
} else {
	# This is the new YAML format
	eval {
		require YAML;
		YAML->import();
	};
	if ($@) {
		eval {
			# No YAML found using a more std but less complete one. Old perl only
			require Module::Build::YAML;
			Module::Build::YAML->import();
		};
		if ($@) {
			die "Unable to handle YAML configuration files without a YAML.pm module\n";
		} else {
			$dpfunc = \&Module::Build::YAML::Dump;
		}
	} else {
		$dpfunc = \&YAML::Dump;
	}

	pb_log(1,"Writing YAML conf file $conffile\n");
	print CONF $dpfunc->($h);
}
close(CONF);
}



=item B<pb_conf_get_in_hash_if>

This function returns a table, corresponding to a set of values queried in the hash passed in parameter or undef if it doesn't exist. 
It takes a table of keys as an input parameter.

=cut

sub pb_conf_get_in_hash_if {

my $lh = shift || return(());
my @params = @_;
my @ptr = ();

pb_log(2,"DEBUG: pb_conf_get_in_hash_if on params ".join(' ',@params)."\n");
foreach my $k (@params) {
	push @ptr,$lh->{$k};
}

pb_log(2,"DEBUG: pb_conf_get_in_hash_if returns\n".Dumper(@ptr));
return(@ptr);
}



=item B<pb_conf_get_if>

This function returns a table, corresponding to a set of values queried in the %h hash or undef if it doen't exist. It takes a table of keys as an input parameter.

=cut

sub pb_conf_get_if {

my @param = @_;
my @return = pb_conf_get_in_hash_if($h,@_);
my $proj = undef;

if (not defined $ENV{'PBPROJ'}) {
	$proj = "unknown";
} else {
	$proj = $ENV{'PBPROJ'};
}

foreach my $i (0..$#param) {
	if (not defined $return[$i]->{$proj}) {
		$return[$i]->{$proj} = $return[$i]->{'default'} if (defined $return[$i]->{'default'});
	}
}
return(@return);
}

=item B<pb_conf_add_last_in_hash>

This function merges the values passed in the hash parameter into the %h hash, but only if itdoesn't already contain a value, or if the value is more precise (real value instead of default)

It is used internally by pb_conf_add and is not exported.

=cut

sub pb_conf_add_last_in_hash {

my $ptr = shift;

return if (not defined $ptr);
# TODO: test $ptr is a hash pointer

# When called without correct initialization, try to work anyway with default as project
pb_conf_init("default") if (not defined $ENV{'PBPROJ'});

my @params = (sort keys %$ptr);

# Everything is returned via @h
# @h contains the values overloading what @ptr may contain.
my @h = pb_conf_get_in_hash_if($h,@params);
my @ptr = pb_conf_get_in_hash_if($ptr,@params);

my $p1;
my $p2;

pb_log(2,"DEBUG: pb_conf_add_last_in_hash params: ".Dumper(@params)."\n");
pb_log(2,"DEBUG: pb_conf_add_last_in_hash current hash: ".Dumper(@h)."\n");
pb_log(2,"DEBUG: pb_conf_add_last_in_hash new inputs: ".Dumper(@ptr)."\n");

foreach my $i (0..$#params) {
	$p1 = $h[$i];
	$p2 = $ptr[$i];
	# Always try to take the param from h in priority
	# in order to mask what could be defined already in ptr
	if (not defined $p2) {
		# exit if no p1 either
		next if (not defined $p1);
	} else {
		# Ref found in p2
		if (not defined $p1) {
			# No ref in p1 so use p2's value
			$p1 = $p2;
		} else {
			# Both are defined - handling the overloading
			# Now copy back into p1 all p2 content
			# as p1 content always has priority over p2
			if (not defined $p1->{$ENV{'PBPROJ'}}) {
				if (defined $p2->{$ENV{'PBPROJ'}}) {
					$p1->{$ENV{'PBPROJ'}} = $p2->{$ENV{'PBPROJ'}};
				}
			}
			# Now copy back into p1 all p2 content which doesn't exist in p1
			# # p1 content always has priority over p2
			foreach my $k (keys %$p2) {
				$p1->{$k} = $p2->{$k} if (not defined $p1->{$k});
			}
		}
	}
	$h->{$params[$i]} = $p1;
}
pb_log(2,"DEBUG: pb_conf_add_last_in_hash output: ".Dumper($h)."\n");
}

=item B<pb_conf_get>

This function is the same B<pb_conf_get_if>, except that it tests each returned value as they need to exist in that case.

=cut

sub pb_conf_get {

my @param = @_;
my @return = pb_conf_get_if(@param);
my $proj = undef;

if (not defined $ENV{'PBPROJ'}) {
	$proj = "unknown";
} else {
	$proj = $ENV{'PBPROJ'};
}

confess "No params found for $proj" if (not @return);

foreach my $i (0..$#param) {
	confess "No $param[$i] defined for $proj" if (not defined $return[$i]);
}
return(@return);
}


=item B<pb_conf_get_all>

This function returns an array with all configuration parameters

=cut

sub pb_conf_get_all {

return(sort keys %$h);
}


=item B<pb_conf_get_hash>

This function returns a pointer to the hash with all configuration parameters

=cut

sub pb_conf_get_hash {

return($h);
}

=item B<pb_conf_update_v0>

This function transform the old configuration v0 file as first param into a new v1 one as second param

=cut

sub pb_conf_update_v0 {

my $orig = shift;
my $dest = shift;

open(ORIG,$orig) || confess "Unable to open $orig";
confess "Will not erase existing $dest while transforming $orig" if (-f $dest);
open(DEST,"> $dest") || confess "Unable to write into $dest";
print DEST "---\n";
my $pbconfverbkp = $PBCONFVER;
# We force migration from v0 to v1
$PBCONFVER = 0;
my $lh0;
my $lh1;
$lh0 = pb_conf_cache($orig,$lh0);
pb_log(2,"lh0:\n".Dumper($lh0)."\n");
$PBCONFVER = $pbconfverbkp;

pb_log(0,"Converting v0 conf file $orig to v1 conf file $dest\n");
# We can't just write the YAML if we want to ckeep comments !
while (<ORIG>) {
	if ($_ =~ /^#/) {
		# Keep comments
		print DEST $_;
	} elsif ($_ =~ /^\s*$/) {
		# Replace empty lines by comments
		print DEST "#\n";;
	} else {
		if (/^\s*([A-z0-9-_]+)\s+(.+)$/) {
			# Handle parameters
			my ($param,$void) = ($1, $2);
			if (not defined $lh1->{$param}) {
				pb_log(2,"Converting parameter $param\n");
				print DEST "$param:\n";
				foreach my $k (keys %{$lh0->{$param}}) {
					pb_log(2,"Handling key $k\n");
					if ($lh0->{$param}->{$k} =~ /^\s*$/) {
						print DEST "  $k: !!str \"\"\n";
					} else {
						print DEST "  $k: $lh0->{$param}->{$k}\n";
					}
				}
				$lh1->{$param} = 1;
			}
		} else {
			pb_log(0,"Unable to convert line $_\n");
		}
	}
}
close(ORIG);
close(DEST);
return();
}

=back 

=head1 WEB SITES

The main Web site of the project is available at L<http://www.project-builder.org/>. Bug reports should be filled using the trac instance of the project at L<http://trac.project-builder.org/>.

=head1 USER MAILING LIST

None exists for the moment.

=head1 AUTHORS

The Project-Builder.org team L<http://trac.project-builder.org/> lead by Bruno Cornec L<mailto:bruno@project-builder.org>.

=head1 COPYRIGHT

Project-Builder.org is distributed under the GPL v2.0 license
described in the file C<COPYING> included with the distribution.

=cut


1;