adapt to new agent setup

Makefile.PL

@@ -1,6 +1,6 @@
-
 use inc::Module::Install;
 use English qw(-no_match_vars);
+use File::Which;
 
 name 'FusionInventory-Agent-Task-ESX';
 include 'Module::AutoInstall';
@@ -9,12 +9,91 @@ license 'gpl';
 version_from 'lib/FusionInventory/Agent/Task/ESX.pm';
 perl_version '5.008';
 
+# check for fusioninventory-agent setup
+my $agent = which('fusioninventory-agent');
+die "fusioninventory-agent not found in PATH\n" unless $agent;
+
+my $command = 'fusioninventory-agent --setup 2>/dev/null';
+open (my $handle, '-|', $command) or die "can't run $command: $ERRNO";
+while (my $line = <$handle>) {
+    chomp $line;
+    next unless $line =~ /(\S+): (\S+)/;
+    $MY::setup{uc($1)} = $2;
+}
+close $handle;
+
+die "agent too old (minimal version 2.2.0 required)\n" if $CHILD_ERROR;
+
 # mandatory dependencies
-requires 'FusionInventory::Agent' => 2.2.0;
 requires 'JSON'                   => undef;
 
 test_requires 'Test::Exception'   => undef;
 
 install_script  'fusioninventory-esx';
 
 WriteAll;
+
+# substitute prefix everywhere
+$MY::variables{DATADIR} =~ s/\$\(PREFIX\)/$MY::variables{PREFIX}/;
+
+print <<EOF;
+
+Installation summary
+--------------------
+prefix: $MY::variables{PREFIX}
+constant data installation directory: $MY::variables{DATADIR}
+
+EOF
+
+package MY;
+
+our %setup;
+our %variables;
+
+# force a perl-independant prefix for everything but perl modules
+sub constants {
+    my ($self) = @_;
+
+    # for some reason, initialising variables from the global scope doesn't work
+    %variables = (
+        PREFIX               => '/usr/local',
+        INSTALLLIB           => '$(DATADIR)/lib',
+        INSTALLSITELIB       => '$(DATADIR)/lib',
+        INSTALLVENDORLIB     => '$(DATADIR)/lib',
+        INSTALLMAN3DIR       => '$(PREFIX)/share/man/man3',
+        INSTALLSITEMAN3DIR   => '$(PREFIX)/share/man/man3',
+        INSTALLVENDORMAN3DIR => '$(PREFIX)/share/man/man3',
+        DATADIR              => '$(PREFIX)/share/fusioninventory'
+    );
+
+    # allow variables detected from agent setup to override defaults
+    foreach my $name (keys %variables) {
+        $variables{$name} = $setup{$name} if $setup{$name};
+    }
+
+    # allow variables defined on command line to override defaults
+    foreach my $name (keys %variables) {
+        $variables{$name} = $self->{ARGS}->{$name} if $self->{ARGS}->{$name};
+    }
+
+    # get all standard MM variables definitions, and override them if needed
+    my @code = split(/\n/, $self->SUPER::constants(@_));
+    foreach my $line (@code) {
+        # Skip comments
+        next if $line =~ /^\s*#/;
+        # Skip everything which isn't a var assignment.
+        next unless $line =~ /^([A-Z0-9_]+) =/;
+        my $name = $1;
+        # skip variables we're not interested
+        next unless $variables{$name};
+
+        $line = "$name = $variables{$name}";
+    }
+
+    # add out own variables
+    foreach my $name (qw/DATADIR/) {
+        push @code, "$name = $variables{$name}";
+    }
+
+    return join("\n", @code);
+}