1 files changed, 131 insertions, 0 deletions
diff --git a/src/build_order.pm b/src/build_order.pm
new file mode 100755
index 0000000..37beb64
--- /dev/null
+++ b/src/build_order.pm
@@ -0,0 +1,131 @@
+#!/usr/bin/env perl
+
+# TODO for building the whole system
+# We first need to have a base system that we can build from
+#   (up to chapter 6 in lfs book, done by make_tools.sh)
+# packages need to be build in order of importance
+# need to some how find out which packages are the most important and build and install them to the chroot first
+# build a package, install it if necessary
+# copy the generated package/info to a safe place
+# sign the package
+# put the package in the export folder
+
+# TODO for building a single package:
+# do all the preliminary checks (exists, deps are installed, etc)
+# download source to $chroot/source
+# download additional tools 
+# copy xibuild to the chroot
+# create a "build.sh" script in the chroot
+# - run the 3 stages of package building
+# - create the pacakage in $chroot/$name.xipkg
+# - add some info to package info
+# - if requested, install to the chroot
+
+use strict;
+use warnings;
+
+use Env;
+use File::Basename;
+use lib dirname (__FILE__);
+use Sort::TSort "tsort";
+
+our $buildfiles = $ENV{XIB_BUILDFILES};
+
+sub list_dependencies{
+    my $file = $_;
+    my @deps = ();
+
+    open (my $fh, "<", $file) or warn "Cannot open $file";
+
+    while (my $line = <$fh>) {
+        if ($line =~ /DEPS=\((.+)\)/) {
+            my @words = split(/ /, $1);
+            push(@deps, @words);
+        }
+    }
+
+    return @deps;
+}
+
+sub list_buildfiles{
+    my @files = glob("$buildfiles/repo/*/*.xibuild");
+    # ignore any meta packages during this stage, they can be added later
+    return grep(!/\/meta\//, @files);
+}
+
+sub list_meta_pkgs{
+    return map({basename($_, ".xibuild")} glob("$buildfiles/repo/meta/*.xibuild"));
+}
+
+sub get_packages{
+    my %pkgs = ();
+    
+    my @files = list_buildfiles();
+
+    foreach (@files) {
+        my $pkg_file = $_;
+        my $pkg_name = basename($pkg_file, ".xibuild");
+
+        my @deps = list_dependencies($pkg_file);
+        $pkgs{$pkg_name} = \@deps;
+    }
+
+    return %pkgs;
+}
+
+# Get a list of all the edges 
+sub get_edges{
+    my %pkgs = @_;
+
+    my @edges = ();
+    foreach (keys(%pkgs)) {
+        my $pkg = $_;
+        my @deps = @{$pkgs{$_}};
+        foreach (@deps) {
+            my $dep = $_;
+
+            my @edge = ($pkg, $dep);
+            push @edges, [ @edge ];
+
+        }
+    }
+    return @edges;
+}
+
+# Determine which packages are depended on
+sub get_depended_on{
+    my @edges = @_;
+
+    my %install = ();
+    foreach (@edges) {
+        my @edge = @{$_};
+        $install{$edge[1]} = $edge[0];
+    }
+    
+    return keys(%install);
+}
+
+sub determine_build_order{
+    my %pkgs = get_packages();
+
+    my @edges = get_edges(%pkgs);
+
+    my @install = get_depended_on(@edges);
+
+    # use tsort to determine the build order
+    my @sorted = reverse(@{tsort(\@edges)});
+
+    my @meta = list_meta_pkgs();
+    push(@sorted, @meta);
+
+    foreach(@sorted) {
+        my $pkg = $_;
+        print("$pkg");
+        print("+") if (grep(/^$pkg/, @install));
+        print("\n");
+    }
+}
+
+unless (caller) {
+    determine_build_order();
+}