#! /usr/bin/env perl

use Getopt::Long qw(:config bundling no_ignore_case);
use POSIX;

use strict;
use warnings;

my $help = 0;
GetOptions ("h|help" => \$help);

usage () if $help;

die "$0: exactly one or two nonoption arguments are required\n"
  if @ARGV != 1 && @ARGV != 2;

my $buildslave = `hostname`;
chomp $buildslave;

# Select build number.
my $buildnumber = POSIX::strftime("%Y%m%d%H%M%S", localtime);
print "\tBUILDNUMBER=$buildnumber\n";

# Create build directory.
my $builddir = "builds/$buildnumber";
print "Create $builddir\n";
mkdir "builds" or die "builds: mkdir: $!\n" if ! -d "builds";
mkdir $builddir or die "$builddir: mkdir: $!\n";

if (@ARGV == 2) {
    my ($repo, $branch) = @ARGV;

    # Fetch branch
    print "Fetch $repo, branch $branch\n";
    run ("git fetch $repo +$branch:buildtmp/$$/pspp");

    # Get revision number.
    my $revision = `git rev-parse buildtmp/$$/pspp`;
    chomp $revision;
    print "\tREVISION=$revision\n";
    my $abbrev_revision = substr ($revision, 0, 6);

    # Extract source.
    print "Extract branch into $builddir/pspp$buildnumber\n";
    run ("git archive --format=tar --prefix=pspp$buildnumber/ buildtmp/$$/pspp | (cd $builddir && tar xf -)");

    # Extract version number.
    print "Extract version number\n";
    my $trace = `cd $builddir/pspp$buildnumber && autoconf -t AC_INIT`;
    chomp $trace;
    my ($file, $line, $macro, $package, $version, @rest) = split (':', $trace);
    print "\tVERSION=$version\n";

    # Append -g012345 to AC_INIT version number.
    my $fullname = "$builddir/pspp$buildnumber/$file";
    open (OLDFILE, '<', $fullname)
      or die "opening $fullname failed: $!\n";
    open (NEWFILE, '>', "$fullname.new")
      or die "creating $fullname.new failed: $!\n";
    while (<OLDFILE>) {
	if ($. != $line) {
	    print NEWFILE $_;
	} else {
	    print NEWFILE "AC_INIT([[$package]]";
	    print NEWFILE ", [[$version-g$abbrev_revision]]";
	    print NEWFILE ", [[$_]]" foreach @rest;
	    print NEWFILE ")\n";
	}
    }
    close (NEWFILE);
    close (OLDFILE);
    rename ("$fullname.new", $fullname)
      or die "rename $fullname.new to $fullname failed: $!\n";

    # Add note to beginning of NEWS (otherwise "make dist" fails).
    $fullname = "$builddir/pspp$buildnumber/NEWS";
    open (OLDFILE, '<', $fullname)
      or die "opening $fullname failed: $!\n";
    open (NEWFILE, '>', "$fullname.new")
      or die "creating $fullname.new failed: $!\n";
    my $found_changes = 0;
    while (<OLDFILE>) {
	if (!$found_changes && /^Changes/) {
	    $found_changes = 1;
	    print NEWFILE <<EOF;
Changes from $version to $version-g$abbrev_revision:

 * Built automatically from commit $revision
   in branch $branch on build slave $buildslave

EOF
	}
	print NEWFILE $_;
    }
    close (NEWFILE);
    close (OLDFILE);
    rename ("$fullname.new", $fullname)
      or die "rename $fullname.new to $fullname failed: $!\n";

    
}

sub usage {
    print <<EOF;
$0, for building and testing PSPP
usage: $0 [OPTIONS] [TARBALL | REPO REFSPEC]
where TARBALL is the name of a tarball produced by "make dist"
   or REPO and REFSPEC are a Git repo and refspec (e.g. branch) to clone.

Options:
  --help            Print this usage message and exit
EOF
    exit(0);
}

sub run {
    my ($command) = @_;
    return if system ($command) == 0;
    if ($? == -1) {
	print "$command: failed to execute: $!\n";
    } elsif ($? & 127) {
	printf "%s: child died with signal %d, %s coredump\n",
	  $command, ($? & 127),  ($? & 128) ? 'with' : 'without';
    } else {
	printf "%s: child exited with value %d\n", $command, $? >> 8;
    }
    exit 1;
}

# Clone source
# Add build number
# Tag build
# Clone gnulib at correct commit number
# Run gnulib-tool.
# Run configure
# Make dist

# Unpack dist
# Run configure
# Check
# Install
# Make binary dist
# Build mingw32 installer
# Other distcheck stuff?