#!/bin/env perl

use strict;

use Getopt::Long;
use DBI;

# We use an in-memory SQLite database as SQL is good for doing queries
# of differences between data sets, and doing that in perl is annoying.
my $db = "dbi:SQLite:dbname=release-notes.sqlite";
#my $dbh = DBI->connect("dbi:SQLite:dbname=:memory:","","");
my $dbh = DBI->connect($db,undef,undef, {AutoCommit => 1, RaiseError=>1});

my $repos =
{
    'op-build' => { REPO => "http://github.com/open-power/op-build" },
    'hostboot' => { REPO => "http://github.com/open-power/hostboot" ,
                    DIR => "openpower/package/hostboot" },
    'sbe'      => { REPO => "http://github.com/open-power/sbe" ,
                    DIR => "openpower/package/sbe"},
    'skiboot'  => { REPO => "http://github.com/open-power/skiboot" ,
                    DIR => "openpower/package/skiboot"},
    'occ'      => { REPO => "http://github.com/open-power/occ" ,
                    DIR => "openpower/package/occ"},
    'pnor'     => { REPO => "http://github.com/open-power/pnor" ,
                    DIR => "openpower/package/openpower-pnor"},
    'petitboot'     => { REPO => "http://github.com/open-power/petitboot" ,
			 DIR => "openpower/package/petitboot"},
};

my $begin_release;
my $end_release;
my $begin_worktree;
my $end_worktree;
my $platform;

GetOptions("begin-release=s" => \$begin_release,
	   "end-release=s" => \$end_release,
	   "begin-worktree=s" => \$begin_worktree,
	   "platform=s" => \$platform,
	   "end-worktree=s" => \$end_worktree)
    or die("Error in command line arguments");

die "Required argument missing" unless ($begin_release and $end_release and $begin_worktree and $end_worktree);

open(OUTPUT, "> RELEASE.md") || die "Failed to open RELEASE.md";

print OUTPUT "# Release Notes for OpenPower Firmware $end_release\n";

if (-e $begin_worktree) {
    system("cd $begin_worktree && git checkout $begin_release && git submodule update --reference ../buildroot && git submodule update") and die "Could not update $begin_worktree";
} else {
    system("git worktree add $begin_worktree $begin_release && cd $begin_worktree&& git submodule update --reference ../buildroot && git submodule update && rm -rf dl && ln -s ../dl dl") and die "Couldn't init $begin_worktree";
}

if (-e $end_worktree) {
    system("cd $end_worktree && git checkout $end_release  && git submodule update --reference ../buildroot && git submodule update") and die "Could not update $end_worktree";
} else {
    system("git worktree add $end_worktree $end_release && cd $end_worktree && git submodule update --reference ../buildroot && git submodule update && rm -rf dl && ln -s ../dl dl") and die "Couldn't init $end_worktree";
}

opendir (my $dh, "$begin_worktree/openpower/configs")
    or die "can't scan $begin_worktree defconfigs";
my @begin_platforms = grep { /.*_defconfig/ } readdir($dh);
closedir $dh;

opendir (my $dh, "$end_worktree/openpower/configs")
    or die "can't scan $end_worktree defconfigs";
my @end_platforms = grep { /.*_defconfig/ } readdir($dh);
closedir $dh;

s/_defconfig// foreach (@begin_platforms);
s/_defconfig// foreach (@end_platforms);

if ($platform) {
    @begin_platforms = ($platform);
    @end_platforms = ($platform);
}

$dbh->do("CREATE TABLE platforms (platform TEXT, version TEXT);") or die "$!";
{
    my $q = "INSERT INTO platforms (platform,version) VALUES (?,?)";
    my $sth = $dbh->prepare($q) or die "$!";
    $sth->execute($_, $begin_release) foreach (@begin_platforms);
    $sth->execute($_, $end_release) foreach (@end_platforms);
}

{
    my $q = "SELECT platform FROM platforms WHERE version is ? AND platform NOT IN (SELECT platform FROM platforms WHERE version is ?)";
    my $sth = $dbh->prepare($q) or die $!;
    $sth->execute($begin_release, $end_release);
    my $r;
    print OUTPUT "## Removed platforms\n\n- ".$r->{platform}."\n" if $r = $sth->fetchrow_hashref;
    print OUTPUT "- ".$_->{platform}."\n" while ($r = $sth->fetchrow_hashref);

    $sth->execute($end_release, $begin_release);
    print OUTPUT "## New platforms\n\n- ".$r->{platform}."\n" if $r = $sth->fetchrow_hashref;
    print OUTPUT "- ".$_->{platform}."\n" while($r = $sth->fetchrow_hashref);
}

my @common_platforms;
{
    my $q = "SELECT platform FROM platforms WHERE version is ? AND EXISTS (select platform from platforms where version is ?)";
    my $sth = $dbh->prepare($q) or die $!;
    $sth->execute($begin_release, $end_release);
    my $r;
    push @common_platforms, $r->{platform} while ($r = $sth->fetchrow_hashref);
}

foreach my $p (@common_platforms) {
    next if $p =~ /firenze/;
    next if $p =~ /^zz$/;
    next if $p =~ /mambo/;
    $repos->{"$p-xml"} = { REPO => "http://github.com/open-power/$p-xml" ,
			   DIR => "openpower/package/$p-xml" };
}

foreach my $p (@begin_platforms) {
    system("bash -c '(cd $begin_worktree && . op-build-env && op-build ".$p."_defconfig && op-build legal-info)'");
    # Forgive me for this....
    system("sqlite3 release-notes.sqlite \".mode csv\" \".import $begin_worktree/output/legal-info/manifest.csv begin_".$p."_manifest\"");
}

foreach my $p (@end_platforms) {
    system("bash -c '(cd $end_worktree && . op-build-env && op-build ".$p."_defconfig && op-build legal-info)'");
    # Forgive me for this....
    system("sqlite3 release-notes.sqlite \".mode csv\" \".import $end_worktree/output/legal-info/manifest.csv end_".$p."_manifest\"");
}

$dbh->do(<<'SQL') or die "$!";
CREATE TABLE package_upgrades (
  PACKAGE TEXT,
  OLDVERSION TEXT,
  NEWVERSION TEXT,
  PLATFORM TEXT
)
SQL

foreach my $p (@common_platforms) {
    $dbh->do("INSERT INTO package_upgrades select b.package,b.version,e.version,'$p' from begin_".$p."_manifest as b LEFT JOIN end_".$p."_manifest AS e ON b.package=e.package WHERE b.version != e.version") or die $!;
}

$dbh->do(<<'SQL') or die "$!";
CREATE TABLE new_package (
  PACKAGE TEXT,
  VERSION TEXT,
  PLATFORM TEXT
)
SQL

foreach my $p (@common_platforms) {
    $dbh->do("INSERT INTO new_package select b.package,b.version,'$p' from end_".$p."_manifest as b WHERE NOT EXISTS(SELECT package FROM begin_".$p."_manifest AS e WHERE b.package=e.package)") or die $!;
}

$dbh->do(<<'SQL') or die "$!";
CREATE TABLE removed_package (
  PACKAGE TEXT,
  VERSION TEXT,
  PLATFORM TEXT
)
SQL

foreach my $p (@common_platforms) {
    $dbh->do("INSERT INTO removed_package select b.package,b.version,'$p' from begin_".$p."_manifest as b WHERE NOT EXISTS(SELECT package FROM end_".$p."_manifest AS e WHERE b.package=e.package)") or die $!;
}

my $old_level = {};
my $new_level = {};

{
    my $q = <<'SQL';
select package as pk ,oldversion as o ,newversion as n, 
	GROUP_CONCAT(platform) as ps
FROM package_upgrades 
	GROUP BY package,oldversion,newversion
ORDER BY package,platform
SQL
    my $sth = $dbh->prepare($q) or die $!;
    $sth->execute();

    print OUTPUT "## Updated Packages\n\n";
    print OUTPUT "Package | Old Version | New Version | Platforms\n";
    print OUTPUT "--- | --- | --- | ---\n";
    while (my $r = $sth->fetchrow_hashref) {
	print OUTPUT join(' | ',($r->{pk}, $r->{o}, $r->{n}, $r->{ps}))."\n" ;
	if ($r->{pk} eq 'machine-xml') {
	    $old_level->{$r->{ps}."-xml"} = $r->{o};
	    $new_level->{$r->{ps}."-xml"} = $r->{n};
	} else {
	    $old_level->{$r->{pk}} = $r->{o};
	    $new_level->{$r->{pk}} = $r->{n};
	}
    }
}

{
    my $q = <<'SQL';
select package as pk ,version as v,
	GROUP_CONCAT(platform) as ps
FROM new_package
	GROUP BY package,version
ORDER BY package,platform
SQL
    my $sth = $dbh->prepare($q) or die $!;
    $sth->execute();

    print OUTPUT "\n\n## New Packages\n\n";
    print OUTPUT "Package | Version | Platforms\n";
    print OUTPUT "--- | --- | ---\n";
    while (my $r = $sth->fetchrow_hashref) {
	print OUTPUT join(' | ',($r->{pk}, $r->{v}, $r->{ps}))."\n" ;
	if ($r->{pk} eq 'machine-xml') {
	    $new_level->{$r->{ps}."-xml"} = $r->{v};
	}
    }
}

{
    my $q = <<'SQL';
select package as pk ,version as v,
	GROUP_CONCAT(platform) as ps
FROM removed_package
	GROUP BY package,version
ORDER BY package,platform
SQL
    my $sth = $dbh->prepare($q) or die $!;
    $sth->execute();

    print OUTPUT "\n\n## Removed Packages\n\n";
    print OUTPUT "Package | Version | Platforms\n";
    print OUTPUT "--- | --- | ---\n";
    while (my $r = $sth->fetchrow_hashref) {
	print OUTPUT join(' | ',($r->{pk}, $r->{v}, $r->{ps}))."\n" ;
	if ($r->{pk} eq $r->{ps}."-xml") {
	    $old_level->{$r->{ps}."-xml"} = $r->{v};
	}
    }
    print OUTPUT "\n\n";
}

foreach my $repo (keys %{$repos})
{
    if (-e $repo)
    {
        system("cd $repo; git fetch") && die "Could not fetch $repo";
    }
    else
    {
        system("git clone $repos->{$repo}->{REPO} $repo") &&
            die "Could not clone $repo";
    }
}

system("cd op-build; git checkout $end_release --force; git reset HEAD --hard");


my $op_url = $repos->{'op-build'}->{REPO};

foreach my $repo (sort keys %{$repos})
{
    my $package = $repo;
    my $url = $repos->{$repo}->{REPO};
    my $dir = $repos->{$repo}->{DIR};

    print OUTPUT "## Package: $repo\n";
    print OUTPUT "[Repository]($url)\n";
    print OUTPUT "\n";

    # Display patches.
    if (open(LSLOG, "ls op-build/$dir/*.patch | ".
                    "xargs -n1 --no-run-if-empty basename |"))
    {
        print OUTPUT "### Patches\n";
        while (my $logline = <LSLOG>)
        {
            chomp $logline;
            print OUTPUT "* [$logline]".
                "($op_url/tree/$end_release/$dir/$logline)\n";
        }
        close LSLOG;
        print OUTPUT "\n";
    }
    else
    {
        print OUTPUT "None.\n";
    }

    # Display changes.
    print OUTPUT "### Commits\n";
    if ((not exists $old_level->{$package}) &&
        (not exists $new_level->{$package}))
    {
        # No change identified.
        print "No changes: $repo\n";
        print OUTPUT "No changes.\n";
        next;
    }

    if ((exists $old_level->{$package}) &&
        (exists $new_level->{$package}))
    {
        print "Changes in $repo...\n";
        open(GITLOG, "cd $repo; git shortlog $old_level->{$package}...".
                     "$new_level->{$package} --no-merges --format=".
                     "\"* [%h]($url/commit/%h) %s\" |");

        while (my $logline = <GITLOG>)
        {
            chomp $logline;
            $logline =~ s/^[[:space:]]*//;
            print OUTPUT "$logline\n";
        }
        close GITLOG;
        print OUTPUT "\n";
        next;
    }

    if (not exists $old_level->{$package})
    {
        print "New package $repo.\n";
        print OUTPUT "New package.\n";
        next;
    }

    if (not exists $new_level->{$package})
    {
        print "Deleted package $repo.\n";
        print OUTPUT "Package removed.\n";
        next;
    }
}