#!/usr/bin/env perl
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use strict;
use warnings;

package Qt::InitRepository;


=head1 NAME

init-repository - initialize the Qt5 repository and all submodules

=head1 SYNOPSIS

  ./init-repository [options]

This script may be run after an initial `git clone' of Qt5 in order to check
out all submodules.


=head2 Global options:

=over

=item --force, -f

Force initialization (even if the submodules are already checked out).


=item --quiet, -q

Be quiet.  Will exit cleanly if the repository is already initialized.

=back


=head2 Module options:

=over

=item --no-webkit

Skip webkit and webkit examples submodules.
It may be desirable to skip these modules due to the large size of the webkit
git repository.


=item --no-update

Skip the `git submodule update' command.


=item --ignore-submodules

Set git config to ignore submodules by default when doing operations on the
qt5 repo, such as `pull', `fetch', `diff' etc.

After using this option, pass `--ignore-submodules=none' to git to override
it as needed.

=back


=head2 Repository options:

=over

=item --nokia-developer

Switch to internal Nokia URLs.


=item --brisbane

Switch to internal Nokia URLs and make use of the Brisbane git mirrors.
(Implies `--mirror' and `--mirror-webkit').


=item --ssh

Use the SSH protocol for git operations.  This may be useful if the git
protocol is blocked by a firewall. Note that this requires a user account
with an uploaded SSH key on all servers used.  (Implies `--nokia-developer').


=item --http

Use the HTTP protocol for git operations.  This may be useful if the git
protocol is blocked by a firewall.  Note that this only works with the
external Gitorious server.


=item --alternates <path to other Qt5 repo>

Adds alternates for each submodule to another full qt5 checkout. This makes
this qt5 checkout very small, as it will use the object store of the
alternates before unique objects are stored in its own object store.

This option has no effect when using `--no-update'.

B<NOTE:> This will make this repo dependent on the alternate, which is
potentially dangerous!  The dependency can be broken by also using
the `--copy-objects' option, or by running C<git repack -a> in each
submodule, where required.  Please read the note about the `--shared' option
in the documentation of `git clone' for more information.


=item --copy-objects

When `--alternates' is used, automatically do a C<git repack -a> in each
submodule after cloning, to ensure that the repositories are independent
from the source used as a reference for cloning.

Note that this negates the disk usage benefits gained from the use of
`--alternates'.


=item --mirror <url-base>

Uses <url-base> as the base URL for submodule git mirrors.

For example:

  --mirror user@machine:/foo/bar

...will use the following as a mirror for qtbase:

  user@machine:/foo/bar/qtbase.git


=item --mirror-webkit <url>

Uses <url> as the URL for the webkit git mirror.

=back

=cut

use Carp         qw( confess             );
use English      qw( -no_match_vars      );
use Getopt::Long qw( GetOptionsFromArray );
use Pod::Usage   qw( pod2usage           );

my %PROTOCOLS = (
    'internal'  => 'git://scm.dev.nokia.troll.no/' ,
    'ssh'       => 'git@scm.dev.nokia.troll.no:'   ,
    'http'      => 'http://git.gitorious.org/'     ,
);

my %STAGING_REPOS = map { $_ => "git://gitorious.org/qt/$_.git" } qw(
    qt5-staging
    qt3support-staging
    qtactiveqt-staging
    qtbase-earth-staging
    qtbase-staging
    qtdeclarative-staging
    qtdoc-staging
    qtmultimedia-staging
    qtphonon-staging
    qtqa-staging
    qtscript-staging
    qtsvg-staging
    qttools-staging
    qttranslations-staging
    qtwebkit-examples-and-demos-staging
    qtxmlpatterns-staging
    qtlocation-staging
);

my $BNE_MIRROR_URL_BASE
    = 'git://bq-git.apac.nokia.com/qtsoftware/qt/';

my $BNE_MIRROR_WEBKIT_URL
    = 'git://bq-git.apac.nokia.com/qtsoftware/research/gitorious-org-webkit-qtwebkit-mirror.git';

sub new
{
    my ($class, @arguments) = @_;

    my $self = {};
    bless $self, $class;
    $self->parse_arguments(@arguments);

    return $self;
}

# Like `system', but possibly log the command, and die on non-zero exit code
sub exe
{
    my ($self, @cmd) = @_;

    if (!$self->{quiet}) {
        print "+ @cmd\n";
    }

    if (system(@cmd) != 0) {
        confess "@cmd exited with status $CHILD_ERROR";
    }

    return;
}

sub parse_arguments
{
    my ($self, @args) = @_;

    %{$self} = (%{$self},
        'alternates'          => "",
        'detach-alternates'   => 0 ,
        'force'               => 0 ,
        'ignore-submodules'   => 0 ,
        'mirror-url'          => "",
        'mirror-webkit-url'   => "",
        'nokia-developer'     => 0 ,
        'protocol'            => "",
        'update'              => 1 ,
        'webkit'              => 1 ,
    );

    GetOptionsFromArray(\@args,
        'alternates=s'      =>  \$self->{qw{ alternates        }},
        'copy-objects'      =>  \$self->{qw{ detach-alternates }},
        'force'             =>  \$self->{qw{ force             }},
        'ignore-submodules' =>  \$self->{qw{ ignore_submodules }},
        'mirror-webkit=s'   =>  \$self->{qw{ mirror-webkit-url }},
        'mirror=s'          =>  \$self->{qw{ mirror-url        }},
        'nokia-developer'   =>  \$self->{qw{ nokia-developer   }},
        'quiet'             =>  \$self->{qw{ quiet             }},
        'update!'           =>  \$self->{qw{ update            }},
        'webkit!'           =>  \$self->{qw{ webkit            }},

        'help|?'            =>  sub { pod2usage(1);                   },
        'http'              =>  sub { $self->{protocol} = 'http'; },
        'ssh|ssh-protocol'  =>  sub { $self->{protocol} = 'ssh';  },

        'brisbane|brisbane-nokia-developer' => sub {
            $self->{'nokia-developer'}   = 1;
            $self->{'protocol'}          = 'internal';
            $self->{'mirror-url'}        = $BNE_MIRROR_URL_BASE;
            $self->{'mirror-webkit-url'} = $BNE_MIRROR_WEBKIT_URL;
        },

        'nokia-developer' => sub {
            $self->{'nokia-developer'}   = 1;
            $self->{'protocol'}          = 'internal';
        },
    ) || pod2usage(2);

    if ($self->{'nokia-developer'} && $self->{'protocol'} eq 'http') {
        print "*** Ignoring use of HTTP protocol, as it's only usable with external server\n";
        $self->{'protocol'} = '';
    }

    # Replace any double trailing slashes from end of mirror
    $self->{'mirror-url'} =~ s{//+$}{/};

    return;
}

sub check_if_already_initialized
{
    my ($self) = @_;

    # We consider the repo as `initialized' if submodule.qtbase.url is set
    if (qx(git config --get submodule.qtbase.url)) {
        if ($self->{force}) {
            my @configresult = qx(git config -l);
            foreach (@configresult) {
                # Example line: submodule.qtqa.url=git://gitorious.org/qt/qtqa.git
                if (/(submodule\.[^.=]+)\.url=.*/) {
                    $self->exe('git', 'config', '--remove-section', $1);
                }
            }
        }
        else {
            exit 0 if ($self->{quiet});
            print "Will not reinitialize already initialized repository (use -f to force)!\n";
            exit 1;
        }
    }

    return;
}

sub git_submodule_init
{
    my ($self) = @_;

    my @init_args;
    if ($self->{quiet}) {
        push @init_args, '--quiet';
    }
    $self->exe('git', 'submodule', 'init', @init_args);

    return;
}

sub git_disable_webkit_submodule
{
    my ($self) = @_;

    $self->exe('git', 'config', '--remove', 'submodule.qtwebkit');
    $self->exe('git', 'config', '--remove', 'submodule.qtwebkit-examples-and-demos');

    return;
}

sub git_set_submodule_config
{
    my ($self) = @_;

    my @configresult          = qx(git config -l);
    my $protocol              = $self->{protocol};
    my $url_base_for_protocol = $PROTOCOLS{$protocol};

    GITCONFIG:
    foreach my $line (@configresult) {
        # Example line: submodule.qtqa.url=git://gitorious.org/qt/qtqa.git
        next GITCONFIG if ($line !~ /(submodule\.[^.=]+\.url)=(.*)/);

        my $key   = $1;
        my $value = $2;

        if ($protocol) {
            # WebKit is special, and has only external link.
            if ($key ne 'submodule.qtwebkit.url') {
                # qt-labs projects are still hosted under qt internally.
                if ($protocol ne 'http') {
                    $value =~ s,^git://gitorious\.org/qt-labs/,${url_base_for_protocol}qt/,;
                }
                $value =~ s,^git://gitorious\.org/,$url_base_for_protocol,;
            }
        }

        $self->exe('git', 'config', $key, $value);

        if ($self->{'ignore-submodules'}) {
            $key =~ s,\.url,.ignore,;
            $self->exe('git', 'config', $key, 'all');
        }
    }

    return;
}

sub git_clone_all_submodules
{
    my ($self) = @_;

    # manually clone each repo here, so we can easily use reference repos, mirrors and
    # add all staging repos
    my @configresult = qx(git config -l);
    foreach my $line (@configresult) {
        if ($line =~ /submodule\.([^.=]+)\.url=(.*)/) {
            $self->git_clone_one_submodule($1, $2);
        }
    }

    $self->exe('git', 'submodule', 'update');

    return;
}

sub git_add_staging_remote
{
    my ($self, $repo_basename) = @_;

    my $protocol              = $self->{protocol};
    my $url_base_for_protocol = $PROTOCOLS{$protocol};

    my %current_remotes;
    for my $line (qx(git remote show)) {
        chomp $line;
        $current_remotes{$line} = 1;
    }

    # We assume that any staging starting with `$repo_basename-' relates to this
    # repo.  For example, for the `qtbase' module, `qtbase-staging'
    # and `qtbase-earth-staging' are considered as related staging repos.
    my @staging = grep { /^\Q$repo_basename\E-/; } keys %STAGING_REPOS;

    STAGING:
    foreach my $staging_repo (@staging) {
        # nothing to do if remote already exists
        next STAGING if ($current_remotes{$staging_repo});

        my $staging_repo_url = $STAGING_REPOS{$staging_repo};
        if ($protocol) {
            if ($protocol ne 'http') {
                $staging_repo_url =~ s,^git://gitorious\.org/qt-labs/,${url_base_for_protocol}qt/,;
            }
            $staging_repo_url =~ s,^git://gitorious\.org/,$url_base_for_protocol,;
        }
        $self->exe('git', 'remote', 'add', $staging_repo, $staging_repo_url);
    }

    return;
}

sub git_clone_one_submodule
{
    my ($self, $submodule, $url) = @_;

    my $alternates            = $self->{ 'alternates'        };
    my $mirror_url            = $self->{ 'mirror-url'        };
    my $mirror_webkit_url     = $self->{ 'mirror-webkit-url' };

    # `--reference FOO' args for the clone, if any.
    my @reference_args;

    if ($alternates) {
        # alternates is a qt5 repo, so the submodule will be under that.
        if (-d "$alternates/$submodule") {
            @reference_args = ('--reference', "$alternates/$submodule");
        }
        else {
            print " *** $alternates/$submodule not found, ignoring alternate for this submodule\n";
        }
    }

    my $mirror;
    if ($mirror_url && ($submodule ne 'qtwebkit')) {
        $mirror = $mirror_url.$submodule;
        $mirror .= ".git" unless (-d $mirror); # Support local disk mirror
    }
    elsif ($mirror_webkit_url && ($submodule eq 'qtwebkit')) {
        $mirror = $mirror_webkit_url;
    }

    my $do_clone = (! -d "$submodule/.git");
    if ($do_clone) {
        $self->exe('git', 'clone', @reference_args, ($mirror ? $mirror : $url), $submodule);
    }

    chdir($submodule) or confess "chdir $submodule: $OS_ERROR";

    if (!$do_clone) {
        $self->exe('git', 'fetch', ($mirror ? $mirror : $url));
    }

    if ($mirror) {
        $self->exe('git', 'config', 'remote.origin.url', $url);

        # In `force' mode, remove the mirror if it already exists,
        # since we may be reinitializing the module.
        if ($self->{force}) {
            eval { $self->exe('git', 'remote', 'rm', 'mirror'); }; # failure is OK
        }

        $self->exe('git', 'remote', 'add', 'mirror', $mirror);
    }

    $self->git_add_staging_remote($submodule);

    if ($self->{'detach-alternates'}) {
        $self->exe('git', 'repack', '-a');

        my $alternates_path = '.git/objects/info/alternates';
        unlink($alternates_path) || confess "unlink $alternates_path: $OS_ERROR";
    }

    chdir("..") or confess "cd ..: $OS_ERROR";

    return;
}

sub run
{
    my ($self) = @_;

    $self->check_if_already_initialized;
    $self->git_submodule_init;

    if (!$self->{webkit}) {
        $self->git_disable_webkit_submodule;
    }

    $self->git_set_submodule_config;

    if ($self->{update}) {
        $self->git_clone_all_submodules;
    }

    $self->git_add_staging_remote('qt5');

    return;
}

#==============================================================================

Qt::InitRepository->new(@ARGV)->run if (!caller);
1;