detangle_sqitch_deploy_args.pl

# If two params, first is URI, second is target.
# If two params and either --to-target or --database is passed, it's an error.
# If one param:
#   - If --to-target is passed, it's a database
#   - If --database is passed, it's a target
#   - If both --to-target and --database are passed, it's an error.
#   - If contains ":", it's a URI; pass it through
#   - If it is a database key name, return the URI value
#   - If it's part of the plan, pass it as part of the plan.
#   - Otherwise throw an exception.

sub _args {
    my ($self, @params) = @_;
    my ($uri, $target);
    if (@params) {
        if (@params == 1) {
            my ($thing) = @params;
            if ($self->database) {

                # Die if both params were specified.
                hurl deploy => __ 'Cannot detangle multiple database and target params'
                    if $self->to_target;

                # Otherwise, it's a target.
                return (undef, $thing);
                $target = $thing;

            } elsif ($thing =~ /:/) {
                # It's a database URI.
                return (URI::db->new($thing), undef);

            } elsif (my $uri = $self->db_for_key($thing)) {
                # It's a database.
                return ($uri, undef);

            } elsif ($self->to_target) {
                # It's supposed to be a database.
                return (URI::db->new($thing), undef);

            } elsif ( defined try { $self->sqitch->plan->index_of($thing) } ) {
                # It's a target.
                return (undef, $thing);
            } else {
                hurl deploy => __x(
                    'Argument "{arg}" does not appear to be a change name or database URI',
                    arg => $thing
                );
            }

        } elsif (@params >= 2) {
            my ($db, $target) = @params;

            # Die if we have two databases.
            hurl deploy => join(
                "\n"
                __('Cannot determine which databases to use:'),
                '    ' . $self->database,
                "    $db",
                __('Try specifying only one'),
            ) if $self->database;

            # Die if we have two targets.
            hurl deploy => join(
                "\n"
                __('Cannot determine which target to use:'),
                '    ' . $self->to_target,
                "    $target",
                __('Try specifying only one'),
            ) if $self->to_target;

            if ($db !~ /:/) {
                $db = $self->db_for_key($db) or hurl deploy => __x(
                    '"{dbkey}" does not appear to be a known database',
                    dbkey => $db
                );
            }

            return ($db, $target);

        }
    } else {
        $db = $self->database;
        if ($db && $db !~ /:/) {
            $db = $self->db_for_key($db) or hurl deploy => __x(
                '"{dbkey}" does not appear to be a known database',
                dbkey => $db
            );
        }
        return ($db, $self->to_target);
    }

}

sub db_for_key {
    my ($self, $key) = @_;
    my $db = $self->sqitch->config->get( key => "database.$key" ) or return;
    return URI::db->new($db);
}