#!/usr/bin/perl -w
###############################################################################
=pod

=head1 NAME

mig-unlink

Clear any association between the specified file and a parent table within the
migration schema.

=head1 SYNOPSIS

B<mig-unlink> <file>

=cut

###############################################################################

use strict;
use Switch;
use Env qw(
    HOME PGHOST PGPORT PGUSER PGDATABASE MIGSCHEMA
    MIGBASEWORKDIR MIGBASEGITDIR MIGGITDIR MIGWORKDIR
);
use Pod::Usage;
use DBI;
use Cwd 'abs_path';
use FindBin;
my $mig_bin = "$FindBin::Bin/";
use lib "$FindBin::Bin/";
use Mig;

pod2usage(-verbose => 2) if ! $ARGV[0] || $ARGV[0] eq '--help';

Mig::die_if_no_env_migschema();
Mig::die_if_mig_tracking_table_does_not_exist();

my $file = abs_path($ARGV[0]);
if ($file =~ /^$MIGBASEWORKDIR/) {
    unlink_table(@ARGV);
} else {
    print "File falls outside of MIGWORKDIR ($MIGWORKDIR): $file\n";
}

exit 0;

###############################################################################

sub unlink_table {
    my $file = abs_path(shift);

    my $tracked_file_id = Mig::check_for_tracked_file($file);
    if ($tracked_file_id) {
        my $data = Mig::status_this_file($file);
        my $table = $data->{'parent_table'} || '';

        print "unlinking table ($table) from file: $file\n";

        my $dbh = Mig::db_connect();
        my $rv = $dbh->do("
            UPDATE $MIGSCHEMA.tracked_file
            SET parent_table = ''
            WHERE base_filename = " . $dbh->quote($file) . "
            ;
        ") || die "Error updating table $MIGSCHEMA.tracked_file: $!\n";
        Mig::db_disconnect($dbh);
    } else {
        print "File not currently tracked: $file\n";
    }
}