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

=head1 NAME

mig-init - This will add or recreate tracking tables for the B<mig> toolset to
the migration schema specified by the MIGSCHEMA environment variable, in the
PostgreSQL database specified by various PG environment variables.

In practice, you should invoke 'mig env use schema_name' prior to calling
B<init>

=head1 SYNOPSIS

B<mig-init>

B<mig-init> <help>

=cut

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

use strict;
use Switch;
use Env qw(
    HOME PGHOST PGPORT PGUSER PGDATABASE MIGSCHEMA
    MIGBASEWORKDIR MIGBASEGITDIR MIGGITDIR MIGWORKDIR
);
use Pod::Usage;
use DBI;
use FindBin;
my $mig_bin = "$FindBin::Bin/";
my $mig_sql = $mig_bin . "../mig-sql/init/";
use lib "$FindBin::Bin/";
use Mig;

pod2usage(-verbose => 2) if $ARGV[0];

Mig::die_if_no_env_migschema();

if (! Mig::check_for_db_migschema()) {
    try_to_create_schema();
}

if (! Mig::check_db_migschema_for_migration_tables()) {
    try_to_init_schema_with_migration_tools();
}
Mig::die_if_mig_tracking_table_exists();
Mig::die_if_mig_column_tracking_table_exists();
loop_through_mig_sql_templates();

exit 0;

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

sub try_to_create_schema {
    if ($MIGSCHEMA =~ /[^\w_]/) {
        die "$MIGSCHEMA is not suitable for a schema name in PostgreSQL\n";
    }
    my $dbh = Mig::db_connect();
    my $rv = $dbh->do("CREATE SCHEMA $MIGSCHEMA;")
        || die "Error creating migration schema ($MIGSCHEMA): $!\n";
    print "Created schema $MIGSCHEMA\n";
    Mig::db_disconnect($dbh);
}

sub try_to_init_schema_with_migration_tools {
    Mig::die_if_no_migration_tools();
    print "Calling migration_tools.init() and .build()\n";
    my $dbh = Mig::db_connect();
    my $rv = $dbh->do("SELECT migration_tools.init(" . $dbh->quote($MIGSCHEMA) . ");")
        || die "Error running migration_tools.init($MIGSCHEMA): $!\n";
    print "migration_tools.init() finished\n";
    my $rv2 = $dbh->do("SELECT migration_tools.build(" . $dbh->quote($MIGSCHEMA) . ");")
        || die "Error running migration_tools.build($MIGSCHEMA): $!\n";
    print "migration_tools.build() finished\n";
    Mig::db_disconnect($dbh);
}

sub loop_through_mig_sql_templates {
    print "Looping through mig-sql/init/ templates\n";
    opendir my $dir, $mig_sql or die "Cannot open directory: $!";
    my @files = sort readdir $dir;
    closedir $dir;
    foreach my $file (@files) {
        if ($file =~ /.sql$/) {
            print "executing $file:\n";
            system( $mig_bin . "mig-sql", ('-f',$mig_sql . $file) )
        }
    }
}