package Teng::Schema::Dumper;
use strict;
use warnings;
use DBIx::Inspector 0.06;
use Carp ();
use DBI ();

my %SQLTYPE2NAME = map { &{$DBI::{$_}} => $_ } @{$DBI::EXPORT_TAGS{sql_types}};

sub dump {
    my $class = shift;
    my %args = @_==1 ? %{$_[0]} : @_;

    my $dbh       = $args{dbh} or Carp::croak("missing mandatory parameter 'dbh'");
    my $namespace = $args{namespace} or Carp::croak("missing mandatory parameter 'namespace'");

    my $inspector = DBIx::Inspector->new(dbh => $dbh);

    my $ret = "";

    if ( ref $args{tables} eq "ARRAY" ) {
        for my $table_name (@{ $args{tables} }) {
            $ret .= _render_table($inspector->table($table_name), \%args);
        }
    }
    elsif ( $args{tables} ) {
        $ret .= _render_table($inspector->table($args{tables}), \%args);
    }
    else {
        $ret .= "package ${namespace}::Schema;\n";
        $ret .= "use strict;\n";
        $ret .= "use warnings;\n";
        $ret .= "use DBI qw/:sql_types/;\n";
        $ret .= "use Teng::Schema::Declare;\n";
        $ret .= "base_row_class '$args{base_row_class}';\n" if $args{base_row_class};
        for my $table_info (sort { $a->name cmp $b->name } $inspector->tables) {
            $ret .= _render_table($table_info, \%args);
        }
        $ret .= "1;\n";
    }

    return $ret;
}

sub _render_table {
    my ($table_info, $args) = @_;

    my $ret = "";

    $ret .= "table {\n";
    $ret .= sprintf("    name '%s';\n", $table_info->name);
    $ret .= sprintf("    pk %s;\n", join ',' , map { q{'}.$_->name.q{'} } $table_info->primary_key);
    $ret .= "    columns (\n";
    for my $col ($table_info->columns) {
        if ($col->data_type) {
            $ret .= sprintf("        {name => '%s', type => %s},\n", $col->name, $SQLTYPE2NAME{$col->data_type} || $col->data_type);
        } else {
            $ret .= sprintf("        '%s',\n", $col->name);
        }
    }
    $ret .= "    );\n";

    if (my $rule = $args->{inflate}->{$table_info->name}) {
        $ret .= $rule;
    }

    $ret .= "};\n\n";

    return $ret;
}

1;
__END__

=head1 NAME

Teng::Schema::Dumper - Schema code generator

=head1 SYNOPSIS

    use DBI;
    use Teng::Schema::Dumper;

    my $dbh = DBI->connect(@dsn) or die;
    print Teng::Schema::Dumper->dump(
        dbh       => $dbh,
        namespace => 'Mock::DB',
        inflate   => +{
            user => q|
                use Mock::Inflate::Name;
                inflate 'name' => sub {
                    my ($col_value) = @_;
                    return Mock::Inflate::Name->new(name => $col_value);
                };
                deflate 'name' => sub {
                    my ($col_value) = @_;
                    return ref $col_value ? $col_value->name : $col_value . '_deflate';
                };
                inflate qr/.+oo/ => sub {
                    my ($col_value) = @_;
                    return Mock::Inflate::Name->new(name => $col_value);
                };
                deflate qr/.+oo/ => sub {
                    my ($col_value) = @_;
                    return ref $col_value ? $col_value->name : $col_value . '_deflate';
                };
            |,
        },
    );

=head1 DESCRIPTION

This module generates the Perl code to generate L<Teng::Schema> instance.

You can use it by C<do "my/schema.pl"> or embed it to the package.

=head1 METHODS

=over 4

=item C<Teng::Schema::Dumper-E<gt>dump(dbh =E<gt> $dbh, namespace =E<gt> $namespace)>

This is the method to generate code from DB. It returns the Perl5 code in string.

The arguments are:

=over 4

=item C<dbh>

Database handle from DBI.

=item C<namespace>

your project Teng namespace.

=item C<base_row_class>

Specify the default base row class for L<Teng::Schema::Declare>.

=back

=back