package DBIx::Class::Schema::Loader::DBI::Informix;

use strict;
use warnings;
use mro 'c3';
use base qw/DBIx::Class::Schema::Loader::DBI/;
use Carp::Clan qw/^DBIx::Class/;
use Scalar::Util 'looks_like_number';
use namespace::clean;

our $VERSION = '0.07001';

=head1 NAME

DBIx::Class::Schema::Loader::DBI::Informix - DBIx::Class::Schema::Loader::DBI
Informix Implementation.

=head1 DESCRIPTION

See L<DBIx::Class::Schema::Loader> and L<DBIx::Class::Schema::Loader::Base>.

=cut

sub _setup {
    my $self = shift;

    $self->next::method(@_);

    if (not defined $self->preserve_case) {
        $self->preserve_case(0);
    }
    elsif ($self->preserve_case) {
        $self->schema->storage->sql_maker->quote_char('"');
        $self->schema->storage->sql_maker->name_sep('.');
    }
}

sub _tables_list {
    my ($self, $opts) = @_;

    my $dbh = $self->schema->storage->dbh;
    my $sth = $dbh->prepare(<<'EOF');
select tabname from systables t
where t.owner <> 'informix' and t.owner <> '' and t.tabname <> ' VERSION'
EOF
    $sth->execute;

    my @tables = map @$_, @{ $sth->fetchall_arrayref };

    return $self->_filter_tables(\@tables, $opts);
}

sub _constraints_for {
    my ($self, $table, $type) = @_;

    my $dbh = $self->schema->storage->dbh;
    local $dbh->{FetchHashKeyName} = 'NAME_lc';

    my $sth = $dbh->prepare(<<'EOF');
select c.constrname, i.*
from sysconstraints c
join systables t on t.tabid = c.tabid
join sysindexes i on c.idxname = i.idxname
where t.tabname = ? and c.constrtype = ?
EOF
    $sth->execute($table, $type);
    my $indexes = $sth->fetchall_hashref('constrname');
    $sth->finish;

    my $cols = $self->_colnames_by_colno($table);

    my $constraints;
    while (my ($constr_name, $idx_def) = each %$indexes) {
        $constraints->{$constr_name} = $self->_idx_colnames($idx_def, $cols);
    }

    return $constraints;
}

sub _idx_colnames {
    my ($self, $idx_info, $table_cols_by_colno) = @_;

    return [ map $self->_lc($table_cols_by_colno->{$_}), grep $_, map $idx_info->{$_}, map "part$_", (1..16) ];
}

sub _colnames_by_colno {
    my ($self, $table) = @_;

    my $dbh = $self->schema->storage->dbh;
    local $dbh->{FetchHashKeyName} = 'NAME_lc';

    my $sth = $dbh->prepare(<<'EOF');
select c.colname, c.colno
from syscolumns c
join systables t on c.tabid = t.tabid
where t.tabname = ?
EOF
    $sth->execute($table);
    my $cols = $sth->fetchall_hashref('colno');
    $cols = { map +($_, $cols->{$_}{colname}), keys %$cols };

    return $cols;
}

sub _table_pk_info {
    my ($self, $table) = @_;

    my $pk = (values %{ $self->_constraints_for($table, 'P') || {} })[0];

    return $pk;
}

sub _table_uniq_info {
    my ($self, $table) = @_;

    my $constraints = $self->_constraints_for($table, 'U');

    my @uniqs = map { [ $_ => $constraints->{$_} ] } keys %$constraints;
    return \@uniqs;
}

sub _table_fk_info {
    my ($self, $table) = @_;

    my $local_columns = $self->_constraints_for($table, 'R');

    my $dbh = $self->schema->storage->dbh;
    local $dbh->{FetchHashKeyName} = 'NAME_lc';

    my $sth = $dbh->prepare(<<'EOF');
select c.constrname local_constraint, rt.tabname remote_table, rc.constrname remote_constraint, ri.*
from sysconstraints c
join systables t on c.tabid = t.tabid
join sysreferences r on c.constrid = r.constrid
join sysconstraints rc on rc.constrid = r.primary
join systables rt on r.ptabid = rt.tabid
join sysindexes ri on rc.idxname = ri.idxname
where t.tabname = ? and c.constrtype = 'R'
EOF
    $sth->execute($table);
    my $remotes = $sth->fetchall_hashref('local_constraint');
    $sth->finish;

    my @rels;

    while (my ($local_constraint, $remote_info) = each %$remotes) {
        push @rels, {
            local_columns => $local_columns->{$local_constraint},
            remote_columns => $self->_idx_colnames($remote_info, $self->_colnames_by_colno($remote_info->{remote_table})),
            remote_table => $remote_info->{remote_table},
        };
    }

    return \@rels;
}

# This is directly from http://www.ibm.com/developerworks/data/zones/informix/library/techarticle/0305parker/0305parker.html
# it doesn't work at all
sub _informix_datetime_precision {
    my @date_type = qw/DUMMY year  month day   hour   minute  second  fraction(1) fraction(2) fraction(3) fraction(4) fraction(5)/;
    my @start_end = (  [],   [1,5],[5,7],[7,9],[9,11],[11,13],[13,15],[15,16],    [16,17],    [17,18],    [18,19],    [19,20]    );

    my ($self, $collength) = @_;

    my $i = ($collength % 16) + 1;
    my $j = int(($collength % 256) / 16) + 1;
    my $k = int($collength / 256);

    my $len = $start_end[$i][1] - $start_end[$j][0];
    $len = $k - $len;

    if ($len == 0 || $j > 11) {
        return $date_type[$j] . ' to ' . $date_type[$i];
    }

    $k  = $start_end[$j][1] - $start_end[$j][0];
    $k += $len;

    return $date_type[$j] . "($k) to " . $date_type[$i];
}

sub _columns_info_for {
    my $self = shift;
    my ($table) = @_;

    my $result = $self->next::method(@_);

    my $dbh = $self->schema->storage->dbh;
    local $dbh->{FetchHashKeyName} = 'NAME_lc';

    my $sth = $dbh->prepare(<<'EOF');
select c.colname, c.coltype, c.collength, c.colmin, d.type deflt_type, d.default deflt
from syscolumns c
join systables t on c.tabid = t.tabid
left join sysdefaults d on t.tabid = d.tabid and c.colno = d.colno
where t.tabname = ?
EOF
    $sth->execute($table);
    my $cols = $sth->fetchall_hashref('colname');
    $sth->finish;

    while (my ($col, $info) = each %$cols) {
        $col = $self->_lc($col);

        my $type = $info->{coltype} % 256;

        if ($type == 6) { # SERIAL
            $result->{$col}{is_auto_increment} = 1;
        }

        my $data_type = $result->{$col}{data_type};

        if (looks_like_number $data_type) {
            if ($type == 7) {
                $result->{$col}{data_type} = 'date';
            }
            elsif ($type == 10) {
                $result->{$col}{data_type} = 'datetime year to fraction(5)';
                # this doesn't work yet
#                $result->{$col}{data_type} = 'datetime ' . $self->_informix_datetime_precision($info->{collength});
            }
            elsif ($type == 17 || $type == 52) {
                $result->{$col}{data_type} = 'bigint';
            }
            elsif ($type == 40) {
                $result->{$col}{data_type} = 'lvarchar';
                $result->{$col}{size}      = $info->{collength};
            }
            elsif ($type == 12) {
                $result->{$col}{data_type} = 'text';
            }
            elsif ($type == 11) {
                $result->{$col}{data_type}           = 'bytea';
                $result->{$col}{original}{data_type} = 'byte';
            }
            elsif ($type == 41) {
                # XXX no way to distinguish opaque types boolean, blob and clob
                $result->{$col}{data_type} = 'blob';
            }
            elsif ($type == 21) {
                $result->{$col}{data_type} = 'list';
            }
            elsif ($type == 20) {
                $result->{$col}{data_type} = 'multiset';
            }
            elsif ($type == 19) {
                $result->{$col}{data_type} = 'set';
            }
        }

        if ($type == 15) {
            $result->{$col}{data_type} = 'nchar';
        }
        elsif ($type == 16) {
            $result->{$col}{data_type} = 'nvarchar';
        }
        # XXX untested!
        elsif ($info->{coltype} == 2061) {
            $result->{$col}{data_type} = 'idssecuritylabel';
        }

        # XXX colmin doesn't work for min size of varchar columns, it's NULL
#        if (lc($data_type) eq 'varchar') {
#            $result->{$col}{size}[1] = $info->{colmin};
#        }
       
        my ($default_type, $default) = @{$info}{qw/deflt_type deflt/};

        next unless $default_type;

        if ($default_type eq 'C') {
            my $current = 'current year to fraction(5)';
            $result->{$col}{default_value} = \$current;
        }
        elsif ($default_type eq 'T') {
            my $today = 'today';
            $result->{$col}{default_value} = \$today;
        }
        else {
            $default = (split ' ', $default, 2)[-1];

            $default =~ s/\s+\z// if looks_like_number $default;

            # remove trailing 0s in floating point defaults
            # disabled, this is unsafe since it might be a varchar default
            #$default =~ s/0+\z// if $default =~ /^\d+\.\d+\z/;

            $result->{$col}{default_value} = $default;
        }
    }

    # fix up data_types some more
    while (my ($col, $info) = each %$result) {
        my $data_type = $info->{data_type};

        if ($data_type !~ /^(?:[nl]?(?:var)?char|decimal)\z/i) {
            delete $info->{size};
        }

        if (lc($data_type) eq 'decimal') {
            no warnings 'uninitialized';

            $info->{data_type} = 'numeric';

            my @size = @{ $info->{size} || [] };

            if ($size[0] == 16 && $size[1] == -4) {
                delete $info->{size};
            }
            elsif ($size[0] == 16 && $size[1] == 2) {
                $info->{data_type} = 'money';
                delete $info->{size};
            }
        }
        elsif (lc($data_type) eq 'smallfloat') {
            $info->{data_type} = 'real';
        }
        elsif (lc($data_type) eq 'float') {
            $info->{data_type} = 'double precision';
        }
        elsif ($data_type =~ /^n?(?:var)?char\z/i) {
            $info->{size} = $info->{size}[0];
        }
    }

    return $result;
}

=head1 SEE ALSO

L<DBIx::Class::Schema::Loader>, L<DBIx::Class::Schema::Loader::Base>,
L<DBIx::Class::Schema::Loader::DBI>

=head1 AUTHOR

See L<DBIx::Class::Schema::Loader/AUTHOR> and L<DBIx::Class::Schema::Loader/CONTRIBUTORS>.

=head1 LICENSE

This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.

=cut

1;
# vim:et sw=4 sts=4 tw=0:
