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package Alzabo::Table;

use strict;
use vars qw($VERSION);

use Alzabo;

use Params::Validate qw( :all );
Params::Validate::validation_options( on_fail => sub { Alzabo::Exception::Params->throw( error => join '', @_ ) } );

use Tie::IxHash;

$VERSION = 2.0;

1;

sub schema
{
    my $self = shift;

    return $self->{schema};
}

sub name
{
    my $self = shift;

    return $self->{name};
}

use constant HAS_COLUMN_SPEC => { type => SCALAR };

sub has_column
{
    my $self = shift;

    validate_pos( @_, HAS_COLUMN_SPEC );

    return $self->{columns}->FETCH(shift);
}

sub column
{
    my $self = shift;
    my $name = shift;

    if ( my $col = $self->{columns}->FETCH($name) )
    {
        return $col;
    }
    else
    {
        Alzabo::Exception::Params->throw
            ( error => "Column $name doesn't exist in $self->{name}" );
    }
}

sub columns
{
    my $self = shift;

    return $self->column(@_) if @_ ==1 ;
    return map { $self->column($_) } @_ if @_ > 1;
    return $self->{columns}->Values;
}

sub primary_key
{
    my $self = shift;

    return unless @{ $self->{pk} };

    return ( wantarray ?
             $self->{columns}->Values( @{ $self->{pk} } ) :
             $self->{columns}->Values( $self->{pk}[0] )
           );
}

sub primary_key_size
{
    my $self = shift;

    return scalar @{ $self->{pk} };
}

use constant COLUMN_IS_PRIMARY_KEY_SPEC => { isa => 'Alzabo::Column' };

sub column_is_primary_key
{
    my $self = shift;

    validate_pos( @_, COLUMN_IS_PRIMARY_KEY_SPEC );

    my $name = shift->name;

    Alzabo::Exception::Params->throw( error => "Column $name doesn't exist in $self->{name}" )
        unless $self->{columns}->EXISTS($name);

    my $idx = $self->{columns}->Indices($name);
    return 1 if grep { $idx == $_ } @{ $self->{pk} };

    return 0;
}

sub attributes
{
    return keys %{ $_[0]->{attributes} };
}

use constant HAS_ATTRIBUTE_SPEC => { attribute => { type => SCALAR },
                                     case_sensitive => { type => SCALAR,
                                                         default => 0 },
                                   };

sub has_attribute
{
    my $self = shift;
    my %p = validate( @_, HAS_ATTRIBUTE_SPEC );

    if ( $p{case_sensitive} )
    {
        return exists $self->{attributes}{ $p{attribute} };
    }
    else
    {
        return 1 if grep { lc $p{attribute} eq lc $_ } keys %{ $self->{attributes} };
    }
}

use constant FOREIGN_KEYS_SPEC => { column => { isa => 'Alzabo::Column' },
                                    table  => { isa => 'Alzabo::Table' },
                                  };

sub foreign_keys
{
    my $self = shift;

    validate( @_, FOREIGN_KEYS_SPEC );
    my %p = @_;

    my $c_name = $p{column}->name;
    my $t_name = $p{table}->name;

    Alzabo::Exception::Params->throw( error => "Column $c_name doesn't exist in $self->{name}" )
        unless $self->{columns}->EXISTS($c_name);

    Alzabo::Exception::Params->throw( error => "No foreign keys to $t_name exist in $self->{name}" )
        unless exists $self->{fk}{$t_name};

    Alzabo::Exception::Params->throw( error => "Column $c_name is not a foreign key to $t_name in $self->{name}" )
        unless exists $self->{fk}{$t_name}{$c_name};

    return wantarray ? @{ $self->{fk}{$t_name}{$c_name} } : $self->{fk}{$t_name}{$c_name}[0];
}

use constant FOREIGN_KEYS_BY_TABLE_SPEC => { isa => 'Alzabo::Table' };

sub foreign_keys_by_table
{
    my $self = shift;

    validate_pos( @_, FOREIGN_KEYS_BY_TABLE_SPEC );
    my $name = shift->name;

    my $fk = $self->{fk};

    my %fk;
    if ( exists $fk->{$name} )
    {
        foreach my $c ( keys %{ $fk->{$name} } )
        {
            return $fk->{$name}{$c}[0] unless wantarray;

            $fk{$_} = $_ for @{ $fk->{$name}{$c} };
        }
    }

    return values %fk;
}

use constant FOREIGN_KEYS_BY_COLUMN_SPEC => { isa => 'Alzabo::Column' };

sub foreign_keys_by_column
{
    my $self = shift;

    my ($col) = validate_pos( @_, FOREIGN_KEYS_BY_COLUMN_SPEC );

    Alzabo::Exception::Params->throw( error => "Column " . $col->name . " doesn't exist in $self->{name}" )
        unless $self->{columns}->EXISTS( $col->name );

    my $fk = $self->{fk};

    my %fk;
    foreach my $t (keys %$fk)
    {
        if ( exists $fk->{$t}{ $col->name } )
        {
            return $fk->{$t}{ $col->name }[0] unless wantarray;

            $fk{$_} = $_ for @{ $fk->{$t}{ $col->name } };
        }
    }

    return values %fk;
}

sub all_foreign_keys
{
    my $self = shift;

    my %seen;
    my @fk;
    my $fk = $self->{fk};
    foreach my $t (keys %$fk)
    {
        foreach my $c ( keys %{ $fk->{$t} } )
        {
            foreach my $key ( @{ $fk->{$t}{$c} } )
            {
                next if $seen{$key};
                push @fk, $key;
                $seen{$key} = 1;
            }
        }
    }

    return wantarray ? @fk : $fk[0];
}

sub index
{
    my $self = shift;

    validate_pos( @_, { type => SCALAR } );
    my $id = shift;

    Alzabo::Exception::Params->throw( error => "Index $id doesn't exist in $self->{name}" )
        unless $self->{indexes}->EXISTS($id);

    return $self->{indexes}->FETCH($id);
}

sub has_index
{
    my $self = shift;

    validate_pos( @_, { type => SCALAR } );
    my $id = shift;

    return $self->{indexes}->EXISTS($id);
}

sub indexes
{
    my $self = shift;

    return $self->{indexes}->Values;
}

sub comment { $_[0]->{comment} }

__END__

=head1 NAME

Alzabo::Table - Table objects

=head1 SYNOPSIS

  use Alzabo::Table;

  my $t = $schema->table('foo');

  foreach $pk ($t->primary_keys)
  {
     print $pk->name;
  }

=head1 DESCRIPTION

Objects in this class represent tables.  They contain foreign key,
index, and column objects.

=head1 METHODS

=head2 schema

Returns the L<C<Alzabo::Schema>|Alzabo::Schema> object to which this
table belongs.

=head2 name

Returns the name of the table.

=head2 column ($name)

Returns the L<C<Alzabo::Column>|Alzabo::Column> object that matches
the name given.

An L<C<Alzabo::Exception::Params>|Alzabo::Exceptions> exception is
throws if the table does not contain the column.

=head2 columns (@optional_list_of_column_names)

If no arguments are given, returns a list of all
L<C<Alzabo::Column>|Alzabo::Column> objects in the schema, or in a
scalar context the number of such tables.  If one or more arguments