package Fey::SQL::Delete;

use strict;
use warnings;
use namespace::autoclean;

our $VERSION = '0.43';

use Fey::Types qw( ArrayRef CanQuote Table );
use Scalar::Util qw( blessed );

use Moose 2.1200;
use MooseX::Params::Validate 0.21 qw( pos_validated_list );
use MooseX::SemiAffordanceAccessor 0.03;
use MooseX::StrictConstructor 0.13;

with 'Fey::Role::SQL::HasWhereClause',
    'Fey::Role::SQL::HasOrderByClause',
    'Fey::Role::SQL::HasLimitClause';

with 'Fey::Role::SQL::HasBindParams' => { -excludes => 'bind_params' };

has '_from' => (
    is       => 'rw',
    isa      => ArrayRef,
    default  => sub { [] },
    init_arg => undef,
);

with 'Fey::Role::SQL::Cloneable';

sub delete { return $_[0] }

sub from {
    my $self = shift;

    my $count = @_ ? @_ : 1;
    my (@tables) = pos_validated_list(
        \@_,
        ( ( { isa => Table } ) x $count ),
        MX_PARAMS_VALIDATE_NO_CACHE => 1,
    );

    $self->_set_from( \@tables );

    return $self;
}

sub sql {
    my $self = shift;
    my ($dbh) = pos_validated_list( \@_, { isa => CanQuote } );

    return (
        join ' ',
        $self->delete_clause($dbh),
        $self->where_clause($dbh),
        $self->order_by_clause($dbh),
        $self->limit_clause($dbh),
    );
}

sub delete_clause {
    return 'DELETE FROM ' . $_[0]->_tables_subclause( $_[1] );
}

sub _tables_subclause {
    return (
        join ', ',
        map { $_[1]->quote_identifier( $_->name() ) } @{ $_[0]->_from() }
    );
}

__PACKAGE__->meta()->make_immutable();

1;

# ABSTRACT: Represents a DELETE query

__END__

=pod

=head1 NAME

Fey::SQL::Delete - Represents a DELETE query

=head1 VERSION

version 0.43

=head1 SYNOPSIS

  my $sql = Fey::SQL->new_delete();

  # DELETE FROM Part
  #       WHERE Part.name LIKE '%Widget'
  $sql->delete();
  $sql->from($Part);
  $sql->where( $name, 'LIKE', '%Widget' );

  print $sql->sql($dbh);

=head1 DESCRIPTION

This class represents a C<DELETE> query.

=head1 METHODS

This class provides the following methods:

=head2 Constructor

To construct an object of this class, call C<< $query->delete() >> on
a C<Fey::SQL> object.

=head2 $delete->delete()

This method is basically a no-op that exists to so that L<Fey::SQL>
has something to call after it constructs an object in this class.

=head2 $delete->from(...)

This method specifies the C<FROM> clause of the query. It expects one
or more L<Fey::Table> objects (not aliases). Most RDBMS
implementations only allow for a single table here, but some (like
MySQL) do allow for multi-table deletes.

=head2 $delete->where(...)

See the L<Fey::SQL section on WHERE Clauses|Fey::SQL/WHERE Clauses>
for more details.

=head2 $delete->order_by(...)

See the L<Fey::SQL section on ORDER BY Clauses|Fey::SQL/ORDER BY
Clauses> for more details.

=head2 $delete->limit(...)

See the L<Fey::SQL section on LIMIT Clauses|Fey::SQL/LIMIT Clauses>
for more details.

=head2 $delete->sql()

Returns the full SQL statement which this object represents. A DBI
handle must be passed so that identifiers can be properly quoted.

=head2 $delete->bind_params()

See the L<Fey::SQL section on Bind Parameters|Fey::SQL/Bind
Parameters> for more details.

=head2 $delete->delete_clause()

Returns the C<DELETE> clause portion of the SQL statement as a string.

=head2 $delete->where_clause()

Returns the C<WHERE> clause portion of the SQL statement as a string.

=head2 $delete->order_by_clause()

Returns the C<ORDER BY> clause portion of the SQL statement as a
string.

=head2 $delete->limit_clause()

Returns the C<LIMIT> clause portion of the SQL statement as a string.

=head1 ROLES

=over 4

=item * L<Fey::Role::SQL::HasBindParams>

=item * L<Fey::Role::SQL::HasWhereClause>

=item * L<Fey::Role::SQL::HasOrderByClause>

=item * L<Fey::Role::SQL::HasLimitClause>

=item * L<Fey::Role::SQL::Cloneable>

=back

=head1 BUGS

See L<Fey> for details on how to report bugs.

=head1 AUTHOR

Dave Rolsky <autarch@urth.org>

=head1 COPYRIGHT AND LICENSE

This software is Copyright (c) 2011 - 2015 by Dave Rolsky.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)

=cut