package DBI::Gofer::Request;

# $Id: Request.pm 12536 2009-02-24 22:37:09Z Tim $
#
# Copyright (c) 2007, Tim Bunce, Ireland
#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the Perl README file.

use strict;

use DBI qw(neat neat_list);

use base qw(DBI::Util::_accessor);

our $VERSION = "0.012537";

use constant GOf_REQUEST_IDEMPOTENT => 0x0001;
use constant GOf_REQUEST_READONLY => 0x0002;

our @EXPORT = qw(GOf_REQUEST_IDEMPOTENT GOf_REQUEST_READONLY);


__PACKAGE__->mk_accessors(qw(
version
flags
dbh_connect_call
dbh_method_call
dbh_attributes
dbh_last_insert_id_args
sth_method_calls
sth_result_attr
));
__PACKAGE__->mk_accessors_using(make_accessor_autoviv_hashref => qw(
meta
));


sub new {
my ($self, $args) = @_;
$args->{version} ||= $VERSION;
return $self->SUPER::new($args);
}


sub reset {
my ($self, $flags) = @_;
# remove everything except connect and version
%$self = (
version => $self->{version},
dbh_connect_call => $self->{dbh_connect_call},
);
$self->{flags} = $flags if $flags;
}


sub init_request {
my ($self, $method_and_args, $dbh) = @_;
$self->reset( $dbh->{ReadOnly} ? GOf_REQUEST_READONLY : 0 );
$self->dbh_method_call($method_and_args);
}


sub is_sth_request {
return shift->{sth_result_attr};
}


sub statements {
my $self = shift;
my @statements;
if (my $dbh_method_call = $self->dbh_method_call) {
my $statement_method_regex = qr/^(?:do|prepare)$/;
my (undef, $method, $arg1) = @$dbh_method_call;
push @statements, $arg1 if $method && $method =~ $statement_method_regex;
}
return @statements;
}


sub is_idempotent {
my $self = shift;

if (my $flags = $self->flags) {
return 1 if $flags & (GOf_REQUEST_IDEMPOTENT|GOf_REQUEST_READONLY);
}

# else check if all statements are SELECT statement that don't include FOR UPDATE
my @statements = $self->statements;
# XXX this is very minimal for now, doesn't even allow comments before the select
# (and can't ever work for "exec stored_procedure_name" kinds of statements)
# XXX it also doesn't deal with multiple statements: prepare("select foo; update bar")
return 1 if @statements == grep {
m/^ \s* SELECT \b /xmsi && !m/ \b FOR \s+ UPDATE \b /xmsi
} @statements;

return 0;
}


sub summary_as_text {
my $self = shift;
my ($context) = @_;
my @s = '';

if ($context && %$context) {
my @keys = sort keys %$context;
push @s, join(", ", map { "$_=>".$context->{$_} } @keys);
}

my ($method, $dsn, $user, $pass, $attr) = @{ $self->dbh_connect_call };
$method ||= 'connect_cached';
$pass = '***' if defined $pass;
my $tmp = '';
if ($attr) {
$tmp = { %{$attr||{}} }; # copy so we can edit
$tmp->{Password} = '***' if exists $tmp->{Password};
$tmp = "{ ".neat_list([ %$tmp ])." }";
}
push @s, sprintf "dbh= $method(%s, %s)", neat_list([$dsn, $user, $pass]), $tmp;

if (my $flags = $self->flags) {
push @s, sprintf "flags: 0x%x", $flags;
}

if (my $dbh_attr = $self->dbh_attributes) {
push @s, sprintf "dbh->FETCH: %s", @$dbh_attr
if @$dbh_attr;
}

my ($wantarray, $meth, @args) = @{ $self->dbh_method_call };
my $args = neat_list(\@args);
$args =~ s/\n+/ /g;
push @s, sprintf "dbh->%s(%s)", $meth, $args;

if (my $lii_args = $self->dbh_last_insert_id_args) {
push @s, sprintf "dbh->last_insert_id(%s)", neat_list($lii_args);
}

for my $call (@{ $self->sth_method_calls || [] }) {
my ($meth, @args) = @$call;
($args = neat_list(\@args)) =~ s/\n+/ /g;
push @s, sprintf "sth->%s(%s)", $meth, $args;
}

if (my $sth_attr = $self->sth_result_attr) {
push @s, sprintf "sth->FETCH: %s", %$sth_attr
if %$sth_attr;
}

return join("\n\t", @s) . "\n";
}


sub outline_as_text { # one-line version of summary_as_text
my $self = shift;
my @s = '';
my $neatlen = 80;

if (my $flags = $self->flags) {
push @s, sprintf "flags=0x%x", $flags;
}

my (undef, $meth, @args) = @{ $self->dbh_method_call };
push @s, sprintf "%s(%s)", $meth, neat_list(\@args, $neatlen);

for my $call (@{ $self->sth_method_calls || [] }) {
my ($meth, @args) = @$call;
push @s, sprintf "%s(%s)", $meth, neat_list(\@args, $neatlen);
}

my ($method, $dsn) = @{ $self->dbh_connect_call };
push @s, "$method($dsn,...)"; # dsn last as it's usually less interesting

(my $outline = join("; ", @s)) =~ s/\s+/ /g; # squish whitespace, incl newlines
return $outline;
}

1;

=head1 NAME

DBI::Gofer::Request - Encapsulate a request from DBD::Gofer to DBI::Gofer::Execute

=head1 DESCRIPTION

This is an internal class.

=head1 AUTHOR

Tim Bunce, L<http://www.tim.bunce.name>

=head1 LICENCE AND COPYRIGHT

Copyright (c) 2007, Tim Bunce, Ireland. All rights reserved.

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself. See L<perlartistic>.

=cut