New plugin: repeat (undocumented), new hook: "added"

lib/RevBank/Cart.pm

@@ -10,7 +10,7 @@ use RevBank::Global;
 
 sub new {
     my ($class) = @_;
-    return bless { }, $class;
+    return bless { items => {} }, $class;
 }
 
 sub add {
@@ -22,18 +22,21 @@ sub add {
         description => $description,
     };
     RevBank::Plugins::call_hooks("add", $self, $user, $item);
-    $user ||= '$you';
-    push @{ $self->{ $user } }, $item;
+    push @{ $self->{items}{ $user || '$you' } }, $item;
+    $self->{changed}++;
+    RevBank::Plugins::call_hooks("added", $self, $user, $item);
 }
 
 sub delete {
     my ($self, $user, $index) = @_;
-    splice @{ $self->{ $user } }, $index, 1, ();
+    splice @{ $self->{items}{ $user } }, $index, 1, ();
+    $self->{changed}++;
 }
 
 sub empty {
     my ($self) = @_;
-    %$self = ();
+    %$self = (items => {});
+    $self->{changed}++;
 }
 
 sub _dump_item {
@@ -54,8 +57,9 @@ sub as_strings {
 
     my @s;
 
-    for my $user (sort keys %$self) {
-        my @items = @{ $self->{$user} };
+    my $items = $self->{items};
+    for my $user (sort keys %$items) {
+        my @items = @{ $items->{$user} };
         my $sum = List::Util::sum(map $_->{amount}, @items);
 
         push @s, _dump_item($prefix, $user, $_->{amount}, "# $_->{description}")
@@ -74,20 +78,22 @@ sub display {
 
 sub size {
     my ($self) = @_;
-    return List::Util::sum(map scalar @{ $self->{$_} }, keys %$self) || 0;
+    my $items = $self->{items};
+    return List::Util::sum(map scalar @{ $items->{$_} }, keys %$items) || 0;
 }
 
 sub _set_user {
     my ($self, $user) = @_;
+    my $items = $self->{items};
 
-    exists $self->{'$you'}
+    exists $items->{'$you'}
         or Carp::croak("Error: no cart items for shell user");
 
-    $self->{$user} ||= [];
+    $items->{$user} ||= [];
 
-    push @{ $self->{$user} }, @{ delete $self->{'$you'} };
+    push @{ $items->{$user} }, @{ delete $items->{'$you'} };
 
-    for (values %$self) {
+    for (values %$items) {
         $_->{description} =~ s/\$you\b/$user/g for @$_;
     }
 }
@@ -96,14 +102,15 @@ sub checkout {
     my ($self, $user) = @_;
 
     $self->_set_user($user) if $user;
+    my $items = $self->{items};
 
-    exists $self->{'$you'} and die "Incomplete transaction; user not set.";
+    exists $items->{'$you'} and die "Incomplete transaction; user not set.";
 
     my $transaction_id = time() - 1300000000;
     RevBank::Plugins::call_hooks("checkout", $self, $user, $transaction_id);
 
-    for my $account (keys %$self) {
-        my $sum = List::Util::sum(map $_->{amount}, @{ $self->{$account} });
+    for my $account (keys %$items) {
+        my $sum = List::Util::sum(map $_->{amount}, @{ $items->{$account} });
         RevBank::Users::update($account, $sum, $transaction_id);
     }
 
@@ -114,10 +121,11 @@ sub checkout {
 
 sub select_items {
     my ($self, $key) = @_;
+    my $items = $self->{items};
 
     my @matches;
-    for my $user (keys %$self) {
-        for my $item (@{ $self->{$user} }) {
+    for my $user (keys %$items) {
+        for my $item (@{ $items->{$user} }) {
             push @matches, { user => $user, %$item }
                 if @_ == 1  # No key or match given: match everything
                 or @_ == 2 and exists $item->{ $key }   # Just a key
@@ -129,7 +137,12 @@ sub select_items {
 
 sub is_multi_user {
     my ($self) = @_;
-    return keys(%$self) > 1;
+    return keys(%{ $self->{items} }) > 1;
+}
+
+sub changed {
+    my ($self) = @_;
+    return delete $self->{changed};
 }
 
 1;

lib/RevBank/Plugins.pm

@@ -2,6 +2,7 @@ package RevBank::Plugins;
 use strict;
 use RevBank::Eval;
 use RevBank::Plugin;
+use RevBank::Global;
 use Exporter;
 our @EXPORT = qw(call_hooks load_plugins);
 
@@ -16,7 +17,14 @@ sub call_hooks {
     my $hook = shift;
     my $method = "hook_$hook";
     for my $class (@plugins) {
-         $class->$method(@_) if $class->can($method);
+         if ($class->can($method)) {
+            my ($rv, $message) = $class->$method(@_);
+
+            if (defined $rv and ref $rv) {
+                main::abort($message) if $rv == ABORT;
+                warn "$class->$method returned an unsupported value.\n";
+            }
+        }
     }
 };
 

plugins/pfand

@@ -27,7 +27,7 @@ sub product :Tab(&tab) {
     my $pfand = _read_pfand->{ $product };
 
     if ($pfand) {
-        $cart->add(undef, +$pfand, "Pfand zurueck", { is_pfand => 1 });
+        $cart->add(undef, +$pfand, "Pfand zurueck", { is_return => 1 });
     } else {
         say "$product: Kein Pfand";
     }
@@ -41,11 +41,11 @@ sub tab {
 sub hook_add {
     my ($class, $cart, $user, $item) = @_;
     return if defined $user;
-    return if exists $item->{is_pfand};
+    return if exists $item->{is_return};
     return if not exists $item->{product_id};
 
     my $pfand = _read_pfand->{ $item->{product_id} } or return;
 
-    $cart->add(undef, -$pfand, "Pfand");
+    $cart->add(undef, -$pfand, "Pfand", { is_pfand => 1 });
 }
 

plugins/repeat

@@ -0,0 +1,111 @@
+my $err_stacked = "Stacked repetition is not supported.";
+my $err_multi = "Repetition not supported in multi-user transactions.";
+my $err_pfand = "Plugins 'pfand' and 'repeat' cannot be combined.";
+
+my $limit = 24;
+my $err_limit = "Repetition is limited at $limit items.";
+
+sub _do_repeat {
+    my ($cart, $item, $num) = @_;
+
+    my $data = $item->{data};
+    $data->{_repeated} = 1;
+
+    $cart->add( @{ $item }{qw/user amount description/}, $data ) for 2..$num;
+}
+
+sub command {
+    my ($self, $cart, $command) = @_;
+
+    my @items = $cart->select_items;
+    my $last = $items[-1];
+
+    return ABORT, $err_pfand if grep $_->{is_pfand}, @items;
+
+    my ($pre, $post) = $command =~ /^(\d+)?[x*](\d+)?$/
+        or return NEXT;
+
+    return NEXT if $pre and $post;  # 123x123 -> invalid syntax
+
+    return REJECT, $err_multi if $cart->is_multi_user;
+
+    if ($post) {
+        return REJECT, $err_limit if $post > $limit;
+        return ABORT, "Can't repeat an empty transaction." if not $cart->size;
+        return REJECT, $err_stacked if $last->{_repeated};
+
+        _do_repeat($cart, $last, $post);
+        return ACCEPT;
+    }
+
+    my $item_replaced;
+
+    if (not $pre and not $post) {
+        # Lone operator. Convert withdrawal into repetition.
+
+        if ($last->{is_withdrawal}) {
+            $pre = abs $last->{amount};
+            $pre == int $pre or return REJECT, "Repeat only works on integers.";
+            $cart->delete($last->{user}, -1);
+            $item_replaced = 1;
+        } elsif (not $cart->size) {
+            return ABORT, "Can't repeat an empty transaction.";
+        }
+    }
+
+    if ($pre) {
+        $pre = abs $pre;  # withdrawal is negative
+
+        return REJECT, $err_limit if $pre > $limit;
+        $cart->add(undef, 0, "Next product repeated $pre times", { _repeat => abs $pre });
+        return ACCEPT;
+    }
+
+    return REJECT, $err_stacked if $last->{_repeated};
+    return "Multiply previous product by", \&repeat;
+}
+
+sub repeat {
+    my ($self, $cart, $arg) = @_;
+
+    $arg =~ /^\d+$/ and $arg > 0
+        or return REJECT, "Invalid value.";
+
+    return REJECT, $err_limit if $arg > $limit;
+
+    my @items = $cart->select_items;
+    my $last = $items[-1];
+
+    _do_repeat($cart, $last, $arg);
+    return ACCEPT;
+}
+
+sub hook_added {
+    my ($self, $cart, $user, $item) = @_;
+    $cart->size >= 2 or return;
+
+    return ABORT, $err_multi if $cart->is_multi_user;
+
+    my @repeats = $cart->select_items('_repeat');
+    return ABORT, "Multiple repeats queued; I'm confused." if @repeats > 1;
+    return if not @repeats;
+
+    my @items = $cart->select_items;
+    return ABORT, $err_pfand if grep $_->{is_pfand}, @items;
+
+    for my $i (0 .. $#items - 1) {
+        my $item = $items[$i];
+        $item->{_repeat} or next;
+
+        my $next = $items[$i + 1];
+
+        return ABORT, $err_stacked if $next->{_repeat};
+
+        my $num = $item->{_repeat};
+        $cart->delete($item->{user}, $i);
+
+        _do_repeat($cart, $next, $num);
+
+        return;
+    }
+}

plugins/voorbeeld

@@ -0,0 +1,14 @@
+sub command { print "@_\n"; NEXT }
+
+
+sub hook_user_balance {
+    my ($class, $username, $old, $delta, $new) = @_;
+
+    print "c: $class\n";
+    print "u: $username\n";
+    print "o: $old\n";
+    print "d: $delta\n";
+    print "n: $new\n";
+}
+
+

plugins/withdraw

@@ -8,7 +8,8 @@ sub command {
     my $amount = parse_amount($command);
     defined $amount or return NEXT;
 
-    $cart->add(undef, -$amount, "Withdrawal or unlisted product");
+    $cart->add(undef, -$amount, "Withdrawal or unlisted product",
+        { is_withdrawal => 1 });
 
     return ACCEPT;
 }

revbank

@@ -79,16 +79,13 @@ RevBank::Plugins->load;
 
 call_hooks("startup");
 
-my $old_cart_size = 0;
-
 my @words;
 
 OUTER: for (;;) {
     print "\n" if not @words;
 
-    if (not @words and $cart->size != $old_cart_size) {
+    if (not @words and $cart->changed) {
         call_hooks("cart_changed", $cart);
-        $old_cart_size = $cart->size;
     }
 
     my $split_input = 1;