LibCards+Games: Move "create a deck" logic to LibCards

`create_standard_deck()` is the usual 52-card deck, but more custom
setups (such as Spider's multiples-of-one-suit) can be created by
passing suit counts to `create_deck()`.

2 files changed, 46 insertions, 0 deletions

diff --git a/Userland/Libraries/LibCards/Card.cpp b/Userland/Libraries/LibCards/Card.cpp
index a42d0279e6..8bb98e2d55 100644
--- a/Userland/Libraries/LibCards/Card.cpp
+++ b/Userland/Libraries/LibCards/Card.cpp
@@ -1,11 +1,13 @@
 /*
  * Copyright (c) 2020, Till Mayer <till.mayer@web.de>
  * Copyright (c) 2022, the SerenityOS developers.
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #include "Card.h"
+#include <AK/Random.h>
 #include <LibCards/CardPainter.h>
 
 namespace Cards {
@@ -50,4 +52,40 @@ void Card::clear_and_draw(GUI::Painter& painter, Color const& background_color)
     save_old_position();
 }
 
+NonnullRefPtrVector<Card> create_standard_deck(Shuffle shuffle)
+{
+    return create_deck(1, 1, 1, 1, shuffle);
+}
+
+NonnullRefPtrVector<Card> create_deck(unsigned full_club_suit_count, unsigned full_diamond_suit_count, unsigned full_heart_suit_count, unsigned full_spade_suit_count, Shuffle shuffle)
+{
+    NonnullRefPtrVector<Card> deck;
+    deck.ensure_capacity(Card::card_count * (full_club_suit_count + full_diamond_suit_count + full_heart_suit_count + full_spade_suit_count));
+
+    auto add_cards_for_suit = [&deck](Cards::Suit suit, unsigned number_of_suits) {
+        for (auto i = 0u; i < number_of_suits; ++i) {
+            for (auto rank = 0; rank < Card::card_count; ++rank) {
+                deck.append(Card::construct(suit, static_cast<Cards::Rank>(rank)));
+            }
+        }
+    };
+
+    add_cards_for_suit(Cards::Suit::Clubs, full_club_suit_count);
+    add_cards_for_suit(Cards::Suit::Diamonds, full_diamond_suit_count);
+    add_cards_for_suit(Cards::Suit::Hearts, full_heart_suit_count);
+    add_cards_for_suit(Cards::Suit::Spades, full_spade_suit_count);
+
+    if (shuffle == Shuffle::Yes)
+        shuffle_deck(deck);
+
+    return deck;
+}
+
+void shuffle_deck(NonnullRefPtrVector<Card>& deck)
+{
+    auto iteration_count = deck.size() * 4;
+    for (auto i = 0u; i < iteration_count; ++i)
+        deck.append(deck.take(get_random_uniform(deck.size())));
+}
+
 }
diff --git a/Userland/Libraries/LibCards/Card.h b/Userland/Libraries/LibCards/Card.h
index b3644013a4..ec4255807b 100644
--- a/Userland/Libraries/LibCards/Card.h
+++ b/Userland/Libraries/LibCards/Card.h
@@ -123,6 +123,14 @@ private:
     bool m_inverted { false };
 };
 
+enum class Shuffle {
+    No,
+    Yes,
+};
+NonnullRefPtrVector<Card> create_standard_deck(Shuffle);
+NonnullRefPtrVector<Card> create_deck(unsigned full_club_suit_count, unsigned full_diamond_suit_count, unsigned full_heart_suit_count, unsigned full_spade_suit_count, Shuffle);
+void shuffle_deck(NonnullRefPtrVector<Card>&);
+
 }
 
 template<>