Character items and inventory, with ability to add and remove items

2 files changed, 35 insertions, 0 deletions

diff --git a/app/models/character.rb b/app/models/character.rb
index 1c022ea..a158d88 100644
--- a/app/models/character.rb
+++ b/app/models/character.rb
@@ -1,5 +1,15 @@
 class Character < ApplicationRecord
   belongs_to :user
   belongs_to :activity, optional: true
+  has_many :character_items
+  has_many :items, through: :character_items
   validates :name, presence: true
+
+  def shift_item(gid, amount)
+    CharacterItem.transaction do
+      item = self.character_items.find_or_initialize_by(item: Item.find_by_gid(gid))
+      item.increment(:quantity, amount)
+      item.save
+    end
+  end
 end
diff --git a/app/models/character_item.rb b/app/models/character_item.rb
new file mode 100644
index 0000000..b54f799
--- /dev/null
+++ b/app/models/character_item.rb
@@ -0,0 +1,25 @@
+class CharacterItem < ApplicationRecord
+  belongs_to :character
+  belongs_to :item
+  validates :quantity, presence: true
+
+  after_initialize do
+    if self.new_record?
+      self.quantity ||= 0
+    end
+  end
+
+  after_save :destroy_if_zero_quantity
+
+  scope :ordered_by_item_name, -> { includes(:item).order("items.name") }
+
+  private
+    def destroy_if_zero_quantity
+      if self.quantity == 0
+        destroy
+      elsif self.quantity < 0
+        # TODO: Can improve this (at the least, with reporting, later).
+        raise ItemQuantityError
+      end
+    end
+end