Add item components for kit management and enhance stock transaction …

app/controllers/items_controller.rb

@@ -28,6 +28,8 @@ def index
 
   def new
     @item = @team.items.build
+    @locations = @team.locations.ordered
+    3.times { @item.kit_components.build }
   end
 
   def create
@@ -44,6 +46,7 @@ def create
 
   def edit
     @locations = @team.locations.ordered
+    @item.kit_components.build while @item.kit_components.size < 3
   end
 
   def update
@@ -198,7 +201,8 @@ def set_item
 
   def item_params
     params.require(:item).permit(:sku, :name, :barcode, :cost, :price,
-                               :item_type, :brand, :location_id)
+                               :item_type, :brand, :location_id,
+                               kit_components_attributes: [ :id, :component_item_id, :quantity, :_destroy ])
   end
 
   def trigger_webhook(event, item)

app/controllers/stock_transactions_controller.rb

@@ -59,21 +59,48 @@ def stock_out
 
         params[:items].each do |item_data|
           item = @team.items.find(item_data[:id])
+          requested_qty = BigDecimal(item_data[:quantity].to_s)
+
+          if item.kit_components.any?
+            # Validate all components availability
+            item.kit_components.each do |kc|
+              comp = kc.component_item
+              needed = (requested_qty * BigDecimal(kc.quantity.to_s))
+              if comp.current_stock.to_d < needed
+                raise StandardError, "Not enough stock for component #{comp.name} in kit #{item.name}"
+              end
+            end
 
-          # Validate stock availability
-          if item.current_stock < item_data[:quantity].to_i
-            raise StandardError, "Not enough stock for #{item.name}"
-          end
+            # Create stock_out for each component
+            item.kit_components.each do |kc|
+              comp = kc.component_item
+              qty = -(requested_qty * BigDecimal(kc.quantity.to_s))
+              @team.stock_transactions.create!(
+                item: comp,
+                transaction_type: "stock_out",
+                quantity: qty,
+                source_location: source_location,
+                notes: "Kit #{item.sku || item.name}: #{params[:notes]}",
+                user: current_user
+              )
+              trigger_stock_webhook("stock.updated", comp)
+            end
+          else
+            # Validate stock availability for simple item
+            if item.current_stock.to_d < requested_qty
+              raise StandardError, "Not enough stock for #{item.name}"
+            end
 
-          @team.stock_transactions.create!(
-            item: item,
-            transaction_type: "stock_out",
-            quantity: -item_data[:quantity].to_i, # Make quantity negative for stock out
-            source_location: source_location,
-            notes: params[:notes],
-            user: current_user
-          )
-          trigger_stock_webhook("stock.updated", item)
+            @team.stock_transactions.create!(
+              item: item,
+              transaction_type: "stock_out",
+              quantity: -requested_qty, # Make quantity negative for stock out
+              source_location: source_location,
+              notes: params[:notes],
+              user: current_user
+            )
+            trigger_stock_webhook("stock.updated", item)
+          end
         end
 
         render json: { success: true, redirect_url: team_stock_transactions_path(@team) }
@@ -208,14 +235,14 @@ def create
         # Find the location first
         location = @team.locations.find(params[:location])
 
-        # Process each item as its own transaction record
+        # Process each item as its own transaction record (expand kits on stock_out)
         items_params.each do |item_data|
           item_id = item_data[:id]
-          quantity = item_data[:quantity].to_f
+          quantity = BigDecimal(item_data[:quantity].to_s)
 
           item = @team.items.find(item_id)
 
-          # Create a separate transaction for each item
+          # Create transactions
           if @transaction_type == "adjust"
             # For adjust, calculate the difference
             difference = quantity - item.current_stock
@@ -228,15 +255,42 @@ def create
               user: current_user
             )
           elsif @transaction_type == "stock_out"
-            # For stock out
-            @team.stock_transactions.create!(
-              item: item,
-              transaction_type: "stock_out",
-              quantity: quantity * -1, # Make negative for stock out
-              source_location: location,
-              notes: @notes,
-              user: current_user
-            )
+            if item.kit_components.any?
+              # Validate all component availability first
+              item.kit_components.each do |kc|
+                comp = kc.component_item
+                needed = (quantity * BigDecimal(kc.quantity.to_s))
+                if comp.current_stock.to_d < needed
+                  raise StandardError, "Not enough stock for component #{comp.name} in kit #{item.name}"
+                end
+              end
+
+              # Create stock out for each component
+              item.kit_components.each do |kc|
+                comp = kc.component_item
+                qty = -(quantity * BigDecimal(kc.quantity.to_s))
+                @team.stock_transactions.create!(
+                  item: comp,
+                  transaction_type: "stock_out",
+                  quantity: qty,
+                  source_location: location,
+                  notes: "Kit #{item.sku || item.name}: #{@notes}",
+                  user: current_user
+                )
+                trigger_stock_webhook("stock.updated", comp)
+              end
+            else
+              # Simple item stock out
+              @team.stock_transactions.create!(
+                item: item,
+                transaction_type: "stock_out",
+                quantity: quantity * -1, # Make negative for stock out
+                source_location: location,
+                notes: @notes,
+                user: current_user
+              )
+              trigger_stock_webhook("stock.updated", item)
+            end
           else
             # For stock in
             @team.stock_transactions.create!(

app/models/item.rb

@@ -34,6 +34,12 @@ class Item < ApplicationRecord
   belongs_to :team
   belongs_to :location, optional: true
   has_many :stock_transactions, dependent: :destroy
+  # Kit relationships
+  has_many :kit_components, class_name: "ItemComponent", foreign_key: :kit_item_id, dependent: :destroy
+  has_many :components, through: :kit_components, source: :component_item
+  has_many :reverse_kit_components, class_name: "ItemComponent", foreign_key: :component_item_id, dependent: :destroy
+  has_many :used_in_kits, through: :reverse_kit_components, source: :kit_item
+  accepts_nested_attributes_for :kit_components, allow_destroy: true
 
   validates :name, presence: true
   validates :sku, presence: true, uniqueness: { scope: :team_id }
@@ -46,6 +52,11 @@ class Item < ApplicationRecord
   before_validation :generate_sku, on: :create, if: -> { sku.blank? }
 
   def current_stock
+    # If this item is a kit (has components), derive stock from components
+    if kit?
+      return kit_available_stock
+    end
+
     total = 0
     stock_transactions.each do |transaction|
       case transaction.transaction_type
@@ -106,4 +117,20 @@ def generate_sku
       .map { |word| word.first(3).upcase }
       .join("-")
   end
+
+  def kit?
+    kit_components.any?
+  end
+
+  def kit_available_stock
+    return 0 if kit_components.empty?
+
+    # Minimum of (component current stock / required quantity) across all components
+    kit_components.map do |kc|
+      comp_stock = BigDecimal(kc.component_item.current_stock.to_s)
+      req = BigDecimal(kc.quantity.to_s)
+      next 0 if req <= 0
+      (comp_stock / req).floor(2)
+    end.min || 0
+  end
 end

app/models/item_component.rb

@@ -0,0 +1,26 @@
+class ItemComponent < ApplicationRecord
+  belongs_to :team
+  belongs_to :kit_item, class_name: "Item"
+  belongs_to :component_item, class_name: "Item"
+
+  validates :quantity, presence: true, numericality: { greater_than: 0 }
+  validate :kit_and_component_must_belong_to_same_team
+  validate :kit_and_component_cannot_be_same
+
+  private
+
+  def kit_and_component_must_belong_to_same_team
+    return if kit_item.blank? || component_item.blank? || team.blank?
+    if kit_item.team_id != team_id || component_item.team_id != team_id
+      errors.add(:base, "Kit and component must belong to the same team")
+    end
+  end
+
+  def kit_and_component_cannot_be_same
+    return if kit_item_id.blank? || component_item_id.blank?
+    if kit_item_id == component_item_id
+      errors.add(:component_item_id, "cannot be the same as kit item")
+    end
+  end
+end
+

app/views/items/_form.html.erb

@@ -79,8 +79,49 @@
     </div>
   </div>
 
+  <%# Kit components section (optional) %>
+  <%# Render only if the item is/will be a kit (by convention: item_type == 'kit') %>
+  <% if item.item_type&.downcase == 'kit' || item.kit_components.any? %>
+    <div class="mt-10 bg-white p-6 rounded-lg border">
+      <h3 class="text-lg font-medium text-gray-900 mb-4">Kit Components</h3>
+      <p class="text-sm text-gray-500 mb-4">Select items and quantities that compose this kit.</p>
+
+      <div class="space-y-4">
+        <div class="grid grid-cols-12 gap-4 font-semibold text-gray-600">
+          <div class="col-span-7">Item</div>
+          <div class="col-span-3">Quantity</div>
+          <div class="col-span-2"></div>
+        </div>
+
+        <div class="space-y-3">
+          <%= f.fields_for :kit_components do |kc| %>
+            <div class="grid grid-cols-12 gap-4 items-center">
+              <div class="col-span-7">
+                <%= kc.collection_select :component_item_id,
+                      @team.items.where.not(id: item.id).order(:name),
+                      :id, :name,
+                      { include_blank: 'Select item' },
+                      class: 'mt-1 block w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500 sm:text-sm' %>
+              </div>
+              <div class="col-span-3">
+                <%= kc.number_field :quantity, step: '0.01', min: 0.01,
+                      class: 'mt-1 block w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500 sm:text-sm' %>
+              </div>
+              <div class="col-span-2">
+                <label class="inline-flex items-center space-x-2 text-sm">
+                  <%= kc.check_box :_destroy %>
+                  <span>Remove</span>
+                </label>
+              </div>
+            </div>
+          <% end %>
+        </div>
+      </div>
+    </div>
+  <% end %>
+
   <div class="flex justify-end space-x-3 mt-6">
     <%= link_to t('items.form.buttons.cancel'), team_items_path(@team), class: "btn btn-secondary" %>
     <%= f.submit class: "btn btn-primary" %>
   </div>
-<% end %> 
+<% end %>

db/migrate/20250915090000_create_item_components.rb

@@ -0,0 +1,15 @@
+class CreateItemComponents < ActiveRecord::Migration[8.0]
+  def change
+    create_table :item_components do |t|
+      t.references :team, null: false, foreign_key: true
+      t.references :kit_item, null: false, foreign_key: { to_table: :items }
+      t.references :component_item, null: false, foreign_key: { to_table: :items }
+      t.decimal :quantity, precision: 10, scale: 2, null: false
+
+      t.timestamps
+    end
+
+    add_index :item_components, [:kit_item_id, :component_item_id], unique: true
+  end
+end
+