compute the price based on custom durations

app/controllers/api/prices_controller.rb

@@ -30,6 +30,6 @@ class API::PricesController < API::ApiController
   private
 
   def price_params
-    params.require(:price).permit(:amount)
+    params.require(:price).permit(:amount, :duration)
   end
 end

app/models/cart_item/reservation.rb

@@ -3,7 +3,7 @@
 MINUTES_PER_HOUR = 60.0
 SECONDS_PER_MINUTE = 60.0
 
-GET_SLOT_PRICE_DEFAULT_OPTS = { has_credits: false, elements: nil, is_division: true, prepaid: { minutes: 0 } }.freeze
+GET_SLOT_PRICE_DEFAULT_OPTS = { has_credits: false, elements: nil, is_division: true, prepaid: { minutes: 0 }, custom_duration: nil }.freeze
 
 # A generic reservation added to the shopping cart
 class CartItem::Reservation < CartItem::BaseItem
@@ -16,7 +16,7 @@ class CartItem::Reservation < CartItem::BaseItem
   end
 
   def price
-    base_amount = @reservable.prices.find_by(group_id: @customer.group_id, plan_id: @plan.try(:id), duration: 60).amount
+    base_amount = get_hourly_rate
     is_privileged = @operator.privileged? && @operator.id != @customer.id
     prepaid = { minutes: PrepaidPackService.minutes_available(@customer, @reservable) }
 
@@ -103,6 +103,35 @@ class CartItem::Reservation < CartItem::BaseItem
     real_price
   end
 
+  # We compute the hourly rate according to the prices of the current reservation
+  # If there are prices for durations longer than 1 hour, but shorter than the total duration,
+  # we use these prices before using the hourly rate.
+  # Eg. If the reservation is for 12 hours, and there are prices for 3 hours, 7 hours,
+  # and the base price (1 hours), we use the 7 hours price, then 3 hours price, and finally the base price.
+  # Then we divide the total price by the total duration to get the hourly rate.
+  def get_hourly_rate
+    total_duration = @slots.map { |slot| (slot[:end_at].to_time - slot[:start_at].to_time) / SECONDS_PER_MINUTE }.reduce(:+)
+    price = 0
+
+    remaining_duration = total_duration
+    while remaining_duration > 60
+      max_duration = @reservable.prices.where(group_id: @customer.group_id, plan_id: @plan.try(:id))
+                                .where(Price.arel_table[:duration].lteq(remaining_duration))
+                                .maximum(:duration)
+      max_duration_amount = @reservable.prices.find_by(group_id: @customer.group_id, plan_id: @plan.try(:id), duration: max_duration)
+                                       .amount
+
+      price += max_duration_amount
+      remaining_duration -= max_duration
+    end
+
+    # base price for the last hour or less
+    base_amount = @reservable.prices.find_by(group_id: @customer.group_id, plan_id: @plan.try(:id), duration: 60).amount
+    price += (base_amount / MINUTES_PER_HOUR) * remaining_duration
+
+    price / (total_duration / MINUTES_PER_HOUR)
+  end
+
   ##
   # Compute the number of remaining hours in the users current credits (for machine or space)
   ##

app/services/prepaid_pack_service.rb

@@ -61,10 +61,7 @@ class PrepaidPackService
 
     ## Total number of prepaid minutes available
     def minutes_available(user, priceable)
-      is_pack_only_for_subscription = Setting.find_by(name: "pack_only_for_subscription")&.value
-      if is_pack_only_for_subscription == 'true' && !user.subscribed_plan
-        return 0
-      end
+      return 0 if Setting.get('pack_only_for_subscription') && !user.subscribed_plan
 
       user_packs = user_packs(user, priceable)
       total_available = user_packs.map { |up| up.prepaid_pack.minutes }.reduce(:+) || 0