Split naphtha carrier from crude oil (#1607)

* Scaffold for naphtha migration

* Add default dumps for naphtha migration

* Update values in naphtha migration dumps

---------

Co-authored-by: Nora Schinkel <ncschinkel@gmail.com>

Author: kndehaan

db/migrate/20250722144555_naphtha_migration.rb

@@ -0,0 +1,104 @@
+class NaphthaMigration < ActiveRecord::Migration[7.1]
+  include ETEngine::ScenarioMigration
+
+  RelativeChange = Struct.new(:input_oil, :input_naphtha, :default_key, :naphtha_default_key) do
+    def skip?(scenario)
+      !scenario.user_values.key?(input_oil)
+    end
+
+    # Calculates and sets the inputs for crude oil and naphtha on the scenario.
+    # Uses the old and new defaults (start values) of the inputs.
+    def set_new_values(scenario, old_defaults, new_defaults)
+      if change = relative_change(scenario, old_defaults)
+        # If a change can be calculated: the inputs are set to the
+        # relative change times the new default for both oil and naptha
+        scenario.user_values[input_oil] = new_defaults[default_key] * change
+        scenario.user_values[input_naphtha] = new_defaults[naphtha_default_key] * change
+      else
+        # If change can't be calculated, set naphtha to zero, oil stays
+        # unchanged
+        scenario.user_values[input_naphtha] = 0
+      end
+    end
+
+    # Returns the relative change of the input, based on the old default
+    # of the input, and what it was set to by the user
+    def relative_change(scenario, defaults)
+      unless defaults[default_key].zero?
+        return scenario.user_values[input_oil] / defaults[default_key]
+      end
+    end
+  end
+
+  # Inputs that need to be recalculated when they were set by the user.
+  CHANGES = [
+    # Normal energetic
+    RelativeChange.new(
+      input_oil: 'industry_chemicals_other_burner_crude_oil_share',
+      input_naphtha: 'industry_chemicals_other_burner_naphtha_share',
+      default_key: 'industry_chemicals_other_burner_crude_oil_share',
+      naphtha_default_key: 'industry_chemicals_other_burner_naphtha_share'
+    ),
+    # Normal non-energetic
+    RelativeChange.new(
+      input_oil: 'industry_chemicals_other_crude_oil_non_energetic_share',
+      input_naphtha: 'industry_chemicals_other_naphtha_non_energetic_share',
+      default_key: 'industry_useful_demand_for_chemical_other_crude_oil_non_energetic_share',
+      naphtha_default_key: 'industry_useful_demand_for_chemical_other_naphtha_non_energetic_share'
+    ),
+    # External coupling energetic
+    RelativeChange.new(
+      input_oil: 'external_coupling_industry_chemical_other_burner_crude_oil_share',
+      input_naphtha: 'external_coupling_industry_chemical_other_burner_naphtha_share',
+      default_key: 'industry_chemicals_other_burner_crude_oil_share', # same start value
+      naphtha_default_key: 'industry_chemicals_other_burner_naphtha_share'
+    ),
+    # External coupling non-energetic
+    RelativeChange.new(
+      input_oil: 'external_coupling_industry_chemical_other_non_energetic_crude_oil_share',
+      input_naphtha: 'external_coupling_industry_chemical_other_non_energetic_naphtha_share',
+      default_key: 'industry_useful_demand_for_chemical_other_crude_oil_non_energetic_share', # same start value
+      naphtha_default_key: 'industry_useful_demand_for_chemical_other_naphtha_non_energetic_share'
+    )
+  ].freeze
+
+  RENAME = %w[fertilizers refineries other].to_h do |sector|
+    [
+      "external_coupling_energy_chemical_#{sector}_transformation_external_coupling_node_crude_oil_output_share",
+      "external_coupling_energy_chemical_#{sector}_transformation_external_coupling_node_naphtha_output_share"
+    ]
+  end.freeze
+
+  def up
+    # Load up defaults from dumps
+    old_defaults = load_defaults('old')
+    new_defaults = load_defaults('new')
+
+    migrate_scenarios do |scenario|
+      CHANGES.each do |change|
+        next if change.skip?(scenario)
+        # NOTE: Some datasets do not work yet on the naphtha branch, skip them
+        next unless new_defaults.key?(scenario.area_code)
+
+        change.set_new_values(
+          scenario,
+          old_defaults[scenario.area_code],
+          new_defaults[scenario.area_code]
+        )
+      end
+      RENAME.each do |old_input, new_input|
+        if scenario.user_values.key?(old_input)
+          scenario.user_values[new_input] = scenario.user_values.delete(old_input)
+        end
+      end
+    end
+  end
+
+  def load_defaults(tag)
+    JSON.load(File.read(
+      Rails.root.join(
+        "db/migrate/#{File.basename(__FILE__, '.rb')}/dataset_values_#{tag}.json"
+      )
+    ))
+  end
+end

db/migrate/20250722144555_naphtha_migration/dataset_values_new.json

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2025_07_02_112742) do
+ActiveRecord::Schema[7.1].define(version: 2025_07_22_144555) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.string "name", limit: 191, null: false
     t.string "record_type", limit: 191, null: false
@@ -122,8 +122,8 @@
     t.string "source"
     t.binary "user_values", size: :long
     t.binary "balanced_values", size: :medium
-    t.binary "active_couplings", size: :medium
     t.binary "metadata", size: :medium
+    t.binary "active_couplings", size: :medium
     t.index ["created_at"], name: "index_scenarios_on_created_at"
   end
 
@@ -161,7 +161,6 @@
     t.string "user_email"
   end
 
-  add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
   add_foreign_key "forecast_storage_orders", "scenarios"
   add_foreign_key "heat_network_orders", "scenarios"